SecsPort - A .NET Component for Deploying Equipment SECS Interfaces


Hume Integration has created a .NET component for rapidly deploying SEMI standard GEM compliant SECS equipment interfaces.   The .NET component features a fully CLS (Common Language Specification) compliant API and can be used from any of the Microsoft .NET programming languages, including C#, C++, Visual Basic, and Java.  Without any customization, the component implements almost all of the Fundamental GEM Requirements and the Additional GEM Capabilities.  Method calls are provided for the developer to add his own Status Variables, Equipment Configuration Variables, Alarm Definitions, and Event Definitions to complement the existing items specified in the GEM standard.  The developer uses event handlers to receive asynchronous inputs such as Remote Command invocations, Terminal Display invocations, or the reception of any SECS message type of his choosing.  

Feature Summary

GEM Compliance Statement

The software is written to conform to SEMI Standard E30 - Generic Model for Communications and Control of SEMI Equipment (GEM).  It also provides compliance to SEMI standards E5, E37, E37.1, and E10.  The software is also fully compliant with photovoltaic industry standard SEMI PV2-0709 (draft standard #4557 (PVEC-Interface)).

The Equipment OEM developer needs to be mindful of the standards when using the Hume SecsPort Component in order to insure that compliance is fully met.
 
 
Fundamental GEM Requirement Implemented Gem Compliant Implementation Notes
State Models Yes Yes The Communication State model is implemented by the SecsPort and controlled by calling the CommEnable and CommDisable methods.  The current Communication State value is readable as the property, CommState. Your application receives notification of CommState and similar state changes by handling the SecsPort StateChange event.  This event notifies you of important changes such as communication with the Host starting or ending.

Your logic and your Operator GUI affect the Control State by setting the ControlIntentOnline and ControlModeRemote properties. 

The standards require the persistent configuration of the communication connection properties, communication enablement, and the control state start properties.  The example application uses the methods StartupSave, StartupLoad and StartupRestore, and the StartupDialog class for this purpose.  You may substitute your own configuration and persistence mechanisms or use the provided ones.

Comments on the Process State model follows in the next row.  Other equipment models such as Spooling are described below in this table.

Equipment Processing States Yes Yes The example application fully implements a Process State model that you can copy and modify.  Follow the example as far as posting standard GEM events for Process State changes and related events such as selecting a different Process Program.  You also need to update Status Variables to keep track of the previous and current process states, just as the example application demonstrates.
Host Initiated S1F13/F14 Scenario Yes Yes This behavior is fully provided by the SecsPort component.
Event Notification Yes Yes Your logic needs to call the EventPost() method at the occurrence of standard collection events.  You may choose to define and report additional event types for the activities of your equipment.
On-Line Identification Yes Yes You are obligated to set the property values MDLN and SOFTREV to reflect the hardware and software configuration of the equipment.  Any change in the equipment software should result in a new unique value of SOFTREV.
Error Messages Yes Yes The standard requires use of Stream 9 Error reporting.  The SecsPort sends specific Stream 9 messages for communication faults, conversation timeouts, incorrect device ID, unhandled message stream or function types, and non-standard data.  In the custom message handling logic that you write, use the method SendS9 to send error messages when the received message data is not in the expected format or has improper values.
Documentation Yes Yes Hume Integration has example documentation which meets requirements of the GEM and SECS standards.  This documentation is provided to Equipment providers with permission to create derivative works.

 The SECS Server has the ability to export HTML documents of the configured event, alarm, and variable table data.  You may want to use this feature of the table window that is display by executing the DebugTableWindow method.

Control (Operator Initiated) Yes Yes Use the GemGui application as a worked example.  The startup control state is settable using the property ControlStateStartup.  The operator choice of ON-LINE or OFF-LINE control is settable as the property value ControlIntentOnline.  The desired substate of ON-LINE control, LOCAL or REMOTE, is settable as the property ControlModeRemote.  The actual control state value reflects interaction with the Host and is readable as the property ControlState.  Your application receives notification of ControlState and similar state changes by handling the SecsPort StateChange event.
ADDITIONAL CAPABILITIES      
Establish Communications Yes Yes This behavior is fully provided by the SecsPort component.
Dynamic Event Report Configuration  Yes Yes This behavior is fully provided by the SecsPort component.

With the capabilities that involve Status Variable values (SV) or Data Variable values (DVVAL), your job is to add equipment specific variables using the VariableAdd method.  You either provide their values through a callback using VariableMethodSet or by calling VariableSet when their values are changed. 

Variable Data Collection Yes Yes This behavior is fully provided by the SecsPort component. 
Trace Data Collection Yes Yes This behavior is fully provided by the SecsPort component. 
Status Data Collection Yes Yes This behavior is fully provided by the SecsPort component. 
Alarm Management Yes Yes This behavior is fully provided by the SecsPort component.  Your job is to add equipment specific alarm types using the AlarmAdd method.  You use the method AlarmSet to indicate when an alarm condition is set or cleared.  You can optionally use the method AlarmEnable to enable or disable reporting of an alarm type as a Stream 5 message.  Gem also requires event reports for the Alarm Set and Alarm Clear events.  These event definitions are automatically created and managed for you by the SecsPort when you use the AlarmAdd method.
Remote Control Yes  Yes The SecsPort defines an event, RemoteCommand which you use to receive Remote Commands (S2F21, S2F41, or S2F49) in your application code.  You can use the MessageTypeRemove method to selectively not handle any of the Remote Command message types. You need to implement control logic that is mindful of the Process State model and the Control State model.  For example, you need to disallow Remote Commands that affect processing when you are in the Online Local Control State. 
Equipment Configuration Variables (ECV's)
Yes Yes This behavior is fully provided by the SecsPort component.  Your job is to add equipment specific ECV's using the ParameterAdd method.  You call ParameterSet if your GUI logic or controller logic changes the value so that the SECS Server can update the ECIDChangeName GEM variable, and issue the GEM OperatorECVChange event.  If the host changes an ECV, you are notified via a ParameterChange event.
Process Program Management Yes Yes The SecsPort component fully implements process program management features with upload and download capabilities.  You can set the directory used for process programs as the property RecipeDirectory.  You can set whether process program data is transferred as binary or text using the RecipesAreBinary property.  Your application is notified of process program change events by handling the SecsPort StateChange event.   You will receive notice when recipes are downloaded from the host, uploaded to the host, or deleted by the host.  You can use these notifications to trigger validation of downloaded recipes, or you can defer validation until the time the process program is loaded for use.
Material Movement Yes Yes The GEM standard only requires that the equipment provide Data Collection events when material is sent from any port on the equipment, or received by any port, whether the transfers are automated or manual.

Automated Material Movement is implemented by calling the method MessageTypeAdd and registering to receive each of the primary message types that the host sends.  In your event handling logic, you parse the received SECS message data using the ListSplit and ListElement methods.  You send reply messages using the SendReply method.  You initiate your own primary messages and optionally wait for the SECS replies using the SendSecsMsg method.

Equipment Terminal Services Yes Yes The example application for the SecsPort demonstrates displaying data received from the host, sending acknowledgment events, and sending display data to the host.  For your own implementation, use the event  TerminalDisplay with your own display logic, use the method TerminalDisplayAck to send acknowledgment events, and follow the example of the GemGui.BTerminalSend_Click method for sending input data to the host using SendSecsMsg.
Clock Yes Yes The SecsPort component fully implements a host-settable Clock variable value with standard data format choices.  The implementation does not affect the system clock, the host's setting is saved as an offset.
Limits Monitoring No   See the notes for Material Movement, above, to understand the general approach that is taken to implement this capability. 
Spooling Yes Yes The SecsPort component fully implements Spooling.  We recommend that the equipment supplier only allow spooling of Alarm messages, and Event report messages or similar messages where there is no control logic tied to the receiving of the reply messages.  These are exactly the message types that most factory CIM workers want to collect with spooling.  If restricting the spooled message types is not done, there are complex issues with implementation and timing that cannot be adequately tested and verified correct.  The standard describes allowing the spooling of nearly any primary message type, out of consideration that any message may occur when the spool is being unloaded, and it should take its proper sequence at the end of the spool.  In practice this is a rare circumstance because an HSMS implementation can unload thousands of messages in a few seconds.  The downside of allowing messages that have control implications to be spooled is that they are queued for a variable and potentially lengthy delay before delivery.  The equipment provider's job is to provide a robust control system, and we think that knowing immediately that a near real-time message conversation cannot be initiated is the right choice. 

The Equipment provider can add to the message types allowed for spooling using the SpoolingAllow method.  The default behavior is to allow only Stream 5 (Alarms) and Stream 6 (Event reports) to be spooled.

Control (Host-Initiated) Yes Yes The SecsPort component fully implements this behavior.


User Guide


The SecsPort .NET component is provided as the following files:

The files for .NET 2.0 and newer .NET versions are distributed in a .zip archive named  DotNet20EqApp.zip.   If you received the DMH software on CDROM, this archive is in the subdirectory LAN_IMAGE.  

The distribution is designed and tested for up-to-date Windows Professional versions such as Windows 7 or 8, Vista or Windows XP.

The Hume developed SecsPort component is a "component" as defined by the Microsoft .NET Framework.  As such, it implements the System.ComponentModel.IComponent interface.  Hume Integration is also using the word "component" to describe high level customizable applications such as their Data Collection Component.

Installation

Installation consists of extracting files in the DotNet20EqApp.zip archive to a directory of your choice such as the "Projects" directory in your Visual Studio directory under the "My Documents" folder.  If you have already installed the Hume Datahub SDK, you should not add the files in the DotNet20EqApp.zip archive to any of the Datahub SDK GEM application directories.  The SecsPort component is able to find and use the Datahub SDK GEM directories without usage of a common directory.

The SecsPort .NET component uses the SECS/GEM application files provided in the Hume Datahub SDK product.  A developer needs to install the Hume Datahub SDK, and specify on the SETUP screen that the GEM/SECS applications should be installed.  The SecsPort component is able to find the Datahub SDK files using the environment variable DMH_BIN which is set when the Datahub SDK is installed.

The situation is simpler for a runtime deployment of your equipment SECS interface.  Instead of installing the Datahub SDK, you can simply deploy a single file executeable, HumeSDK.exe or SecsServer.exe.  The HumeSDK.exe includes OPC device integration features that the SecsServer.exe does not contain.  These files are provided by Hume Integration for the usual case of using the as-provided SDK files.  If you have customized the SDK files, you are able to create a custom versions using a build script.   We encourage you to use the full SDK during development so that you have the toolset documentation, the debugging tools, and you are able to view the SDK GEM application source code.  When you are ready for deployment, you can download the HumeSDK85.zip or SecsServer85.zip archive from the Hume customer support website to obtain the server program and its build script.

In order to run the example application, you need to have either the .NET development software installed, or the .NET runtime installed.  The .NET runtime can be downloaded from  Microsoft as the file, dotnetfx.exe.  Note that the .NET runtime is not distributed with or built into all Windows operating system versions.
 

Environment Variables DMH_DOTNET_TCLDIR and HUME_OPC_DATA_DIR

When the SecsPort component is initialized, it needs to find the Datahub SDK files or the HumeSDK.exe or the SecsServer.exe executable. The startup logic first looks for the server program in (1) the directory pointed to by the environment variable DMH_DOTNET_TCLDIR and then (2) the current working directory, and then (3) two directory levels up from the current working directory, which is the common development scenario when an executable is run from the subdirectory bin/Debug or bin/Release.   If the HumeSDK.exe or SecsServer.exe program is not found, then the startup logic looks for the SecsServer.tcl application script and the supporting files that are part of the Datahub SDK.  The search order for the SecsServer.tcl file is (1) the directory pointed to by the environment variable, DMH_DOTNET_TCLDIR,   and (2)  the gem2/server directory of the Datahub SDK installation found using the environment variable DMH_BIN or by checking the default installation path.

This default logic may fail to find the files in the scenario when the Component is dragged and dropped on a design surface. We recommend you  define and set the environment variable DMH_DOTNET_TCLDIR to establish a well defined startup.  Use slash directory separators.  Environment variables are set by navigating from the Start menu - Start/Settings/Control Panel/System/Advanced/Environment Variables.  An example value is:
DMH_DOTNET_TCLDIR=C:/usr/local/gem2/server
In a runtime deployment, the HumeSDK.exe or SecsServer.exe executeable file is placed in a directory of your choice as specified by the DMH_DOTNET_TCLDIR environment variable.  The default directories used for process program transfer and trace logging are subdirectories of where the SecsServer.exe or SecsServer.tcl file is found.

When you are using OPC features combined with the SecsPort software, you should set the environment HUME_OPC_DATA_DIR to specify the directory where your OPC configuration data resides using Unix style /slash/directory/separators.  Both the Hume OPC Supervisor application and the SecsPort logic will use the value of this environment variable to find and use the same configuration.  An example value is:

HUME_OPC_DATA_DIR=c:/usr/local/lib/humeopc1.0/data

Development

You can use the Hume SecsPort .NET Component with your own application either by adding References to the SecsPort.dll and HumeDMH.dll files, or by adding the SecsPort project to your application solution.  It is our experience that you are better off adding the SecsPort project to your application solution because you will see better prompting when editing code using the Visual Studio IDE.  

To add the SecsPort project to your application solution, follow any of the usual procedures - you can use the main menu (File/Add/Existing Project...) or right click on your solution in the Solution Explorer (Add/Existing Project...).  Navigate to the SecsPort folder and choose the SecsPort.csproj file.

If you choose instead to simply add references to your existing project, you first add a reference to the SecsPort.dll.  A C# user chooses the Add Reference... menu item from the Project menu.  From the Add Reference dialog, the Browse... button on the .NET tab notebook page is used to indicate the path to the SecsPort.dll.  Similarly, add a Reference to the HumeDMH.dll.

When using the Hume GemEqApp example solution the first time, depending on your circumstances, you may need to fixup the references to the DLLs and dependent project files.   Start with the SecsPort project as displayed in the Solution Explorer and see if the Reference to HumeDMH is resolved successfully.  If not, remove the existing reference, and then add it back,  using the Add Reference... action from the right-click menu on the References section.  Click on the Browse tab of the Add Reference dialog, and then select the HumeDMH.dll file in the GemEqApp directory.   Next, examine the GemEqApp project and display the References.  If the HumeDMH reference is not resolved, then remove the reference and add it back by Browse'ing to the same DLL file as you did for the SecsPort project.  If the SecsPort reference is not resolved, remove it, and again use the Add Reference... action.  This time, press the Projects tab of the Add Reference dialog, and select the SecsPort project.

The SecsPort software uses the namespace Hume.SECS.  Coding is easier if you add the statement using Hume.SECS; to the using statements of your application source code.  By doing this, the namespace name, Hume.SECS, can be omitted from name references.  A Visual Basic developer uses the Imports statement for the same purpose. 

Usage of the SecsPort software was greatly simplified in June 2009 by substituting Events for several features that formerly required delegates (callbacks).  Also, the Events are presented to your application in the same single thread that constructs the SecsPort instance.  So your application can enjoy the simplificity of a single threaded application with the power of having multiple threads carry out communication in the background.

The SecsPort software uses the HumeDMH.dll component internally to control the SECS interface server using the Hume DMH message system.  You may want to explore using the DMH message for your own application requirements such as integrating your User Interface with Controller systems, intelligent devices, and instruments.  The Hume SECS software is able to play the equipment role and the host role in multiple instances in the same SECS server process.  You may want to consider using the Hume SECS software to control SECS sub equipment.  In this situation, you would play the role of the host to the sub equipment, and the role of the equipment to the factory host.

Your primary focus as a developer is using the class SecsPort.  This class implements public methods to send and receive SECS messages, and manage an equipment SECS interface.  You will find the example application code in the GemToolUI/ToolUI.cs or GemEqApp/GemGui.cs files to be very informative.

Here is the general flow of using and configuring the SecsPort:
 

  1. If you have a GUI application, perform the SECS interface initialization from the Load event for your main window.  This way your window entities all exist when the SecsPort events and callbacks start executing your application code.  You double-click on your main window to have the IDE generate an event handling method for the Load event.
  2. If you are using OPC device integration features, we recommend you call SecsPort.OpcStart before constructing SECS interfaces to initialize and start your OPC connection(s). 
  3. Construct a SecsPort instance.   At runtime, constructing the instance causes the child SECS server process to be started.  You may want to surround your instance construction with try and catch to trap startup problems with an improper installation or licensing.
  4. Setup your event handlers to receive inputs from the SecsPort.  These events execute on the same thread that constructs the SecsPort instance so you do not have to deal with the complexity of thread synchronization issues.
  5. Call StartupLoad and StartupRestore to initialize the communication and control state properties to their persisted values.  Alternatively you may use your own persistence mechanisms and call ConnectTypeSet or one of the ConnectType<Type> methods.  Do this early in the initialization so that the SECS Server creates a data array and table records for the SECS interface.   These items are needed for further configuration.  It ok to change the connection type later in the initialization.  When you call the ConnectTypeSet method, StateChange events occur to provide your application with the initial values of the state data.  That is why we recommend you have the callback and event handlers in place before setting the connection type.  StartupRestore does not enable SECS communication.  You need to complete the remaining configuration work before enabling communication.
  6. Now you can perform the bulk of your SECS interface configuration.  Do the following, in any order:
  7. Your configuration and initialization is complete so you now are ready to enable SECS communication.  The standards require that the initial communication and control states are configurable and persistent.  Set the CommIsEnabled property value in accordance with the desired startup.
  8. You can set the CommIsEnabled property to false to disable SECS communication.  The SecsPort Dispose method may be called directly at program exit - it does provide for a proper shutdown of the SECS communication.

Tcl Secs Notation, TSN

SECS messages are passed into and out of the application as formatted strings.  The format is similar to the notation in the SEMI documents except that the list formatting conventions of the Tcl programming language are followed.  The SecsPort API provides methods to split, join, append, and extract list elements.  In general, curly braces, { }, are used to surround list elements which contain white space.  By using the API calls to append list elements or join strings as list elements, you can be sure that your strings are properly formatted, and you do not need to manually balance opening and closing curly braces.  Developers who have worked with both XML and TSN list notation have found that the TSN notation is more compact, closer to the SEMI documentation, and easier for a human to scan and validate when reviewing diagnostic output.

As general guidance, when you expect a string value, you will get a two element list, of the form "A:n {this is n chars of text}".  If a string value does not have imbedded white space, it may be formatted without braces, such as "A:8 OneToken".  When you use the ListElement or ListSplit methods to parse the text, they take care of parsing and removing surrounding braces for you.  If an empty string is sent, you will see a one element list, A:0.  With ASCII string data that contains null characters, the Unicode replacement character \uFFFD may optionally be used by the .NET application as a replacement for the null character \u0000.  This provides a work-around for the behavior of the .NET System.Text.StringBuilder class which truncates StringBuilder text at the first null character when the ToString() method is used.  The Hume .NET API converts the replacement character to the modified UTF-8 byte sequence for null when communicating with the SECS Server.

SECS has the notion of array data - 0 or more values of a given type.  When you expect to receive a single numeric value, you receive a two element list, with the type code as the first element, such as "U4:1 290".  You can also receive an empty array "U4:0" or an array with more than one value as in "U4:3 0 1 2".  Binary data values are formatted using C-language hexadecimal integer notation, for example, "B:3 0x00 0x01 0x02".  You can use the BinToInt method to convert these values to integer values.  With received data, the type code has a length value appended to it after a colon.  With data that you format for sending, the length information is optional, the data is parsed to determine the length.  See the TSN.html document for more details.
 
Semi Octal type code TSN type code Meaning & Examples
00 L List,  L, L:0,   "L {A {atc 100}} {A 1.0.0}", "L:2 {L:2 {U4 200} {U4 210}} {B 0}"
10 B binary - unsigned 8 bit data, "B 0", "B 1 2 3"
11 TF  boolean data, TSN type codes BL or BOOLEAN are also accepted as input, "TF 1"
20 A Character string data.  Traditionally this has meant printable ASCII characters but some implementations are sending any 8 bit characters including nulls using this type.
"A {hello world}", "A hello"
21 J Japan International Standard (JIS-8) encoded text.  This format is not commonly used or supported because in the past the SEMI standards have failed to identify specific reference documents.
22 V1..VE Variant data, also known as Localized Character Strings.  Your .NET unicode text is automatically converted into the chosen encoding.  V1 is for Unicode 2.0, V2 is for UTF-8 encoding.  See the TSN.html document for more details. "V1 {sent as Unicode}"
30 I8 8-byte signed integer, "I8 -1"
31 I1 1-byte signed integer, "I1 -3"
32 I2 2-byte signed integer, "I2 99",  "I2 15 -7 99"
34 I4 4-byte integer signed, "I4 -5"
40 F8 8-byte floating point, "F8 6.02e23", "F8 0.1"
44 F4 4-byte floating point, "F4 1.0"
50 U8 8-byte unsigned integer, "U8 0"
51 U1 1-byte unsigned integer, "U1 0"
52 U2 2-byte unsigned integer, "U2 512"
54 U4 4-byte unsigned integer, "U2 979"

 

Built-in SECS Data, Message Handling, Events

The SecsPort component has built-in logic to handle more than 100 of the standard SECS message types.  You do not have to code or provide for complex GEM capabilities such as dynamic event reports, or the communication and state models.  See the reference table for more detail on the built-in message types.

Similarly, the variables required for GEM compliance are already defined, and are listed in the built-in variables table. In some cases, such as the PPExecName variable, your custom application logic has to provide current data values.  The example application demonstrates using the VariableSet method or the VariableMethodSet method as techniques to supply variable values.  If a data item's value is changed infrequently by your logic, its more efficient to use VariableSet which provides the current value to the SECS server process.  The VariableMethodSet method is the right choice for data items whose value changes more often such as a process temperature reading, or are easier to manage as .NET application data items.

The SecsPort software uses type U4 numeric identifiers for the numeric IDs called out by GEM such as ALID, CEID, ECID, and SVID.  These identifiers are passed as unsigned, 4 byte integers - SEMI Octal code 54.

 There also some standard event report types specified by GEM and pre-defined for you as listed in the built-in events table. Your application logic needs to call EventPost as these events and your own defined events occur during processing.
 

Custom SECS Message Handling

Use the method MessageTypeAdd to have SECS messages routed to your event handling code.  Use SendReply, SendS9, or SendAbort to respond to the inbound message.  The method SendSecsMsg can be used to initiate sending a new SECS message with optionally waiting for a reply message.  The SendSecsMsg method has an option to execute using a background thread.  With this option, events are still processed, and your application can be making method calls to report events, or alarms.  Because of the internal design of the SecsPort, these other method calls are not blocked or delayed because your handler is busy with a conversation.  The API is threadsafe so if you want to start and use your own threads to make method calls, you may.  However, the SendSecsMsg method does not permit re-entrant execution if using the background thread.  If you do not choose to wait for a reply, sending a new message is nearly instantaneous.  Therefore, the re-entrancy restriction only affects usage when you choose to wait for a reply message and you elect to use the background thread.  You may need to disable and enable button actions that use SendSecsMsg with the wait reply option to prevent inadvertant re-entry.  The background thread option eliminates the risk of your GUI application being unresponsive when the host fails to reply promptly, but realize that it allows button actions to be re-entered.

Logic in your application can send SECS messages or initiate conversations using the SendSecsMsg method without choosing to use the background thread.  In this mode you will avoid a re-entrant execution error return because multiple invocations of SendSecsMsg are serialized in a DMH message system queue.  For HSMS communication,  if you are sending a message and not waiting for the reply, SendSecsMsg can be used from your GUI code without fear of making your GUI unresponsive.  In the cases where you wait for a SECS reply message, when using HSMS, under most circumstances, the host's reply or failure to reply will be resolved within a few seconds.   The unusual circumstance is that you still have a TCP/IP connection to the host so your send is successful, but then the host does not reply, and a timeout takes the full T3 period.  So the default choice of the SendSecsMsg logic is to use a background thread if you are waiting for the reply.  With SECS-I serial communication, timing is completely different.  In this day and age an equipment provider should not deploy a SECS-I interface unless there are compelling reasons for doing so.  Serial ports are no longer commonly provided on new computers. With SECS-I there is no underlying TCP/IP connection that can signal the application when it is broken.  So there is a higher risk of the sending thread being in an unresponsive wait to determine if a send is successful, or in a long wait to obtain the reply.  So you may want to indicate use of the background thread with a SECS-I connection.

SendSecsMsg and Threading Choices Summary (SecsEquip)
Calling Thread/ WaitForReply
useWorkerThread=true
useWorkerThread=false
GUI thread, WaitForReply=true
(useWorkerThread defaults to true)
Events are dispatched.  A re-entrant execution error is possible.  You may want to disable and enable button actions since the GUI stays responsive.
Events are not dispatched.  A re-entrant execution error is not possible because multiple invocations are serialized in a DMH message system queue.  The GUI may be unresponsive if the other party does not respond promptly.
GUI thread, WaitForReply=false
(useWorkerThread defaults to true if you are using VarValueRequest events, otherwise false)
Events are dispatched.  A re-entrant execution error is possible but highly unlikely with HSMS since the method returns almost immediately.
Events are not dispatched.  A re-entrant execution error is not possible.   For HSMS communication, the method call returns almost immediately.
Other thread, WaitForReply=true
(useWorkerThread defaults to false)
Event dispatching is not affected.  A re-entrant execution error is possible. 

Since you have your own worker thread, go ahead and use it either by letting the useWorkerThread choice default, or by setting it false.
Event dispatching is not affected.  A re-entrant execution error is not possible.

This is a smart choice to provide your own worker thread(s) but it adds complexity to your application.
Other thread, WaitForReply=false
(useWorkerThread defaults to false)
Event dispatching is not affected.  A re-entrant execution error is possible but highly unlikely with HSMS since the method returns almost immediately. Event dispatching is not affected.  A re-entrant execution error is not possible.  For HSMS communication, the method call returns almost immediately.


You should never wait for a reply unless you have a valid reason to do so.   Just because the standard says that a message type should request a reply, does not mean that you should wait for the reply to arrive.  You can use the MessageTypeAdd to register handling code for the asynchronous receiving of replies too.

Miscellaneous Notes

Your design will typically use one instance of a SecsPort component to provide a single SECS interface.  You can use multiple instances of the class to provide more than one SECS interface.  Each interface can have its own custom handling of message types.  You may also use multiple instances of the Hume SecsHost component in the same application.  A typical use of multiple host instances is to act as a host for sub equipment and provide a single control interface to the factory software.   The Equipment OEM can also provide more than one SECS equipment interface to support multiple factory host applications if provision is made for coordinating control.  The latter can be as simple as telling every interface except one that the equipment is under local control.  This provides the benefits of the newer EDA standards without the complexity of implementing additional protocols.

SecsPort API Reference


 SecsPort Properties
Property Access Description

bool AlarmsShareEvents
Set this property value true to have the same AlarmDetected and AlarmCleared data collection events reported for any alarm type.  The preferred value of this property should be set before calling the AlarmAdd() methods.  The behavior preferred by the Photovoltaic Industry Draft Standard #4557 is to have the value set true and to share generic events.  The default value of the property is true.
int BAUD If you are using the SECS-I, RS-232 connection type, this property sets the baudrate of the serial port.  The default value is 9600.
static DmhClient dmh SecsPort instances use a shared connection to the DMH message system in order to communicate with the SECS server process.  The connection instance, dmh, is public in case you want to access it in your application.  Since it is shared (static) the access is SecsPort.dmh.
bool CommIsEnabled
The CommIsEnabled property is an alternative to using the methods CommEnable() and CommDisable().  The read/write property is used to set or query whether SECS communication is enabled.  The default value is false.  The application should initialize the handling of events and other properties before enabling communication.
string CommState Read-only value of your GEM Communication State.  Possible values are DISABLED, ENABLED {NOT COMMUNICATING}, and COMMUNICATING.   The StateChange event is used to obtain asynchronous notification of this property value change.
bool ControlIntentOnline Whether your intended GEM Control State is an ON-LINE substate.  The default setting is false indicating the OFF-LINE intention.
bool ControlModeRemote When in ON-LINE control, whether your intended substate is REMOTE, meaning contolled by the host..  The default setting is false meaning LOCAL control.
string ControlState Read-only, your actual GEM Control State which reflects your ControlModeRemote, ControlIntentOnline and host dynamics.  Possible values are ON-LINE LOCAL, ON-LINE REMOTE, OFF-LINE Equipment, OFF-LINE Host, and OFF-LINE SeekOnline.  These string values are enumerated in the ControlStateText string array, in the same order as ControlStateEnum values.  The StateChange event is used to obtain asynchronous notification of this property value change. 
enum ControlStateEnum ControlStateStartup Your software is able to specify the initial state for the GEM Control State model.  The choices are:  OfflineEquipment, OfflineAttemptOnline, OfflineHost, OnlineLocal, or OnlineRemote.  This setting defaults to OfflineEquipment, but is overruled to be consistent with your ControlIntentOnline and ControlModeRemote values.  If your ControlIntentOnline is false, and your startup is an Online state, the startup state is changed to OfflineEquipment.  If your ControlIntentOnline is true and your startup state is OfflineEquipment, your startup state is changed to OfflineAttemptOnline.  Similarly the setting of ControlModeRemote can overrule an online startup state corresponding to the opposite LOCAL or REMOTE online substate choice.  This logic is applied when CommEnable is called.
int DEVID The SECS Device ID.  An identifier imbedded in SECS header data usually left at the default of 0.  You can change it anytime but you are better off setting it before enabling communication.  Per the standard, the SecsPort rejects messages from the host that are not for the equipment's Device ID.  Settable range is 0..32767.
static SecsPort.DMHGroupName The DMH message system groupname used by the SECS server.  The same groupname should be specified to the constructor of every SecsPort or SecsHost instance in the application in order to share the same SECS server process.
bool Hsms Whether the Connection type is HSMS (LAN based).  False implies SEC-I, serial RS-232 communication.  Defaults to true.
string HsmsHost For an active HSMS connection, specifies the TCP/IP hostname or IP address of the Host computer.
bool HsmsPassive For an HSMS connection, whether the SecsPort plays the passive, TCP/IP server role.  The default value is true which is the usual role of equipment. 
int HsmsPort For an HSMS connection, the TCP/IP socket port number.  Defaults to 5555.
bool IdRangeChecked By default, the methods to add Alarm, Event, Variable, and Parameter definitions, restrict the numeric ID values allowed to ranges which prevent you from colliding with built-in values, or colliding with each other's values.  However, the range checking can be disabled by setting this property value false.  Also, you can renumber the built-in events and variables, and customize the events that are assigned for alarm set and clear events.  Thus, you are able to completely customize the identifiers used by the SECS interface.  If you choose to renumber and customize the identifiers, do it in your initialization logic before enabling communication, but after restoring or configuring the connection type.  This insures that connection instance data exists in the SECS server to hold your customization.
string MDLN The SECS Equipment Model Type - limited to no more than 20 characters by the E5 standard.
string Name The SecsPort name passed to the constructor and used in the SECS server process as a Tcl command name, a global array name, and an identifier in SQL table records.
bool ParametersAreSaved This property controls whether the values of parameters (ECV's) are saved at the program exit and restored during the next session.  Saving the values is standard GEM behavior so the default value is true.  If the value is true, the saved values are restored the first time that CommEnable is called, unless it has been already restored by calling the method ParametersRestore.  In other words, you can use the method ParametersRestore to force loading of the saved values before CommEnable is called.   The value data is saved as a file of SQL statements in the subdirectory spooldata.  The filename used is "EcvParms_" + Name + ".sql".



bool PPbodyFileMode
This boolean property controls whether S7F3 and S7F6 process program transfer messages are handled by direct data transfers to and from files bypassing handling the messages in memory.  This avoids possibly large memory allocations and enables transferring process programs that are as large as the 16 meg limit of Stream 7.   Setting the option also reduces the data that is seen by tracing and logging - only summary information can be seen in the diagnostics.  The default value is false.  It is recommended to set the option true if process programs sizes are as large as 1 meg.  The mode is transparent to the application; the ProcessProgramDownload and Upload methods work the same and the built-in SECS Server Stream 7 receiving with StateChange notifications work the same irrespective of the PPbodyFileMode setting.
bool PPFilesByRequest
This boolean property is set true if the app must prepare process program files for upload transfer to support SECS message types S7F5R or S7F41R which are handled by the built-in SECS Server logic.  The value is left at the default value of false if process programs already exist as files in the recipe directory or if the equipment does not feature process program transfers.  When the value is set true, the app must handle PPFileRequest events as the trigger to write process program files.  See the description of the PPFileRequest event for more details.
bool RecipesAreBinary A boolean flag to indicate whether Process Program files should be transferred as type B (binary) data, or type A (ASCII) data.  The default is true, meaning binary transfer.  If Process Program files are printable text, the type A transfer is easier for the factory personnel to work with.  The software is able to transfer binary data as type A but not all host software can accommodate this.
string RecipeDirectory A pathname to the file system directory where Process Program files are located.  The default is "./recipes" - a subdirectory of the current working directory.
bool ReportsAreSaved This property controls whether the state of event reporting is saved at the program exit and restored during the next program run.  Saving the state of dynamic reporting is standard GEM behavior so the default value is true.  If the value is true, the saved event reporting configuration is restored the first time that CommEnable is called, unless it has been already restored by calling the method ReportsRestore.  In other words, you can use the method ReportsRestore to load the saved reporting configuration before CommEnable is called.   The report configuration data is saved as a file of SQL statements in the subdirectory spooldata.  The filename used is "reportdata_" + Name + ".sql". 
bool secsTraceUseGuiThread
Set this property true to force SecsTrace events to occur in the SecsPort constructor thread, which is typically the main GUI thread of the application.   You would only set this true if you were receiving the SecsTrace events in your application instead of using the built-in Trace Window class.  The SecsPort behavior prior to August 2013 was to post these events on the main GUI thread.  The behavior was changed to improve the GUI performance of the Tracewin class.   The default value is false.
string SerialPort For a SECS-I connection, the serial port device such as "COM1".
string SOFTREV The SECS Software revision - limited to no more than 20 characters.  Default value is "1.0.0".  You may wish to consider a pattern of major.minor.patchlevel.
string SpoolDirectory
The file system directory for spooling, report configuration, and parameter (ECV) persistence files.  The default TraceSaving logging directory is also underneath the spooling directory. The get method returns a fully qualified path that uses slash path separators on all platforms.  The default spooling directory is the sub-directory spooling under the working directory of the SECS server.  For a default Datahub SDK installation and startup, the directory is /usr/local/gem2/server/spooling.  The directory value may be set early in the initialization before StartupRestore() or ConnectTypeSet is called.  An exception is thrown by the set method if the specified directory is not valid or if the method call is not made before the connection type is set.
string SpoolingAllow This property is set to specify the streams which the host is allowed to specify for spooling in message type S2F43.  It is formatted as a space separated list of "S<s>" tokens where the <s> value is stream number.  The standard does not allow Stream 1 to be spooled.  The default value is "S5 S6" which allows for spooling alarm messages and event reports.  An empty string value disallows any spooling.  The value only affects the handling of S2F43 messages from the host.  Your software is able to change at any time which message types are being spooled using the method, SpoolStreamFns.
string State A read-only value of the low-level connection state.  Possible values include OFFLINE, LISTENING, and COMMUNICATING.  You will see the OFFLINE state if the connection to the host is broken, or in the case of SECS-I implicitly broken by a conversation timeout.  The StateChange event is used to obtain asynchronous notification of this property value change.
int RTY SECS-I maximum send retry, range 0..31, default 3
int T1 SECS-I Inter-Character Timeout in milliseconds, range 100..10000, default 500
int T2 SECS-I Protocol Timeout in milliseconds, range 200..25000, default 10000
int T3 SECS Reply Timeout in milliseconds, range 1000..120000, default 45000
int T4 SECS-I Inter-Block Timeout in milliseconds, range 1000..120000, default 45000
int T5 HSMS Connect Separation Timeout - the delay between re-connection attempts in milliseconds, range 1000..240000, default 10000
int T6 HSMS Control Transaction Timeout in milliseconds, range 1000..240000, default 5000
int T7 HSMS Not Selected Timeout in milliseconds, range 1000..240000, default 10000
int T8 HSMS Network Intercharacter Timeout, default value 5000.  This value is not used.
int TRACE Used as a bitfield to control diagnostic trace information for SECS port activity which is passed to the application in the SecsTrace event.  By setting specific bits, the corresponding output is turned on. 

General Tracing: (TraceType = trace) 
Bit        Output Description 
0x0001     Read and write calls
0x0002     state changes including connection attempts 

Receive Tracing: (TraceType = rtrace) 
Bit        Description for Received Messages 
0x0100     Header binary dump 
0x0200     Header interpretation 
0x0400     Stream and Function description
0x0800     Message data binary dump 
0x0004     The Message as TSN 

Send Tracing: (TraceType = strace) 
Bit        Description for Sent Messages 
0x1000     Header binary dump
0x2000     Header interpretation
0x4000     Stream and Function description
0x8000     Message data binary dump
0x0008     The Message as TSN 

int TraceLogMaxWidth This property allows setting an approximate maximum number of characters in text lines when saving Trace data to log files.  Lines that are longer than the maximum are trimmed and a short explanation message is appended.  The property helps you reduce the size of the log files when large Process Programs are transferred or other long data messages are logged.  The value may be configured as 0 for no limit, or a value greater than or equal to 1000; the default is 4000.
RcResult SetTraceSaving(bool save, bool compress, int maxDayFiles, string saveDir, string zipCmd)

public class RcResult {
   int rc;   // return code
   string result;
   }

bool TraceDataSaved

bool TraceDataIsCompressed

string TraceSaveDir

int TraceSaveMaxDayFiles

string TraceSaveZipCmd

The toolset software has the configurable feature of continuously saving the SECS communication trace data to files - one file per day, up to a maximum number per year, and optionally compressing the closed file from the previous day shortly after midnight.  The SetTraceSaving method is used to reconfigure the logging feature with the various properties being set atomically in one call.  The RcResult return value is used as follows.  If the rc value is less than 0 the SetTraceSaving() arguments were not acceptable and an error message is provided as the resultstring.  If the rc value is 0, the call succeeded.  If the rc value is greater than 0, the call succeeded with an advisory message as the result string.  For example, a message occurs if compression is set true but there is a maximum of only 1 file, so there is no distinct file for the previous day to compress.

The saving logic writes each day's output to a distinct file, in the directory named by the saveDir argument.  The maxDayFiles argument controls how many day files are saved per year.  It can be configured between 1 and 366.  When file saving is initiated, the output filename is set to traceNNN.txt where the NNN value is the current day of the year, 0 to 365, modulo the maxDayFiles value.  If this file already exists and has been written to earlier in the same day, then the output is appended to it, otherwise the file is created as a new file. Note that if the maxDayFiles value is set to 1, each day's output is saved to the same filename, trace000.txt.  The default values provide for saving the data from each connection in a separate directory.  Separate directories are required for each connection.  When trace data is being written, the compress argument controls whether the logic attempts to compress the output file when it is closed at the end of the day (midnight).  For compression to occur, the maxDayFiles value must be greater than 1 and a non-blank compression command must exist as the zipCmd argument.  The default assignment of zipCmd is similar to zip -m tracetxt.zip. This command causes the data file from the previous day to be moved into the tracetxt.zip archive, creating the archive if it does not exist.   The compression logic appends the day file name to the configured command before execution.  Only trusted persons should be allowed to configure the compression command because of the security considerations.


int TracewinMaxWidth
The approximate maximum number of characters to display in a single line of the trace window.  This value guards against excessive data use when long messages such as recipe transfer occur and the trace window is displaying connection activity.  Range 1000..120000, default 4000.
bool useS13
This boolean property chooses whether to enable using Stream 13 large process program transfer message types when an online control state exists.  In addition to the Stream 13 messages, this property also enables or disables using S7F29, S7F37, S7F38, S7F41, and S7F42 which are used with Stream 13 for transferring large unformatted, process programs.  The default value is false. Stream 13 message types are preferred for transferring large data sets because the data is split into multiple smaller messages which require less memory use.  If Stream 13 message types are enabled, per GEM your application should implement sending S7F27 process program verification messages for  received process programs.


 
SecsPort Events
Event Handler and Argument Data  Description


All event handlers - NOTES
 
 
 
 
 

 

It is possible to use the SecsPort using only events and not any other type of delegate callback.

Events are somewhat easier to develop with than other callbacks because of better handling by the .NET IDE tools.  In some cases we have provided for use of delegate callbacks as an alternative to handling an event.

The IntelliSense code generation of the .NET IDE turns around the usual sequence of writing an event handling method and then registering it.  Instead, try registering an event handler using the += operator.  Press the Tab key when prompted to create event handling methods with the correct arguments.

The .NET framework hides the difference between executing a static method or an object method as an event handler.  You are able to use either kind of method.

When the event happens, your handler method is called.  You can cast the event sender object to (SecsPort) to have a reference to the component instance.  Your event handler is executed by the same thread that constructed the SecsPort instance.


static
void DebugEvent(object sender, StringEventArgs sea)

class StringEventArgs : EventArgs {
    public string message;
}

delegate type DebugEventHander
DebugEvents are available to troubleshoot the initial connection to the SECS Server background process at startup.  When the first SecsPort instance is instantiated, a SECS Server background process is started, and the .NET application is usually able to setup DMH communication with the SECS Server within a few seconds. In an uncommon situation such as a computer system that is running low on resources, the connection setup may require more time.  The timing and retry logic is optionally affected by defining and setting the following environment variables:

DMH_CONNECT_DEBUG=1    Define and set this environment variable to 1 to obtain DebugEvents.   DebugEvents provide diagnostic messages for each connection attempt.  They show the timing and the error messages of failed attempts.

DMH_CONNECT_WAIT=milliseconds    This variable can be defined and set to the desired number of milliseconds of waiting per connection attempt.  The default is 500.  The value may be set from 1 to 60000.

DMH_CONNECT_RETRY=maxAttempts    This environment variable can be defined and set to the desired maximum number of communication attempts.  The default is 20.  The value may be set from 1 to 100.

Code for the receiving the DebugEvent events is generated automatically by the IntelliSense feature of Visual Studio once you have typed SecsPort.DebugEvent +=.  The GemEqApp application has demonstration code to receive and display DebugEvent messages.

See the DmhConnect method coded in the SecsPort.cs file for more details.  Note that the DMH_CONNECT_* environment variables can be defined and set on a deployed system to affect the startup timing  without making code changes, and without having coded a DebugEvent handler.  This is a new feature of the SecsPort component as of January 2016.


void OpcDataChange(object sender, OpcDataEventArgs e)

class OpcDataEventArgs : EventArgs
    {
        public NotificationEnum notification;
        public string tablename;
        public string [] columns;
        public string [] keyColumns;
        public int rowCount;
        public string errorInfo;
        public string [] rows;
        public string createStatement;
}

public enum NotificationEnum : int
    {
  undefined = 0,
  create = 1,
  insert = 2,
  update = 3,
  delete = 4,
  drop = 5,
  select  = 6
    };

delegate type OpcDataEventHandler

If you are using the optional OPC features and you open a subscription to OPC data changes, then the OpcDataChange event notifies your application as data values and quality attributes change.

Here is example code to receive this event.  The method stub is generated automatically by the IntelliSense feature of Visual Studio once you have typed sp.OpcDataChange +=.

// sp is our SecsPort instance
sp.OpcDataChange  += new OpcDataEventHandler(sp_OpcDataChange);

 void sp_OpcDataChange(object sender, OpcDataEventArgs oea)
        {
            OutputAppend("Opc data change event");
            string[] values;
             for (int i = 0; i < oea.rowCount; i++)
             {
                    values = ListSplit(oea.rows[i]);
                    for (int j = 0; j < oea.columns.Length; j++)
                    {
                          // name="value"
                          Console.Write(oea.columns[j] + "=\"" + values[j] + "\"");
                          if (j < oea.columns.Length - 1) Console.Write(", ");
                          else Console.Write("\n");
                    }
             }
       }

The initial event has the notification value set to NotificationEnum.create and the createStatement set to an SQL statement for the opc_item table.   Subsequent events are similar to SQL selection results for the opc_item table.   The notification value is set to NotificationEnum.select, and the rowCount value is set to 1 or more.   The opc_item table is described in the OPC Supervisor documentation.  The columns field contains the column names of the opc_item table for the subset of data that is passed in the event.  Each element of the rows array value is a string containing a list of table data column values corresponding to the column names in the columns array.  You use the ListSplit() method to split each row of data into the column values corresponding to the column names.

void ParameterChange(object sender, ValueChangeEventArgs e)

class ValueChangeEventArgs : EventArgs {
string varname;
string newvalue;
}

delegate type ValueChangeEventHandler
 

The ParameterChange event notifies you of host initiated Equipment Configuration Variable (ECV) changes.  The new value is within the limits you have configured. 

Here is example code to receive this event which is generated automatically by the IntelliSense feature of Visual Studio once you have typed sp.ParameterChange +=:

// sp is our SecsPort instance
sp.ParameterChange += new ValueChangeEventHandler(sp_ParameterChange);

 void sp_ParameterChange(object sender, ValueChangeEventArgs e)
        {
            OutputAppend("GemGui.sp_ParameterChange " + e.varname + "=" + e.newvalue);
        }
void PPFileRequest(object sender, PPFileRequestEventArgs e)

class PPFileRequestEventArgs {
string ppid;
string recipeDir;
string filename;
returnCode ackc7;
void FileWriteOk(string filename);
void FileWriteFailure(returnCode rc,
string description);
}

delegate type PPFileRequestEventHander

An application which manages Process Programs in a database or in non-file representations should set the property PPFilesByRequest true and code a handler for this event type.  When the host sends S7F5R or S7F41R to initiate an upload, a PPFileRequest event is raised to trigger the application to write the process program file in the recipe directory.  The app should use the event argument data, ppid for the name of the desired process program, and recipeDir for the file system directory where the file is written.  The filename assigned by the app may differ from the ppid value.  The app writes the file or fails, and calls the PPFileRequestEventArgs method FileWriteOk() or FileWriteFailure().  The pathname for the output file is computed by concatenating the recipeDir with a slash and then the filename which is provided by the call to FileWriteOk().  Set the filename argument value to the filename only, do not include the directory path.  See the GemEqApp/Tests.cs file for example usage of this feature. 

The filename and ackc7 data items in the event argument data structure are used to communicate success or failure to the SECS Server and subsequently to the host.  Error values from the SEMI E5 data item ACKC7 are applicable.  Approximately 20 seconds are provided to write the file.  If this timeout period is not adequate, the app should instead offer a remote command that initiates a file export and then performs an equipment initiated upload.

Visual Studio will create an event handler in your app when you start typing the following:

// sp is the SecsPort instance
sp.PPFileRequest += new PPFileRequestEventHandler(sp_PPFileRequest);

This event is only part of what the application must do to properly manage process programs that are not managed as files in the recipe directory.  The app should call MessageTypeAdd(7, 17) and (7,19) to handle delete and directory requests.  The app should also use the StateChange events, recipe_download, and dataset_download to trigger file import logic.  The app can use recipe_upload and dataset_upload to trigger deletion of the export files if desired, or they can left alone to be overwritten by future uploads and downloads.
void RemoteCommand(object sender, RemoteCommandEventArgs e)

class RemoteCommandEventArgs : EventArgs
    {
        public int stream;
        public int function;
        public string rcmd;
        public string dataid;
        public string objspec;
        public string TsnCmdArgs;
        public bool replyWanted;
        public int replyFunction;
        public int transactionID;
        public string header;
}

delegate type RemoteCommandEventHandler
As the example application demonstrates, the RemoteCommand event delivers Remote Command invocations to your application.  Your handler should send the reply message to the received S2F21, S2F41, or S2F49 message.  Look at the RemoteCommandReceive method code in the SecsPort class to understand the parsing of the remote command event data, and then look at the handling logic in the sp_RemoteCommand method of the GemGui class to understand preparing and sending a reply message.

If you do not want to support Remote Commands call MessageTypeRemove during initialization to remove the handling of these three message types, or just code your event handler to execute SendS9(5, e.header); which means that the message type is not supported.
void SecsMsgReceive(object sender, SecsMsgReceiveEventArgs e)

class SecsMsgReceiveEventArgs : EventArgs
    {
        public int stream;
        public int function;
        public bool sendReply;
        public int transactionID;
        public string TsnData;
        public string header;
}

delegate type for events SecsMsgReceiveEventHandler
See the MessageTypeAdd method described in the next section to register to receive specific SECS messages in your application with the SecsMsgReceive event.

Events are easier to use than other callbacks and they are supported by third party platforms such as LabView.  However, it is also possible to use a delegate callback to have a specific message type delivered to a custom handler.  There is a form of MessageTypeAdd using the following delegate type:

delegate void SecsMsgReceiveDelegate(object sender, int stream, int function, bool send_reply, int transactionID, string TSN_data, string header)
void SecsTrace(object sender, SecsTraceEventArgs e)

class SecsTraceEventArgs : EventArgs {
string traceType;
string text;
}

delegate type SecsTraceEventHandler

The SecsTrace event provides you with the detailed information of SECS message traffic that is viewed in the SECS Trace window.  The information is controlled by setting the TRACE property.
void ServerDisconnected(object sender, EventArgs e)

delegate type EventHandler
If the SECS Server process exits your application receives the ServerDisconnected event.  This event is not ordinarily expected.  A production application will limit access to the SECS Server windows so that users will not use the Exit menu items on these windows.
void ServerError(object sender, ServerErrorEventArgs e)

class ServerErrorEventArgs : EventArgs {
string message;
}

delegate type ServerErrorEventHandler

The ServerError event reports Tcl programming errors that are trapped in the SECS Server process.  An example would be trying to send an improperly formatted SECS message.  These error events will happen during development but should be rare once the code is debugged.   If you have more than one SecsPort instance, the ServerError event is reported only to the latest instantiated instance.  The event is passed using an instance in order to present the event on your application thread.
void SpoolingAlert(object sender, EqSpoolingAlertEventArgs s)

class EqSpoolingAlertEventArgs : EventArgs {
string msgid;
}

delegate type EqSpoolingAlertEventHandler

The GEM standard describes Spooling events that are to be brought to the attention of the equipment operator.  The msgid values include SPOOLING_ACTIVATED, SPOOLING_FULL, SPOOLING_TERMINATED, SPOOLING_NOT_PERSISTENT, and SPOOLING_DATA_DISCARDED.  See example explanation messages in the application method GuiSpoolingAlert.  The latter two values are not seen in normal circumstances.
void StateChange(object sender, ValueChangeEventArgs e)

class ValueChangeEventArgs : EventArgs {
string varname;
string newvalue;
}

delegate type ValueChangeEventHandler

This event notifies your application of state value changes. Possible varname values include 
  • state - the State property value changed
  • clock_offset - this value is the number of seconds added to the system clock to provide CLOCK variable values for the host.  If the value differs from 0, the host has used S2F31 to set the clock.  Your logic can work with host specified time values by adjusting the system time using this offset value, or by reading the CLOCK variable using VariableGet().  We recommend that you avoid this complexity by instructing your customers to use NTP time synchronization and that you disable S2F31 using MessageTypeRemove().
  • comm_state - the CommState property value changed
  • control_state - the ControlState property value changed
  • dataset_download - a process program has been downloaded from the host using Stream 13 transfer messages.  The newValue argument is a two item list, the ppid, and the pathname to the newly received file.  Use the ListSplit or ListElement method to parse the list.  See the discussion of downloaded files in the description of method ProcessProgramLargeRequest.
  • dataset_upload - a process program was successfully transmitted to the host using Stream 13 transfer messages.  The newValue argument is the ppid.
  • event - this value changes when a data collection event is posted either by your logic calling the EventPost method, or by the built-in SECS server logic.  The newValue argument is a two item list, the CEID of the event, and a 1 or 0 indicating whether an event report message was sent or not.  A report is not sent or spooled if communication is disabled, or if the event type is disabled, or if the control state is offline.  Also, when spooling is active, the event report may not be spooled.
  • recipe_delete - the name of a recipe that is being deleted by the host, or being replaced with a downloaded version using Stream 7 messages.
  • recipe_download - the name of a recipe that has just been received from the host using Stream 7 messages.  However, if the PPFilesByRequest feature is being used, the newValue argument is a two item list, the ppid, and the pathname to the newly received file.
  • recipe_upload - the name of a recipe that has just been uploaded to the host using Stream 7 messages.
  • spooling_state - the SecsPort spooling state, ACTIVE or INACTIVE
  • SpoolCountActual - the number of SECS messages currently spooled
  • SpoolCountTotal - the total number of messages spooled and/or discarded
  • SpoolMax - the configured maximum number of spooled messages
  • SpoolStreamFns - the list of S<s>, S<s>F<f> message types that configured for spooling
Your application gets notified of the initial values of these items when the SecsPort connection type is initialized.
void TerminalDisplay(object sender, TerminalDisplayEventArgs e)

class TerminalDisplayEventArgs : EventArgs
    {
        public int tid;
        public string [] text;
        public bool replyWanted;
        public int replyStream;
        public int replyFunction;
        public int transactionID;
}

delegate type TerminalDisplayEventHandler
The TerminalDisplay event is used to dispatch Host sent Terminal Data into your application.  The string array text holds the communicated data - one string element for the case of S10F3, or multiple elements in the case of S10F5.  Your application should send a SECS reply with the values of the ACKC10 SECS reply item - "B 0" for success, "B 1" for not displayed, and "B 2" for terminal not available. 

If you do not wish to support Terminal Displays, use MessageTypeRemove against message types S10F3 and S10F5.
void VarValueRequest(object sender, VarValueRequestEventArgs e)

class VarValueRequestEventArgs : EventArgs
    {
        public int varCount;
        public int [] varID;
        public string [] value;
}

delegate type VarValueRequestEventHandler
The VarValueRequest event is used to ask your application for variable values if you have elected to manage the variable values in your own code.  You call the method VariableMethodSet to specify the variables that your code will manage.  In your event handler, loop through the varID array and assign the current variable value to each corresponding element in the value array.  This event only occurs when one or more variable values are actually needed to respond to a host query, or to provide data in an event report.

Using this feature causes the SendSecsMsg method to default to using a background worker thread so that your application stays responsive to possible VarValueRequests that may overlap with your message sending.

SecsPort Methods
METHOD DESCRIPTION
General Comments
 
 

 

The List manipulation methods are actually implemented by the HumeDMH.dll component, and exposed for your convenience by the SecsPort component.   These methods may be called from  different threads.
void AlarmAdd(int ALID, string ALTX)

void AlarmAdd(int ALID, string ALTX, int alarmSetCEID, int alarmClearCEID)

Add an alarm type definition. Newly created alarms are enabled.  The first form is the commonly used choice for new SECS interfaces where the CEID's for the GEM Alarm events are configured automatically.   Depending on the setting of the AlarmsShareEvents property, the GEM alarm set and clear data collection events will either be the same events shared by all alarm types, or two new events will be created for each alarm type.  Set your preferred value of AlarmsShareEvents before using the AlarmAdd methods.

If the AlarmsShareEvents property is true, use only the first form of AlarmAdd where the set and clear event IDs are not specified.  Use any ALID value from 1000 to 3999.  If the AlarmsShareEvents property is false, choose only even numbers for the ALID from 1000 to 3998  to allow for two enabled events which are created for each alarm, an alarm set event with CEID == ALID, and an alarm clear event with  CEID == ALID+1.

The ALTX argument is a description of the alarm and it has a length limit of 120 ASCII characters.  The ALTX should not contain single quote characters.

The second form of AlarmAdd() lets you specify the CEID values used for the Alarm Set and Clear event reports.  Use this form if you need to customize which data collection events are posted for the alarm's Set and Clear events.  If the event types do not already exist, they are created.  There is no validation performed on the specified CEID values, they only need to be representable as 4 byte unsigned integers.   With this form of AlarmAdd you are able to specify any ALID value from 1000 to 3999 with the default range restriction in place.

With either form, you are able to bypass the usual range restriction of the ALID value by setting the property IdRangeChecked false

void AlarmEnable(int ALID, bool is_enabled) Enable or disable reporting of an Alarm type (S5F1).
bool AlarmIsEnabled(int ALID) Test if the reporting of an alarm type is enabled 
bool AlarmIsSet(int ALID) Test if the alarmed state is currently set
void AlarmSet(int ALID, bool is_set) Set or Clear the alarmed state of an alarm.
int BinToInt(string binValue)

 

Converts a SECS B (Binary  - Semi "10") data value usually formatted as a hexadecimal string to an integer value.
void CommDisable() Disable SECS communication.  The SecsPort is initialized without communication enabled so using this method only makes sense after CommEnable has been called.  This method call is equivalent to setting the CommIsEnabled property false.
void CommEnable() Enables SECS communication.  The CommEnable method call is equivalent to setting the CommIsEnabled property true.  The CommState property value will change and StateChange events will be received.  These changes are the asynchronous indications for success or failure to establish communication.  When your equipment is configured for the Active HSMS role, field personnel will want to display the trace window with the 0x0002 TRACE property bit set in order to see detailed information on the status of communication attempts. 
int ConnectTypeHsmsActive(string host_or_ip, int port) This method is an alternative to setting the underlying property values to specify an active HSMS connection type, and calling ConnectTypeSet().
int ConnectTypeHsmsPassive(int port) This method is an alternative to setting the underlying property values to specify a passive HSMS connection type, and calling ConnectTypeSet().
int ConnectTypeSerial(string comDevice, int baudrate) This method is an alternative to setting the underlying property values to specify a SECS-I connection type, and calling ConnectTypeSet().
int ConnectTypeSet() This method is called to use the current property values and initialize a SECS interface for the indicated connection type.  It is called by the ConnectType<Type> methods.  If you are setting connection property data directly, call this method after your property values are set.  The method returns the value 0 to indicate success.
void DebugDMHStatus(bool show) This method causes the DMH message system status window to either be shown or dismissed.
void DebugInspect() This method can be used to exec the Inspect introspection debugger.
void DebugTclConsole(bool show) This method causes a console window for the SECS Server to be shown or dismissed.
void DebugTableWindow(bool show) This method causes the Datahub table management GUI to be shown or dismissed. 
void DebugTraceWindow(bool show) This method is used to display a window which updates to show SECS message traffic and state information for the SecsPort.   There are menu options to control the data displayed, and menu actions to save the displayed data to the file system.  This method invokes the Tcl version of the Trace window which is created by the SECS Server process.  See the Tracewin method in order to instantiate a native .NET window with similar function.  Including the .NET window in the administration area of your equipment GUI may be desirable to help field personnel diagnose communication problems. 
void Delete() The Delete method is called when an instance is no longer wanted, and there is no intention of future use.  The method disables communication as well as deleting data structures and resources used by the instance.  It also deletes the interface's persisted data including the TraceSaveDir directory.  The Dispose method should be used instead of Delete for a shutdown that does not delete persisted data.
void Dispose() As a .NET component, the SecsPort inherits a public Dispose method that can be called to shutdown.   The Delete method can be called if there is no intention of future use.
void EventAdd(int CEID, bool is_reported, string description)

void EventAdd(string eventName, int CEID, bool is_reported, string description)

This method is used to create an Event type.  With the default range checking of ID values, you are restricted to use CEID values between 5000 and 9999 so you do not collide with Alarm Set and Clear events, or the built-in events.  You can set the IdRangeChecked property false if you need to customize the assigned IDs.  Events can be given meaningful names, and the names can be used when posting event occurrences.  Choose names that are less than 256 characters and consist of alphanumeric characters and/or the hyphen or underscore.  The first form of eventAdd() defaults the event name to the CEID value expressed as a String.  The second form of the eventAdd() method allows you to specify your own event name value which should be unique among all of the event names for the SecsEquip instance.
void EventDvvals(string eventName, string [] dvvalNames)
This method is used by the application to provide descriptive information used in the S1F24 reply which is a newly proposed standard message as of October 2011.  To support this message type, the application provides eventName values when creating events using EventAdd().  Then, for event types which have associated Data Value variables (class DVVAL), the application uses this method to inform the SECS Server of the association using the variable varname values.   This method is used late in the initialization after the event type and the associated DVVAL variables have been added.
void EventEnable(int CEID, bool is_enabled) Event reports are enabled for an event type when first created.  You can use this method to control whether an event report is enabled.
bool EventIsEnabled(int CEID) Test if reporting of an event type is currently enabled.
void EventPost(int CEID)

void EventPostByName(string eventName)

These methods are used to announce when an event has occurred.  In general, make sure that the data items that the host might want in an event report are set to their proper values before eventPost is called.  You should make this call without testing to see if reporting of the event is enabled and without other testing of the communication or control states. The two method forms allow for posting the event by its CEID or its name.
int EventRenumber(string eventName, int newCEID) This method is provided so that the CEID values of the built-in events can be customized.  Use the method after restoring or configuring the connection type, and before enabling communication.  If the newCEID value is in use by a different event, that event is given a "temporary" ID value of the current value plus 1 million under the assumption that it will be renumbered as well.  After initialization, if events are found with ID values greater than 1 million, they indicate that more than one event has been assigned to the same ID value. 

A positive return value is a warning, and the value 0 indicates success. Negative values indicate error condtions.   In more detail, the return values and their meanings are:

0
The event already has the desired ID, or the event was renumbered successfully.
1
The newCEID was in in-use so the existing event was renumbered to a "temporary" ID.
2 or more
The return value is the number of events of this name that were found.  The extra table records were deleted and the surviving table record has the desired ID or was renumbered successfully.  This condition is not ordinarily expected.
-1
The eventName does not identify an existing variable.
-2
The method did not succeed from an unexpected error such as a timeout.
-3
The connection type has not been set and table records do not exist for renumbering.
System.Collections.ArrayList EventReportLinks() This method call returns a list of integer pairs for the current associations of event types and event report definitions.  Each int [2] pair has the CEID value at subscript 0, and then the RPTID value at subscript 1.  These association links are setup by the host using S2F35.  They can also be setup using the ReportLink method.  This method supports helping you display or provide for editing of the event report configuration.
void EventUnlink(int CEID) This method can be used to unlink (disassociate) any reports that are associated with an event type.  The call can be used if your tool supports manual editing of event reports. 
int HexValue(char b) This method can be used to convert a single hexadecimal character to an integer value.  The BinToInt method will convert a hexadecimal string.
string HtmlSave()
This method is used when fully initialized to save the configuration of Alarms, Events, Parameters, and Variables to an HTML file in a form that is useful for preparing documentation.  The return value of the method is the pathname of the output file which is written in the working directory of the SECS Server.  The method is equivalent to invoking the procedure, ei_html_save, at the Tcl command prompt of the SECS Server.
bool IsHexDigit(char b) This method can be used to determine if a single character can be parsed as a hexadecimal digit.
bool Linktest() Synchronously test a COMMUNICATING HSMS connection to verify that the link is responsive.  May take up to timeout period T6 to return. On failure, the HSMS socket connection is closed and the CommState will no longer be COMMUNICATING.  Useful for equipment to force a broken connection to be discovered just before important event reports so that the report messages are spooled or so that the app is in sync with the actual communication state. Returns true if the link is up, false if the link is down
void LinktestAsync() Cause a linktest HSMS control message to be sent to test if a healthy connection still exists.  Forces discovery of a bad connection after a T6 timeout. If the link test fails, the HSMS socket connection is closed and the CommState is no longer COMMUNICATING.  The method is useful for periodic polling if there is an issue with broken connections not being discovered soon enough.
StringBuilder ListAppend(string list, string element);

StringBuilder ListAppend(StringBuilder list, string element1);

StringBuilder ListAppend(StringBuilder list, string element1, string element2);

StringBuilder ListAppend(StringBuilder list, string element1, string element2, element3);

StringBuilder ListAppend(StringBuilder list, string element1, string element2, element3, element4);
 

These methods are used to add one to four list elements to text that is formatted as a Tcl list.  It is a good programming practice to use ListAppend or ListJoin to build a Tcl list, in order to make sure that imbedded white space or other special characters are properly delimited with curly braces or escaped with backslashes.  A null value may be passed as any of the string argument values, in order to represent an empty list or empty element.  However, a null value should not be passed as a System.Text.StringBuilder argument.  The System.Text.StringBuilder class is designed to support more efficient string modification than using instances of the string class.  The input StringBuilder objects are modified by reference and returned as the return value of the methods.  You can construct a StringBuilder instance that does not contain any characters to represent an empty list.   The overloaded method calls make it convenient to add up to four list elements in one call.  If you need to add more elements, call the methods repeatedly.
string ListElement(string list, int index1);

string ListElement(string list, int index1, int index2);

string ListElement(string list, int index1, int index2, int index3);

This function is similar to the lindex function of Tcl.  It will parse text formatted as a Tcl list and return the specified element.  Indexing starts from 0.  Arguments index2 and index3 may be used to indicate that parsing of the TclList should continue up to two additional levels as a nested list structure. If a specified index is out of bounds, an empty string is returned.  Not all strings are valid Tcl lists.  If an invalid list is parsed, the method call throws the FormatException.
string ListJoin(string [] argv); Joins together strings as Tcl list elements forming a result string that is a Tcl list.  Braces are added as needed to delimit empty elements, or to delimit special Tcl character sequences involving backslashes , square brackets, etc. 
string [] ListSplit(string list) ListSplit( ) parses a string formatted as a Tcl list into an array of string elements.  The function understands the Tcl usage of quotes, braces and backslash sequences.  Not all strings are valid Tcl lists.  If an invalid list is parsed, the method call throws the FormatException.  Failure occurs when there are unmatched braces, unmatched quotes, or non-whitespace following braces or quotes.
void MessageTypeAdd(int stream, int function)

void MessageTypeAdd(int stream, int function, SecsMsgReceiveDelegate callback)

delegate void SecsMsgReceiveDelegate(object sender, int stream, int function, bool send_reply, int transactionID, string TSN_data, string header)

Use the first form of MessageTypeAdd to have received SECS messages of the specified type delivered to your application as a SecsMsgReceive event.  Events are easier to code than other callbacks because the support of the IDE.

Use the second form of the method to have SECS messages dispatched to your callback handler.

To receive a message from the host, an online control state must exist.  These methods provide for handling new SECS message types, or for replacing the existing SecsPort handling of particular messages.  Use the SendReply, SendS9, and SendAbort methods to send reply messages. 
void MessageTypeRemove(int stream, int function) This method is used to cancel SECS message handlers that you have setup using MessageTypeAdd or to cancel the handling of particular messages during the online control state by the built-in SecsPort logic.  For example, you may wish to turn off Process Program management message types for a tool that does not use Process Programs.  If you have called MessageTypeAdd for the specified message type, the Add is cancelled.  If you have not called MessageTypeAdd, the SECS server is told not to handle the message. Unhandled messages are replied to with an abort reply.  If the unhandled message does not ask for a reply, an S9F5 message is sent to indicate an unknown function.
void OpcAlarmAdd(string opcConnectionName, string opcItemId, int ALID, string ALTX)

void OpcAlarmAdd(string opcConnectionName, string opcItemId, int ALID, string ALTX,             bool hasMin, float min, bool hasMax, float max)

void OpcAlarmAdd(string opcConnectionName, string opcItemId, int ALID, string ALTX,             int alarmSetCEID, int alarmClearCEID, bool hasMin, float min, bool hasMax, float max)

Changes to some OPC item values may signify SECS alarms.  An alarm is an undesirable condition with a set and clear state.  In the usual case, you assign ALID integer identifiers to each alarm type starting from 1000.   As you add alarm definitions, the SECS software assigns Events for the Setting and Clearing transitions of the alarm condition.  These events will be signalled automatically.  There is a property configuration value, AlarmsShareEvents, to specify whether different Alarm types share the same Events which is the default.   In this case you may number your ALID values to increase in sequence by 1.  

The method OpcAlarmAdd() is called to map the data of an OPC item to a SECS alarm condition.  The opcConnectionName argument is the OPC connection name that has been previously configured using the OPC Supervisor application.    The opcItemId argument is the fully qualified OPC item name.  The ALID and ALTX arguments represent the SECS data items for the alarm identifier and its description.  The description is limited to 120 characters. 

The second form of OpcAlarmAdd provides for specifying a lower bound, an upper bound, or a range of values that indicate an alarm condition.   The alarm condition is set for the item if (hasMin && (value < min)) || (hasMax && (value > max)).  The default behavior is to map any non-zero value to the alarm set state which works well for any representation of a boolean value. 

The most complex form of OpcAlarmAdd allows you to specify the SECS Event ID values for the setting and clearing of the alarm condition to meet custom requirements.   Both alarmSetCEID and alarmClearCEID argument values are ignored if the property AlarmsShareEvents is true which causes the default assignment of Event ID values.   The default value range checking is obtained by setting hasMin = true, min = 0.0, hasMax = true, and max = 0.0.
void OpcConnectionAlarmAdd(string opcConnectionName, int ALID, string ALTX)
The OpcConnectionAlarmAdd method installs logic so that if the OPC connection opcConnectionName is ever lost, a SECS alarm is indicated.  You can test this alarm by using the OPC GUI to disconnect and re-connect to the OPC Server.  When you are using OPC, there is a button action on the ServerDebug dialog that shows the OPC GUI.  The integration logic is able to recover automatically when the connection is restored.  In the few cases where transient server handle values are used, new values are re-acquired.
void OpcEventAdd(string opcConnectionName, string opcItemId, int CEID, bool isReported, string Description)

void OpcEventAdd(string opcConnectionName, string opcItemId, int CEID, bool isReported, string Description, string criteria, int delayMilliseconds)
Changes to some OPC item values may signify SECS Events.  A good example is a enumerated integer which represents the process state and every value change is an Event.  A batch tool is required to post data collection Events on the transitions of its process state.  Another example is when a data item value is a counter of something non-trivial.

The procedure OpcEventAdd is used to map OPC value changes to SECS Events.  The event identifier, CEID, is an integer value from 5000 to 9999.  By default any value change of the OPC item signals a SECS event.  The optional criteria argument enables you to specify an expression involving the opc_item table field  last_value such as {$last_value > 0} to filter which value changes signify events.   There is also an optional argument, delayMilliseconds, which can be used to specify a timed interval delay in milliseconds before the SECS event is posted.  The default delay value is 0 which causes the SECS event to be posted immediately after the OPC group refresh which contained the data update which triggered the event has been completely processed.  Additional delay can be used to allow for receiving updated data values coming later or coming from different OPC group refreshes.

You are able to specify a CEID value of one of the standard built-in SECS events  to indicate that the standard event is triggered by the OPC item value change.   A common situation is to specify the CEID value of 4050 for the ProcessStateUpdate event and link it to an OPC process state variable.
RcResult OpcGroupSubscribe(string opcConnectionName, string opcGroupname)

RcResult OpcSubscribeClose(string opcConnectionName)
The OpcGroupSubscribe method opens a subscription to data changes for a specified OPC connection and group that you have configured using the OPC Supervisor application.  As changes occur, your application receives OpcDataChange events.

OPC client software can potentially collect large volumes of data and consume lots of network bandwidth.  In the implementation of this method and the underlying Datahub table subscription, optimizations have been made to reduce network usage by combining multiple data changes into single DMH messages.   Do not perform time-consuming actions in your OpcDataChange event handling logic.  If your application does not keep up with the flow of messages and events, the subscription is closed automatically.   You can change your Group refresh period or change the sampling period of individual items to reduce performance requirements.

Use the OpcSubscribeClose method to shutdown all of your subscriptions and end the OpcDataChange events.
void OpcParameterAdd(string opcConnectionName, string opcGroupname, string opcItemId, int varID, string varname, string description, string value_TSN, string minValue, string maxValue, string defaultValue,  string units, bool affectsProcessing)
A Parameter is a read/write data item served on the SECS interface such as a configuration choice or a setpoint.  The OpcParameterAdd method is used to configure OPC read/write items as SECS ECV Parameters.  The description of the ParameterAdd method has more background information including descriptions of the argument values which also apply to this method.  Per the standards, a Parameter should be a scalar value and not an array or list of values. 

The SECS standards specify that Parameter values set by the host are persistent.  The toolset has Parameter persistence features built-in.  The parameter value is initialized to the defaultValue when this method is invoked.  However, before communicating, the logic restores any non-default values set by the host.
static void SecsPort.OpcStart(string dmhGroup)
In order to use OPC features with your SECS interface, your application must call SecsPort.OpcStart.  We suggest you call it before instantiating any SecsPort (or SecsHost) instances.  Use the same DMH Group name for the OpcStart call and the construction of your SecsPort instances.  

To get started with OPC, run the OPC Supervisor application and configure connections to your OPC servers.  Then configure Groups of OPC items, and configure the membership of items in Groups.  Define and set the environment variable, HUME_OPC_DATA_DIR to the directory path where your OPC configuration data exists.  You can set a persistent environment variable using the Windows "My Computer"/"Properties"/"Advanced" configuration dialog.  Both the OPC Supervisor and the SecsPort initialization use the value of this environment variable.  Use a Unix style c:/slash/directory/path specification.

The SecsServer.exe program does not include OPC features.  Instead, use the HumeSDK.exe program or the full Hume Datahub SDK installation to combine both OPC and SECS/GEM features.  If both the HumeSDK.exe and the SecsServer.exe are installed, the initialization logic chooses to use the HumeSDK.exe program.
static void SecsPort.OpcStop()
Your application can call SecsPort.OpcStop() at termination when running the OPC/SECS server is no longer desired.  The server process does not terminate until all using SecsPort instances are closed.
void OpcVariableAdd(string opcConnectionName, string opcItemId, int varID, string varname, string description, string value_TSN, string units, bool addQuality, int qualVarID, string qualVarname, string qualDescription, bool linkWrites, string opcGroupname, string valueMapping)
An OPC item is easily mapped to a Status Variable value on the SECS interface.  A SECS host is able to dynamically configure data collection event reports and ask to receive certain Variable values at the occurrence of specified Events.  See the VariableAdd method description for more background.

The varID argument is an integer identifier which is set to a unique value between 3000 and 9999 for new SECS variables.  You are also able to specify the varID value and the varname value of a standard built-in variable to specify that an OPC item supplies the value.  For example, a batch processing tool that uses process programs should support the PPExecName and PPUsedName Status Variables.

The method adds the quality property of the OPC item as a second SECS Status Variable when the boolean argument addQuality is true.  Use the qualVarID, qualVarname, and qualDescription arguments to specify properties for the quality variable.  Typical values are (varID+1), (varname + " quality"), and ("OPC quality bitfield for " + varname + " value") respectively. The TSN value type for the quality variable is set to "U2".   

A variable value can be an array.  The value_TSN type code for a scalar type such as "I4" also works for an array of scalar values, so specify the type code of the array element type.  For an array of string values or variant values, specify the value_TSN as "L" in order to map the OPC array to a SECS list of string values.   A non-array variant value can be passed as SECS value_TSN type "A".

The linkWrites boolean value specifies whether you want calls to VariableSet to be able to write values to the underlying OPC item.  If you set this argument true, be sure to use a read/write OPC item, and specify an OPC group name, opcGroupname, that includes the OPC item.

The valueMapping argument provides for optionally supplying an expression to compute the value for the SECS variable from the OPC value.  For example, OPC uses enumerated integer values starting from 0.  SECS process state variables are enumerated integer values that start from 64.  Supplying the valueMapping argument of {expr {$last_raw + 64}} maps the OPC value into the desired SECS value.   Use the variable last_raw to access the OPC item latest value in your valueMapping expression.
void ParameterAdd(int varID, string varname, string description, string value_TSN, string initialValue, string minValue, string maxValue, string defaultValue, string units)

void ParameterAdd(int varID, string varname, string description, string value_TSN, string initialValue, string minValue, string maxValue, string defaultValue, string units, bool affectsProcessing)
This method is used to add Equipment Configuration Variable definitions (ECV's).  ECV's are also referred to as Equipment Constant Variables, but this is a misnomer in the SECS standards and an oxymoron as well; they are the only variable type that the host is allowed to change.  Our suggestion to you and the industry at large is to refer to ECV's as Equipment Configuration Variables.

With the default range checking active, use varID values that are between 1000 to 2999.  Use a unique value for each parameter.  The variable name value, varname, should start with an alphanumeric character or the underscore and not have trailing spaces.  Limit yourself to 32 alphanumeric ASCII characters including the underscore, hyphen, and internal spaces.  We suggest you use a single token PascalCase name and make each name unique. The value_TSN argument is the Tcl SECS notation type code for the ECV value such as F4 for floating point, or A:80 for an ASCII string up to 80 characters long.  A Parameter should be a scalar value and not an array or list of values.  With ASCII types, indicate the maximum number of characters, n, that you wish to allow the host to set, by using a type code of the form A:n.  The value of n can be as large as 60000.

Call ParameterSet when the ECV value is changed by your GUI or controller logic so that the SECS Server knows the desired value and can manage the appropriate GEM event. 

The SECS standards prohibit the host from changing Parameter values that affect processing when the tool is in LOCAL control.  A common practice has been to allow the host to change ECV values in LOCAL mode if the value does not affect the current processing run, even if it does affect future runs.  The first form of ParameterAdd() assumes that the value does not affect processing (at least for the current run) and so the host is allowed to change values in LOCAL mode.  The second form of ParameterAdd() includes the argument affectsProcessing which enables you to explicitly control whether the host is allowed to change the parameter value in LOCAL control mode.

If you have custom ID requirements, you can set the IdRangeChecked property false to disable varID range checking, and you can renumber existing Parameters and Variables using the VariableRenumber method.

string ParameterGet(int varID)
string ParameterGetByName(string varname)
These methods are used to get the current value of an ECV.  The return value is null if there is an error.  Lookup by varID instead of varname is marginally more efficient.
VariableInfo ParameterGetInfo(int varID)
VariableInfo ParameterGetInfoByName(string varname)
These methods return the configuration data of an ECV.  The return value is a VariableInfo data structure - see VariableGetInfo.
int ParameterSet(int varID, string newvalue)
int ParameterSetByName(string varname, string newvalue)
These methods are used to update the value of an ECV.  The  SecsPort takes care of notifying the host with any GEM Data Collection event.
void ParametersRestore() Restores the saved values of the parameters (ECV's).  The ParametersRestore() method gets called automatically when you first enable communication if property ParametersAreSaved is true, and ParametersRestore() has not already been called.  The call restores the values of parameters from the last session, and it initializes saving for the current session. There is logic so that restoring only occurs once.  It is useful to make this call if you want to force the restore action to occur before communication is enabled.  For example, this could support viewing the current values of the parameters before communication is enabled.  The connection type should be set and all of the parameters should be defined before calling this method.
RcResult ProcessProgramDownload(string ppid)

struct RcResult {
   int rc;  // return code
   string result;
   }

Used by the equipment to initiate the download of a process program from the host using S7F5.  The ppid argument value is both the process program identifier and the file name that is used by the equipment for the process program file.  There is no standard SECS command for the equipment to know what process programs are available from the host for downloading.  If the return code value is 0 which indicates success, the result string is the full pathname to the process program file.  Negative return code values indicate error.  Possible errors include those described with SendSecsMsg().  In addition the following error codes are also possible: 
-10 file system error,
-11 improper data received,
-12 request denied by the host.

In the case of error, the result string is a diagnostic message.


RcResult ProcessProgramLargeRequest(string ppid)

struct RcResult {
   int rc;  // return code
   string result;
   }
This method initiates the download of a process program from the host using the message types of Stream 13 which are designed for large data set transfers.  Using these messages is more complex than the usual Stream 7 transfer messages so they are less commonly supported.  The ppid argument value is both the process program identifier and the file name that is used by the equipment for the process program file. There is no standard SECS message for the equipment to know what process programs are available for download.  The return value is a two element structure, a return code and text.  The return code is 0 if the transfer is initiated successfully as determined by the host's reply to S7F41.  The transfer is not complete when the method returns.   The large data set transfer logic receives the downloaded file in the subdirectory, dataset_transfer, of the directory set by the RecipeDirectory property.  When the transfer is complete, there is a StateChange event with the name dataset_download and the newvalue being a two element list consisting of the ppid value and the full pathname to the newly received file.  To fully comply with the large process program transfer scenarios specified by GEM E30, your application should react to the StateChange event by verifying the newly received process program and sending the S7F27 Process Program Verification message to the host using SendSecsMsg.  The S7F27 message is sent with replyIsWanted true, but there is no reason to wait for the host's reply.  After verification, your application can move the file into the RecipeDirectory for use, possibly overwriting an earlier version.

If the transfer does not complete successfully, there is additional status information is the SECS server table ei_dataset_xfer.   It is possible to query this table or subscribe to data changes of this table to better integrate transfer status information.

Possible error results include values of the ACKC7 reply to S7F41 and the following:
1 permission not granted
4 PPID not found
6 other error
-6  error when sending S7F41 or receiving the S7F42 reply
-13 PP transfers are disabled when spooling is active
-14 A large PP receive is already in progress for ppid
-15 Stream 13 transfers are disabled either from configuration or initialization failure
-16 PPID is not usable as a restricted filename
-17 error when parsing the S7F42 reply

RcResult ProcessProgramLargeSend(String filename)

struct RcResult {
   int rc;  // return code
   string result;
   }
This method initiates the upload of a process program to the host using the message types of Stream 13 which are designed for large data set transfers.  Using these messages is more complex than the usual Stream 7 transfer messages so they are less commonly supported.  In most cases, the filename argument value is both the process program identifier and the file name that is used by the equipment for the process program file. However, when using the PPFilesByRequest feature, the argument value should be the process program identifier, ppid, instead of the filename.  The return value is a two element structure, a return code and text.  The return code is 0 if the transfer is initiated successfully as determined by the host's reply to S7F37.  The transfer is not complete when the method returns.   The large data set transfer logic makes a temporary copy of the file for transfer in the subdirectory, dataset_transfer, of the directory set by the RecipeDirectory property.  This allows your application to change or access the process program while the copy is being transferred.  When the transfer is complete, there is a StateChange event with the name dataset_upload and the newvalue being the filename value.   If the transfer does not complete successfully, there is additional status information is the SECS server table ei_dataset_xfer.   The SECS Server also posts UploadSuccess, UploadTimeout, and UploadFailure data collection events that can be monitored as StateChange events with the name event.

Possible error results include values of the ACKC7 reply to S7F37 and the following:
1 permission not granted
6 other error
-4  PPID filename not found
-6  error when sending S7F37 or receiving the S7F37 reply
-13 PP transfers are disabled when spooling is active
-14 A large PP receive is already in progress for ppid
-15 Stream 13 transfers are disabled either from configuration or initialization failure
-16 error copying the PPID for large send
-17 error when parsing the S7F38 reply
RcResult ProcessProgramUpload(string ppid)

struct RcResult {
   int rc;  // return code
   string result;
   }

Used by the equipment to initiate transferring a process program to the host using S7F3.  The ppid argument value is identically the file name of the process program and the identifier for the process program.  The return code value is 0 for complete success.  Negative return code values indicate an error.  Possible error values include those possible with ProcessProgramDownload().  In addition, the return code value of -13 is used to indicate "upload disabled during spooling".  A positive return code value is the SECS standard ACKC7 code value sent by the host.  Diagnostic text is provided in the result string for all return code values. 

Important:  Do not assume that the host saves process program files with the same file names or in the same format that the equipment does.  The only proper way to use an uploaded process program file is to download it using the same host software that uploaded it.

void ProcessStateNames(int[] stateVal, string[] stateName)

Calling this method during initialization adds a Status Variable named ProcessStateNames whose value is a list of Process State values and their names.  The variable is not required by the standards but including it is strongly recommended.  It helps the host provide better displays of processing status.  The stateVal argument is an array of process state integer values.  The stateName argument is a corresponding array of state names. 
int ReportDefine(int rptID, int [] varIDs) This method is optionally used to update, create, or delete an event report definition.  If the varIDs array argument is null or empty, the report configuration is deleted.  The return values are: 0 - a new report created, 1 - an existing report updated, 2 - report deleted, -2 unknown variable ID, -3 invalid rptID , -1 unexpected transaction error.  Any unsigned number can be used for a report ID (rptID) value.  (Unsigned integer types are not supported by the Microsoft Common Language Specification.)

Manual editing of event reports, or the creation of built-in event reports  is not required by GEM since dynamic reporting is provided.   We recommend that you do not provide predefined, built-in reports.  Let the host configure the reporting that is desired.  If you do provide built-in reports, you have a complex situation since GEM specifies that the state of event reporting setup by the host is persistent.  This means the saved and restored reports can delete your predefined ones.  If you choose to implement built-in reports, we recommend that you add an equipment parameter (ECV) and make the user choose between having the built-in reports or having the saved reports defined at startup.  Do one of the following to insure built-in reports are available:  (1) Set the property ReportsAreSaved to false to prevent your built-in reports from being replaced by the restore logic, or (2) Call ReportsRestore after your events and variables are defined, and then add your built-in reports after the restore logic has run.

void ReportDelete(int rptID) Delete an event report definition.  ReportsClear can be used to delete all of the event reports.
int [] ReportGetDef(int rptID) Returns an array of the variable IDs in an event report definition.  An empty array is returned if the report does not exist. 
System.Collections.ArrayList ReportGetInfo(int rptID) Returns a list of VariableInfo structures for the variables in an event report definition.  An empty list is returned if the report does not exist.
int ReportLink(int rptID, int CEID) This method supports optional manual editing of the event report configuration or providing for built-in event reports linked to specified events.  The method is used to link or associate a report definition to an event type, causing the report to be sent as part of the event report message.  Both the report and the event type should exist at the time the method is called.  The return values are: 0 success, -2 invalid rptID, -3 invalid CEID, -1 unexpected internal error.
void ReportUnlink(int rptID, int CEID)
void ReportUnlink(int rptID)
This overloaded method is used to remove the link or association of a report and an event type.  If just the rptID is specified, the report is unlinked from all event types.
void ReportsClear() This method erases any existing event report definitions, unlinks the event reports from event types, and disables the event reports that were linked to the deleted reports.  The call also deletes any saved event report data, so it can be used to prevent or nullify the restoring of event reports from the previous saved session.  The method is not usually called since saving and restoring the dynamic event report configuration is standard GEM behavior.
int [] ReportsList() The method returns an array of the report ID values for the current report definitions.
void ReportsRestore() ReportsRestore gets called automatically when you first enable communication if property ReportsAreSaved is true, and ReportsRestore has not already been called.  The call restores the state of event reporting from the last session, and it initializes saving for the current session.  Restoring overwrites the existing event report definitions.  There is logic so that restoring only occurs once.  It is useful to make this call if you want to force the restore action to occur before communication is enabled.  For example, this could support viewing the event report configuration before communication is enabled.  A connection type should be set and the variables and event types should be defined before calling this method.
void SecsPort() 

void SecsPort(string spname, string dmhGroup)

void SecsPort(System.ComponentModel.Icontainer c)

The constructor.  The spname argument becomes the name of a global data item and a Tcl command in the SECS Server process.  It needs to be unique for each SecsPort instance, and not coincide with a keyword in the Tcl programming language.  The default value of spname is similar to equip0.  The example application uses the spname value, eqsim.  The name should be a single alphanumeric token. 

The dmhGroup argument becomes the DMH message system group name used by the SecsPort and SECS Server process.  If you are instantiating more than one SecsPort instance in your process, construct each instance using the same dmhGroup name argument so that the SECS Server process is shared.  The groupname chosen needs to be unique among other DMH server instances on the computer where the SecsPort is executing.  The default value is GEM.  This value does not conflict with the default value for Hume Datahub instances which is mbx.  The name should be a single alphanumeric token. 

The SecsPort SECS Server process can be debugged remotely by connecting to the DMH mailbox SERVER_RPC@hostname:dmhGroup using the Inspect application or using the DMH mailbox SERVER_SQL@hostname:dmhGroup by the hubclient application.

void SendAbort(int stream, int primaryFunction) This method is used to send an F0 abort message in lieu of a proper reply.  It is used to indicate that the received message is not appropriate in the current context.   For example, when the control state is ON-LINE LOCAL, the abort reply should be sent to a host message that would affect processing.
void SendReply(int stream, int function, int transactionID)

void SendReply(int stream, int function, int transactionID, string TSN_data)

This method is used by your custom SECS message handling logic to send reply messages either with or without data.  The reply data is formatted as Tcl Secs Notation text.
void SendS9(int function, string header) This method is used to indicate an error condition response to a received message - it is sent in lieu of a normal reply.  The SecsPort software takes care of many of the possible error conditions automatically, including, 1- bad Device ID, 3 - bad stream, 5 - bad function, and 9 - T3 timeout.  You will not receive a message type, unless you register for it.  Therefore, you will mostly send the function value 7 to indicate improper data.
RcResult SendSecsMsg(int stream, int function, bool replyWanted, string TsnData, bool waitForReply)

RcResult SendSecsMsg(int stream, int function, bool replyWanted, string TsnData, bool waitForReply, bool useWorkerThread)

struct RcResult {
   int rc;  // return code
   string result;
   }

These methods are used to send a primary SECS message, optionally indicating a reply is wanted, and optionally indicating that the call should wait for a reply.  The stream and function arguments are the message type identifiers of SECS.  The TsnData argument is a string representation of the message body using the type notation of TSN.   The list methods ListAppend and ListJoin are recommended for building complex messages to insure valid formats.  A null or empty string value may be used for the TSN_data argument when a header only message is to be sent.

The methods differ in that the second form provides the boolean argument useWorkerThread which is used to explicitly specify whether a background thread should be used to perform the call.   If this option is defaulted by using the first form, then a worker thread is used if you are executing on the thread that constructed the SecsPort, and you are waiting for a reply, or you are managing Variable values using VarValueRequest events.  When the background thread is used, the method call continues to service the application event loop.  See the detailed discussion above.

The SendSecsMsg() return value is a structure containing an integer return code and a string result.  The possible return code values are:
-1
errorMessage  - the error message starts with "ERROR" and describes the fault
-2
DISABLED   - communication is disabled so the message could not be sent
-3 
OFF-LINE   - the control state is OFF-LINE and per GEM only S1F1, S1F13, and S9FX are sendable.
-4 
DISCARDED   - spooling is active and this message type is not spooled.  Usually the connection is down.  But this result can also occur for a newly established connection before the host has purged or finished unloading the spool.
-5 
BUSY   - the background thread is currently active.  You may see this error when the worker thread is used if you re-enter your sending logic.  If the worker thread is not used, you should not see this error, since by design send commands are serialized using DMH messages to the connection's command mailbox.
SPOOLED    Your message has been spooled for later sending.  Even if you specify waiting for the reply result you receive this instead of the reply data if the message is spooled.  We recommend you not allowing spooling of message types where you care about the reply.
SENT_NO_REPLY  - sent successfully no reply requested
SENT_NO_REPLY_WAIT  - sent successfully, a reply was indicated, not waiting for the reply was indicated.  The reply will be ignored when it arrives.
ReplyTsnData   -sent ok, reply requested and received.
-6 
TIMEOUT  - sent ok, reply requested, no reply, T3 timeout. 
-7 
ABORTED  - sent ok, F0 abort reply received.
-9
REJECTED  - sent ok, Stream 9 error message "reply".
Prior to June 2009,  the SendSecsMsg method returned a string result and the method SendSecsMsgRcResult was used to obtain the RcResult structure.  The RcResult class does support casting to a string result if the older format is desired.
static int ServerLicenseCheck()
This function returns an integer code for the license status when using the SecsServer.exe or HumeSDK.exe.  An  OEM who features SECS/GEM as an option, can test whether a valid license is installed, in which case the return value is 0.  The check does not test or validate running with a Datahub SDK installation.  Return code values are:
-1
SecsServer.exe or HumeSDK.exe is not found. An SDK installation is not checked.
0
a valid license is installed
1
no licenses.txt found
2
the licenses.txt file contains improperly formatted data
3
no license code found for the system in the licenses.txt file
4
invalid license code found for the system in the licenses.txt file
static void ServerSQLCmd(string sql) Send an SQL command to the SECS Server process without waiting for a reply.  This method is used by the SecsPort software and made public in case of custom requirements.
static string ServerSQLReply(string sql) Send an SQL command to the SECS Server process and wait for the reply.  This method is used by the SecsPort software and made public in case of custom requirements.  The return values vary by SQL statement type and they are described in the Datahub documentation.
static void ServerTclCmd(string tclCommand); Send a Tcl command to the SECS Server process without waiting for a reply.  This method is used by the SecsPort software and made public in case of custom requirements.  After a SecsPort instance has been constructed and the connection type set, the TclCmd( ) method should be used instead of this method for commands that are directed to a particular interface instance.  Why?  Doing so serializes the commands for a particular interface, and provides re-entrant execution protection.
static string ServerTclReply(string tclCommand); Send a Tcl command to the SECS Server process and wait for the reply message.  This call is used by the SecsPort software and made public in case of custom requirements.  After a SecsPort instance has been constructed and the connection type set, the TclReply( ) method should be used instead of this method for commands that are directed to a particular interface instance.
void SpoolPurge() This method discards any spooled messages that are queued for the host.
void SpoolStop() This method sets the messages types that are enabled for spooling to an empty string, thus, further spooling is stopped.
void SpoolStreamFns()
void SpoolStreamFns(string StreamFns)
The method is used to set the spooled message types.  If called with no arguments, the streams that are allowed for the host to enable (property SpoolingAllow) are enabled.  If called with an argument, the call bypasses the SpoolingAllow property and enables spooling for the S<s> and S<s>F<f> message types that are specified in the input string.
static EquipStartupData SecsPort.StartupLoad(String name) This method retrieves the persisted startup configuration for the named interface.  If no startup data is found, the returned data structure is populated with reasonable defaults, and the name field in the data structure is set to null to indicate that a saved record did not exist.  The method uses the SECS server's ei_equipment data table.  The table data is saved as the file ei_equipment.tab in the SECS server's working directory when the StartupSave() method is called. 
void StartupRestore(EquipStartupData esd) The method applies the passed startup configuration to the instance, configuring properties according to the data and calling ConnectTypeSet(). The method does not call CommEnable() which allows you to fully configure the instance before going online.  The name field in the input structure is ignored since the instance has already been constructed and given a name.
static RcResult SecsPort.StartupSave(EquipStartupData esd) This method assumes that StartupLoad() was called during initialization so that the SECS server creates the ei_equipment table which is used to manage equipment startup data.  The method creates or updates a row in the table using the passed configuration, and then saves all of the table data to the file system as the file ei_equipment.tab in the SECS server's working directory.  An exception is thrown if the table data is not saved successfully.  There is only partial checking of the validity of the passed data.  The return value data structure is used to pass a possible warning message for the values controlling tracing and logging.  In this case, the return code value is greater than 0.

This method is used by the StartupDialog class in the example application.

void TclCmd(string tcl) This method is used to send Tcl code to the SECS server command mailbox for the connection.  It is used by the SecsPort software and made public to support custom requirements.
string TclReply(string tcl)

RcResult TclReplyRcResult(string tcl)

struct RcResult {
   int rc;  // return code
   string result;
   }

These methods are used to send Tcl code to the SECS server command mailbox for the connection and wait for the evaluation result.  The methods are used by the SecsPort software and made public to support custom requirements.  With TclReply() the string return value is structured as a list and may be parsed using ListSplit or ListElement.  The first element is a return code for the evaluation with 0 meaning success.  The second element is the return value from the executed Tcl code, or an error message if the return code is not 0.  With TclReplyRcResult( ) the same data has been parsed and is returned as separate fields in the RcResult data structure.
void TerminalDisplayAck() Calling this method posts the data collection event named TerminalServicesOperatorAck which is used by the equipment to indicate acknowledgment of a host Terminal Display.
void Tracewin(bool show);
void Tracewin(bool show, bool allowLogging)
The SecsPort is able to instantiate and manage a Form window class, Tracewin, which provides a controllable display of the data being exchanged across the SECS interface.  The show argument is set to true to display the window, or false to close the window.  The allowLogging argument is set true to selectively display menu items that configuring logging - the feature of continuously saving trace data to the file system.  There are menu options to provide hex dump formatting of the data, or higher level descriptive formatting.  There are also menu actions to save the currently displayed data to the file system. 
string TsnI8Value(long int64bit) Format a Tcl SECS Notation (TSN) I8 (signed 8 byte) integer value using hexadecimal notation.  The C# body of this method is just:

return "0x" + int64bit.ToString("x16");

A similar method would be defined for unsigned 8 byte integer values except that the ulong data type is not supported by the .NET Common Language Specification.   The C# code for formatting a TSN U8 value is:

return "0x" + uint64bit.ToString("x16");
 

bool TsnTypeIsOk(string value_TSN) This method is used to check value_TSN argument values that you pass to the various Add methods.

void VarGroupSet(int [] varIDs, string [] values)
This method is a more efficient alternative to calling variableSet() multiple times, the method sends the updated values to the SECS Server in one message.
Tip: Define an enum or const values for your variable IDs.

void VarGroupSetEventPost(int [] varIDs, String [] values, int CEID)
This method is a more efficient alternative to calling variableSet() multiple times and then posting a Data Collection event using eventPost().  The method sends the variable values and posts the event using one message to the SECS Server which provides better data integrity and better performance.  The array of varID values should be the same length as the array of variable values, and the elements of each array should correspond by subscript value.

If the CEID value is less than 0, no event is posted, and the method is equivalent to varGroupSet(). 

The method is most efficient for applications which use the SECS Server ei_variable table to manage variable values instead of using VarValueRequest callbacks.   When callbacks are used, the event posting methods should be called directly.  They feature an optimization which queries the SECS Server for needed variable values and sends them in a single second message.
void VariableAdd(int varID, string varname, string description, string varClass, string value_TSN, string varmethod, string initialValue, string units) Use this method to add a Status Value variable (varClass == "SV") or a Data Value variable (varClass == "DVVAL").  Both classes of variables are available for the host to configure in event reports.  A DVVAL does not need to have a valid value, for example the alarm ID of the latest alarm when there have been no alarms.  The variable name value, varname, should start with an alphanumeric character or the underscore and not have trailing spaces.  The length limit is 256 alphanumeric ASCII characters including the underscore, hyphen, and internal spaces.  We suggest you use a single token PascalCase name, limit yourself to 32 characters, and make each name unique.  With the default checking of Id values, use varID values between 3000 and 9999.  Leave the varmethod argument as null or an empty string if the variable value will be represented in the ei_variable table, or you will subsequently call VariableMethodSet to specify an evaluation callback. 

If you have custom ID requirements, you can set the IdRangeChecked property false to disable varID range checking, and you can renumber existing Parameters and Variables using the VariableRenumber method.

string VariableGet(int varID)
string VariableGetByName(string varname)
These methods are used to get the current value of a variable.  The methods use the same access logic that host requests use so they can test your custom value logic.  The return value is null if there is an error.
VariableInfo VariableGetInfo(int varID)
VariableInfo VariableGetInfoByName(string varname)

struct VariableInfo {
  int varID;
  string varname;
  string description;
  string varClass;
  string value_TSN;
  string varmethod;
  string units;
  string minValue;
  string maxValue;
  string defaultValue;
  }

These methods return the configuration information of a variable or parameter (ECV). 
int VariableRenumber(string varname, int newID) This method is provided so that the ID values of the built-in variables and parameters (ECVs)  can be customized.  All of these data items are represented in the same table, and should be given unique numeric identifiers.  Use the method after restoring or configuring the connection type, and before enabling communication.   If the newVarId value is in use by a different variable, that variable is given a "temporary" varID value of the current value plus 1 million under the assumption that it will be renumbered as well.  After initialization, if variables are found with ID values greater than 1 million, they indicate that more than one variable has been assigned to the same ID value. 

A positive return value is a warning, and the value 0 indicates success. Negative values indicate error condtions.   In more detail, the return values and their meanings are:

0
The variable already has the desired ID, or the variable was renumbered successfully.
1
The newVarId was in in-use so the existing variable was renumbered to a "temporary" ID.
2 or more
The return value is the number of variables of this name that were found.  The extra table records were deleted and the surviving table record has the desired ID or was renumbered successfully.  This condition is not ordinarily expected.
-1
The varname does not identify an existing variable.
-2
The method did not succeed from an unexpected error such as a timeout.
-3
The connection type has not been set and table records do not exist for renumbering.
void VariableSet(int varID, string newValue)
void VariableSetByName(string varname, string newValue)
These methods are used to update the value of a Status or Data Value variable whose current value is represented in the SECS Server's ei_variable table.  It is marginally more efficient to set the value using the varID to identify the variable.
void VariableMethodSet(int varID, bool useVarValueRequestEvent) You use this method to specify using a VarValueRequest event handler that is executed by the SecsPort software when the value of a Status Value or Data Value variable is needed. 

If the useVarValueRequestEvent argument value is false, then the variable method is changed so that the value is managed in the SECS Server's ei_variable table using the VariableSet method.


Built-in Features

The table of contents link in the frameset viewer shows the SECS Equipment Built-in Features document for this section. Having a separate document shared with the multiple Equipment libraries helps us provide you with more accurate, detailed information.

License Terms

Subject to Change Without Notice

The Hume .NET SecsPort software is licensed for development and runtime use at no additional charge for computers that are licensed for development use of the Hume Integration Datahub SDK.

Hume Integration is also pleased to offer separate runtime licenses for using the SecsPort software on systems that are not licensed as development systems.  Contact Hume Integration for information on the Resale Licensing program.


Version Information

Date of last document revision: $Date: 2016/04/06 13:43:06 $.

The SecsPort class was revised in June 2009 to simplify its usage and make it suitable for platforms such as LabView.  These changes broke compatibility with earlier versions so other edits were made at the same time.  Here is a summary of differences to aid in migration: