Configuring and Starting the OPCIS
The tasks required to add an OPCIS to your CygNet site are the same as adding any other type of service. Note that when adding the service to the ARS the Service Type is CVS.
OPCIS Configuration File
In addition to the standard current value service keywords, the OPCIS configuration file contains additional keywords used to define the connection to the OPC server. Note that some of the configuration file keyword settings can be overridden by the corresponding point attributes.
For example, if the configuration file keyword OPC_SERVER is set to Server1, and the point’s External ID property is set to server_name=Server2 then the connection for that group will be to Server2.
See OPCIS Configuration File Keywords for a complete list of keywords.
| Keyword | Description |
|---|---|
|
OPC_HEALTHCHECK_RATE |
When the OPC_IO_TYPE keyword is set to ASYNC, a synchronous retrieval is performed periodically as a health check. The OPC_HEALTHCHECK_RATE specifies the frequency in milliseconds, at which the OPCIS will send a health check to the OPC server. The default value is 60000 milliseconds. See OPCIS Health Check for more information. |
|
OPC_IO_TYPE |
The OPC_IO_TYPE keyword specifies the type of communication between the OPCIS and the OPC server (ASYNC or SYNC). The default value is ASYNC. Note: You can set the OPC_IO_TYPE by group. Asynchronous communication for the OPCIS is supported via setting the OPC IO type at the group level to OPCIOASYNC in the Table Driven 3 field on the Application page of the point configuration record. In this context, "asynchronous" means that asynchronous callbacks are enabled, since asynchronous I/O is not supported by the OPCIS. See OPCIS Groups for more information. |
|
OPC_MACHINE_NAME |
The OPC_MACHINE_NAME keyword specifies the name of the remote computer on which the OPC server is running. Both UNC (for example, \\SERVER or SERVER) and DNS (for example, server.com or IP address) formats are acceptable. |
|
OPC_MAX_UPDATE |
The OPC_MAX_UPDATE keyword specifies the maximum rate at which the OPC server can push changed values to the OPCIS or the maximum rate at which the OPCIS requests data from the OPC server. The rate depends on the communications type (OPC_IO_TYPE).
The default value is 1000 milliseconds. |
|
OPC_SERVER |
The OPC_SERVER keyword specifies the name of the OPC server (either the PROGID or CLSID from the registry). The name is case sensitive. The name must be enclosed in quotation marks if it contains spaces. |
|
OPC_STARTUP_DELAY |
The OPC_STARTUP_DELAY keyword specifies the time (in milliseconds) that the OPCIS delays at startup before sending messages to the OPC server. The default value is 1000 milliseconds. |
|
OPC_SYNC_IO |
The OPC_SYNC_IO keyword specifies whether the OPC server retrieves data from the device or cache (DEVICE or CACHE). Applies to all synchronous communication. The default value is CACHE. |
|
PERSIST_FILE_REFRESH_RATE |
The PERSIST_FILE_REFRESH_RATE keyword specifies the rate (in minutes) at which to write current persisted values to the CVS.Persist.dat file. The default value is 60 minutes. |
By default, other standard CVS keywords are commented out. These are: CAS, GNS, TRS, and VHS. Uncomment these if you want OPCIS tags to alarm, notify, or report data.
Note: When using OPCIS tunnelling software such as the MatrikonOPC Tunneller client, both the OPC_SERVER and OPC_MACHINE_NAME keywords must be uncommented and specified in the Opcis.cfg file.
Verifying OPCIS Startup
Once the OPCIS has been started you can use the CygNet Console to look at the service screen and verify connectivity to the OPC server. The System screen (F2) and the Trace screen (F3) will show information about the connection.
