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 field is set to server_name=Server2 then the connection for that group will be to Server2.

Keyword	Description
OPC_HEALTHCHECK_RATE	When the OPC_IO_TYPE is ASYNC, a synchronous retrieval is performed periodically as a health check. This keyword specifies the frequency in milliseconds, at which the OPCIS will send a health check to the OPC server. See OPCIS Health Check for more information.
OPC_IO_TYPE	Specifies the type of communications between the OPCIS and the OPC server (ASYNC or SYNC). Note: You can set the OPC_IO_TYPE by group by setting point configuration attributes. See OPCIS Groups for more information.
OPC_MACHINE_NAME	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	Depends on the communications type (OPC_IO_TYPE). Value is in milliseconds. ASYNC — The maximum rate the OPC server can push changed values to the OPCIS. SYNC — The rate at which the OPCIS requests data from the OPC server.
OPC_SERVER	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	Specifies the time (in milliseconds) that the OPCIS delays at startup before sending messages to the OPC server.
OPC_SYNC_IO	Specifies whether the OPC server retrieves data from the device or cache. Applies to all synchronous communication.
PERSIST_FILE_REFRESH_RATE	Specifies the rate (in minutes) at which to write current persisted values to the CVS.Persist.dat file.

Keyword

Description

OPC_HEALTHCHECK_RATE

When the OPC_IO_TYPE is ASYNC, a synchronous retrieval is performed periodically as a health check. This keyword specifies the frequency in milliseconds, at which the OPCIS will send a health check to the OPC server.

See OPCIS Health Check for more information.

OPC_IO_TYPE

Specifies the type of communications between the OPCIS and the OPC server (ASYNC or SYNC).

Note: You can set the OPC_IO_TYPE by group by setting point configuration attributes. See OPCIS Groups for more information.

OPC_MACHINE_NAME

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

Depends on the communications type (OPC_IO_TYPE). Value is in milliseconds.

ASYNC — The maximum rate the OPC server can push changed values to the OPCIS.
SYNC — The rate at which the OPCIS requests data from the OPC server.

OPC_SERVER

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

Specifies the time (in milliseconds) that the OPCIS delays at startup before sending messages to the OPC server.

OPC_SYNC_IO

Specifies whether the OPC server retrieves data from the device or cache. Applies to all synchronous communication.

PERSIST_FILE_REFRESH_RATE

Specifies the rate (in minutes) at which to write current persisted values to the CVS.Persist.dat file.

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.