OPC Driver

The OPC method of communication to OPC devices uses the OPC driver. OPC specifications v1.0a and v2.0 are supported. Using this method you can connect to single or multiple OPC devices, as shown in this example configuration:

The OPC server can also exist on the same computer as the OPC client. Be reminded that the maximum request length (that is, the maximum of data bits that can be read from the I/O device at any one time) for the OPC protocol is 2040.

Citect SCADA 7.20 or later (or a later version of Plant SCADA) is required to use the OPC Driver.

Note: With the release of version 7.20, Plant SCADA supports the retrieval of time-stamped data directly from field devices. This capability is enabled by the Driver Runtime Interface (DRI), a component of Plant SCADA that is used by the OPC driver to directly update time-stamped digital alarms, time-stamped analog alarms and event-based trends. For more information, see the topic Retrieving Time-stamped Data from Field Devices in the main Plant SCADA help.

See Also

Preparing the OPC System

OPC Devices and Clients

Advanced Configuration and Maintenance

Troubleshooting