When CitectSCADA is used to monitor and control a plant, data from PLCs is collected and displayed in the CitectSCADA runtime environment. OPC Clients can access device and tag information from CitectSCADA through the OPC interface to the OPC Server, which in turn interacts with the CtAPI interface to the CitectSCADA Runtime, as shown here:
The CitectSCADA OPC Server can be invoked from an OPC Client on the same machine or on a different machine. When connecting to an OPC Server running on the same machine as the client, use the Citect.OPC connection option. When connecting to an OPC Server running on a remote machine, use the Citect.OPCRemote option.
The OPC Server starts automatically when you start the CitectSCADA runtime environment and does not require configuring.