OPC - OLE for Process Control|
OPC stands for OLE (Object Linking and Embedding) for Process Control -- an open standard used to expose information from industrial devices in a form that can be accessed by OPC clients, including but not limited to, SCADA software.
Further to this, OPC actually defines various sets of functionality, some of which relate to providing raw data values, and others of which relate to providing data logging or alarm functionality. For example, OPC Data Access, ie. OPC DA, is used to move data between devices and a client, while OPC Alarms & Events, ie. OPC AE, allows event and alarm notifications to be sent on demand.
What does that mean?
Simply put, OPC servers allow your customer to get data out of their industrial device, and into their computer. For example, the PC below could be running a SCADA package from Wonderware, Intellution, Iconics, etc. The SCADA package needs data from the devices on the plant floor. Historically, the aforementioned companies would write their own “drivers” in order to communicate with these devices.
Now, those same companies bundle an OPC client within their SCADA package, allowing them to make use of any third-party server. The server does the work of moving data between the PC and the field device, while the SCADA package provides the control, visualization, trending, etc.|
The most exciting server Red Lion offers is the G3 server (Which actually allows you to communicate to a G3, Data Station or an Enhanced Master). By using this server, SCADA packages are immediately “aware” of what tags have been created within the G3, as well as how to access them.
Further to this, any device connected to the G3 also becomes accessible via the OPC server. In the following application, a G3 is configured to communicate to three devices. Since the various devices’ registers exist as tags within the G3, the PC has access to them as well. Therefore, the server is providing the functionality of three OPC servers for the price of one.
OPCWorx was designed to make use of Red Lion’s existing library of device drivers. That being said, the list of available servers will certainly grow. Keep your eye on OPCWorx updates at www.redlion.net.