OPC
OPC is open connectivity in industrial automation and the enterprise systems that support industry. Interoperability is assured throught the creation and maintenance of open standards specifications. Based on fundamental standards and technology of the general computing market, the OPC Foundation adapts and creates specifications that fill industry-specific needs.
OPC is implemented in server/client pairs. The OPC server is a software program that converts the hardware communication protocol used by a PLC or similar device into the OPC protocol. The OPC client software is any program that needs to connect to the hardware, such as an HMI. The OPC client uses the OPC server to get data from or send commands to the hardware.
OPC Data Access is used to move real-time data from PLCs, DCSs and other control devices to HMIs and other display clients. The current standard, Data Access 2.0 is used on all FieldServer OPC Products.