و كاربرد آن در كنترل فرآيندهاي صنعتي opc

Use of OPC in Industrial Process Control

Object linking and embedding for process control(OPC) is an interface between components of one or more computers. OPC is based on distributed component object model (DCOM) technology from Microsoft. OPC clients can establish an interface with any OPC servers and retrieve data from them. OPC Data Access explains interface functions, objects, operational facilities and relationship of this interface. OPC server read/write data from/to resources. OPC clients and servers communicate through interfaces. Client creates and configures server groups. The OPC Groups provide a way for clients to organize data. OPC alarm and event interfaces provide the mechanisms for OPC clients to be notified of the occurrence of specified events and alarm conditions. They also provide services which allow OPC clients to determine the events and conditions supported by an OPC Server, and to obtain their current status. An event may or may not be associated with a condition. OPC Clients may subscribe to be notified of the occurrence of specified events. HMI from Isograph package is used for implementing an example of OPC interface. By using this tool, data gathering and command sending is possible from human-machine interface in a standard manner.