What does OPC mean ?

  • Thread starter Raymundo D. Balderas
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Raymundo D. Balderas

I am a programming engineer, I have worked only with PLC's and serial interfaces. I have no idea about OPC, can anybody explain me what can I do with OPC, what is its meaning, and so on. Thanks in advance

Greg Goodman

From the OPC Foundation website, http://www.opcfoundation.org/, the following definition: "The OPC Specification is a non-proprietary technical specification that defines a set of standard interfaces based upon Microsoft's OLE/COM technology. The application of the OPC standard interface makes possible interoperability between automation/control applications, field systems/devices and business/office applications." OPC stands for OLE for Process Control. It's a "standard" for applying OLE-based communications between Windows applications and plant floor equipment. While OPC as a spec may be non-proprietary, it is completely dependent on proprietary Microsoft technology. (Imagine a widely accepted standard for using Excel macros in the actuarial business, and calling it a non-proprietary standard.) Mostly what you can do with it is buy SCADA/HMI software that supports OPC as a communications interface and buy equipment for which OPC comm drivers exist. (OPC comm drivers are mostly Windows wrapper programs around whatever protocol the devices speak natively.) In an all-Windows SCADA environment, this can have the effect of simplifying the comm configuration of a system, because it hides protocol-specific configuration issues from the integrator.
Like you, I am not too familiar what OPC can do. I do know, however, that it means OLE (object linking and embedding) for Process Control. OLE is the technology that, in part, allows users to cut data from one software package (say Excel) and paste it into another (say Word). My understanding of OPC is that it allows a similar functionality for use in process control software. I think it basically provides a way for software from different companies to interact and exchange data. I will be interested to see replies from people far more knowledgable than myself.