Process Control Communucation Protocols

How do instruments and controllers communicate in a process control? Has it ever came in your mind how instruments and controllers communicate? We know for a fact that communication may come wired or wireless but with the wast variety of process instruments nowadays how do this instruments work when connected to controllers of a different make. Communication protocols is what we call the digital message formats and rules required to exchange messages in or between computers and instruments. This is required in process automation.   The following are the different types of communication protocols, its uses and its makers in the field of […]

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Process Control & Instrumentation Terms

Analog Signal Analog signals are like voltage or electric current signal, representing temperature, pressure, level etc. Usually the electrical current signal is of magnitude 4-20 mA where 4 mA is the minimum point of span and 20 mA is the maximum point of span. Analog to Digital Converting, A-D Converting Electronic hardware converts analog signal like voltage, electric current, temperature, or pressure into digital data a computer can process and interpret. Auto Mode In auto mode the output is calculated by the controller using the error signal – the difference between set point and the process variable. Closed Loop Controller […]

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