How to draw an instrument circuit diagram for a PLC?
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A newbie, a complete idiot. It’s my first time dealing with instrument circuit diagrams; I’ve looked up a lot of them, all of which are for DCS and conventional instruments. I’ve never seen a circuit diagram for PLCs (I even suspected for a while that PLCs couldn’t have circuit diagrams). Could any experienced person explain the differences, or at least show me an example of a PLC circuit diagram? In other words, how are PLCs connected to field instruments, and how should this be illustrated in diagrams?
Is there any difference? It’s so strange
I was wondering, DCS systems have things like control stations and operation stations, and conventional instruments come in panel-mounted and rack-mounted versions – how is it described for PLCs?
The indoor PLC architecture is the same as that of DCS: controllers, communication cards, I/O cards/terminal boards, power distribution modules, cabinets, etc. From a certain perspective, the hardware configurations are indistinguishable, which makes no difference when you draw wiring diagrams.
A PLC is equivalent to a controller installed within the control cabinet of a DCS; of course, the circuit diagrams are similar.
Mm-hmm, I understand. Thank you very much.