Can it be determined from the PID whether a PLC or a DCS is being used?
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According to industry insiders, at the current stage, ordinary projects can achieve similar results with PLCs and DCS. If there is no textual description on the PID, can it be determined whether a PLC or a DCS is being used simply by looking at the way the control instruments are indicated on the PID?
Unless specified otherwise, it is generally not noticeable.
It can be seen by comparing with the legend symbols.
Now, PLCs and DCS are becoming increasingly integrated, and the boundaries between them are no longer very clear; it’s impossible to tell them apart based on PID settings.
Personal experience: DCS is powerful, features a compact display, offers a high degree of flexibility in operation, and has different legends; it is suitable for complex systems that require precise control
The new standard HG/T20505-2014 considers the two to be identical, as both share display and control functions. It is simply decided whether to use a PLC or DCS during implementation based on factors such as the scale and complexity of the project, as well as funding.
All I’ve seen is an indication that some interlocks use the SIS system; I haven’t seen whether PLCs or DCS are used, unless otherwise specified.
It can be seen that the prerequisite is to have a clear legend on the homepage image.
The symbols on the instruments are different; you should be able to tell them apart by looking at the legend
The legends are different; the legends for PLC instruments are polygonal, while those for DCS instruments are circular, making them very easy to distinguish