DCS data acquisition issues
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May I ask, when the DCS is in operation, how do data flow from the field devices to the modules and then to the DCS controller? I’m a beginner; please give me some advice. I would be very grateful.
For example, the pressure value detected by the pressure transmitter on site is converted by the transmitter itself into a 4-20 milliampere current signal (there are also signals in the form of 0-20 milliamps, or 0-5V or 10V). This signal is sent to the analog input module of the DCS, which then uses its analog-to-digital conversion function to transform the signal into a digital signal, which is sent to the controller. The controller processes this signal to generate the appropriate output
Hehe, as a supplementary note: various signals from different sources may need to be fed into junction boxes at the site, and then combined into a multi-core cable. If they are intrinsically safe signals, they must pass through safety barriers after entering the control room, in order to limit the current and voltage that reach the site. They also need to go into a patch panel where the terminals are arranged, and then connected to the terminal blocks of the DCS cabinet, before finally being fed into the circuit channels using connectors.
There are plenty of options upstairs,,, there are those with junction boxes and those without!
4-20MA analog to digital conversion