Issues regarding remote instrument signals and DCS/PLC
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Dear experts, I have a flow meter that has both on-site display and remote transmission capabilities. So, is there a difference in transmitting remote signals to PLC system displays and DCS system displays? Can it be transmitted arbitrarily? DCS systems use Honeywell or Siemens products.
As long as the signals match, it’s definitely possible to transmit them freely
As PLCs and DCS systems integrate with each other, their functions become quite similar; there are no major issues with display, and signal transmission is generally carried out using standard 4–20mA signals.
Nowadays, all signals are standard signals with unified standards; the signal types of DCS and PLC are the same. If both need to be displayed, a signal distributor is used so that both the DCS and the PLC can be shown.
It’s the concern about signal matching. Thank you to the teacher for the answer.
There is no difference; the output signals from flow transmitters are all 4–20mA, and the analog input modules of PLCs and DCSs also receive signals in the 4–20mA range, which are then converted into the corresponding flow values. The range of the flow meter gauge must be consistent with the system configuration range.
LZ, what do you mean by remote transmission? By my understanding, remote transmission refers to a very long distance – one that exceeds the maximum transmission range of traditional field instruments. If that’s the case, I think it’s necessary to first carry out an A/D conversion, and then use GPRS-DTU to transmit the data to a PLC or DCS
Firstly, both PLCs and DCS can receive standard 4–20 mA + Hart signals. Secondly, which system to use depends on the operation partition.