Division of I/O points between ESD and DCS
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I’m now facing issues with pump control; the pump’s signals are already sent to the ESD system. Is it still necessary to have hardwired connections in the DCS to display the pump’s status and to control its shutdown?
If there are terminal blocks that can handle two connections, that would work, but it’s better to use communication for this purpose; we have already implemented both wired connections and communication solutions
It is possible to divide into two by using an isolation safety barrier
Reply to 2# nihaocarter: Oh, then how many points are required to enter each of your systems? When entering the DCS here, one of the pump DI values is actually 3.
Reply to 2# nihaocarter: What about the other aspects? For the hardwired connections to ESD, how is it handled for those connected to DCS? Is it through communication or some other method? I hope experts can give some advice.
Reply to 4# jml11: The points related to ESD are all critical points of the equipment; the DCS is used to record trends, while the communication-related aspects can be handled casually
On our side, if a pump is connected in series with four points in total, there are two feedback signals from the DCS and one DO signal, while there is one DO signal from the ESD system; they are all wired together in series. Action ESD takes priority, causing the entire circuit to be shut off in a cascade manner. DCS operates by opening the valves provided that there is no cascade ESD that would prevent the circuit from remaining powered; therefore, cascading connections are quite common.
We all use separate signals with one input and two outputs via safety barriers.
We all use separate signals with one input and two outputs via safety barriers.
We all use separate signals with one input and two outputs via safety barriers.