In my past experience on PLC systems, it was fairly common to remove power to one or more of your DO cards via a master control relay when the application was machine control. If someone pulled an e-stop, then some or all DO's lost their power, and the status of the master control relay is used to logically move all the DO's to the de-energized state.
I'm being asked to do that for a DCS (although this machine application is still commonly executed on a PLC/PAC). Before knowing this requirement, the selected IO was M-Series DO 24VDC High Side. If the 24VDC field power is switched off upstream of field power connector to the 8-wide, wouldn't I get a flood of integrity errors? I know there are various masking capabilities of module and block errors, but is it possible to prevent the operator from seeing bad status, integrity alarms, etc?
Maybe the better question is... if you had this requirement, how would you handle it?
Many thanks...