tadamsmar

I have the PLC5 programming manuals but I am asking to see if there is an easier approach than slogging through those. I have the task of writing a maintenance manual for our PLC latter logic. I have never learned how to program the PLCs so I am looking for a gentle introduction. I have the PLC5 manuals used by the in engineers who programmed it and I have access to a smart engineer(who is my technical lead) who helped program it and currently maintains it. I have access the the PC used to maintain the latter logic. It has RSLogix 5 installed. So I can look at the configuration and even probably modify it in a playpen, but it would be harder for me to test anything on a real PLC because we only have production PLCs, none for testing. But there is one production system that is not in use so I could test on that one, I guess. I have a good understanding of the functional requirements since I maintain a compter interface to the PLC output tables on a central master control computer (in FORTRAN and C). It's all just analog inputs, analog outputs, digital inputs, digital outputs and status tables. Nothing more than that. Just scanning.

I guess the 13.5 is between 1/2 and 1 cycle, and they rounded down to 1/2 cycle. The small in-rack power supplies we have are 1771-P4S models. The P7 mentions conformance to an EU low voltage directive, but the P4S does not mention that directive. But it's not clear if the P4S is less sensitive to very short AC low voltage.

Thank you! We have the 1771-P7 B in the main PLC racks. There are smaller power supplies in the other racks that fit in a slot, but I cannot see the part number on them, I'd have to look it up or pull one I think. By 1/2 cycle they mean 1/120th of a second, right? They fail on a 1/120th of a second power glitch. Can you tell if the P7 B fails on a short glitch? They seem to just mention the P1 and P2. I should have access to the Rockwell KB, but I I have not used my account for a long while and I had trouble logging in so I need to resolve that.

We had a incident where the PLC5s shutdown due to a very short AC power glitch that did not shutdown computers or anything else. Are the Allen Bradley power supplied designed to be very sensitive to very short power glitches? Does anyone know the specs/parameters for this? We don't have UPSes for our whole control system so we typically don't need the PLCs to stay up. But does reduce reliability if the PLCs shutdown when nothing else shuts down.