Point to Point Verification Information

Point to point identification of the IO's conected to the control panels of my PLC is needed since the documentation and tags of the wires are missing. The question is if the only way performing point to point verification and identification of where the IO's wires go is shuting down the system?

Most of that would depend on safety issues and the location of the I/O.

The fastest way to get it done would be to have the system down. Deactivate the outputs then check the inputs one by one. Output devices should be disconnected from their load and then activated one at a time thru the plc if possible.

This sounds like a long drawn out procedure but it can be quick and allow the time to mark the wires as needed.

Have to agree with Ron, best way is with system down. I've done this a few times, here's a couple of pointers. Have two or more people with 2-way communications, radios, cell phones,something. Check the inputs, then write up some type of timed based toggle logic, disconnect all outputs but one, use the toggle logic to toggle the output, have someone in the field, look for the pulsing device, identify it, the move on to the next one.

Good luck,

Ken

I have had to do the same thing recently - with the system online and running. Had a few incidents where when the electricians were tracing wires they pulled the wire out due to loose connections. This led to a quick thermal scan to find loose connections.

Overall, went well and got point to point checks and drawings complete.