omron plc - Electrician Talk - Professional Electrical Contractors Forum

firelient · 08-16-2012, 05:42 PM

Got a question on some PLC logic A little back ground I have been doing a little programming on a/b 500 and 5000 along with Mitsubishi plc's. We got a new machine in that has Omron in it so need to learn it. While reading about it there was a section on N/C coils I have never heard of a coil that was n/c. My question is why would you need one?? sorry if a dumb question

Splash · 08-16-2012, 06:02 PM

It's the opposite of a regular coil; normally its closed rather than open. It can be used in shutdown or alarm logic where it gives you a way to monitor a string of logic and it will give you a trip whether you get an alarm or lose power in the string.

Sometimes you may have a need for it on timer done bits depending on how the PLC scans and processes it's inputs and outputs.

I mostly use it in alarm and shutdown logic.

It's just another way to skin a cat....