P
Hello All,
New member here with a new problem.
I have an 1747-L532 with a 13 slot rack a P4 PSU 1 I/p module 1 O/P module and a 1746-NR4.
The PLC would intermittently die. I mean no lights on the PSU the CPU or the modules. 120V OK. No load on the PSU 24VDC.
Actions so far. Changed the CPU, both digital I/O Modules the Rack.
All to no avail. Re-did all the grounding. Still the same. I didn't have a spare NR4 so I decided to remove it to see and it did not fail. (It was getting very frequent, like 4 times a day). I put it back in without the Sensors connected and it failed. I ordered another used one and as soon as I put it in it failed. I tried another slot closer to the CPU and it failed immediately.
The PLC ran for 3 days without fail while I awaited the new one.
When I reset the power it stays dead and eventually comes back on.
When the CPU powers back up the ladder has gone. no fault messages.
I can power off manually and the ladder is always there.
I'm pulling my hair out here. I hope someone has some ideas.
Many Thanks,
Peter
New member here with a new problem.
I have an 1747-L532 with a 13 slot rack a P4 PSU 1 I/p module 1 O/P module and a 1746-NR4.
The PLC would intermittently die. I mean no lights on the PSU the CPU or the modules. 120V OK. No load on the PSU 24VDC.
Actions so far. Changed the CPU, both digital I/O Modules the Rack.
All to no avail. Re-did all the grounding. Still the same. I didn't have a spare NR4 so I decided to remove it to see and it did not fail. (It was getting very frequent, like 4 times a day). I put it back in without the Sensors connected and it failed. I ordered another used one and as soon as I put it in it failed. I tried another slot closer to the CPU and it failed immediately.
The PLC ran for 3 days without fail while I awaited the new one.
When I reset the power it stays dead and eventually comes back on.
When the CPU powers back up the ladder has gone. no fault messages.
I can power off manually and the ladder is always there.
I'm pulling my hair out here. I hope someone has some ideas.
Many Thanks,
Peter