Micrologix 1500 fault

Hi,

I came into work today and my co-worker had tried to do some electrical wiring in the panel where we have a Micrologix 1500 running. It was for a motor, so he set up the output to run it through a relay. When he tried to turn on the motor he faulted out the PLC. He got Major Error Halt S:1/13 bit turning on with the note being an expansion I/O hardware error. He got it to run again and he disconnected the wiring he had done. Now we can plug into the PLC with our comm cable to go online, but if i try to plug the panelview back into the PLC, or just have a cable plugged into the PLC, it faults out again and i get the same error that he had before. I tried 2 different cables, and it did it with both of them, i can plug it in so it does work, but if i move the cable the wrong way it faults out. Everything is fine when i have the comm cable plugged into my computer.
Did he fry something in the PLC? and that is why i am getting this fault everytime i plug the comm cable into it? Or would it be something else? The PLC is running fine right now without anything plugged into the comm port. Only happens when something is plugged in the comm port and wiggled around a bit.

Sounds like you have heated up a comms driver IC and it has a dry joint. Or the Comms IC is fried and shorts the Power enough to error out but not cycle the PLC power. The connector could have heated up and now shorts on one of the tracks. Only way is to have a look at the Micrologix board that is take it apart - what about warranty. This happened to me with a mitsubishi PLC although a soldering iron on the plug was the fix. Maybe the others can help with the fault. IC & components will be surface mount not easy to repair. Good luck!

Ok, would there being electrical work being done in the panel affected this? Or was this something that would have happened anyways? He said the fault was saying that it noise problems and possibly grounding issues. Would him trying to wire in the motor brought up this problem?

If your Pc can connect then the comms is working for a DTE device. Unless the wiring for the comms to the PV is different and more or different signals are needed than required for online comms. I can only assume that the plug is loose and shorting on the tracks for eg. Electrical noise will interfere with comms but it shouldn't stop it from working at all. I suggest you look more closely at the socket solder on the pc board. However the problem could lie in on the expansion I/O where the 5V is being grounded with your comms cable.