Micrologix 1400 Major error code 0000h

Hello everyone I was called into a situation at a food plant where a "spiral" freezer MCC is encountering problems. The panel consists of a micrologix 1400, a panelview 1000 and (6) powerflex 40 drives. The drives are daisy chained together back to the micrologix DSI port. In the past few weeks I've had to change some of the drives out due to water getting in panel and burning them up. The Microologix input terminal block was contaminated as well but showed no errors, but as a precautioned I changed the terminal strip out as well. I set the parameters in the drives as per the documentation I had, for example: start and speed parameters set to communications port. Each vfd has its own address 1-6. If one drive is powered down the rest show communication faults F81 Comm loss. This has shown to be normal when one or more drives are disconnecting from the comm chain. Everything started up fine and was running for a few days and then a new problem arose. HMI wont communicate with micrologix communication flag=0 errors. I open the cabinet and micrologix is faulted. Major error code 0000h. I reset it by using the user display by going from run mode to prog and back to run mode. Fault is cleared but nothing communicates. I checked all cables, Ethernet cabling between HMI and micrologix seem fine, green and orange lights. Is it possible the program is lost? I also find weird is that I can shut off one of the vfds and the rest don't fault out like before F81 Comm loss. I don't have access to a laptop with the program here. I told the plant manager he is going to have to get in contact with the programmer and possibly reload the program. Any help with what could be causing these errors would be appreciated. I am an electrical contractor, construction maintenance/Industrial, and I've done quite a few small jobs for this new customer. Thank you

Sounds like you will have to get online with the controller to see what is happening.

There isn't supposed to be an "Error Code 0000h". The Error code list starts at 0001h.

I agree that the program has probably been cleared. This happens most frequently when there is a major voltage spike to the controller input power.

I have a special dislike for the technique of running drives from the serial or network port of a MicroLogix, because it's dependent on the skill of the programmer and how well he has tested his logic to handle fault conditions.

The fact that the drives would all fault when one was powered down is because the programmer didn't account for a drive failing to respond to a Message instruction, so they all time out. That might be intentional, if the machine cannot run without all of the drives available, or it might just be an oversight.

The fact that they don't fault when you unplug the cable now is consistent with the loss of the user program. If they never get a "this is your communications timeout value", they never start the timeout timer and therefore won't fault if you unplug the network cable.

Is there an EEPROM module installed ? That might be your only hope to re-load the controller if you don't have access to the program.