CompactLogix Fault 61

Hi, I have two Clx L32E with the same configuration and program but only one of them is making fault 61 a lot of times. Manual says that I have to download the program again, I´m doing it twice a week more/less. I´m using firmware 19.15 in both PLCs. Do you have an idea about what could be the problem?
Thanks in advance!

Jorge

The online help for major error 61 does not help to identify the cause. The stated resolution is to contact tech. support to resolve the problem.

But before you do, check the obvious things...

1, Clean power

2, Grounding

3, Installation "to the book"

4, Interference from external sources, especially "high-power" devices, welders, motors etc.

Have you tried swapping the controllers to see if the fault moves with the controller, or stays in the same panel?

Hi daba, thanks! I opened a ticket at rockwell support and they told me that I should upgrade to ver. 20 (the firmware). I will check the energy quality, it is very strange because the PLC is powered by a UPS, but with no isolation transformer. I have 4 60HP Powerflex400 and three Powerflex40 for the pumps involved on the process, so, from your comments, it is possible that some electric disturbances may be the reason of this fault.