Hello,
We have a customer with a 1756-L72 ControlLogix PLC. They have recently got a T01:C62 Fault Code. I am trying to figure out how to recover with the least amount of potential for changes as this is a medical machine.
The HMI buttons indicate that they are not communicating with the PLC. I don't know if this is just due to the major fault, or if the PLC program was lost from RAM altogether.
The PLC has a compactflash card installed, but we didn't have a backup of the program on it (mainly to avoid confusion as to which program is the latest if the main PLC program is lost and the one from the compactflash is loaded.) This fault seems to indicate that the PLC program was saved, but I'm not sure how it is saved. This PLC doesn't have a battery and I believe it uses a capacitor to save the PLC program to non-volatile memory. Is this non-volatile memory where the PLC program is now stored after this major fault? Is this non-volatile memory separate from the compactflash card or is it the compactflash card? How would you restore this? The customer has tried cycling power which didn't help. I also thought that you may be able to clear the fault by flipping the keyswitch from Remote Run to Program-->Run-->Remote.
I believe it also writes an error log to the compactflash card, but I was a little leery to have them pull that out until I knew how this worked on the 1756-Lxx PLCs. Is there any information in the error log in a human readable format that would help us determine the cause of this issue, or is this only for Rockwell to decipher?
I guess after this is back up and running, I can wipe the compactflash card again so there is no confusion as to which is the latest.
Any help would be greatly appreciated.
Thanks!
We have a customer with a 1756-L72 ControlLogix PLC. They have recently got a T01:C62 Fault Code. I am trying to figure out how to recover with the least amount of potential for changes as this is a medical machine.
The HMI buttons indicate that they are not communicating with the PLC. I don't know if this is just due to the major fault, or if the PLC program was lost from RAM altogether.
The PLC has a compactflash card installed, but we didn't have a backup of the program on it (mainly to avoid confusion as to which program is the latest if the main PLC program is lost and the one from the compactflash is loaded.) This fault seems to indicate that the PLC program was saved, but I'm not sure how it is saved. This PLC doesn't have a battery and I believe it uses a capacitor to save the PLC program to non-volatile memory. Is this non-volatile memory where the PLC program is now stored after this major fault? Is this non-volatile memory separate from the compactflash card or is it the compactflash card? How would you restore this? The customer has tried cycling power which didn't help. I also thought that you may be able to clear the fault by flipping the keyswitch from Remote Run to Program-->Run-->Remote.
I believe it also writes an error log to the compactflash card, but I was a little leery to have them pull that out until I knew how this worked on the 1756-Lxx PLCs. Is there any information in the error log in a human readable format that would help us determine the cause of this issue, or is this only for Rockwell to decipher?
I guess after this is back up and running, I can wipe the compactflash card again so there is no confusion as to which is the latest.
Any help would be greatly appreciated.
Thanks!