This error 922 is caused by:
1. Digital Signal Failure
This problem is caused by CPU, Motherboard and Input board.
This will mainly be a hardware failure but is sometimes a connection failure.
If the problem is connection failure, it is possible to get back to normal operation.
2. Zero-Calibration Failure
This problem is caused by Input board. Normally, this is a hardware failure and will not recover automatically. This cause could be (sometimes) intermittent.