This bit activates if EFAIL1 is enabled for the axis and if no active signal on either phase A or phase B of an axis encoder is detected.
This bit can be used to trigger programmed responses from ASX bit 5. This bit also corresponds to ERROR bit 17 which can be used to trigger the ERRORP program.
When EFAIL is set to 1 the firmware actively monitors the signals. If EFAIL is set to 0 the firmware no longer monitors the encoder signals.
1) Check encoder cable.
2) Use the TPE command to determine a reference position. Then rotate the motor one revolution and use TPE again to see if the encoder counted correctly according to your encoder resolution.
3) Pin out the encoder cable to make sure the encoder wires are continuous.
4) Supply your encoder from a 5 volt source and use an oscilloscope to determine if the A and B channeles are changing.