Servomotors have a error counter inside the driver unit, which counts the error between input pulses and feedback pulses.
When pulses are input to the driver, the counter accumulates the pulses (accumulated pulses), and when the motor rotates, the feedback signal subtracts the accumulated pulses from the counter and performs positioning control so that the accumulated pulses become 0.
In General, the signal to clear this error counter is called ERC (ERror
counter).
And some manufacturers call ERCC (ERror Counter Clear).
When a Zero return operation is performed, the motor is stopped immediately when the origin is detected, so there is a possibility that pulses may remain in the error counter. At this time, by setting the error counter clear signal to the driver unit, the Zero return is completed.
If zero return operation end direction is not specified, the first ORG
input decelerates to stop and changes direction, and the second ORG signal
input completes the operation. However, if it stops during ORG input,
the operation is completed without changing direction.
CONTEC's SMC board is designed to automatically output the error counter
clear signal when the ORG signal is input from the second time onwards
for zero return operation. Therefore, If it stops during ORG input, the
error counter clear signal will not be output.