If you disconnect the motor from the ball screw, the physical relationship between the encoder and the machine zero changes.
Parameter 1860 is a where each bit typically corresponds to a different controlled axis (X, Y, Z, etc.). fanuc parameter 1860 full
When a machine is equipped with absolute encoders, it does not require a manual "home" or zero-return operation every time it is powered on, provided the absolute position is correctly saved. Parameter 1860 is the system's "flag" that tells it whether this position is currently valid. 1. The Core Meaning of Parameter 1860 If you disconnect the motor from the ball