After a severe crash or over time, the mechanical zero may drift. Instead of moving limit switches, you can shift the reference position via Parameter 1860. However, this is a band-aid, not a repair . For significant shifts, fix the mechanics first.
Indicates if the reference position (zero point) is established. If it is 0, a 300 APC alarm occurs.
If you are trying to fix a persistent zero error, consider these alternatives before editing Parameter 1860: fanuc parameter 1860 full
The following is a general procedure for re-establishing the absolute reference position using Parameters 1815 and 1860/1861:
Achieving high-precision machining on a Fanuc-controlled machine tool requires more than just a rigid structure; it requires precise control of servo movement. One critical, yet often misunderstood, parameter in the servo adjustment suite is . After a severe crash or over time, the
This parameter sets the number of pulses required to move the axis by one unit of detection. It is part of the "Calculation of Detection Unit" formula. The CNC uses this value alongside the gear ratio and ball screw pitch to determine the "Detection Unit" (the smallest moveable distance the CNC recognizes).
If Parameter 1860 is set incorrectly (e.g., after a servo swap or battery backup loss), the following issues will occur: For significant shifts, fix the mechanics first
The function of Parameter 1860 changes completely depending on control series:
While this guide covers common cases, FANUC and the machine tool builder's original manuals are the ultimate authority. If you lack them, request official documentation before altering parameters.
Reference position updating is not performed . This forces the control system to bypass automatic synchronization updates when crossing the coordinate boundary. This setting is mandatory when an external feedback scale lacks structural rotation data markers and relies strictly on continuous physical accumulation. 2. Interaction with Related Parameters