You would change this value if your machine’s home position is physically "off" by a small, consistent amount. Instead of re-mounting a cam or switch, you enter a "shift" value here to tell the control where the true zero is relative to the first grid pulse it detects. How to Set It
You cannot effectively manage Parameter 1860 without understanding , as they are the two halves of the absolute positioning system.
In Fanuc CNC systems, Parameter 1860 is a read-only axis parameter that stores the current position of the absolute position detector (absolute encoder). It is often referred to as the current position in the absolute detector or the "encoder count". Technical Overview
Adjusts the electrical reference position by a specific number of pulses (detection units). Data Type: 2-word (Signed long integer). fanuc parameter 1860 full
, cycle power, move to the physical home, and set it back to
If you are experiencing vibration or servo alarms during rapid direction changes (like a G01 moving from X to Y), adjusting Parameter 1860 (along with 1620/1622) acts as a "dampener." It forces the axis to hesitate slightly during the transition, eliminating the shock to the ball screw.
When you execute G28 X... Y... Z... , the reference point return occurs in : You would change this value if your machine’s
| Feature | Detail | |---------|--------| | | 1860 (axis 1), 1861 (axis 2), … | | Purpose | Final approach speed for G28 reference return | | Units | mm/min (metric) or 0.1 inch/min (inch) | | Typical range | 500 – 6000 mm/min | | Key constraint | Must be ≤ parameter 1420 (Rapid) | | Failure mode if too high | Missed reference signal → alarm or position drift | | Failure mode if too low | Long cycle time, but safe |
Detection units (the smallest increment the machine can move).
Sets the total degree threshold (usually 360.000 degrees) after which a rotary axis wraps its position back to zero. Grid Shift In Fanuc CNC systems, Parameter 1860 is a
Specifies whether an absolute pulse coder is used for that axis. How to Change Parameters
If your axis moves away from the zero-return switch instead of toward it, check if Parameter 1860 needs to be accompanied by a change in Parameter 4006 (or individual axis direction parameters).