Reduce 1860 by 20% and test. If hunting stops, then fine-tune upward in smaller steps.
Like many FANUC parameters, 1860 is set per axis. Depending on your specific FANUC control generation, it may be presented as a simple integer value or a bit-based configuration. When configuring a standard alpha i ( ) or beta i (
Here is a comprehensive breakdown of what Parameter 1860 does, how it works with related parameters, and how to troubleshoot it. What is FANUC Parameter 1860?
This bit acts as a flag indicating whether the reference position (home) has been established. It flips to 1 automatically once you successfully home the axis after a battery failure. fanuc parameter 1860
The reference position (Parameter No. 1860/1861) is not updated during homing. 2. When to Change Parameter 1860
Request for zero return (the system has lost its position).
If the setting of this parameter is modified, it is mandatory to perform a new reference position establishment operation. 3. How to Access and Change Parameter 1860 Reduce 1860 by 20% and test
If your machine's home position is incorrect—causing a tool-change misalignment or incorrect work coordinates—do not alter Parameter 1860 directly. Follow this standard operational protocol to let the CNC update Parameter 1860 automatically: Step 1: Enable Parameter Write (PWE) Ensure the machine is in . Press the SETTING function key on the MDI panel. Locate the field labeled PARAMETER WRITE (PWE) .
You should never treat Parameter 1860 as a "tuning" parameter. Its primary role in modern FANUC controls is as a storage location for reference point data calculated by the system. Changing it arbitrarily can disrupt the absolute positioning system, leading to machine crashes. The correct method is to follow the absolute positioning setup procedure and let the system update it automatically.
Always take a full SRAM or ALLPARAM backup to a PCMCIA card or USB drive before changing any parameter in the 1000–2000 range. Depending on your specific FANUC control generation, it
If Parameter 1860 sets a target verification point that conflicts with your physical axis limit switches or encoder resolution limits, the CNC will trigger an absolute pulse coder error. This indicates that the alignment loop did not locate its expected reference grid step within the designated window. 2. Rotational Coordinate Drift
It is a vital "sanity check" for your machine. Without a properly tuned 1860 value, a slight mechanical shift or encoder glitch could go unnoticed, leading to inaccurate machining or tool collisions.
It works in tandem with Parameter 1850 (Grid Shift) to precisely establish the machine zero point. The Relationship Between Parameter 1860 and 1815
Sarah began the delicate process of "teaching" the machine its home again: