Fanuc Parameter 1860 Full Fixed < UPDATED >

Fanuc Parameter 1860 stores the absolute encoder pulse count for each axis, which is crucial for resolving 300 APC alarms caused by lost positional data, often due to dead batteries. Fixing the alarm involves replacing the batteries, setting Parameter 1815 (bit 4) to 1, and re-establishing the physical home position to automatically update Parameter 1860. For detailed instructions, you can read the Practical Machinist discussion and CNCmakers technical support . CNC Fanuc Resetting home position After switching batteries

Function:

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). fanuc parameter 1860 full

• Too fast (low ms) = vibration, alarms, potential crashes.
• Too slow (high ms) = rounded corners, wasted time, poor surface finish.

B. Adjusting for Slower Deceleration

Battery failure

: If the backup battery for the absolute pulse coder dies, causing the machine to lose its zero position. Fanuc Parameter 1860 stores the absolute encoder pulse

If 1860 = 1

, the counter capacity equals the number of feedback pulses per motor revolution. This is the most common "full" setting. Values >1 are possible but rare; they effectively shorten the counter range, which can cause reference point shift issues. Too fast (low ms) = vibration, alarms, potential crashes

: It tracks the raw position data from the absolute pulse coder. Unlike coordinate parameters you can manually edit (like 1240 for reference positions), this parameter is updated automatically by the system. : It is typically a 2-word axis parameter (long integer).