Fanuc Parameter 1860 Full ~upd~ Jun 2026

Understanding and correctly setting Parameter 1860 is essential for ensuring that the rotary axis behaves predictably, especially when moving beyond 360° or using absolute encoders. 1. What is Parameter 1860? (Full Definition)

Parameter 1860 is a small, unassuming number that connects the physical world of machine mechanics to the digital world of CNC logic. Understanding its function helps demystify the absolute encoder setup process and is crucial for troubleshooting reference point alarms. When respected and set correctly, it is one of the key pillars of a reliable and accurate CNC machine tool.

To correctly set Parameter 1860, you must understand the relationship between the mechanical drive components and the detection unit.

Fanuc (Position of the absolute position detector) is a read-only parameter that displays the current position value from the absolute pulse coder. While it is not a setting you typically edit manually, it serves as a critical reference point for the CNC system to maintain axis alignment without needing to re-home after a power cycle. Key Characteristics and Function Data Type : 4-word (integer). fanuc parameter 1860 full

: If the absolute pulse coder (APC) batteries die, the absolute position is lost. After replacing batteries, you must move the axis to its physical home and toggle Parameter 1815 bit 4 (APZ) to "1". This action updates Parameter 1860 with the new zero-point data. Parameter Backup

When you adjust Parameter 1860, you are not moving the physical limit dog. You are electronically shifting where the control the grid point is.

An incorrect setting in Parameter 1860 will result in the machine moving an incorrect distance (e.g., commanding 100mm but moving 50mm or 200mm), rendering the machine unable to perform accurate machining or threading. (Full Definition) Parameter 1860 is a small, unassuming

| Indicator | Interpretation | |---|---| | Manual skips 1860 | The MTB may be using 1860 for a custom function not covered in base FANUC docs. | | 1860 has non-zero value | The MTB configured it; do not change without documentation. | | 1860 listed same axis format as 1853–1856 | Suggests gear ratio or specialized axis compensation use. |

A "full" or correct setting ensures the reference counter exactly matches the number of position feedback pulses in one motor revolution.

Technicians often confuse 1860 with other parameters. Here is a clear comparison: To correctly set Parameter 1860, you must understand

In FANUC control systems, Parameter 1860 is specifically used to define the current position of an axis when using an Absolute Position Detector

If you are tuning a worn ballscrew, adjusting 1860 without adjusting 1848 will usually result in a "bump" feeling during reverse motion rather than a smooth pickup.