: The internal computer calculates the discrepancy between the mechanical "Zero" and the current digital encoder count.
Note: The CNC will immediately generate a non-critical . This is normal and serves as a safety warning. Step 3: Navigate to Parameter 1860 Press the SYSTEM function key.
: 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
| Machine Type | Rigidity | Typical 1860 Range (ms) | | :--- | :--- | :--- | | Small VMC (BT30) | High | 30–60 | | Large VMC (BT40/BT50) | Medium | 60–120 | | Heavy-duty lathe (X-axis) | Medium | 80–150 | | Gantry mill (heavy slide) | Low | 120–250 | | High-speed machining center | Very High | 10–40 | fanuc parameter 1860 full
Note: In newer FANUC controls (31i-B, 0i-F), parameter 1860 is often replaced or augmented by (grid check tolerance), but 1860 remains active for legacy mode or specific axis setups.
Press the soft key to open the Handy Setting screen. Move your cursor to the item labeled PARAMETER WRITE . Input 1 and press the [INPUT] key.
FANUC Parameter 1860 is a fundamental internal calculator for absolute encoder alignment. It should be treated as a of your machine's physical calibration. Always allow the CNC to manage this value natively through proper home positioning procedures or by relying on Parameter 1850 for manual adjustments. : The internal computer calculates the discrepancy between
FANUC servo systems rely on precise counts to determine where the machine axis is at any given millisecond. If the CNC control does not know the exact number of pulses to expect per motor rotation, it cannot accurately calculate axis velocity, actual position, or synchronization. Why Parameter 1860 Matters
You will typically need to check or modify parameter 1860 during the following scenarios:
After replacing a motor with an absolute encoder on a rotary axis. Step 3: Navigate to Parameter 1860 Press the
For a standard linear axis with an absolute encoder, when you successfully complete a reference point return, the control automatically updates these values. The specification guide for the Series 30i/31i/32i explicitly states: "When machine position passes 0 degree or the shift value per one rotation... the data for the reference position (parameter No.1860, 1861) is renewed."
: It is typically a 2-word (long integer) axis-specific parameter.
Defines the amount of backlash acceleration needed to reverse the torque 2. Technical Explanation: How It Works
This comprehensive technical guide outlines everything an engineer, maintenance technician, or CNC operator needs to know about Fanuc Parameter 1860, its companion parameters, and how to safely navigate it during repairs. Technical Overview of Parameter 1860