Fanuc Parameter 1860 !free! Full May 2026

In Fanuc CNC systems (Series 16i/18i/21i and 0i-MODEL B/C/D/F), Parameter 1860 current position of the Absolute Pulse Coder (APC) at the reference position. While parameter is used to tell the control "where" home is, parameter

is the underlying numerical value the encoder reports at that exact spot. It is almost never manually edited by an operator; instead, the CNC system calculates and updates this value automatically when you perform a reference point return or set the (Absolute Position Zero) bit. ⚙️ The Mechanics of Parameter 1860

: Stores the APC counter value when the axis is at the reference point. Relationship to 1861 : Because APC values can be very large, parameter

is often used as a continuation of 1860 to handle higher-order bits. : Typically a 2-word axis

type, meaning it can store large integers separately for each axis. ⚠️ When to Interact with 1860 Reference Point Recovery

: When an absolute encoder battery dies, the machine "forgets" the relationship between its physical position and the encoder count. Setting 1815 bit 4 (APZ) fanuc parameter 1860 full

to 1 at the correct physical location triggers the CNC to take the current encoder reading and write it into Maintenance Warnings : Changing manually will force a Power Cycle (Alarm 000) and will likely cause the to reset to 0, requiring a new homing procedure. 🛠️ How to View and Set Reference Positions

If you are looking for "1860 full" because you are resetting your machine's home after a battery failure, follow this standard procedure: Series 16i-18i -MODEL B - Parameter Manual.pdf - Drivesul

Mastering Fanuc Parameter 1860: The Complete Guide to Axis Acceleration/Deceleration Time Constants

7. Real-World Example (Machine: Vertical Machining Center)

Specs:

• Axis X rapid (1420) = 30,000 mm/min
• Dog length = 20 mm
• Desired repeatability = ±0.002 mm

Setting:

Parameter 1860 (X) = 3000 mm/min

Result:

• Phase 2 speed = 1/10 of rapid
• Dog travel time = 20 mm / (3000/60) = 0.4 seconds
• Position coder reliably captures reference mark every time.

10. Summary Table

| Feature | Detail | |---------|--------| | Parameter # | 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 |

8. Related Parameters

| Parameter | Function | |-----------|----------| | 1850 | Grid shift amount (reference position fine offset) | | 1851 | Reference position coarse shift | | 1820 | Number of pulses per motor rotation / detection unit | | 1420 | Rapid traverse speed | | 1421 | FL speed (deceleration speed for ZRN) | | 3003 (bit 5) | ZRN direction selection |

Difference Between 1850, 1851, and 1860

A common confusion exists among Fanuc parameters. Here is the breakdown:

| Parameter | Name | Purpose | | :--- | :--- | :--- | | 1850 | Grid Shift (Reference Position) | Shifts the grid point for all reference returns. Used for mechanical dog adjustment. | | 1851 | Grid Shift Fine | Fine adjustment (usually in 1/1000 mm or 1/100000 inch increments). | | 1860 | Reference Position Shift | Shifts the position the machine considers "Zero" after the reference return is complete. Often used with Absolute Pusle Coders. |

On many newer Fanuc controls (0i, 31i, 32i), Parameter 1860 is specifically for the absolute position detector reference position. In Fanuc CNC systems (Series 16i/18i/21i and 0i-MODEL

Parameter 1860 vs. Other Time Constants (Crucial Distinctions)

Technicians often confuse 1860 with other parameters. Here is a clear comparison:

| Parameter | Function | When Active | Typical Range | | :--- | :--- | :--- | :--- | | 1860 | Cutting feed ACC/DEC time constant | G01, G02, G03 | 20–200 ms | | 1620 | Rapid traverse (G00) ACC/DEC time constant | G00 | 50–500 ms | | 1622 | Rapid traverse DEC time constant (linear) | G00 (end of move) | 0 (off) to 500 ms | | 1825 | Servo loop gain (Position loop gain) | All motions | 30–200 (1/sec) |

Critical Insight: Parameter 1860 and Parameter 1825 (position loop gain) work in tandem. If you increase 1825 for higher stiffness, you may need to decrease 1860 to avoid instability. Conversely, a low 1825 with a very low 1860 will cause overshoot.

6. Troubleshooting Alarms Linked to P1860

What is Fanuc Parameter 1860?

Fanuc Parameter 1860 is defined as the Reference Position Shift Value on the Z-axis (or the axis to which it is assigned). In many standard Fanuc configurations (especially on lathes and machining centers with absolute encoders), Parameter 1860 holds the distance (in detection units) that the machine moves to find its Grid Point during a reference return operation.

To understand 1860, we must first understand the Grid Method. When you perform a Zero Return (often written as G28 or manually pressing the reference return button), the machine does not simply "know" where zero is. Instead, it moves toward a Deceleration Dog (physical limit switch). Once it hits the dog, the axis decelerates and searches for the first "Grid Point" of the servo motor's encoder. Parameter 1860 tells the control to shift that Grid Point by a specific amount. Mastering Fanuc Parameter 1860: The Complete Guide to