Changing servo parameters can cause axis runaways or crashes. Clear the machine work zone and be prepared to hit E-STOP immediately.
In essence, Parameter 1860 is the machine’s internal "truth"—a raw digital heartbeat that tells the system exactly where it is in the physical world, long before those numbers are translated into the user-friendly coordinates we see on the screen.
Type using the keypad and press the [No. SRH] (Number Search) soft key.
Parameter 1860 is mathematically linked to .
In FANUC control systems, Parameter 1860 is specifically used to define the current position of an axis when using an Absolute Position Detector fanuc parameter 1860 full
If a machine experiences a Z-axis "drop" during an E-stop , technicians can check the change in Parameter 1860 to see exactly how much the axis moved before the mechanical brake engaged.
This setting enables machine technicians to shift the reference point electronically. This removes the need to physically move limit switches or detach motor couplings during calibration. It works alongside Parameter 1815 (which sets up absolute encoders). Together, they form the foundation of a CNC machine’s coordinate system. Complete Parameter Overview Specifications 1860 Data Type 2-word / 4-byte Signed Integer ( Long data type) Axis Dependency
| Encoder Type | Reference Pulses/Rev | Typical 1820 | Calculated 1860 | |--------------|----------------------|--------------|------------------| | αiA 4096 P/rev | 4096 | 4096 | 1 | | αiB 16384 P/rev | 16384 | 16384 | 1 | | αiCZ 10000 P/rev | 10000 | 10000 | 1 | | βiA 8000 P/rev | 8000 | 8000 | 1 |
. This value represents the amount of shift required to align the absolute encoder's internal reading with the machine's actual reference position. Key Functions & Characteristics Changing servo parameters can cause axis runaways or crashes
Parameter 1860 might be too high, forcing the servo to react too aggressively, causing a sudden impact in the backlash-free zone.
Because you cannot simply "type in" a fix for Parameter 1860, resolving errors associated with it requires a structural reference position recovery routine using . Follow this methodology to cleanly update Parameter 1860 through the CNC interface: Step 1: Enable Parameter Writing (PWE) FANUC? M6 toolchange position. | Practical Machinist
Must be set to use specialized backlash compensation. Parameter 1851: Backlash compensation amount (low speed). Parameter 1852: Backlash compensation amount (high speed).
bits), which tells the system that an absolute pulse coder is being used and whether the reference position has been established. Coordinate Synchronization Type using the keypad and press the [No
For servo parameters like 1860 to fully initialize in the servo software loop, turn off the main CNC control power, wait 30 seconds, and turn it back on. Troubleshooting SV0411 Alarms Linked to Parameter 1860
) is vital for complex multi-axis milling, turning, and profiling. Parameter 1860 works closely with Parameter 1815 and Parameter 1861 to dictate exactly how and when the CNC system refreshes its reference position calculation relative to physical coordinates.
Use a precision indicator to measure the "blip" at the 90°, 180°, 270°, and 360° points. Adjust Parameter 1860:
The relationship between time constant (T) and acceleration (a) is: