On many FANUC systems, Parameter 1860 is automatically used by the control as a storage location for the machine's reference point position when used with an absolute pulse coder (absolute encoder). Essentially, the FANUC control uses Parameter 1860, along with 1861, to remember the exact mechanical position of the machine's axes. This is what allows a machine with absolute encoders to know its position immediately upon power-up, eliminating the need for a manual zero-return operation each morning .
[ Feedback Device Absolute Zero ] ---> + [ Parameter 1860 Grid Shift Offset ] ---> = [ Actual Machine Zero ]
: Unlike incremental systems that require a physical trip to a limit switch (homing) every morning, systems using Parameter 1860 "remember" their position. This parameter stores the necessary data to maintain that reference. How Parameter 1860 Works in Practice fanuc parameter 1860 work
In the end, the parameter taught us that machines inherit the human traces they are given. We can clear the memory, overwrite the defaults, and stamp new protocols across the lines—but there will always be that margin where someone's habit becomes the machine's caution, where a decimal written in a coffee-stained notebook slows an arm to spare a scrape.
Sets the feedback direction to normal/positive. Value = -1: Inverts the feedback direction to negative. On many FANUC systems, Parameter 1860 is automatically
: This parameter holds the current machine coordinate value for each axis. When you power off the machine, the encoder's battery keeps the internal pulse count active. Upon restart, the CNC compares the encoder's data with the value in Parameter 1860 to re-establish the absolute position without physical movement. Interaction with Parameter 1815 :
A common point of confusion for CNC technicians is the relationship between and Parameter 1815 . Both are used for setting reference positions, but they handle different parts of the process. [ Feedback Device Absolute Zero ] ---> +
: Parameter 1860 serves as the translation bridge. When the CNC starts up, it reads the communication strings from the APC. It calculates the exact distance from the current physical grid mark to the machine's true coordinate origin.
The humming cabinet smelled of ozone and cold metal. In the dim maintenance bay, a row of machines sat like sleeping beasts, their control panels dark except for the soft green heartbeat of LEDs. I stood in front of Unit 7, fingers hovering over the keypad where the label read FANUC - model R-2000. On the display, a single line of text blinked: PARM 1860.
These indicate that the absolute position data has been lost.
Essential for syncing the feedrate of the Z-axis with the spindle's rotation to cut threads without a floating tap holder.