The CNC community continues to debate the exact function of 1860 on different controls. As one technician noted, "My book doesn't say what the units are either". This is why a combination of official documentation, community knowledge, and careful experimentation is necessary.

The CNC will trigger a non-destructive 100 PARAMETER WRITE ENABLED alarm. This is normal. Step 2: Navigate to Parameter 1860 Press the hard key. Press the PARAM soft key. Type 1860 and press the No. SRH (Number Search) soft key.

Always back up your machine parameters to a memory card or USB stick before making any changes. Incorrect parameter settings can cause the machine to behave unpredictably.

The Two-Stage Backlash Acceleration attempts to address this by using a two-stage "kick" to overcome the static friction and take up the slack quickly. Parameter 1860 likely defines the first stage of this acceleration. If you are working with a modern FANUC control, this definition is probably not applicable, but it remains a critical piece of knowledge for maintaining legacy systems.

This article draws information from the following technical resources:

These encoders use a battery backup (or a specialized glass scale) to keep track of the axis position while the power is off. When you turn the machine on, it instantly knows exactly where it is.

Go to the MDI mode, press the SETTING key, and change PARAMETER WRITE from 0 to 1 . Ignore the resulting emergency stop/alarm.

For engineers and technicians working with FANUC controls, is one of the most critical settings for managing this coordination. Specifically, it dictates the Grid Shift or Reference Position Shift for synchronized or multi-path control axes, playing a pivotal role in maintaining alignment across the machine's workspace.

During a linear move, an axis moves smoothly under the control of the position and velocity loops. However, when an axis changes direction (e.g., from positive X to negative X), it must come to a stop and accelerate in the opposite direction.