LinuxCNC M65

M65 is a LinuxCNC M-code that turns off a digital output immediately. It acts as soon as the motion controller receives it, so it is not synchronized with axis movement. The output to switch is given by the P word.

Source checked5/5 values · 2026-10-26

Specification

1 source

Language	gcode
Code	M65
Group	Digital Output Control
Syntax	M65 P-
Dialect	LinuxCNC

Parameters

Name	Description
P	Digital output number to turn off; range 0 to a default of 3, extendable with num dio.

Study notes

M65 is paired with M64 (turn on digital output immediately); M62/M63 are the motion-synchronized equivalents.
The P word specifies the digital output number and ranges from 0 to a default maximum of 3.
The number of digital I/O can be increased with the num_dio parameter when loading the motion controller.
M65 requires the corresponding motion.digital-out-nn HAL pin to be connected to an output in the HAL file, otherwise it does not function.

Safety

M64 and M65 take effect immediately as received by the motion controller; they are not synchronized with movement and will break blending.