An error (error:number) means Grbl did not execute one line. The machine stays where it is and is not in alarm. In a running program the app pauses so that nothing unexpected happens. Numbers 1 to 38 come from Grbl 1.1, higher ones from grblHAL.
error:1 · Command without a letter
Command without a letter – a G-code word always consists of a letter and a number.
error:2 · Number missing or in an invalid format
Number missing or in an invalid format.
error:3 · Unknown or unsupported $ command
Unknown or unsupported $ command.
error:4 · Negative value where a positive one is expected
Negative value where a positive one is expected.
error:5 · Homing is not enabled in the settings ($22)
Homing is not enabled in the settings ($22).
error:6 · Step pulse too short
Step pulse too short: at least 3 µs ($0).
error:7 · Settings memory (EEPROM) not readable
Settings memory (EEPROM) not readable – the controller loaded the defaults. Please check the settings.
error:8 · This $ command only works while the machine is idle
This $ command only works while the machine is idle.
error:9 · G-code locked
G-code locked: the machine is in alarm or jogging.
error:10 · Soft limits need homing enabled
Soft limits need homing enabled.
error:11 · Line too long
Line too long – it was not executed.
error:12 · Setting exceeds the highest possible step rate
Setting exceeds the highest possible step rate.
error:13 · Safety door open
Safety door open.
error:14 · Text for startup line or build info is too long
Text for startup line or build info is too long.
error:15 · Jog target outside the work area
Jog target outside the work area – jog ignored.
error:16 · Invalid jog command ($J= missing or contains forbidden G-code)
Invalid jog command ($J= missing or contains forbidden G-code).
error:17 · Laser mode needs a PWM output
Laser mode needs a PWM output.
error:20 · Unsupported or invalid G-code command in the line
Unsupported or invalid G-code command in the line.
error:21 · Two commands of the same group in one line (e.g
Two commands of the same group in one line (e.g. G0 and G1).
error:22 · Feed rate missing
Feed rate missing: an F value must be set before the first cutting move.
error:23 · This command needs a whole number
This command needs a whole number.
error:24 · Two commands in one line both use the axis words
Two commands in one line both use the axis words.
error:25 · A G-code word appears twice in the line
A G-code word appears twice in the line.
error:26 · Command needs axis words (X, Y or Z), but there are none
Command needs axis words (X, Y or Z), but there are none.
error:27 · Line number out of the valid range
Line number out of the valid range.
error:28 · The command is missing a P or L value
The command is missing a P or L value.
error:29 · Only coordinate systems G54 to G59 are supported
Only coordinate systems G54 to G59 are supported.
error:30 · G53 only works together with G0 or G1
G53 only works together with G0 or G1.
error:31 · Axis words without a motion command (G80 is active)
Axis words without a motion command (G80 is active).
error:32 · Arc without axis words in the selected plane
Arc without axis words in the selected plane.
error:33 · Invalid motion target (arc impossible or probe target is the current position)
Invalid motion target (arc impossible or probe target is the current position).
error:34 · Arc with radius cannot be calculated
Arc with radius cannot be calculated.
error:35 · Arc with centre
Arc with centre: I, J or K missing.
error:36 · Unused G-code words left over in the line
Unused G-code words left over in the line.
error:37 · Tool length offset only for the configured axis
Tool length offset only for the configured axis.
error:38 · Tool number too large
Tool number too large.
error:39 · Value out of the allowed range
grblHAL and FluidNC only
Value out of the allowed range.
error:40 · Command not allowed in this state
grblHAL and FluidNC only
Command not allowed in this state.
error:41 · This command is not available on this controller
grblHAL and FluidNC only
This command is not available on this controller.
error:60 · SD card
grblHAL and FluidNC only
SD card: mount failed.
error:79 · This command needs homing
grblHAL and FluidNC only
This command needs homing.