Console
Read LightBurn Console messages and GRBL responses to identify firmware, settings, alarms, connection states and machine faults.
GRBL $#: laser work coordinates and saved positions
Read G54–G59, G28/G30 and G92 reports in a laser workflow without treating CNC-only PRB/TLO data as a LaserLearn feature.
GRBL $G: Reading the Parser State
`$G` reports the controller’s active G-code modal state and is useful when a line behaves differently than expected because of inherited units, distance or motion modes.
GRBL $130–$132: Maximum Travel and Soft Limits
$130–$132 define the controller-known travel extents and directly affect soft-limit checks. They should describe verified machine geometry, not just the design size you want to run.
GRBL $120–$122: Acceleration and Motion Quality
Acceleration affects how quickly axes reach feed rate and how hard the machine changes direction; too aggressive values can cause ringing, lost steps or limit-like symptoms.
GRBL $110–$112: Maximum Axis Rates
$110–$112 cap axis movement speed. Values above what mechanics can sustain can cause missed steps; values below desired job speed limit real output.
GRBL $100–$102: Steps per Millimeter
$100–$102 calibrate commanded distance to physical motion. Wrong values cause scale errors; they are not normal tools for fixing origin or workspace placement.
GRBL $32 Laser Mode and LightBurn M4
$32=1 enables GRBL laser-mode behavior such as variable-power M4 support on suitable GRBL versions. A wrong device type or disabled laser mode can produce Error:20/M4 messages.
GRBL $30: Maximum S Value and Power Scaling
$30 defines the controller maximum spindle/laser command scale; LightBurn device settings must agree with the controller so percentage power maps predictably.
GRBL $10 Status Report Mask
$10 controls parts of classic GRBL status reporting. Its exact interpretation can differ in forks, so decode the active firmware rather than blindly copying a recommended number.
A Safe GRBL $$ Health Check for Laser Use
A useful health check reads settings as a system: laser mode, S range, limits, homing, motion calibration, rates, acceleration and max travel — without assuming one universal “correct” dump.
Decode GRBL Realtime Status: MPos, WPos, FS, Bf, Ov and Pn
A `<...>` status report is structured telemetry: machine state plus position, feed/spindle value, buffers, overrides, pins and other optional fields.
Reading the GRBL Startup Message and $I
The startup line and `$I` reveal firmware family/version/build clues that determine which LightBurn device behavior and commands are appropriate.