| "$-Code"," Setting"," Units"," Setting Description" |
| "0","Step pulse time","microseconds","Sets time length per step. Minimum 3usec." |
| "1","Step idle delay","milliseconds","Sets a short hold delay when stopping to let dynamics settle before disabling steppers. Value 255 keeps motors enabled with no delay." |
| "2","Step pulse invert","mask","Inverts the step signal. Set axis bit to invert (00000ZYX)." |
| "3","Step direction invert","mask","Inverts the direction signal. Set axis bit to invert (00000ZYX)." |
| "4","Invert step enable pin","boolean","Inverts the stepper driver enable pin signal." |
| "5","Invert limit pins","boolean","Inverts the all of the limit input pins." |
| "6","Invert probe pin","boolean","Inverts the probe input pin signal." |
| "10","Status report options","mask","Alters data included in status reports." |
| "11","Junction deviation","millimeters","Sets how fast Grbl travels through consecutive motions. Lower value slows it down." |
| "12","Arc tolerance","millimeters","Sets the G2 and G3 arc tracing accuracy based on radial error. Beware: A very small value may effect performance." |
| "13","Report in inches","boolean","Enables inch units when returning any position and rate value that is not a settings value." |
| "20","Soft limits enable","boolean","Enables soft limits checks within machine travel and sets alarm when exceeded. Requires homing." |
| "21","Hard limits enable","boolean","Enables hard limits. Immediately halts motion and throws an alarm when switch is triggered." |
| "22","Homing cycle enable","boolean","Enables homing cycle. Requires limit switches on all axes." |
| "23","Homing direction invert","mask","Homing searches for a switch in the positive direction. Set axis bit (00000ZYX) to search in negative direction." |
| "24","Homing locate feed rate","mm/min","Feed rate to slowly engage limit switch to determine its location accurately." |
| "25","Homing search seek rate","mm/min","Seek rate to quickly find the limit switch before the slower locating phase." |
| "26","Homing switch debounce delay","milliseconds","Sets a short delay between phases of homing cycle to let a switch debounce." |
| "27","Homing switch pull-off distance","millimeters","Retract distance after triggering switch to disengage it. Homing will fail if switch isn't cleared." |
| "30","Maximum spindle speed","RPM","Maximum spindle speed. Sets PWM to 100% duty cycle." |
| "31","Minimum spindle speed","RPM","Minimum spindle speed. Sets PWM to 0.4% or lowest duty cycle." |
| "32","Laser-mode enable","boolean","Enables laser mode. Consecutive G1/2/3 commands will not halt when spindle speed is changed." |
| "100","X-axis travel resolution","step/mm","X-axis travel resolution in steps per millimeter." |
| "101","Y-axis travel resolution","step/mm","Y-axis travel resolution in steps per millimeter." |
| "102","Z-axis travel resolution","step/mm","Z-axis travel resolution in steps per millimeter." |
| "110","X-axis maximum rate","mm/min","X-axis maximum rate. Used as G0 rapid rate." |
| "111","Y-axis maximum rate","mm/min","Y-axis maximum rate. Used as G0 rapid rate." |
| "112","Z-axis maximum rate","mm/min","Z-axis maximum rate. Used as G0 rapid rate." |
| "120","X-axis acceleration","mm/sec^2","X-axis acceleration. Used for motion planning to not exceed motor torque and lose steps." |
| "121","Y-axis acceleration","mm/sec^2","Y-axis acceleration. Used for motion planning to not exceed motor torque and lose steps." |
| "122","Z-axis acceleration","mm/sec^2","Z-axis acceleration. Used for motion planning to not exceed motor torque and lose steps." |
| "130","X-axis maximum travel","millimeters","Maximum X-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances." |
| "131","Y-axis maximum travel","millimeters","Maximum Y-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances." |
| "132","Z-axis maximum travel","millimeters","Maximum Z-axis travel distance from homing switch. Determines valid machine space for soft-limits and homing search distances." |