Understanding errors

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What is an error?

An error occurs when SmartBench does not recognise or cannot process a machine command. 

When this happens, SmartBench will stop any further commands from running, and cancel the job. 

How do I know that SmartBench is in an error state? 

SmartBench will tell you! SmartBench’s LEDs will turn a static red, and it will immediately stop and display the error screen on the console.

Why did the error happen?

SmartBench is unable to carry out whatever command has just been sent to it. 

The reason for the error will be shown on the screen. 

How do I reset or clear an error? 

Press “Return” on the error screen. 

Sometimes, pressing return will also trigger an alarm (or vice versa, clearing an alarm will trigger an error). This is ok - just follow on screen instructions.

If SmartBench loses position, you will need to re-home before doing anything else. 

How can I prevent errors from happening during my job? 

SmartBench has an error-checking feature that you can use during the job loading process. 

It is strongly recommended that you check your job if you are running it for the first time, or if you have made any modifications to it. 

This will ensure that any errors are caught before you run your job for real! 

If an error happens during a job, the job will be cancelled. 

If SmartBench has also lost position due to the error, you will need to re-home, and potentially start the job again with a new sheet of material. 

Click here to learn more about loading and checking your job on the SmartBench console. 

What are all the different error states?

If you want to know all the different reasons that may cause SmartBench to go into an error state, read through this table: 

Error code

Error description


G-code words consist of a letter and a value. Letter was not found.


Numeric value format is not valid or is missing an expected value.


Grbl '$' system command was not recognized or supported.


Negative value received for an expected positive value.


Homing cycle is not enabled via settings.


Minimum step pulse time must be greater than microseconds.


EEPROM read failed. Reset and restored to default values.


Grbl '$' command cannot be used unless Grbl is IDLE. This ensures smooth operation during a job.


G-code locked out during alarm or jog grbl_state.


Soft limits cannot be enabled without homing also enabled.


Max characters per line exceeded. Line was not processed and executed.


Compile Option Grbl '$' setting value exceeds the maximum step rate supported.


Stop bar detected as pressed. Check all four contacts at the stop bar ends are not pressed. Pressing each switch a few times may clear the contact.


Grbl-Mega Only Build info or startup line exceeded EEPROM line length limit.


Have you homed the machine yet? If not, please do so now.

Jog target exceeds machine travel. Command ignored.


Jog command with no '=', or contains prohibited g-code.


Laser mode requires PWM output.


Unsupported or invalid g-code command found in block.


More than one g-code command from same modal group found in block.


Feed rate has not yet been set or is undefined.


G-code command in block requires an integer value.


Two G-code commands that both require the use of the XYZ axis words were detected in the block.


A G-code word was repeated in the block.


A G-code command implicitly or explicitly requires XYZ axis words in the block, but none were detected.


N line number value is not within the valid range of 1 - 9,999,999.


A G-code command was sent, but is missing some required P or L value words in the line.


Grbl supports six work coordinate systems G54-G59. G59.1, G59.2, and G59.3 are not supported.


The G53 G-code command requires either a G0 seek or G1 feed motion mode to be active. A different motion was active.


There are unused axis words in the block and G80 motion mode cancel is active.


A G2 or G3 arc was commanded but there are no XYZ axis words in the selected plane to trace the arc.


The motion command has an invalid target. G2, G3, and G38.2 generates this error if the arc is impossible to generate, or if the probe target is the current position.


A G2 or G3 arc, traced with the radius definition, had a mathematical error when computing the arc geometry. Try either breaking up the arc into semi-circles or quadrants, or redefine them with the arc offset definition.


A G2 or G3 arc, traced with the offset definition, is missing the IJK offset word in the selected plane to trace the arc.


There are unused, leftover G-code words that aren't used by any command in the block.


The G43.1 dynamic tool length offset command cannot apply an offset to an axis other than its configured axis. The Grbl default axis is the Z-axis


Tool number greater than max supported value.


ASMCNC custom error: this firmware version has not recognized this command.


TMC command received for wrong motor (>5).


Realtime command crc8 error.


Non hex code character received.


Command supplied to the function is outside wanted range.


Parameter supplied to the function is outside wanted range.


Realtime command buffer parser did not find the expected packet start modifier.


Realtime command buffer parser found length that is higher than maximum.


Sequence number does not match the expected one.


Realtime command buffer overflow: slow down sending RTL commands or increase buffer size.

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