Error 20 "Unsupported or invalid g-code command found in block. On or near line 2:"

[ChrisM (Chris Mabey)]

Every time I try to engrave I get error 20.

Unsupported or invalid g-code command found in block.
On or near line 2:

Moves fine and frames fine.
using mks dlc32 board.
Any help is appreciated.

[ednisley]

@ChrisM

using mks dlc32 board.

Make sure you’ve selected GRBL as the device type, rather than the more exotic choices.

It may require the DTR option:

DLC32 not working with lightburn

Looks like the serial connection is made to your controller which returns a small amount of information… but then communications stall for some reason? Did you try to “Enable DTR Signal”? Reboot the laser, then try to reconnect to it, if you could provide a screenshot like this that shows your device settings, along with the Console window, and the Laser window, it would be really helpful; [image]

There are apparently subtle problems depending on the controller’s GRBL version:

MKS DLC32 device

Need help selecting correct device for MKS DCL32 card. GRBL causes M4 gcode error. GRBL pre 1.11f does not have continuous laser power checkbox.

If fiddling around with those variables doesn’t get it running, let us know what happened.

[ChrisM (Chris Mabey)]

I have tried everything I can find online and while different settings appear to fix other people’s problems, I keep getting the same error. I will check what version GRBL I have tonight.

[ChrisM (Chris Mabey)]

I had no luck so have installed an older version of the firmware and it all seems to work perfectly

[berainlb (PY)]

Is it possible you had g-code clustering enabled in Edit->Device Settings? That’s only available on certain controllers and would cause an error if had this set.