A Mach3 compatible motion control board does not work like that, it does not accept G-code. Stick with GRBL for what you want to do.
Thank you, with your help already switched to GRBL direction.. Now, just out of an engineering curiosity... How can I learn about the USB serial communication protocol between the Mach3 board and the computer, and how-which data is sent and received?
If you know, could you or anybody summarize it a bit or share a resource link?
Thank you!
Very brief:
With GRBL, GRBL is the G-code interpreter, motion planner and motion controler. It accepts high level G-code commands via its serial interface and outputs control signals (step & direction) to the motor drivers. Anything than can send plain text commands can "run" the GRBL device.
With Mach3, Mach3 is the G-code interpreter and motion planner while the attached board is the motion controller.
Mach3 reads the G-code commands from a file, interprets it and plans the motion. It is then up to the developer of the attached board (the motion controller) to craft a plugin for Mach3 to act as a middle man between Mach3 and the board, be it USB attached or Ethernet attached. Therefor Mach3 does not have a specified communication protocol. There is, however, documentation available on how to write plugins,
here, for example.
Hope that makes sense.