CNC gcode robot system motor controller

New link to help you with general CNC (Computer Numerical Control), gcode, and how to use.

Every Excitron X controller contains a simple but powerful 8 axis CNC/gcode operating system.  It's named ExROS.  See X Controller Manual page 7, and X features not in Manual yet.

No Arduino, no PC, no PLC, nothing else needed to run a CNC machine. Only Excitron has this major advantage. However, a display and keyboard is almost mandatory. Almost, because in the near future, the X motor stored gcode files can be run via Joystick switches, 10 in all. Then a display or keyboard is not needed at all. This new conceppt is fantastic!

Best method is you can hand write gcode using Notepad, and save your file.  Then use Realterm to download your gcode file into the X Controller.  Do this by:

  • Run Realterm, then select the Send tab.
  • The bottom left has a white bar to select your file.
  • Change the char delay to 5, and line delay to 10.  Try different values.
  • Then in the Realterm black main window, put the Excitron X Controller in the CNC/gcode mode, you should see X 0001> prompt.
  • Type R and a file name, then hit enter.  The Excitron controller is ready to accept a gcode file.
  • Then in the Realterm Send tab, select your file (3 dots to right of filename), then hit Send File .
  • If you do not have an error (marked with ?), your file loaded fine.
  • View your gcode file, stored in SRAM, with thecommand.
  • Type g to run your gcode without the motors running--a great feature.
  • Typeto actually run all your motors according to your gcode file.
  • As each line runs, the gcode is displayed.
  • Save your file to flash by S command and confirm with ~.
  • See all files stored in the motor's flash with F command

Note:  the above assumes:

  • you have already set each axis with a unique address letter A, B, C, D, E, X, Y, or Z.
  • One motor is set as Master.  Use the c submenu.
  • All others are set as Slaves.
  • Each Excitron X controller is daisy chained with single wires from Tx of CNC2 to next motor's Rx CNC2, etc.
  • All motors must have a common ground, using wires or chassis.
  • The last motor's Tx in this serial port daisy chain, plugs into the Master motor's Rx.
  • The Master motor's CNC is plugged into the USB-TTL-3pin cable adapter, and into the PC.

A simple bare bones graphics to gcode generator is, tutorial at  The file output is gcode, and can be Read into the Excitron X controller, then run and saved (inside the motor).  You may have to change or delete some M or G codes.

The Excitron ExROS is better than the popular GRBL.  GRBL has limitations compared to ExROS, however ExROS does not do arcs at this time.  Arcs can be accomplished easily with a spreadsheet equations to generate gcode for arcs.  40 segments gives very smooth arcs.The biggest advantage is ExROS is written 100% in assembly language, making it the fastest robot operating system in the world.  ExROS opertes with only 1,700 instructions, and 2 bytes (not KB or MB) of SRAM.  Incredible!

Amazingly, ExROS requires no external electronics, all is contained inside the motor!  Mach3, Mach4, Max32, Solustan, Linkmotion, turboCNC, and others all require some complicated interface board, and a lot of wires.

Search the internet for a program that creates gcode from graphics.  One method for PCBs is Autocad and Gerbtool.

One popular progtram that lets you draw and convert svg fi;es to gcode is Inkscape, download at

A sophisticated svg to gcode program is free:  jscut works with svg (scalable vector graphics) files, useful for 3D printing, lasercut and CNC metal parts.  Its output is gcode.  Then follow the above method instructions to download in the Excitron X Controller, using only the USB-TTL-3pin serial cable supplied with every X Controller.

See for a video of how to use jscut.  Remeber, you do not need the TinyG board.

Check back soon for more information.