M100 199 - rmu75/linuxcnc-wiki GitHub Wiki

date: '2012-07-08T15:37:56' title: M100-199

Hi guys: I am trying to help someone on cnc zone to use M100 but I don'tunderstand the manual desription nor can I find anything in the wiki to help.the manual says: To invoke a user-defined command, program M- P- Q- where P- and Q- are both optional. The external program “Mnnn” in the directory [DISPLAY]PROGRAM_PREFIX is executed withthe P and Q values as its two arguments. Execution of the RS274NGC file pauses until the invoked program exits.

Does this mean the external program must be named M100-199? What is meant by PROGRAM_PREFIX ? pathway? I assume the external program can be in any supported language or are we talking G code?

 Yes > What is meant by PROGRAM_PREFIX ? pathway?

>From my lathe .ini file:

  1. Sections for display options

[DISPLAY]DISPLAY = axis LATHE = 1 PYVCP = spindle.xml

  1. DISPLAY = usrmot
  2. DISPLAY = tkemc CYCLE_TIME = 0.100 HELP_FILE = doc/help.txt POSITION_OFFSET = RELATIVE POSITION_FEEDBACK = ACTUAL MAX_FEED_OVERRIDE = 1.2 PROGRAM_PREFIX = ../../nc_files/

... you can see that the M1xx files will need to be two directories up from the current directory and in nc_files. I believe that makes it /home/user_name/emc2/nc_files. You can change PROGRAM_PREFIX if you want.

> I assume the external program can be in any supported language or are we talking G code?

My guess is that you can not execute G-code, but bash, python, C or any non-real-time executable would work. I use a bash script to create missing g-codes for my lathe, such as M102 Collet Open: file = /home/kwallace/emc2/nc_files/M102

1.!/bin/sh 2. Custom - Only intended for Kirk Wallace's HNC lathe, KW 20070823 3. M102 - Opens Collet Closer halcmd setp parport.0.pin-07-out False halcmd setp parport.0.pin-06-out True exit 0

I use M102 in my G-code files for opening the collet closer.