M19 does not work in auto mode

I have a for me strange problem.
M19 works fine in when I execute it in the MDI window, but in auto mode (runing a program) the spindle does not turn and no error messages.
The program I have tried is very simple:
M19 R180
M19 R0
M2

I don't even know where to start searching for this problem.

I use master branch from february this year.

Any suggestion would be apreciated!

Have you tried with the Q parameter?
linuxcnc.org/docs/html/gcode/m-code.html#mcode:m19

I have never used M19, but there has been some discussion of this in the past. From the docs it seems Q is necessary.

Rick G

I have not tried that in auto mode, but it for sure make sense. I will try it tonight and it feels like it will solve the problem.

I report back when I have tested.
thanks!
--Per

check that any spindle encoder is in the correct mode and is switching in the correct sense i.e false to true when triggered
and not true and changing to false on triggering . if that makes sense

If the Q parameter dosn't make it I will check that. It could be the problem because I have changed from the index puls on the servo to an external Proxy switch on the spindle throu an opto coupler. Index-enable works as expected, but I have not checket exact position.

And when I'm writing this I realise it must be wrong since I ground the index input pin (IDX5, TB4-pin23) on the 7i77 card when I got a signal from the Proxy switch. I read that the 7i77 has an internal pullup on this pin so grounding it on the input puls was most logical to me. I have to invert this.

Does any one know if a pull down of lets say 470 ohm on that pin to ground be sufficient to get it low ?
I will in that case connect +5V throu the optocopuler instead of grounding throu it.

--Per

The Q parameter solved the problem. I have to start the spindle once before M19 works (both MDI- and auto-mode), but that is no big deal and can be solved during startup.

I didn't have time to check on the index signal. It looks like I shall use: setp hm2_7i77.0.encoder.05.index-invert 0, but since it works I can probably leave it as it is.

--Per

Yes, thats right, and quite obvious if one think.

I will try something like you have described in this post . I have used this with the mux2 already for switching between position and velocity mode. Or if the G33 works in startup code I might use that.

--Per