Reading Hal pins from Gcode [SOLVED]

I've been trying to workout how to read the value of hal pins from gcode so I can access values set in the GUI to set various cutting parameters. I'm using Master branch.

From a link to documentation Andy posted on an earlier thread I have changed my .ini file to include:I have a pin called
So in Gcode on a metric machine in the MDI window, I have tried this
But I get this error
I have not found an example , but it appears to be correct syntax to me.
What am I doing wrong?
Is the upper case in the pin name significant?

A quick example of the correct syntax would be really appreciated.

Tommy, thanks

I tried adding a G21 to set metric before it but that did not work. Same error.

And yes, it will be Z once I get organised but currently that needs a negative value. I know thats easy, but keeping it nice and simple while testing.

I could net see any examples on parameters to G91.

I have to tell you I know nothing about Gcode

Ooops sorry, I meant no examples for G1.

To me, it is clearly not finding the pin #<_hal[plasma.G0-Gap]>

as anything on the line after it does not generate an error.

Here is the GUI



The value I'm trying to read is the 45 above the Rapid Gap - button

Solved.The error is because there is upper case characters in the pin name becasue the interpreter converts everything to lower case.

I tried saving a pin with all lower case characters to parameter #33 with this command

I did not get an error message and after I closed Linuxcnc, the parameter was saved in linuxcnc.var.
I then picked a random gmoccapy plasma pin that was all lower case and it also saved to #33 happily.

Very cool!.

This parameter is the target velocity (frequency) returned by the Mesa THCAD at the required preset torch volts.
For those interested, if you are saving values in your own custom parameters, if you create them in the linuxcnc.var file they become persistent and that are saved from one session to the other.

So now all I need to do is to rename a few pins and I'm in business!

PS. This is feature is very poorly documented

Using the hal pin parameters might work. But I would not trust it for data entered and used during a run. Those parameters are not always updated during a run. A better approach would be to connect the hal pins to motion.analog-in-xx pins and read them in using G66.

Todd wrote:

Using the hal pin parameters might work. But I would not trust it for data entered and used during a run. Those parameters are not always updated during a run. A better approach would be to connect the hal pins to motion.analog-in-xx pins and read them in using G66.

Thanks Todd, I am aware of the limitations but to set the starting parameters, I think they'll be fine.