hi darllly01
I played around an found the easiest way to do is to use a free additional axis ( A , B, or C)
I use the A axis for testing. it is not necessary to assign the axis to any port or pin just check
the axis to enable so that the DRO is working. I attach a g code and a brain where you can see
how it works. The brain switches on the output 1 when the a axis value is less then 0 .
You can play around with the a axis value in the g code to match the optimal points
for switching the output on and off. To activate the brain copy it into the brains folder in mach.
Then start mach, go to operator menu click brain control then click reload all brains then enable
brain test-1.brn then click on the brain and click brain view. then you can watch how it works.
( when the code is running )
hope that helps

Alex