Soft Limits & Instructions within Macros

[Haysys]

Greetings All,

I'm part of the team at BARN (Bainbridge Artisan Resource Network) in Washington State. We've built up a DIY 4'x4' CNC Plasma cutter. The torch is on Z with a Home switch and a second Height switch for setting the starting cut height (we also employ a plasma torch height controller, but that's outside this discussion). We have modified M7 with some M commands, some of which follows:

M105 /Z P2 F30 ;Move Z down until Input 2 is made at 30 IPM

followed by:

M106 /Z P-2 F5 ;Move Z up until switch releases

Our problem is this:

If there is no material under the torch head, the Height switch is never made so M105 never completes, thus Z will continue to dive until manually stopped; this is usually well below the negative Soft Limit. The Z-axis going below the negative soft limit makes no sense to me. Is it the case that while an M code is executing, the Acorn ignores the Soft Limits?? Is there a setting that would negate this??

If anyone has an understanding of how/why this is happening, I'd sure appreciate the input.

Thanks!!

David

[cncsnw]

If you use M115 and M116 instead of M105 and M106, then soft limits will be applied.

To use M115 and M116, you may have to switch the sign of your P value. See http://www.cncsnw.com/AdvancedMacroProgramming.htm.

Optionally, you can also specify a target position (short of the travel limits) with M115/M116, and motion will stop with an error if the machine reaches that position without activating the switch.

[Haysys]

Thanks a tonne for your input on this... Much appreciated!!

And it works as advertised; Solved our problem.