would any of these help?
http://linuxcnc.org/docs/2.7/html/gcode/m-code.html#mcode:m48-m49

On 10/12/2016 1:09 PM, dan...@austin.rr.com wrote:
> As described earlier, I have a probe I used to set the Z after changing 
> tools.  The Probe Z button calls an MDI which calls a .ngc g-code file which 
> uses the G38 probe routine.
>
> What I realized is the Feedrate Override mucks with the probe cycle.  The 
> probe cycle needs to operate at a consistent speed, but Feedrate Override is 
> being used, sometimes resulting in terribly slow or fast probes.
>
> What are the options here?  The g-code can't ignore or set the Feedrate 
> Override, can it?
>
> All I could think of was tying the Probe Z button to a HAL which copies FO to 
> a backup net "FeedOverride_Back" on rising edge, writes FO=1.0, and copies 
> back on falling edge of is-auto.  This sounds super-convoluted.
>
> Also, important question to know overall- how could that work?  If I have a a 
> rising edge of Probe Z button, and I both copy FO to FeedOverride_Back AND 
> write FO=1.0 concurrently, is there a way to predict what gets stored in 
> FeedOverride_Back?  This sounds like it's two separate threads, and you don't 
> have a guarantee as to which executes first.
>
> e.g. Feedrate Override is 0.2.  Does FeedOverride_Back always get 0.2, or 
> could FO=1.0 execute first so both Feedrate Override and FeedOverride_Back = 
> 1.0, and the 0.2 value is lost forever?
>
> Would it make sense to get sneaky and, inside the G-code for the probe, 
> divide the desired F-parameter by the current Feedrate Override, e.g. desire 
> F10, write F10/[some way to get Feedrate Override=0.2] = 50 which will result 
> in a feedrate of 10 due to the 0.2 multiplier?
>
> Danny
>
>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, SlashDot.org! http://sdm.link/slashdot
> _______________________________________________
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
>


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most 
engaging tech sites, SlashDot.org! http://sdm.link/slashdot
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to