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Author Topic: M-command speed and delays  (Read 9481 times)

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Offline jimpinder

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Re: M-command speed and delays
« Reply #10 on: October 30, 2008, 06:54:00 AM »
I was speaking to Brian Barker about this at the UK Model Exhibition. I understand that the disproportionate delay on M3 has been fixed.

If you are wanting a faster response that the activate/deactivate, then are the step and dir controls any faster - and use the A axis as a driver for the laser - using a G0 command. The difficulty would be in the time "on" since this would have to be equated to the distance the A axis supposedly moved - but it seems this could be relatively easily calculated. If the "step" pin was used (to fire a retriggerable monostable) the "distance" travelled could be gradually reduced to give the minimum "fire" time - or indeed the monostable could be hardwired to give the time directly.
Not me driving the engine - I'm better looking.
Re: M-command speed and delays
« Reply #11 on: October 30, 2008, 07:02:15 AM »
Unfortunately the dspmc only has +-10 analog outputs. Yet.
We never have the time or money to do it right the first time, but we somehow manage to do it twice and then spend the money to get it right.
Re: M-command speed and delays
« Reply #12 on: October 31, 2008, 06:32:11 AM »
I have spent some time thinking about this workaround. I could do it for our machine but for machines to be selled out - this would not work well because of the safety reasons.

All in all - this would be a another 'glued on' feature to Mach3.

I think the brain function would be as slow as the others in handling the outputs.

It seems the enthusiasm to develop Mach has gone?

" Perfectness - real or imaginated - is the end of development "

BR. Arto

Offline Hood

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Re: M-command speed and delays
« Reply #13 on: October 31, 2008, 07:14:43 AM »
Are you planning to build and sell these machines?


Re: M-command speed and delays
« Reply #14 on: November 05, 2008, 10:59:07 AM »
SOmewhere in mach there is a code Art put in to turn off/on without delays such as laser use. Can't remember what it is you may want to do a search.

(;-) TP
Re: M-command speed and delays
« Reply #15 on: January 08, 2009, 05:36:08 AM »
The IO delay problem still exists.

After first trials it seems EMC2 does not have this problem. It seems these real time controls are still easier to do in Linux than in Old-un-Faithfull Win.

Any news? Do I need to start re-building the whole CNC-control to suit EMC2?

BR. Arto
Re: M-command speed and delays
« Reply #16 on: August 31, 2013, 05:16:42 PM »
Answering to a question I sent long time ago. I just noticed I have not explained how the workaround was made to get rid of the Mach3 slow IO.

Finally I made a dsp-macro to the dspMC/IP board. I use axis commands G1B1 and G1B0 to trigger the dsp-macro that turns beam on/off. The same macro also gives out the real vector speed to be used in laser PWM control for corner slowdowns.