Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Overloaded on January 24, 2008, 03:22:09 PM
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Hey All,
I will be using axis motors that have an integral controller, driver and encoder. They can be programmed as stand alone but they can also be configured to accept Step and Direction. Which is what I have done. That part works OK.
When set-up for Step and Direction, the only output from the encoder seems to be a "Timed Trigger" on 1 output pin that can be set to "10 to 32767 pulses". Is there a way to utilize this output to Mach for position error or missed steps ?
It appears, to configure an encoder in Mach, A and B channel is required.
I also guess that I would need to match "pulse for pulse", this minimum is 10 pulses.
This doesn't look good, but I'd like to use the encoder if possible.
Thanks,
RC
Oh, by the way..These motors can be set to 50,000 pulses per revolution and have a 10:1 planetary reduction gearhead. That's 500,000 ppr. Put that with a 5 TPI Ball screw makes 2,500,000 pulses per unit. (inch)
Every 10 pulses would probably be OK.
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Mach is open loop, the encoder input is just for reference. You could probably use a brain(or macropump) to compare the true and comanded position and have Mach fault out if your chosen error difference is exceded, but I would imagine your drives do that internally so there probably isnt much point to doing it.
Hood