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Author Topic: Does Mach use encoder feedback to update DRO's  (Read 1725 times)

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Does Mach use encoder feedback to update DRO's
« on: January 03, 2011, 01:14:24 PM »
Hi,

Just want to confirm what I have read about Mach DRO's.  I'm going to use Mach and Smooth Stepper in conjunction with stepping motors on a 2 axis system.  I have read that Mach is an "Open Loop" controller and I assume that means the DRO's aren't updated by external information (i.e. encoders) but rather they reflect the current position based on Mach's position output to the motors.  Is that correct?  I can forgo the encoders unless they will provide feedback that is accurately used by Mach.

Thanks for your help!

CM Johnson

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Re: Does Mach use encoder feedback to update DRO's
« Reply #1 on: January 03, 2011, 01:38:25 PM »
That is correct, for a closed loop system you would need servos and either servo drives capable of position control or one of the external motion controllers.
You could get a board from Ron Rogers that will halt Mach if an error of  a user set amount is reached but whether it is worth it or not is open to debate. On a properly designed and sized stepper system you should never lose position. If your motors are undersized it would of course fault Mach if they are out of position but to me thats not much use as it would be continually happening due to the fact the motors are too small.
Hood
Re: Does Mach use encoder feedback to update DRO's
« Reply #2 on: January 03, 2011, 02:13:04 PM »
Thanks for confirming what I thought.  The motors I'm using have an appreciable margin of error (+torque)  to compensate for possible missed steps scenario.

CM Johnson