Read disable stepper motor

[sppelletier]

Hello, two motors that I use to roll and unroll optical fiber. I want to roll the fiber with motor #1 and, when the fiber is tense, stop to roll.   This will serve as a reference point. I tought to read out the motor #2 current or to disable the motor #2 and read the position change.  I'm using a MID-7604 and 2 compumotor HV171-02-10 (two phase).  Any suggestions?

[Eric_R]

Hi Coolaid

Have you had a chance to look at applying torque control to your system? You can find out more information regarding this in the NI-Motion User Manual in chapter 13. Using some form of analog feed back for force across the spool should accomplish this, you could then command the motor to move until that tension is met.

[sppelletier · Accepted solution]

Thank you, I'll take a look at it.

[sppelletier]

 Sorry, I've mark this one solve but it's not (yet :)).  In order to use the ADC I need to connect my stepper motor to the analog input connector?  if yes, what do I connect to the connector?  I only have 2 wires per phase and a ground.  How do I get the adc reading?  I've tried to replicate what I see in chapter 13 in the machine vision manual, but I get no reading.  I always get 204 for the analog value.  What am I doing wrong?  Thank you in advance.

[Brian_Beal]

Stepper motors are not capable of torque control.  You must use a servo for torque control.  Stepper motors are only good for positioning and (slow) velocity applications.

[sppelletier]

So, if I don't have any feedback from my stepper motor (open loop)  I have now way to know if my motor is rotating or not.  Am I right?

[Brian_Beal]

That is correct.