Stepper motor and a 1100

[nysparky 1]

Whats the best way to drive a stepper with a 1100 for just a forward movement and stop at a prox. Is there a way to use a Bit to move and stop? Sorry if Im confusing Im new to steppers Im using output pulse train 2 and 3 and I can move the motors when I put in the pulse count , I would like to know how to just run at a set speed with a direct bit until the bit is not made.

[JRoss 84]

Check out the PTO function file. You'll want to use the Jog Continuous State.

[nysparky 1]

Thank you , Also is it set to an output but? Im not sure how the rung is written

[JRoss 84]

You set the OUT parameter of the function file to 2 (for output O:0/2) or 3 (for output O:0/3). Those are the only valid options. You use the PTO instruction to enable the function. Then you interact with the sub-elements of the PTO function file to set the speed and start/stop the pulse train that will drive your stepper. The help files in RS Logix 500 have an ok description of the sub-elements. The Micrologix 1100 reference manual (pub 1763-rm001) has more information. I believe you'll use JF to set the frequency (speed) and JC to start/stop the pulse train. You might be able to find sample code in the knowledgebase.

[kaiser_will 65]

If you had a SLC, it would be a 1756-HSTP stepper controller module. Are you running this in pulse-train & direction mode? If so, a direction bit ON or OFF will set your move direction and a Pulse Train will command the stepper motor to move X steps in that direction. I typically program in State-Based mode (i.e., State 10, set direction bit; State 20, move register 1 step value into Register 2; State 30, Send register 2 step command value to stepper; State 40, assume stepper is in position for time). Of course, this is typically open-loop control. So if you need precision, you will need position feedback.