Step motor with closed loop

[KaiRune]

Hi.

I have a V130-J-TR20 that i want to use to position a step motor with closed loop configuration. does anyone have any eksperiance with this? is it possible to use the pto utillity and make some changes?

[Joe Tauser]

Feed the output to the stepper motor back into one of the high speed inputs to track the position of the motor.  There is an example under Help->Examples->Version 900->Project Examples->HSC_HSO

 

Joe T.

[Kikis]

Eventhough PTO function is open loop, i find it to be very accurate for a stepper motor application.

I think that PTO is much easier and faster way to program.

Of course Joe's suggestion is the answer to your question but this way you have to write everything from scratch. If your application is complex, it might be a headache to program.

[ondrej]

Hi

I have tried HSC_HSO V120_stepper_motor example and it works little bit tricky. When i set the Target (number of pulses that i want to generate) PLC always generate Target + 1 pulses.

 

So i have tried to set 1 pulse (Target < 100 pulses) and i have modified the example in place where is set frequency (when Target < 100 pulses). I think there should be defined minimum frequency because when the number of pulses is set < 100 (Target < 100) the plc cannot stop PWM with appropriate accuracy. This modified example generates same strangeness - when i set one pulse so PLC generates two pulses (Target + 1).

 

I have tried use osciloscope, whether there are some reflections on wiring, but it didn't help. Signal is OK.

Please somebody to try this example.

 

I don't know where is problem. Thank you very much for Your HELP! 

 

Edit: It would help if somebody could try to run this example on V120UN2. And check whether TARGET = Position. It should be clear if problem is entirely with my PLC / software.Thx

[AlexUT]

Hi,

There is no problem with this example.

 

VisiLogic Help state, that minimal frequency you can generate by PWM is 8 Hz. There is hardware limitation by design.

PWM is not intended to generate 1 pulse.

 

You have to use other way to manage stepper motor step-by-step.

BR.