Is it better to control a Vexta 2 phase stepper with digital output or pulse?

[GCarter]

 I need to control four steppers individually at the same time. I have both cFP-PG-522 and cFP-DO-400. I was planning on using pulse but would like some insight.

Newbie here.

[TreyB_NI]

Hi GCarter,

The PG-522 would be better for that application.  Here's what some other customers have used:

http://forums.ni.com/ni/board/message?board.id=170&message.id=43509&requireLogin=False
http://forums.ni.com/ni/board/message?board.id=110&message.id=1166&requireLogin=False
http://forums.ni.com/ni/board/message?board.id=170&message.id=240535&requireLogin=False

What kind of duty cycle do your pulses need to be?

Trey B
Applications Engineering
National Instruments

[GCarter]

Hi Trey,

I am really not sure what the duty cycle needs to be. But the steppers are driving a peristaltic pump for precision metering. The rpm will vary between 3.75 rpm to 325 rpm, with a 50% torque capacity. Is that the same as duty cycle?

Regards,

GCarter

[TreyB_NI]

Duty Cycle is the ratio of how long the signal is high versus low in a period.

For example, look at figure 6-24 and the text just above it.

---

Each stepper motor winding is energized one in every four input pulses. Consequently, the pulse train for each winding has a 25 percent duty cycle.

---

http://zone.ni.com/devzone/cda/ph/p/id/287#toc3

Trey B
Applications Engineering
National Instruments

[GCarter]

I think we will be at a 50% duty cycle. We do have the motors running, as of today, but they stop when changing speeds. Any suggestions?