Generating a single channel digital waveform for NI9403 with configurable duty cycle and frequency.

[ManLongAtNI]

Hi Jerry,

Since the 6009 only allows software timing, the transfer speeds are completely software/computer dependant. Rates vary due to programming language, code efficiency, driver version, CPU utilization, and so on.

I included a link that was posted to the last KnowledgeBase article that will allow you to benchmark your device to your system. 

Software-Timed Digital I/O Benchmarks with DAQmx

Glenn

[JSC81]

Chris or anyone else,

I seem to be having some trouble outputing to the step input of the driver.

I can output a T/F to the disable input on the driver and this is working great (First step to lock the motor)

Next I want to send  0/1 digital output to the step input (keeping the duty cycle at 50% and changing the frequency to increase the speed of the motor).

However, I am having trouble accomplishing it.  The current should be strong enough from the DAQ so I am thinking this is not the problem.  

I sent this out earlier but once again " I hooked up my ends to the oscilloscope and I could get accurate readings up to 30hz or so...after this I could not ramp up the frequency.  I am assuming this is a

software issue.  So, I assummed that the motor was getting too low a frequency for the steps to occur.  Do you think this is correct?

I have no idea how to accomplish this but I was trying to get it to output a digital signal so I built something that I thought could work.

I have attached two codes.  The first one called "Short Version for step motor" and the second version called "Pray this works".  

When I hooked up an oscilloscope to the second program I could have it output up to about 250hz (a lot better) but again there is some software issues that are creating noise.  

Can anyone shed some light into:

1. Why the first one is not allowing me to get my motor to step and what would correct this?

2. Would the second program "Praythisworks" work in my situation ? and how come I still cannot get the motor to step?

All information about the driver is in the previous posts

Anyone Please help...thank you thank you,

Jerry

[sharda]

Hi Chris,

I am trying to accoplish pretty much the same task, but by using 9403 on the Crio 9014 controller. Do you have any suggestion from where to start with?? I will much appreciate any help.

Thanks,

Ajay

[PeterGC]

Hi Ajay,

Here is a good document to look on CompactRIO specific motor control.

http://zone.ni.com/devzone/cda/tut/p/id/6143

It's not the exact hardware you are using, but it should help get you started.

-Pete