How generate two pulses per cycle? PCI-6251/6255

[ivkicin]

Hi. I want to generate two or more pulses per cycle like the timming diagram. This pulses will be used to trigger sampling data.

I'm ussing the PCI-6251. The examples VI's for counter outputs can easy generate the first line, but for the second i have no idea. Any information can help.

Another problem could be the synchronization of that lines and the DAQ.

Regards

Ivan C.

[John_P1 · Accepted solution]

I would actually use the digital outputs for this--just generate a continuous clock at 1 MHz using  one of the counters and write the following to your digital output lines:

H H H L L L L L L L

H L H L L L L L L L

If you want to use these signals for sampling a different task on the 625x, you would need to wire the output back into one of the PFI lines.

Best Regards,

[MarisolM]

La mejor forma de crear una señal PWM con la tarjeta 6251 es usar las salidas de contadores . De esta manera puedes ajustar el dity cycle de la onda cuadrada cuando el programa corre. 

Te recomiendo visites estas ligas

Pulse Width Modulation (PWM) Using NI-DAQmx and LabVIEW
http://zone.ni.com/devzone/cda/tut/p/id/2991#toc23

Change Counter Output Frequency on the Fly 

http://zone.ni.com/devzone/cda/epd/p/id/5493

How Can I Change the Duty Cycle on My Continuous Pulse Train?

http://digital.ni.com/public.nsf/allkb/82C9F3C15F62974E86256EBA0058CAF5?OpenDocument

Si quieres generar la señal empleando tus canales analógicos de salida, este ejemplo te será de utilidad

NI-DAQmx: Creating a Custom Pulse Train Using Analog Output

http://www.ni.com/example/26621/en/

Exito en tu aplicación