USB 6343 PWM

[Leonid_Pascar]

Hi,

I need to use more than 10 ports in PWM and frequency tuning mode(range0-10Khz).

Can I convert digital outputs to counter outputs?

If  the answer is no.

Can the digital ouputs  proive pulses as good as the counter outputs?

Thanks,

Leonid

[John_P1]

Hi Leonid,

There are only 4 counters on the 6343 with PWM output capabilities--so unfortunately you can't simply convert the digital lines to counter outputs.

The digital outputs *can* provide pulses, but they don't work exactly like the counters.  Generating pulses using a digital output task would require you to define a digital waveform that produces the desired signal at a certain sample clock rate.  The maximum rate for this sample clock can only be up to 1 MHz and is system and bus-activity dependent (based on the specs).

The pulses from the Digital Outputs will not be "as good" as the counters in the sense that the resolution will be lower (1 MHz sample clock vs. 100 MHz timebase) and the behavior will not be as easy to implement.  However, here is an example that shows one way that you might do this.  It isn't my favorite example in the world and could probably use a bit of optimization in building the waveform, but it might get the job done for you or at least help you get started.

Best Regards,

[Leonid_Pascar]

Thanks

[WillPwr]

Hello, Leonid!

The answer is yes, and you can find details in the following article:

Can I Generate a Clock on a Digital Output Line Using DAQmx?

In response to your other question, the DO pulses are not as "good" as the counter outputs in terms of timing - they will be software (rather than hardware) timed so they will not be as accurate. However, they are definitely suitible for some applications.

[WillPwr]

Haha, I did not see that John had already replied to this. Thanks, John!