Maximum frequency from digital outputs

[ravikanthsomsolencsu]

Hello,

I am using a NI USB 6218 BNC device. I'm trying to toggle the digital IOs hoping to get a frequency of ~1 MHz. However I'm unable to get more than 600 Hz. Is this expected? Is there a way to get a faster frequency? I tried programming in LabVIEW as well as C++(both in Windows 8), but it did not really help.

My goal is to use three outputs as controlled clocks, which should run on demand with a specified number of cycles and, with a phase shift. Is there a way to achieve it with this device?

Thanks,

Ravi

[Dennis_Knutson]

There is no such device as USB 6812.

For whatever device you actually have, look at the specs. If it's hardware timed, the rate would require you to define multiple samples and in general, not 1Samp mode.

[ravikanthsomsolencsu]

Hi Dennis,

Thanks for the quick reply. My bad, I meant USB 6218. Is it possible to define multiple samples for this device? When I tried to do that, I got an error message of -200077. And I couldnt find the timing specifications for the digital output.

Thanks,

Ravi

[Dennis_Knutson · Accepted solution]

The specs say it is software timed. You can only write one sample at a time. MAX rate is dependent on the os bit typically maxes out at around 1kHz. You do have two counters but you'll need different hardware to output three clocks.