digital input with delay from sample clock

[WernerGobel]

Hello,

with a PXI 6229 board we are performing an analog output task (Master task) and a digital input task (Slave task), both with the same sample clock rate (400 kS/s at maximum) and the /ao/Sampleclock of the analog output task being the sample clock source for the digital input task. Is it possible to delay the sample clock for the digital input task by a user defined amount of time. I tried to configure a digital start trigger with delay using trigger property node and delay from sample clock using timing property node  (in both cases the source terminal of the digital task was not connected), but got the error message that these operations are not applicable to the task. Is there any other possibility to perform an analog output task and a digital input task - both with the same sample clock rate - but the digital input task being delayed by a user defined amount of time compared to the analog output task?

Thanks a lot for any help or suggestions!

[Kevin_Price]

Werner,

If you aren't using one of the counters on the 6229, you could configure one to be a retriggerable pulse generator.  It's period would need to be shorter than one AO SampleClock period.  Let the AO SampleClock keep re-triggering the counter to pulse and let the counter output drive the timed Digital input.

Alternately, simply generate a finite (requires both on-board counters) or continuous pulse train where the leading edge is used as the AO SampleClock and the trailing edge is used as the DI SampleClock.  You can vary the width of the pulses to match your timing needs.

-Kevin P.

[WernerGobel]

Hi Kevin,

first of all, thanks a lot for your quick answer!

Unfortunately, we need to use the two onboard counters for other tasks. Is there a solution that doesn't reqire the counters.

Thank you again for any suggestions!

[reddog]

So you're using both counters and AO.  What about AI?  If not, you could set up a dummy AI acquisition with one channel and use the ai/SampleClock as the clock source for your AO task and the ai/ConvertClock as the clock source for your digital task.  You can then use the delay from sample clock timing property to vary the amount of time the convert clock pulse trails the sample clock pulse.  Aside from this, I think you've run out of resources on your board and will need some sort of external signal if you need a programmable delay.