high speed pattern generation

[faisalayaz]

hi everybody, 

I am using a DAQ card NI PCI 6229 and i have to write a vi that generates following digital pulse pattern

101010010110101

pulse width    0.5 u sec

pulse separation   2 u sec   i.e,       f = 400 khz

duty cycle    0.2

Pl help

[danil33]

Hi faisal,

              Your question gives only vague information.What help you are expecting?What all things you have done so far?

[faisalayaz]

Here is the detail explanation of the requirement...

I want to generate a finite pulse pattern of frequency 400 kHz , it would have a burst of pulses paving a period of 2.5 us and pulse width 0.5 sec , I had successfully generated true, fasle pattern out from DIO at lower frequencies (till 15 KHZ ) and subsequently used that to trigger the counter.

The problem.....  if we want to achieve higher frequency from DIO ( 400 kHz) , it goes silent and no more triggering is available for counter to generate pulses .

The Patten picture is depicted below, I hope the problem has been elaborated more , if there is still any question do let me know,  

regards to everyone 

[johnsold]

This pattern is different from what you last posted in your other thread.  Which protocol is correct?

The method I suggested in the other thread is valid for the protocol you show here. However, the maximum DO clock rate for the PCI-6229 is 1 MHz so you cannot create a signal with a 2.5 us period.

Lynn

[faisalayaz]

Hello Lyn, 

this is  the same protocol , but different pulse spacing , and your previous solution was perfectly right , nad worked fine and still working fine ,,,,, but now with pulse spacing of 2 usec I have not been able to trigger the counter .... If u could suggest any solution or vi that triggers ac ounter in a aforsaid pattern to generate the pulse pattern.  I have tried many ways but still not successful.  

regards

[johnsold]

I do not have any experience with triggering counters that fast.  Perhaps someone else will be able to help you.

Lynn

[faisalayaz]

Dear Lyn, I think I should switch over to a better hardware i.e 

NI PCIe-6535

10 MHz Digital I/O for PCI Express,  so that i might be able to generate high resolution pulses to trigger the counter....

whats your opinion,

regards

[johnsold]

With a 10 MHz DO clock you might be able to generate the pulses directly without needing the counters.  Talk to your NI sales representatives.  They should be able to tell you whether you can generate the signals you need with that board or may be able to recommend an alternative.

Lynn