6602-creating a specific pattern

[netanelv]

Hello

I want to use the NI-6602 card for generating a specific pattern. The pattern will be triggered by the rising edge of an external digital input and will be routed to an external digital output. I attached a file which defines the pattern (timing diagram).

I want to use only one counter for generating this pattern because I need many patterns of this kind in parallel.

Please give me an example (if exist) for creating this pattern or give me an idea how to generate it

 

Thanks

netanelv 

[Jarrod_B.]

Hi netanelv,

The short answer to your question is no, the 6602 will not be able to generate your specific pattern with one counter.  You can use a counter to generate a single pulse or a periodic pulse train with user-defined specifications, but your signal does not fall into either of these categories.

Your other options would be to do correlated digital output (pattern output) on an M-Series board or 653x series digital I/O board.  Hope this helps!

Best regards,

[netanelv]

Thank you for the answer.

I have 2 more questions:

1.can I generate this pattern with 2 counters?

2.I didnt understand exactly your suggestion about the 653x cards.

Regards

netanelv

[Jarrod_B.]

Hi netanelv,

Counters are really not designed to generate a non-periodic digital signal such as the one you have described.  In order to do that, you will need to use correlated digital output, also known as pattern output.  With correlated or pattern output, you create a digital waveform in software, and then use a hardware clock signal to clock that waveform out at a certain rate.  In other words, for the signal you were describing, you could create a digital waveform as follows:

      ________________________            _____
___|                                         |_______|
      1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1
                         15-1's                 5-0's     3-1's

You could then clock these bits out at a rate of 1000 Hz to generate the desired signal.  You could also make that task to be triggered on your external trigger pulse.  This type of pattern output can be done using an M-Series board or a 653x.  For more information on this type of operation, please refer to the M Series Help (User Manual and Specifications) or the NI 6533/6534 Devices for NI-DAQmx Help.  Hope this helps!

Best regards,

Message Edited by Jarrod B. on 04-26-2006 09:31 AM

[netanelv]

Thank you for your detailed answer

It was very helpful.

Regards

netanelv