multiple digital pulse trains with daqmx

[tueddelmeister]

Hello guys,
I am new to this forum and to Labview. I use Labview 7.1 with DAQmx 4.5 and the Mio 6251 card.
My problem ist that I want to generate five multiple digital pulse (TTL) trains to trigger some devices, e.g. I have a 2 cameras, flashlamp, image intensifier and an injection device. For all these devices I need triggers that should be referenced to one of the five triggers and they should be flexible in high-lowtime etc. The accuracy should be 1 mys. The national instruments guys where we have bought the hardware, told me that this is possible to do.
In the attached vi I have tried to do that by using a property node. Can anybody please explain how I can solve my problem?
Thank you very much in advance

Sven

[tueddelmeister]

I have to say that I wanted to do that by using one counter where all triggers (PFI channels) from the property node are referenced to that counter. If I change specifically high-lowtimes and initial delay for each seperate PFI Channel at the property node nothing hapended. Can anybody explain why. I think that must be possible cause you can choose high-lowtime and initial delay for each channel seperately. Can anybody explain what I am doing wrong?
I have attached the new vi. It should be more clearly now.
Thanks in advance

Sven

[Jochen]

Sven,

this approach won't work. You can't assign multiple outputs to a single counter. In your property node your subsequent counter output parameter settings always overwrite the previous settings.
Here are two possible solutions:

1. You could use the digital I/Os of your board in correlated DO mode. Here you can find some examples how to do that.
2. If for some reason you want to use counters you will have to use a board that provides 5 or more counters. The PCI-6602 has 8 counters and could do the job.

Best regards,

Jochen Klier
National Instruments Germany

[labview_rookie]

Thanks for the answer. I dont have found anything that matches close to my problem. Can you please explain how to handle two lines and a counter that it is possible to choose hightime lowtime and initial delay, idele state ass well for each line (maybe by attaching one viw??). I have no experience with this kind of stuff.
It would be very kind if you can do that.
Regards
Sven

[Jochen]

Sven,

I think all you will have to do is to output a clocked digital pattern on your digital outputs. The digital pattern should correspond to the timing needs of your application. As the digital outputs on the M Series don't have their own update clock you need to correlate them to either a counter, an AI- or an AO-operation. That's exactly what the examples do that I have linked to my last posting. They might not be a 100% fit to your requirements but they should give you the general idea.

Jochen

[labview_rookie]

One more question please. Does the PCI 6602 card works together with DAQmx? Does the card has an accuracy of 1 microsecond?

Sven

[Jochen]

Yes, the 6602 works with DAQmx. The timing resolution is 12.5 nanoseconds (derived from an internal 80 MHz clock).
The digital outputs of the 6251 can be clocked with a maximum frequency of 10 MHz, resulting in a timing resolution of 100 ns.

Jochen