pci 6133

[maulaz]

It is possible to get a TTL output synchronized with an analog trigger input?

 thanks

[AndreaN]

Ciao,

you cannot assign directly an analog trigger event to a counter output task, but I can show you a workaround that I tested and it's working.

Basically you can create an analog input task with a finite acquisition triggering it with an analog level;you need to export the start trigger on a PFI line and then you create in parallel a counter output task which is synchronized with the analog input task and it's triggered with the digital start trigger on the same PFI line.

I've verified that with a  PCI 6133 you cannot use PFI 0-1-2 because are reserved, so you can use for instance PFI 3.

Here's the example.

I hope this helps!!! 

Message Edited by Ryan_82 on 10-08-2009 07:23 AM

[Mcdan]

maulaz,

I'm not sure exactly what you want this TTL signal to look like, but in addition to the method described by Andrea N, you may also consider exporting the "AnalogComparisonEvent".  Basically you'd want to define a task with an analog trigger to program the analog comparator.  Once this task is started, the exported AnalogComparisonEvent should be high when the trigger condition is met, and low when the trigger condition is not met.

Dan

[bkhan]

I have two NI PCI 6133 cards. Can I acquire 16 simultaneous channels on a single computer by using both cards? How can this be possible?

1. Should I use an RTSI synchronization to do this?

2. Should I provide same external sampling clock to both cards to do this?

Please explain.

Regards,

Bilal

[Mcdan]

bkhan,

Yes, this is possible.  You will need to use RTSI to synchronize your two devices (I'm assuming that you have a RTSI cable).  Make sure that you add a RTSI cable in Measurement and Automation Explorer, and add each of your PCI-6133s to this cable.  Once this is set up, you'll create a DAQmx task for each of your devices.  You'll want to treat each one of these devices as a synchronization master and one as a synchronization slave (for the sake of discussion, we'll assume that Dev1 is the master and Dev2 is the slave).

Set up the task for Dev1 as normal (specify your sample rate, mode, number of samples, etc).  Then when you set up the task for Dev2, you'll set it up with the same parameters, except you'll want to specify /Dev1/ai/sampleClock as the sample clock source.  The last thing you'll need to pay attention to is the order in which you start your tasks.  You'll want to start the synchronization slave task before you start your synchronization master task.  This ensures that the synchronization slave device is ready for sample clocks when the synchronization master begins to issue them.

Hope that helps,

Dan