Trigger USB 4432

[jonas5647]

Hello,
My Experiment consists of speakers and eight PCB106-B sensors. I use two USB 4432 simultaneously and want to trigger them at the same time. I need 4 of the 5 channels of each device to measure pressure signal. The last input channel of each I want to use as a trigger. But this didn't work correct yet. It is always phase shifted betweeen the two devices. I tried to trigger with one sensor not in use and a cable that is splitted into two directions to trigger both devices. Why doesnt it work? What other possibilities do I have to trigger simultaneously? 
Greetings Jonas 

[GerdW]

Hi Jonas,

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@jonas5647 wrote:

My Experiment consists of speakers and eight PCB106-B sensors. I use two USB 4432 simultaneously and want to trigger them at the same time. I need 4 of the 5 channels of each device to measure pressure signal. The last input channel of each I want to use as a trigger. But this didn't work correct yet.

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It seems you still work on the same issue…

What have you tried so far? Mind to attach your VI?

How did you setup the trigger(s)?

[jonas5647]

Hello Gerd,

thanks for your fast answer. I thought I managed my problem, but I recognized my two devices don't measure simultaneously. here is the VI of the first device: 

Here I want to trigger with the first pressure sensor.

Then I have a splitted cable that goes from the same sensor signal to the last input of device 2. The VI looks like:

I already tried a few other things like the before mentioned unused sensor which also gets a high pressure signal. For that I tried to trigger on both devices with the last input channel. That didn't work as well 😞

I also have adapters to use the digital I/O & PFI but I don't know how this one works.

[GerdW]

Hi Jonas,

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@jonas5647 wrote:

here is the VI of the first device: 

I also have adapters to use the digital I/O & PFI but I don't know how this one works.

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There is no VI, there are just some images showing some (but not all) details of those DAQAssistent ExpressVIs. And there are too many ExpressVIs IMHO…

Which kind of "adapters for digital IO" do you have?

In my opinion it would be easier to trigger using a PFI - I never had the need to trigger using an AI channel…

[jonas5647]

Hello Gerd,

I use the attached VIs. 

These are my USB-Devices: 

All the blue cables are my sensors and the one with the big black cable should be for triggering. I have no experience triggering with PFI. How does this work?

Best regards

Jonas 

[GerdW]

Hallo Jonas,

you really should cleanup your VI to improve the readability and maintainability!

Now the block diagram even fits into a FullHD screen…

(You should rework the path building by using BuildPath and path controls!)

On your DAQAssistents:

• One DAQAssistent is set to use Sensor PCB_19145 as trigger source, the other is set to TRIGSensor!?
• The TRIGSensor is set to voltage range of ±40V (without custom scale!), but the trigger level is set to 50µV. Are these the correct and required values?

To learn about using PFIs for triggering you should (re)visit the DAQmx example VIs in the example finder…