Share trigger between PXIe-7972R and PXI-4461 on PXIe-1071 chassis

[centrums.ni]

Hi All,

We are using the PXIe-1071 chassis and PXIe-8840 controller, containing 2 modules:

- NI PXIe-7972R connected to NI 5791

- NI PXI-4461

We would like to share trigger between them, either from 7972R to 4461 or vice versa. Since we want to send signal from both module at the same time. How do we accomplish that?

Thanks,

Ahmad,

Centrums ITB

[Jacobson-ni]

Are both of these cards going to synchronize on the same trigger source or are you trying to get one card to trigger the other? If they are both triggering from the same source, can you describe what the trigger is and where that signal is coming from?

[centrums.ni]

Hi Jacobson,

Thank you for your reply,

We are going to get one card (either 7972R or 4461) to trigger another card. The main goal is to generate two signal from those cards at the same time.

Best Regards,

Ahmad

Centrums ITB

[Jacobson-ni]

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@centrums.ni@centrums.ni wrote:

The main goal is to generate two signal from those cards at the same time.

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If that is the case it sounds like you would rather want a single event, external to both devices, trigger the start of generation. Can you explain more of what the start condition of generation is (software button press, some incoming digital signal, etc.)? Can you also let me know what other modules you have in your PXI chassis?

[centrums.ni]

Yes, the goal is to generate two different signal from two cards using one common/shared trigger, for example a software button press.

For now, in our PXIe-1071 chassis, we have two PXIe-7972R and one PXI-4461.

[centrums.ni]

Hi Jacobson,

We read the NI PXI-4461 specifications file (link: http://www.ni.com/pdf/manuals/373770j.pdf), it shows that it can use digital trigger source from PFI0, PXI_Trig<0..6>.

Is it possible to share PXI_Trig from 7972R to 4461 using one PXI_Trig?

[Jacobson-ni]

You can have both devices trigger off of one of the PXI_Trig lines. For the 4461, you will need to use the DAQmx API to set the start trigger source as the trigger line. The FlexRIO is a bit more manual but basically you can just read the trigger line as you would any other digital input so you would just need to look for a rising edge and then use that condition to begin operation.