PXIe-6124

[Santorro]

Hi,

is it possible to use an external clock for the PXIe-6124 and use a delay trigger to start the acquisition?

Any help is appreciated.

Thank you.

Santorro

[Nick-C]

Santorro,

From Page 4-14 of the Users Manual - AI Sample Clock Signal

You can specify an internal or external source for AI Sample Clock. You
also can specify whether the measurement sample begins on the rising edge
or falling edge of AI Sample Clock.

Using an External Source
Use one of the following external signals as the source of AI Sample Clock:
• PFI <0..15>
• RTSI <0..7>
• PXI_STAR
• Analog Comparison Event (an analog trigger)

Chapter 11 of the users manual details more information about triggering, both Analog and Digital are supported on this device. If you would like to setup a Start Trigger with a delay, this is absolutely possible.

-Nick-

[Santorro]

Hi Nick,

could you explain why I'm getting this error:

Start trigger delay is not available when an external sample clock source is specified

Here is the VI of what I'm trying to do.

Thank you.

Regards,

Santorro

[Nick-C]

Santorro,

The error indicates that the device you are using does not support the simultaneous use of those properties. The start delay references the sample clock on the device, not the external clock. I hadn't considered this when I answered your original post. I will look around for another potential solution since this architecture will not work for you.

-Nick-

[Nick-C]

Santorro,

Have you considered taking your external clock and tying it to the source of one of your onboard counters? You might then be able to use this counter as your "internal" sample clock and thus have access to the start trigger delay property. I've never tried this method, but so long as your external clock frequency does not exceed that of the counters you should be able to implement by trying this. Let me know if this works.

-Nick-

[Santorro]

Hi Nick,

finally, I will use a second signal from my setup to act as a trigger.  I'm using a delay generator (Quantum composer) and communicate via RS232 to create the delay  

It works the way I want but I will have a look to your solution.  In the end I don't want to use a delay generator.

Thanks

Regards,

Santorro

[Nick-C]

Santorro,

Glad to hear that you have found a solution. If you have any other questions as you are implementing, please don't hesitate to start a new thread. Our customer community can be very helpful!

-Nick-