PXI-6551 controlling the delay for triggered generation

[ajog]

Hello,

For externally triggered generation using the 6551, I notice a time delay between the rising edge of the trigger signal to when the waveform is actually generated.

The trigger is on PFI1 and generation begins on Channel DIO 8.

If the sample clock frequency is increased, this delay reduces but is still of the order of 1us for 50MHz sample clock.

Is this to be expected?

Am I doing something wrong?

Is this delay repeatable? - I notice some variability.

Please advise.

Thanks.

Anand

[DJ_L.]

Hey Anand,

The delay you are seeing is expected. If you look in the 655x Specifications document, you will find a section on Triggers. In this section there is a spec called "Delay from trigger to digital data output". For the 655x this spec is 32 Sample Clock Periods + 160 ns. Which is why you are seeing the delay decrease when you increase your sample clock frequency. This delay should be fairly repeatable, depending on when the 655x detects the trigger. How much variability are you seeing? Hope this helps. Please let us know if you have any further questions or concerns. Thanks, and have a great day.

Regards,

DJ L.

[ajog]

Thanks DJ L,

That was indeed very helpful.

Best Regards

Anand