fast AI-acquisition after DI-trigger signal

[mschoeff]

Hi everyone,

the job of the VI I'm working on is basically very simple:

there are 8 analog input channels that need to be read out after a digital input-trigger.

The parameters: sampling rate per channel: 2MS/s, # of samples per channel: 1024

This acquisition is repeated very often (1000x +). So I put the trigger and the read-out part inside a while loop. Initializing the task happens before this loop and the task is closed afterwards.

The problem I suffer from is execution speed! The acquisition itself (1024 Samples/channel at 2MS/s/channel) should (in theory) be done within ~0.5ms but actually takes longer...

My aim is to do the process: triggering->acquisition in 2ms. Currently, it runs reliable with a repetition rate of ~15ms

Do you guys know any way to increase the speed? I played around with manually setting buffer size and initializing a dedicated task for the trigger itself. Both did not improve it.

The DAQ-devices i'm working on is USB6366 and a PXIe system with a PXIe6368 inside.

I really don't know where in this quite simple line the time is lost..

Kind regards and thank you,

Michael

[Duffy2007 · Accepted solution]

Hello mschoeff,

if i understand you correct you want to retrigger the aquisition. Then you have to

configure the trigger outside the while loop and use the property node to enable retriggering.

Here is an explanation:

Retriggerable Task Support on X Series Multifunction DAQ Boards

Hope it helps

[Duffy2007 · Accepted solution]

Hello mschoeff,

like this

[mschoeff]

Thank you so much, Alexander.

Everything is working as it should!

Execution speed is perfect!!!!!

Best regards,

Michael