Excessive datalogging delay

[uil89]

Hi guys,

I'm having the following problem with NXG and cDAQ9189; I'm acquiring analog and digital input at 1000 Hz, analog for 300 s, digital for 5 s, 1 s pretrigger.

I've done 10 tests and everything worked fine but in the past few days I'm experiencing some problems: data acquisition is shifted around 30 s (both digital and analog) so i'm missing pieces; it's like NXG is saving data before the trigger or some buffer.

Funny thing this is happening only when I run real test, if I run a "blank" test everything seems fine.

I'm attacching correct (blank test) and uncorrect (real test) behaviour along with code.

thanks

[fblerg]

Hi uil89,

A couple thoughts:

• Can you confirm the digital trigger is happening on PFI0 when it should be?
• The two Start tasks don't have direct execution ordering, and maybe this is some sort of race condition (one task is configured and starts first, while the other task is still being configured). You could use error wires between the two Start task to enforce execution order. Example (clean- up your block diagram and then use Retain First Error): 

Thanks,

Frank