6259 Analog input precision

[Popo]

Hello,

I 'm using for the first time a USB 6259 DAQ.

I made the acquisition of further analog signal triggered by an analog signal with the Vi express.

Sample rate = 40k

number of sample  = 1600

I should have a 25µs precision measurement over 40ms time measurement.Right?

If I compare my acquired results with a scope I can have a delta higher than 0.1 ms .

how can I improve the precision of my acquisition?

Why I cannot  do the same with a 100K sample rate with 4000 points.Is it due to the buffer size's limitation?.

Thanks for your help

Philippe

[jp_Braud]

Hello Popo,

There is a sub-VI in your project named "untitled" that isn't included into it. I can't see anything bad in your diagram, so I think the problem should be into this sub-VI.

Another thing you could try is to put a "wait until next ms multiple" inside your while loop...

Best Regards,