RT Measuring with 9220 and 9221 at different sample rates

[enricoB]

Hello,

I try to sample NI 9220 at maximum speed (100kS/s/ch) with NI 9221 (200 kS/s) and get synchronised data acquisition. What is the best solution for this problem?

[nanocyte]

Put them in independent loops each sampling at your requested rate. The data should by synchronized because both loops are being derived from the 40MHz base clock. That is, the 200kS loop should be taking a sample once every 200 clock cycles of the 40MHz clock and the 100kS look should be running once ever 400 clock cycles.

[enricoB]

Thanks for your reply. I get data with different sample rate. But there is a uncertain delay between the two different of both loops. How can I avoid this starting delay or how can I synchronize the starting data acquisition?

[enricoB · Accepted solution]

Support recommend to use User-Controlled I/O sampling for NI 9220 (with Generate I/O Sample Pulse Method) and I/O node for NI 9221. Delays can be adjusted with feedback node.