Problem: I have to solve the sequence: Silent and continuous run;operation when the trigger occur; sleeping acquisition when condition requested are satisfied (requisted scans collected)

[Giulia]

My acquisition VI should go running for ever and collect data only when a trigger occur. The attachment is the working VI. How can I add a continuous run?

[Dennis_Knutson]

Do you need anything more than a while loop around AI Read and your processing code? Look at any of the shipping examples with Cont Acq as a prefix.

[Giulia]

Thank u for your attention. I have already tried adding a while loop. It doesn't work. It continues doing just one data collection. I tried ContAcq VI, but these example don't produce a "silent" acquisition: when I add a "write data to file" processing, they write down everything, not only the number of scans requested after each trigger. Have you got some other suggestion?

[Adam_U]

You will also need to change the "number of scans to acquire" input into "AI Start" to 0 (for continuous acquisition). National Instruments has some excellent examples to do what you are looking for. Look at the "Find examples" under the help menu in LabVIEW 6.1 or 7.0 for the DAQ VIs. One VI I think is close to your application is named "Cont Acq&Graph (buffered) D-Trig.vi".

I have attached a copy of the example downconverted from 7.0 to 6.1 for your convenience.