Changing AI Single Scan Loop Rates "On the Fly"

[Hans_PPPL]

Is there a way to change the Loop Rate of AI Single Scan acqisitions on the fly?

I am running a 1ms Loop continuously but need to output data after an "event". After this "event" I would like to slow the loop rate down so I can transmit the "event's" data over an ethernet connection. I can't stop scanning but can go to a slower scan rate during the data transmission.

Any ideas?

[tnewton]

Single Scan is not based on a scan rate (like from a clock), but the loop time; change the delay of the loop after the event.

If you can't change the loop time for other reasons, you'll have to put the DAQ operation in a parallel loop, and change the timing of that loop while leaving the other alone.

[Hans_PPPL]

Maybe I have it wrong but I thought AI Single Scan IS based on a scan rate as setup with the Scan Rate input of the AI Start VI.

[Chad_H]

Hans,

AI Single Scan can be used with hardware timing or software timing. If AI Config and AI Start are not used, it initiates the A/D conversion through software. When using AI Config and AI Start, you can use AI Clock Config between them to specify an external source for the scan clock. You can then change the external source on the fly. The external source could be generated by a counter.

Chad H.
Application Engineer
National Instruments
http://www.ni.com/ask