controling a while loop with external trigger

[Airmag]

I am new to LabView and am trying to put together a VI for a hurry up project. I currently have a VI that works quite well for me using a traditional DAQ card that connot be configured as a DAQmx. The VI reads AI channels using the AI ONE PT Vi, charts the samples and streams them to disk. I currently use the wait ms function to controle loop speed. My problem is this will be a airborn DAQ system and I need to synchronize this with a ground based DAQ system and the only way to do this is to use a Pulses Per Second signal from a GPS unit. My VI sees this pulse just fine. Now how do I get it to control the loop? Please help, I am up against a time limit and the lack of sleep is getting to me.

Thanks

[Jesse_O]

If you need to synchronize the data acquisition based upon a GPS signal that you read into LabVIEW, you could use the user defined event feature in LabVIEW. A good example called Programmatically Fire Events can be found in LabVIEW's example finder.  It demonstrates how to setup, fire and execute events.   You would need to setup a user defined event, and generate the event every time you get the pulse per second signal.  If you generate this event on both machines, they should be executed approximately at the same time.  There are some limitations with synchronizing based upon software events.  How close the two systems perform their data acquisition will also depend on how close in time they receive and process the pulse from the GPS signal.

Regards,

Jesse O.
Application Engineering
National Instruments