sound triggering on PCI-6023E

[ckessler]

I am using a PCI-6023E card. I wish to use a sound signal to trigger the data acquisition. Since it has only external digital triggering, my best guess is to run a sub-VI that reads the microphone channel and then sends a digital output to the external trigger channel. Any better suggestions? Any comments on the brain-drain effects of this on my buffered data (while waiting for the trigger event)?

thanks

[Steven B]

Hello,

Depending on the level of the sound signal that you will be receiving, doing an analog input and then in software determining if the level if your signal is high enough would be your best option if the sound signal you are receiving is not a TTL signal. But, as far as then generating a digital output that then triggers the analog input externally doesn't seem to be needed. If you are producing a software signal to trigger something anyway, you may as well just start the analog acquisition in software once your subvi has determined it is time instead of generating a digital output that then hardware triggers the acquisition.

Regards,
Steven B.
National Instruments

[ckessler]

Thanks for your answer. At first, I though that I was pretty dense for not thinking of it myself, but now I can't figure out how to make it work. I'm using the AI_config to set the trigger type and AI_read for pre-trigger scans etc. What sort of trigger type can I use to represent the microphone input from my sound card? Also, I will eventually need a TTL output to start a high speed camera at the same time.

regards,
ckessler