Hello Forum Members,
I'm something of a greenhorn when it comes to DAQ programming and would appreciate your help. I am essentially trying to do time correlated single photon spectroscopy with a Perkin Elmer SPCM-AQR photon dector module and a a 6321 X series DAQ card. I am exciting a sample with a laser and would like to obtain an accurate timestamp of the first photon detected after shutting down the laser. I intend to repeat the measurement to build up a histogram from which I can obtain the lifetime of my sample (~1 micosecond).
I started with a program (SimpleTimeStamping_v2) from an earlier thread:
http://forums.ni.com/t5/Counter-Timer/Photon-Counting-Time-Stamping-and-basic-help-with-how-DAQmx/td...
After a recieving a digital trigger it counts all the subsequent photons and accurately gives them timestamps. In my modified version (SimpleTimeStamping_mod) I would like the prgram, after recieving a digital trigger i.e. the falling edge of the signal that shuts down the laser, to count and timestamp the first photon signal and then be ready to recieve another trigger signal to repeat the measurement. In order words, it has to be retriggerable.
I read that this kind of retriggering required a work around with M series cards:
http://forums.ni.com/t5/Counter-Timer/start-a-counter-with-digital-trigger/m-p/3254895/highlight/tru...
Does anyone know about X series cards? If they could start me off on the right programming track I would be very grateful.
Regards,
R
