Trigger and Gate - changing stop trigger number of samples dynamically

[Technic]

Hi

I'm building a LabVIEW application (with a NI PCIe 6163) where an audio channel is monitored for random "beeps". A "beep" for example can be a single 900Hz beep for 25ms, or three 300Hz beeps for 50ms each with 10ms of silence in between beeps. Ideally I would like to somehow trigger at the start of a beep (after the signal raises above a certain level), gate for as long the beep lasts (after the signal is below a certain level) and then analyze its frequency and duration. The purpose of this application is to categorize the beeps depending of their pattern of number/frequency/duration of beeps within a certain time period.

My application is currently using the Trigger and Gate VI, which works much better than the Basic Trigger Detection VI in consistently detecting the start of the tone at the exact time of generation, however I have been unable to make my application dynamic in setting the Gate part of the Trigger for the length of the tone pulse "on the run".

Any help will be much appreciated.

[lis@jiang]

Hello Technic,

It seems like you would want to implement Analog Triggering, since your signal is pretty short, and software triggering is likely not fast enough.  Analog triggering isn't supported on all multifunction DAQ devices, however, and I believe you made a typo for the PCIe card you're using.  You can check the product specs for what type of triggering your card supports from the product page online.

Cheers,

Lisa

[Technic]

Thanks Lisa... you are correct, it is NI PCIe 6361.

I will investigate the Analog trigger method... much appreciated.