Data Triggering (and re-triggering)

[currentenglish]

Hello all,

I'd like to start off that I'm new to Labview, so I may not understand some basic concepts. I am using an NI cDAQ-9172 system with a NI 9215 card installed.

My experiment involves receiving two signals, one as a reference signal used as a time (trigger) reference, and the other the actual signal of interest. I wish to create a program that will allow me to monitor the reference signal until a specific condition is met (a minimum slope change, or a minimum % slope change - I am not sure what will be most robust at this point), after which the program will immediately begin saving a set number of data points of both signals to disk. After this, the program will continue to monitor the signal until the trigger is again found, and place this new data in a new column/row of the file. This process should continue until the user manually stops the program.

I was wondering if anybody could help me with solving this problem, or point to me a good example to work from. I've looked at many of the NI Examples with the keyword "trigger" or "triggering" in it, but have not found anything that seems to suit my needs. Additionally, I mentioned a few possible trigger options for my reference signal. A problem is that my trigger signal will have noise in it. Is it also possible to manually program trigger criteria?

If there needs to be any clarifications, please let me know.

Thank you. 

[Josh_L1]

Hi currentenglish,

I would say the first place you want to check out is the "find example" option under "help". LabVIEW contains a large library of shipping examples. They will give you a good understanding of how DAQmx works. The DAQmx examples are located in Hardware/Input and Output - DAQmx.

I've also included a few links below to give you some more information. I apologize if you've already seen some of them.

http://zone.ni.com/devzone/cda/tut/p/id/3216

http://zone.ni.com/devzone/cda/tut/p/id/11369

http://zone.ni.com/devzone/cda/tut/p/id/4329

I hope this helps.

Josh L. 

[currentenglish]

Thank you, Josh.

I will look into this and see what I can come up with.