Using a DAQ trigger to activate TDMS

[ntsirak1]

Hello,

I wish to activate TDMS once a certain condition is met. Rather than using a boolean operation, however, I would like to use a digital trigger so I can gather some pre-trigger samples in my data. Is this possible? Thanks,

ntsirak1

[mikeporter]

So you want to start logging to a TDMS file when a digital input bit on a DIO board goes active? It is possible to create an event that will trigger in that situation. Although I have never done it, I think you can trigger the event on an analog level as well.

Mike...

[ntsirak1]

Yes, but I want the TDMS data to contain the pre-trigger samples as well. The data is also being continuously acquired in the background; I only want it to capture to TDMS at a certain point. Sadly, I think I'm going to need two DAQs. One to continuously capture, the other to trigger the TDMS.

[mikeporter]

Not necessarily, as you acquire data buffer the current data as well as the previous N samples, Then when the tdms trigger occurs, dump the entire contents of the buffer into the file and start adding new data as it comes in.

Mike...