Hi All,
I am trying to write this VI that acquires analog input signals continuously until the user hits the "trigger" button. At that moment, the VI will save X number of pretriggered samples and issue a TTL signal at the same time to one of the digital output lines to trigger another device. I also want to display the analog input signal in realtime so that the user can decide when to trigger. I have ended up with the VI in the attachment.
However, it seems there is an unknown delay between when the "trigger" button is pressed and when the digital output TTL is issued. I have the acquisition run in a while loop until the user hits the trigger button, then the operation will exit the while loop and issue the TTL. I wonder if this is an inefficient way of doing things, and would like to ask if anyone has a better idea to do this task. Alternatively, if there is a way to know the precise delay between the timing of the last pre-triggered sample and the time the TTL is issued, it would be OK too.
Thank you very much!!!
