Triggered single pulse width measurement

[kayotik0987]

I am trying to measure the width of a single pulse, but would like to use the pulse itself as the trigger for a counter input pulse width read using a PXI-6608.  I would like to do this since the pulse can come at any time (much longer than any practical timeout)  and I would like to avoid having to place a DAQmx read in a while loop waiting for the pulse to appear.  Also, while the pulse is high, I would like to produce front panel feedback (light a boolean indicator).  I seem to be able to achieve that by using a digital input line, but again requires a DAQmx read in a while loop.  I haven't had much experience with triggers and my attempts so far appear to seem like triggers are not compatible with counter input pulse width measurement.  Is it possible to set up a trigger for a pulse width measurement?

[ColdenR]

Hello kayotik,

I think the best thing to do here is to use separate while loops. You can put most of your code in a main while loop, and then put your DAQmx read in a separate while loop. Both loops can run in parallel (just don't wire any outputs of one while loop to the other while loop, because then one will become dependant on the other). In order to pass data between the two loops, you will need to use a local variable. The DAQmx read can write to a local variable, and the main loop can read from that local variable. 

You will also need to stop both loops with a single stop button. This article shows how (and also demonstrates the use of local variables to pass data between independent while loops):

http://digital.ni.com/public.nsf/allkb/267704CDE91156D186256F6D00711AAE