Pulse generation

[sukant77]

i am trying to generate a pulse train and later i will try to modulate it , the code generates square waves but the wait function put inside the loop functions correctly only for 5ms or higher, on removing the wait function by default the signals have a width of 5ms. i tried putting wait inside the mathscript (rt_wait(---, 'mSec');) but getting same result . i'm working on PXIe8133 and card is PXI6733 , i read their specs and it should support higher i/o read-write rate . please help to resolve this issue.

[Bob_Schor]

What you really want is a Counter-Timer module for your PXIe-8133.  There probably is one already on the instrument to provide the timing signals for your analog DAQ cards.  Counter-Timers provide ways to deliver digital (0v = low, 5v = high) pulses with high time precision and accuracy (far better than you can obtain with Wait functions).  What are the other cards in your PXIe box?

Bob Schor

[sukant77]

well , the other cards available are PXIe6363 and PXI 7853r .....we don't have a timer...i'm an undergrad student and recently started working in a lab and i'm tasked to generate and control a pulse train for controlling lasers , i was told a previous student could do what i'm trying without and other hardware.. 

[sukant77]

can't it be done without a counter , there are 2 more cards available pxi6289 and pxi6722 , i'm using scb-68 i/o connecter block....

i would really appreciate if someone can help me by providing useful links or any sample vi  for pulse wave generation using DAQ

[Kevin_Price · Accepted solution]

Open MAX, explore test panels for your cards, and you'll find that you *do* have boards with counter/timers that can generate pulse trains.  I can recognize that at least the 6363 and 6289 are capable, and probably the 6722 as well.

You can also explore the shipping examples in LabVIEW to find an example of how to write code to create pulse trains using the DAQmx driver API.

-Kevin P