Hello,
I am using Canon Elura Camcorder (29.97fps) and PCI-1411 to acquire image, also use PCI-6023E to do DAQmx.
I hope to synchronize IMAQ and DAQmx so that each time an image is acquired a DAQmx data is also simultaneously acquired.
Since PCI-1411 does not have RITS connector, I have to use the only trigger line on the PCI-1411.
I first tried to use DAQ board to generate a pulse train, which is used to trigger both DAQmx and IMAQ, and I got correct DAQmx frequency, but there are always missing frame of images. After reading the
this post, I know the reason of the problem:
The analog camera you have is constantly sending
images to the board, and if you are triggering the 1411, you are really
just telling your program when to acquire an image, and this is not a
hardware triggered acquisition. Since the camera is constantly sending
images, and you trigger at a certain frequency, you might be triggering
at a time when a frame is currently being sent to the board, and you
have to wait for that frame to finish sending its signal before you can
acquire the next frame. This in turn is slowing down the images that
you are acquiring. So you are doing more of a software triggering, and
this is causing you to miss frames that are being sent to the frame
grabber.
So, I gave up this approach.Then I turn to an alternative approach: let IMAQ sending triggering signal to DAQmx. Since PCI-1411 does not support IMAQ Generate Pulse3 VI, I have to use IMAQ Trigger Diver2 VI. However, the problem of Trigger Drive2 VI is, it does not generate a pulse train. For example, if I set 'True high' and 'Frame start' to this VI, at the start of each frame, this VI just write 'high' to the digital line, so the digital output is always 'high' instead of pulse train, therefore can not drive DAQmx.
So, is there anyone who can give me some advise to create pulse train to drive DAQmx? Specifically, how to invert the digital status to 'low' before the start of next frame?
Thanks a lot for your advise.
Best,
Dejun
Message Edited by Dejun on 09-18-2007 09:51 AM
