09-07-2010 03:59 AM
Hi,
I am using a pcie-1427 framegrabber to acquire images (@10Hz so pretty slowly) using a PhotonFocus camera.
I would like to use the digital lines of the PCIe framegrabber to trigger an external stimulator, but only on a certain number of frames, not the entire acquisition. I find, in the manual it should be said that these lines are not as easy to use as basic digital I/Os.
I have seen this post about using the digital I/O:
http://forums.ni.com/t5/Machine-Vision/Output-channel-on-NI-PCIe-1427/m-p/534723
What I would like to do is :
During a 100 frame acquisition, the first 40 should provide the baseline signal (no stimulus), the next 60 should acquire the signal due to stimulation and should hence output a digital signal to the stimulator.
I could not find an easy way of starting the trigger line during the acquisition. Is this possible ? Are these lines strictly related to the image acquisition ?
If this is the case, I thought of doing a "40 frame acquisition alone" followed (as fast as possible) by a "60 frame acquisition + digital line" but this does not seem very elegant or precise.
Another way would be to use one of our small USB DAQs, but they are not very precise in their timings.
Any suggestions ?
Thanks
09-08-2010 06:57 AM
UP
Nobody used these lines to do something similar ?
09-09-2010 09:45 AM
From my understanding there are two options:
Hope this helps,
09-09-2010 03:29 PM
By modifying the GeneratePulse3.vi I managed to control the digital output exactly like I wanted. The framerate being low and the pulses being generated relative to the cameras framerate the endresult is pretty precise, at least enough for our purpose.
Thank you for your help