09-24-2010 11:49 AM
dear all,
i am using a CoolSnap HQ camera with a sony ICX285 interline CCD.
I would like to read out the first pixel line just above the serial register (so the ROI is: [0, 1391, 0, 1]) at a high frame rate (1ms expo, 2ms wait before next frame).
We have an old software (without sourcecode), that is able to perform this, as we can see from the logs taken from the camera expo and readout TTL output signals.
The problem is that we can't find a configuration for the camera to do the same at the same frame rate in our own code.
We wrote a code (C + PVCAM 2.6) that instructs the camera to wait for a TTL Trigger (bulb signal) and read out the line we need (and of course sets up other camera parameters that we beleive to be appropriate). The camera receives the high TTL signal, start the 1ms exposure, finishes OK after 1 ms (our TTL trigger now goes to low), after a few microseconds, read out begins (the line we need is just above the serial register, so its fast), readout also finishes after a few microsecs, and then, (after ~1ms) when receiving the new trigger signal from the NIdaq card, it simply refuses to start the new exposure and the new readout. It waits 14-15 ms after every succesfull readout before reacting to the next trigger signal.
So, we the old software, it looks like this: EXPO(1ms)->~100microsecs->READOUT(~100 microsecs)->~1ms->EXPO........
With ours, its: EXPO(1ms)->~100microsecs->READOUT(~100 microsecs)->ignoring TTL for about 14ms->EXPO......
So basically our frame rate is tha same as if we were reading out the topmost pixel line, the furthest from the serial register.
The reason for this seems to be, that we are unable to tell the camera to stop pulling lines down from the CCD into the serial register after the first line is read out, and enter IDLE state and "listen" for the next bulb.
What are we missing ? Thank you in advance
Laszlo
09-29-2010 09:43 AM
Dear Laszlo,
I might lost you reading the post, but can you please tell me which NI software or hardware component did you use in this application?
Is it a question about the algorithm you developed? Is there anything specific we can help you with?
Thanks!
Kind regards,
Matyas