Trigger problems

[nikk]

Hello everyone,

we want to trigger on a flashing LED which is activated by a TTL Signal (1 Hz, 1ms pulse width). The same TTL signal goes into our framegrabber card (NI PCI-1428) and starts the trigger for our camera (firm: SVS-Vistek; model: SVS204MFCL). The camera modus is "triggered internal exposure control" ("triggered external exposure control" doesn't work either) and the problem is, that we don't get an image of our LED in the state of on/lighting (every pulse) until we change the shutter speed to ~23 ms and above, this happens wether we trigger on the rising or falling edge. I know this problem sounds strange but i hope somebody has any clues where our fault is.

thanks for all coming comments so far and for further details just ask.

[BruceAmmons]

Any idea what your LED circuit response time is?  It sounds like it takes about 23 msec for the LED to turn on after receiving the TTL pulse.

Bruce

[nikk]

Our LED has a 90 ns speed of response which is stated in the data sheet. I think it has to do with our camera file, the camera has 2 modes of trigger signals (TTL and LVDS). However, the default seems to be LVDS and you can't change this value with Labview, because there is no attribute for it in the camera file, we can just change it with a software tool that came with the camera but everytime we start again Labview, it seems to reset it to default and theres no chance in turning it back to TTL.

[nikk]

Well i got something wrong out of the camera manual LVDS means only that you trigger the camera through your framegrabber card via camera link, so i think the problem doesnt has to do with this.

[nikk]

After triggering our Camera directly and getting those triggered images with "freerunning" modus in Labview, they get the led in the right time, so its a problem of Labview, the 1428 and the triggering on the framegrabber card or maybe something with cameralink, hope someone still reads this thread an can help us out of this problem.