trigger mode

[AllanFan]

Hello, I am using Pixelink PL-B771F IEEE 1394 camera controlled by Labview 8.5 to take fast photos in black environments. The exposure time is 8 nanoseconds determined by a visible laser. A pulse generator sends external trigger signals to both laser and camera and makes them start working. The camera can also been controlled by free running trigger mode. The shutter time of the camera is set as 1000 microseconds to let the laser flash while the shutter is open. I tried both hardware and free running trigger modes. In free running trigger mode, I could get photos of a sample illuminated by the laser. However, for hardware trigger mode, photos are black. I think there is something wrong for the vi file while using hardware trigger mode. Anyone know a way to solve this problem? Thank you.

[Adam_H]

Hi Allan,

I am not familiar with the different modes of your specific camera so I am not sure what the difference is.  However from you post it sounds like it is working in free running trigger mode.  Is there a reason why you do not want to simply use this mode? 

[BruceAmmons]

8 nanoseconds is very, very fast.  I suspect the camera gets the trigger signal and starts enabling the sensor.  By the time the sensor is active, the laser pulse has already finished.

Ideally, if you want to trigger this, you would send a trigger to the camera then send a delayed trigger to the laser.  For example, trigger the camera with an exposure time of 100 nsec.  25 nsec later, send a pulse to the laser to fire.  If you could just build in a 25 nsec delay on the laser between the trigger and firing, that would also solve the problem.

Bruce