Issue:
Can I externally trigger my Dragonfly camera even with multiple cameras on the bus?

Solution:
Yes, PGR’s FlyCapture software allows you to trigger a Dragonfly camera externally, even with multiple cameras on the bus. Note: the cameras automatically synchronize to each other in free running mode. If you currently have two cameras installed and working you can test the ability to trigger them individually by doing the following:

1. Open two instances of PGR Flycap (Programs > Point Grey Research > PGR FlyCapture > flycap.exe), selecting a different camera for each instance.
   
2. Start grabbing frames on each camera (press the green stop sign icon).
   
3. Open the Camera Control dialog (F11) for one camera, and select the Extended tab.
   
4. Check the External Trigger Mode check box.
   
5. Enter register value 102C (SOFT_ASYNC_TRIGGER), then Get Register.
   
6. To generate a trigger, replace the "1" value in bits 24-31 with "0" i.e. bit 31 = 0. You should see a new frame grabbed. To take multiple images and save each image i.e. to use the Dragonfly like a regular still picture camera, simply uncheck then check the External Trigger Mode box each time you want to take a new picture.

Related Articles:
1.) Hooking a standard Black Burst generator to the external trigger pin on a Dragonfly camera
2.) Dragonfly timing characteristics (integration and shutter times).
3.) How to use the Scorpion general purpose input / output (GPIO) pins.
4.) Maximum frame rate possible in asynchronous (external trigger) mode.