View Full Version : Digital Cameras and External Trigger

November 19, 2004, 13:47:19

Some digital cameras compatible with the IC library have an external trigger that starts the camera integrating a frame of video.

My question is, what happens when the external trigger signal is not there? In other words, what is there on the firewire connection between the camera and the PC? Also, how will the IC library respond to this condition?



Stefan Geissler
November 19, 2004, 14:06:11

Nothing happens. The camera waits for the trigger signal, IC Imaging Controls waits for the next frame sent by the camera.

The trigger is enabled in the camera by IC Imaging Control. The video format and frame rate is set. Startlive() has been called. Now the bandwidth on the FireWire bus is allocated in the same way, as if the camera is running free and delivering a live video stream.
This means: You can not connect as many cameras as wanted (e.g. 20) to one FireWire bus with biggest video format, even if the cameras are external triggered. (I write this, because many people believe, there is no bandwidth allocated, if the camera has no trigger signal.)