This question applies to the legacy Photon camera models. The Photon product line and its accessories have been discontinued. The information here is provided for historical reference. Photon was designed to accept a 3-Volt signal and send a 3-Volt signal, so one Photon can drive one or more Photons in slave mode. There are serial commands to designate a Photon as the master or slave camera.
Photon provides the capability to synchronize the frame start sequence using an external input. The camera completes the frame sequence using internal timing and then waits for the synchronization pulse before starting the next frame. If the sync pulse rate exceeds the maximum FPA frame rate (nominally 30Hz), sync pulses will be ignored and there will be frames dropped from the stream. (Note: this will result in lost data). While operating in slave mode, the analog video output signal is dependent upon the input frame sync rate for compliance with video standards.
Slave mode in slow video mode cameras continues to require an external sync pulse at the nominal 30Hz/ 25Hz frame rate. Digital output frame rate and analog video update rate are both at one fourth the input external frame sync rate independent of video modes (NTSC/PAL).