Hi Eule. The best approach for acquiring from 2 cameras simlutanously is to trigger them both at the same time. Any software solution would introduce a timing jitter between the active edges that start of the exposure. Especially if the images of the cameras are intended to analyse 1 scene of a moving object I would insist in a hardware trigger for both.
A "software trigger" might work like this:
(1) Create a polling loop that checks if camera 1 says "Acquisition in Progress". (Not very clever because the polling loop will introduce a good amount of traffic on the bus to the camera.)
(2) Once camera 1 says "Acquisition in Progress" -> start camera 2.
I would not like the softwre solution and still prefer the trigger cabling to both cameras and use hardware triggering for both.
Hope this helps, Guenter