Master mode: In Master Mode, the camera is free running and the internal 10MHz GPS synced clock will measure and record the shutter’s opening and closing time.
Slave mode: In Slave Mode you can input a target start time and the interval period for two frames. For example: You want three cameras in different locations (maybe thousands of kilometers apart) to start an exposure at 2016.3.9.UTC 14:00:00.000000 and then to continue with exposures at the interval time of 0.100000 sec. After you input these value, all the three cameras will wait until this time and then simultaneously start video recording, e.g.:
2016.3.9 UTC 14:00:00.000033
2016.3.9 UTC 14:00:00.100033
2016.3.9 UTC 14:00:00.200033
2016.3.9 UTC 14:00:00.300033
(The 0.00033 is a global delay of the CMOS shutter).
The time stamp and other GPS information is embedded into the image. The software decodes it in real time and displays the information on left. Since the data is embedded, it will never be lost so long as you keep the original image.