WHY TWO 9-PIN EXT PORTS?
To put it briefly, flexibility and reliability.
One port connects to the camera, the other can be used for many functions: Control, Run/Stop, Timecode, or Genlock!
For example Control is useful for devices like a SmallHD Smart Monitor or wired control with RCP Translator.
The 9-Pin 0B Lemo socket is also more robust than a 4-Pin 00 CTRL port found on DSMC2. The small 00 connectors are notorious for breaking on set!