Mavlink on Pixhawk Serial 5

Hi guys,
im running the ArduCopter V3.2.1 firmware on a pixhawk board. I need a possibility to start mavlink streams on the serial 5 port of pixhawk.
In the APM Planner v2.0.15 there are only Serial 0…4 configurable.
Prefered would be a NSH command on Serial 5 like:

mavlink start -d /dev/ttyS5 -x -m custom -w
mavlink stream -d /dev/ttyS5 -s ATTITUDE -r 10

like it behaves on PX4FMU firmware.

Any ideas? Thanks in advance!

@simonegg,
I believe that Serial 5 is reserved for the debug console.
Regards,
TCIII GM

yeah i know… i would like to activate streams on the shell on serial 5. which works well on the PX4FMU firmware.

Maybe one can start the mavlink stream on serial 5 with a script on the memory card? Or maybe in the APMPlanner2?? Just cant find anything … In the config menue are only Serial 0…4 listed… :open_mouth: