The LED_Mode parameter is missing from the standard params list where this article indicates it should be:
copter.ardupilot.com/wiki/nav-leds/
It can be found in the full params list, however it has no description nor an explination of what the settings mean. The default setting of 9 means that the beeper and the motor LEDs are enabled. This also means that A9 which is required for camera control does not control the camera, it outputs a 60% duty cycle signal making your camera continually take images.
To enable camera functionality on APM2 A9 set the LED_Mode to 8 which enables the beeper but not the motor LEDs. For the rest of the settings you can look at the blog post here:
diydrones.com/profiles/blogs/add … 2#comments
Can someone update either the manual, mission planner, or both please? I ended up spending a few hours on this issue already.