I have my Turnigy 9x Radio flashed with Open9X and it is configured to be able to select 6 different Flight Modes as instructed in this post

It was requested recently "Can you can display the selected Flight Mode of the APM on Open9x main screen?" e.g Manual, Stabilize etc..  I've been trying to understand RC programming recently and this looked like a good exercise to see if I had learnt anything. 

What I understood was Flight Phases built into Open9x can be named, they can be activated by assigning them to a state of a real switch. The problem is that you cannot just check the 3 position switch to see if it's in position of ID0, ID1 or ID2 you have to cope with a modifier such as AIL or T-CUT. To solve this issue you can use internal 'custom switches' that activate based on logic rules. ie. if AIL and ID2 custom switch 6 is enabled, you can use this custom switch to enable the Flight Mode with the correct name.

The first thing I did was set-up six Custom Switches that corresponded to each combination of AIL and the 3 position switch. (i.e IDO, ID1, ID2)

e.g.

CS1 requires !AIL (not aileron) and ID0

CS2 requires !AIL and ID1 etc..

As you move the switches  you should see in bold each combination as it is actuated.

Now move to the Flight Phases Menu. Here you need to assign a switch to each phase (I assumed the default FP0 was CS1, so nothing to assign)

for FP1 press menu and then assign CS2 to switch, and name it the Flight Mode that MP tells you are in. (In my case Circle)

Also make sure that the Trims option is set to 0000 (it read RETA by default) this means that the Flight Phase copies your standard trim values from FP0. 

The screen shot below shows how i set my TX up

Notice that FBW is from CS7, this is since I amalgamated  FBW-A and FBW-B (CS5 & CS4) under the same title since they are similar and there are only 5 flight phases. That means if either are selected CS7 is enabled. (maybe a mod to Open9X is required ;-) )

Once you have all your modes programmed, check against mission planner that what you are requesting on the TX is what mode the APM will switch too.

And that's it really, a simple way to program Open9x to help remember the modes you have programmed on the switches.

Here's some screen shots of the final outcome.

Hope this is helpful; :-)