Nasty problem in pre arm: duplicate aux switch options

dear XX, to our total surprise we got this message:

PreArm: Duplicate Aux Switch Options

We have the chan 6 to 8 all do nothing (in extended tuning) and these channels are all in 0 in the full parameter list. It unfortunately stops us from arming! Do not have any clue on the issue?

Best Winfried

It took me ages to work this out, it’s to do with the servo function options in all parameters conflicting

There are more channels than 6 to 8 :slight_smile: Check in the full parameters list the CHX_OPT values (with X from 7 to 12).

@George_Muirhead If you were seeing that message it couldn’t be about servo functions. You are allowed to set the same function to multiple outputs.

I’ll check when I get home. But I had to do a full reset then set one thing at a time to figure out what the conflict was.

yea your right it was the channel options, it was conflicting with the gimbal channel selection. although i had disabled the servo gimbal the channels were still assigned.

Dear George and Francisco, highly appreciated! It works yesterday did a sonar system on the V shape on the WP flights, and indeed worked neat, today first test flight with 3 m size. Worked perfectly. Highly appreciated guys!

Best, Winfried


Wow, that is quite a vehicle!

Hello, I’m running into this same issue. I have programmed Channels 9, 10, and 11 for aux functions (moving servos and such). I am now getting the “PreArm Duplicate Aux Switch Options” error. Any idea how I can fix this?

Thank you!

You should only see this if you have the same aux function assigned to
multiple channels. Please check your RCn_OPTION parameters are all


OK I will take a look thanks