COMMAND_ACK - result: 4 --- how to debug

Hi All,

How do we debug “result: 4” acks from Pixhawk2.4.8 for a Mavlink command.

My setup is the following:

Frame: QUAD
Pixhawk1 002C001A 3337510D 31313639
ChibiOS: 57801550
ArduCopter V3.7-dev (1c3d90d8)

I am using a Pixhawk 2.4.8 with a RPi3b as a companion computer. Mission planner is 1.3.59

My command on the companion computer is the following: --master=/dev/ttyAMA0 --baudrate 57600 --out=udpin:

I would like to understand why the “result: 4” shows up for my takeoff 15 command. I set moddebug to 3 hoping to get some explicit messages along with result: 4.

ALT_HOLD> set moddebug
ALT_HOLD> moddebug 3

ALT_HOLD> arm throttle
ALT_HOLD> Got MAVLink msg: COMMAND_ACK {command : 400, result : 0}
Arming checks disabled

ALT_HOLD> takeoff 15
ALT_HOLD> Take Off started
Got MAVLink msg: COMMAND_ACK {command : 22, result : 4}

1 Like

Hi dronetail,
Did you find a solution? I am facing the exact same problem…

hi did u found something i have the same problem here i don-t know what to do next I want to graduate before 10 of may 2019 help please

Facing the same problem mate!
Any idea on what the result codes mean?

Why not read the mavlink documentation?
if you do so you can find out that the ACK:4 means NOT_SUPPORTED (
Which is quite understandable since in ALT_HOLD mode you cannot issue Takeoff command.
The correct way to do it is to switch to GUIDED mode than arm and issue takeoff…