There is a bug in the management of the Discrete Mode between multiple controllers.

Issue
During a night flight with Dual Pilots utilising both Controller A and Controller B, the Discrete Mode was unable to be turned off from Controller B.  
I was using Controller B for the takeoff and return / land portion of the flight. The other pilot on Controller A had Discrete mode turned off (ie strobe should have been able to be turned on). During the flight, while he was flying on Controller A, I was able to turn them on and off to determine the drone's position from Controller B.  
On the return flight when I took control, using Controller B, the Strobe was initially off, When I attempted to turn it on, the controller displayed a message that Discrete mode would have to be turned off.  It was indeed on in the menu settings according to Controller B.  When I attempted to turn the Discrete mode off, it turned on again immediately. I tried multiple times.  I was therefore unable to enable the Strobe.  After landing, we confirmed that the Discrete Mode was off supposedly off on Controller A.  It seemed like the state machine was not functioning correctly as a consequence of the change of control.

To reproduce the bug.  

• turn on 2 controllers and the drone.
• from either controller enable Discrete mode.
• from the other controller turn off the discrete mode.
• now neither drone is able to turn the Discrete Mode off.
  

Workaround.
If you turn either of the controllers off, it seems to reset the state machine allowing you to get control of it again.


Any thoughts?

cheers
Paul

Hi there.

Sorry for the late reply.

Please note that only controller A can fully dominate the covert function of the M300RTK. Controller B can only enable the covert mode. Therefore, if you need to enable the covert mode, you can use controller A or controller B to enable it, and only use controller A to disable it.

DJI Natalia Posted at 10-17 00:04
Hi there.Sorry for the late reply.Please note that only controller A can fully dominate the covert function of the M300RTK. Controller B can only enable the covert mode. Therefore, if you need to enable the covert mode, you can use controller A or controller B to enable it, and only use controller A to disable it.

That is not right, in my tests, if you enabled it with either A, or B, then try to disable it with the other controller, then from that moment, neither A, nor B can disable it. I  have tested it again and confirmed that behaviour. You are therefore stuck flying at night with no lights and no landing light.

Just so it is completely clear:
If you turn discrete mode on with Controller A and try and turn it off with controller B, it fails, and you are no longer able to turn it off with either controller.
If you turn discrete mode on with controller B and try and turn it off with controller A, it fails, and you are no longer able to turn it off with either controller.

The only way it works is if you turn it on with A and off with A and for that to work you must not attempt to turn it off with B.


Cheers
Paul

SpeedyPhire Posted at 10-19 23:02
That is not right, in my tests, if you enabled it with either A, or B, then try to disable it with the other controller, then from that moment, neither A, nor B can disable it. I  have tested it again and confirmed that behaviour. You are therefore stuck flying at night with no lights and no landing light.

Just so it is completely clear:

Thank you for this testing and report @SpeedyPhire!

SpeedyPhire Posted at 10-19 23:02
That is not right, in my tests, if you enabled it with either A, or B, then try to disable it with the other controller, then from that moment, neither A, nor B can disable it. I  have tested it again and confirmed that behaviour. You are therefore stuck flying at night with no lights and no landing light.

Just so it is completely clear:

Thanks for your update.
Your problem has been verified. At present, there are the following problems with AB empty opening stealth mode;
1. In the case of two remote control versions, one is V3 version and the other is V4 version: The concealment function of M300 RTK is only controlled by the V4 version of the remote control. The V3 firmware remote control can only open the stealth mode. So if you need to turn on the stealth mode, both V3 and V4 remotes can be turned on, you can only use the V4 remote to trigger the shutdown.
2. When the two remote controllers are of the same version (V4 version): When the two remote controllers and the aircraft are enabled at the same time, any one of the remote controllers can only perform the opening action, but cannot be turned off.

If you upgrade to V4 where you can only fully control stealth mode in a single-control situation, please let us know and we will report back to the relevant team.

DJI Natalia Posted at 10-20 17:18
Thanks for your update.
Your problem has been verified. At present, there are the following problems with AB empty opening stealth mode;
1. In the case of two remote control versions, one is V3 version and the other is V4 version: The concealment function of M300 RTK is only controlled by the V4 version of the remote control. The V3 firmware remote control can only open the stealth mode. So if you need to turn on the stealth mode, both V3 and V4 remotes can be turned on, you can only use the V4 remote to trigger the shutdown.

My Controllers A and B are on 04.01.0101.

I have found if you just use controller A for turning on and off Discrete Mode, it works correctly.   So that becomes a task that can only be performed by Controller A when operating dual controllers.

If by mistake, Pilot B accesses the mode, then the Workaround is to shut down one of the controllers, at which point the other controller gains full control again.

cheers
Paul

SpeedyPhire Posted at 10-20 17:55
My Controllers A and B are on 04.01.0101.

I have found if you just use controller A for turning on and off Discrete Mode, it works correctly.   So that becomes a task that can only be performed by Controller A when operating dual controllers.

Thank you very much for your feedback, we will optimize the control logic of stealth mode under dual control in the future.
If there is anything else that we can help with, please feel free to let us know.
Thank you again for your support.