Hello,

I have found something that is very worrying: I am able to trigger my S900 motors to start up without using CSC input!

This is very dangerous and the S900 tried to take-off in my house while I was testing gimbal controls.

When the motors start up from being triggered this way, they are not responsive to the throttle, but I can exit this unknown "mode" by toggling from GPS to Atti mode in the same way that you can disengage from Return To Home mode.

I have an S900 with an A2 v2.5 and Futaba 14SG TX with R7008SB RX for pilot controls. The A2 X2 port is connected to R7008SB S.BUS2 port.
UPDATE #1: I found this in the A2 Quick Start Guide v1.22, "When using a remote controller alone, a Futaba T14SG remote controller is compatible. Note that 12 channels can be configured for versions below 5.0, while 14 channels can be configured for version 5.0." BUT ... my Futaba TX is v3.1, so maybe there is something strange happening with the DG1 channel from my TX as interpretted by the A2. I wil update the Futaba 14SG to v5.0 and further test.

UPDATE #2: I have upgraded my Futaba 14SG firmware to v5.0 but the problems still exists.

I also have a second R7008SB RX plugged into the Zenmuse Z15-GH4 gimbal for camera controls. The Futaba TX can pair with two RXs, effectively working like a satellite RX. (When I have a separate person operating the camera, I replace the second R7008SB with a Taranis RX.)

The Futaba RX that is connected to the Zenmuse gimbal also has an SBUS decoder, SBD4, with output #1 mapped to DG1 and output #2 mapped to DG2. But again, this RX is not connected in any way to the A2, it is only connected to the Zenmuse.

I have SBD4 output #1 plugged into the Z15-GH4 Shutter port.

On Futaba TX, DG1 is asigned to SF switch. The switch works fine in the sense that it triggers the Shutter correctly, but DG1 was also triggering "Channel 17" in the A2 Assistant channel mapping. For some reason, all the functions that should have read as "Unmapped" were all mapped to "Channel 17".
In the mock up screenshot attached to this post, you can see all the RED "Channel 17" mappings:


I have now unmapped everything that was mysteriously mapped to Channel 17.

I confirmed that toggling SF (DG1 channel) was no longer moving any channels on the A2. I looked at the Channel Mapping dialog and even went through every page of the A2 Assistant PC software to confirm.

But still... if I unplug the A2 from the Assistant software (thus re-enabling MC output) I can trigger the motors to start by flicking SF switch.

UPDATE #3: I have now noticed that when the motors start up from the SF (DG1) switch, the A2 LED blinks BLUE, indicating FailSafe Mode. So why is DG1 triggering FailSafe mode and why are the motors starting without CSC input??

Footnote: Before ugrading to v2.5, I exported all my settings. After the upgrade, I re-imported them and got an error message. I can't recall the exact wording, but it was along the lines of "not everything could be imported".

Please, can anyone offer any advice before I reset the A2 to defaults and try again?

Thanks,
Mark

Regaining control by toggling the A2 mode switch sounds an awful lot like what we autonomous fliers have to do at the end of a photogrammetry flight to disable the waypoint sequences and regain manual control. It makes no sense, but is there any way your A2 could think it's receiving a "GO" command for an autonomous mission from somewhere?

HMArnold Posted at 2015-7-3 22:32
Regaining control by toggling the A2 mode switch sounds an awful lot like what we autonomous fliers  ...

Very interesting observation!

I do in fact have the 2.4G Datalink installed. I will try disconnecting that and do a test.

No luck.

I've disconnected the 2.4G Datalink and the problem is still present.

If I have the Futaba SF switch on DG1 channel it will cause the S900 motors to spin up. Again, I can cancel this strange mode by toggling from GPS to Atti.
So... continuing along this line of thought, are there any other things that can trigger the A2 to start the motors WITHOUT CSC?

I've updated my original post at the top with this:

UPDATE #3: I have now noticed that when the motors start up from the SF (DG1) switch, the A2 LED blinks BLUE, indicating FailSafe Mode. So why is DG1 triggering FailSafe mode and why are the motors starting without CSC input??

I seem to have fixed the problem by resetting the A2 to default settings. I still need to confirm the fix at the flying field, though. On the workbench, at least, things seem to be working correctly and DG1 is no longer triggering the FailSafe Mode.

So it would seem that the problem may have been created by importing pre-v2.5 A2 settings after updating to v2.5.

Unfortunately, I cannot say whether or not this was a specific case due to my old v3.1 Futaba firmware... or something else entirely.