Regarding signal, when you set up your master controller you have to pair it to the aircraft (yes?)
When you set up you slave controller you pair it to the master controller (yes?)
When the slave is paired with the master it receives a link to control the camera & gimbal from the master, this link also gives the necessary information so the the video receiver in the slave can receive the video signal from the aircrat so the slave is never paired to the aircraft but does get to the video feed.
Image below from another topic in this forum (INSPIRE 1 How to set master and slave RC
INSPIRE 1 How to set master and slave RC )
View attachment 15777
Yep....agree with everything you asserted here. Through experimentation I have not only confirmed everything you purported here, but I'd like to add something important.
As you are aware, the master controller is in charge of video channel switching. As I'm sure you're also aware, there are 8 video channels. The master controller constantly searches for the best signal and then switches the bird *and* and slave controller to that channel. This is important to know, because, due to latency issues, this can cause problems.
My partner and I were test flying one of his birds that I had just taken back to FW v1.08. As expected, video feed in the master controller was excellent. We flew out 3000' @ 250' AGL with zero dropped frames. Unfortunately, the slave controller didn't do so well, experiencing dropped frames as early as 1000' out. Hmmm.... So I grabbed another controller, slaved it, and tried the flight again. Same issue. So I asked my partner to check out the video reception page in the Go App. He noted that there was a LOT of channel switching going on. Hmmmm.... So I told him to configure the video channel statically. This instantly cured the dropped frames. We tried this again with another bird and another set of controllers. Same result.
Conclusions:
1) The master controller decides which video channel is to be used.
2) The master controller transmits channel information to the bird and the slave controller.
3) Latency in channel switching will cause dropped frames in the slave controller.
I'm unsure of the channel switching signal path. Either the Master controller tells the slave which channel to use DIRECTLY. OR....the Master tells the bird, who then tells the slave. The latter would certainly cause more latency than the former.
The funny thing is that this dropped frame anomaly is VERY inconsistent. In some locations, the channel switching doesn't seem to cause dropped frames. I attribute this to environment RF effecting the frequency at which the master chooses and changes channels. Lots of RF and/or poor signal (due to signal attenuation from trees, buildings, etc.) = lots of switching. I've also noticed that, even in the same location, RF can change from day to day. We have been using the same test site for over a year. This is the first time we experienced this kind of dropped frames due to channel switching latency.
Worth noting: In the past were were able to minimize 2.4Ghz interference by turning off WiFi and BlueTooth in the iPads. However, on this day, turning these things off did nothing.
So, while your drawing is accurate, it is incomplete. Missing is the channel switching signal path TO the slave controller.
Thoughts?
