Archer GR8 and M+ Wiring for Redundancy

[Jim Miller]

Can anyone help me with the wiring of an Archer GR8 using a Archer M+ as a redundant receiver. I assume the M+ plugs into the SBUS IN (s,+,-) on the GR8 but how do the wires connect to the M+. There is a 4 pin connector I can solder in place (SBUS OUT, S.Port, VIN, GND). Not sure what VIN is. Also info on binding sequencing would be helpful. Thanks

 

[Wayne]

VIN = Voltage In (plus)
GND = Ground (minus)
SBUS OUT will go to SBUS IN on the other receiver.

You will not use the S.Port connection.

 

[Jim Miller]

Thanks VIN through me

 

[Flying Dutchman]

@Jim Miller , the GR8/M+ redundancy scheme does work, but perhaps not as you might assume or expect. When the GR8 drops out for whatever reason, the M+ will indeed take over, BUT it won't let go unless it drops out - and that rarely happens. No, the GR8 does not automatically regain primary control after its communication problem has been resolved. This means that when the M+ takes over, you'll lose GR8-specific functionality (e.g. Vario and V-bat) and it will stay off for the remainder of the flight.

I spent a lot of time troubleshooting this issue, but eventually gave up after discussions with a number of guys on RCG. I have since removed the redundancy M+ from my gliders, and instead added RSSI and VFR telemetry alarms in the model setup. I think using an M+ as redundancy Rx to a large power plane is a great idea, but for gliders I don't find it useful.

 

[yufasa]

O wow, that is good to know. I am just getting into the FrSky world coming from Jeti. This one would have driven me batty.
I am only setting up planes and heli's, when the season gets warmish I am going to have a lot of fun with the new gear

 

[Wayne]

@Jim Miller , the GR8/M+ redundancy scheme does work, but perhaps not as you might assume or expect. When the GR8 drops out for whatever reason, the M+ will indeed take over, BUT it won't let go unless it drops out - and that rarely happens. No, the GR8 does not automatically regain primary control after its communication problem has been resolved. This means that when the M+ takes over, you'll lose GR8-specific functionality (e.g. Vario and V-bat) and it will stay off for the remainder of the flight.

I spent a lot of time troubleshooting this issue, but eventually gave up after discussions with a number of guys on RCG. I have since removed the redundancy M+ from my gliders, and instead added RSSI and VFR telemetry alarms in the model setup. I think using an M+ as redundancy Rx to a large power plane is a great idea, but for gliders I don't find it useful.

We have yelled at FrSky to engineer a better solution to this. Who knows, maybe someday...

On a similar note, external sensors can be shared with multiple receivers. FrSky sent me a wiring diagram a while back for this, but sure can not find it now. Pretty sure it was just "Y"ing the daisey chain to both receivers.

 

[yufasa]

Worth a try…will see if it works