Strange behaviour of Archer SR8 Pro (also with Archer RS)

[lthole]

Main Rx = Archer SR8 Pro on 2.1.14 Radio X20 Pro on Ethos 1.5.7

On April 26 I was using an Archer SR8 Pro when a failsafe occurred on turn to final about 50m away 10m high. The problem started at 12:50:45:400. During the failsafe the RX sensor switched from 0 to 1 and even 2! at some points, see below. I was not using a redundant receiver! What does this mean?

On subsequent days I had different problems, I will post each one in a separate comment.

Ng-2m-2024-04-26-12-24-29.csv.zip

[lthole]

On May 14 I did this test:

Main Rx = Archer SR8 Pro on 2.1.14 - bound as rx1, telemetry port = FBUS Slave Rx = Archer RS on 2.1.10 (also tried 2.1.9) - bound as rx2, telemetry port = FBUS Vari ADV variometer daisy chained via FBUS to both receivers Radio X20 Pro on Ethos 1.5.7

I am unable to connect FBUS to Vari ADV, Archer SR8 Pro and slave Archer RS via daisy chain. Works fine with RS FBUS disconnected, both Altitude and VSpeed are reported. As soon as I connect the RS FBUS, I start getting sensor lost messages. This should work under the FrSky tri-control telemetry system where you can daisy chain up to 3 receivers plus sensors.

On all the days I get a VFR Low warning soon after launch. In the logs the VFR value is always NULL for one record.

I had an RSSI critical value of 22 at 12:56:11.620. I don't believe this should have happened, the glider was about 100m almost above me.

Note also RX changing.

Ng-2m-2024-05-14-12-53-26.csv.zip

[lthole]

On May 17 I did this test:

Main Rx = Archer SR8 Pro on 2.1.14 - bound as rx1, telemetry port = Sport Slave Rx = Archer RS on 2.1.10 (also tried 2.1.9) - bound as rx2, telemetry port = Sport Vari ADV variometer daisy chained via Sport to both receivers Radio X20 Pro on Ethos 1.5.7

I powered up with RS telemetry disabled, I then enable RS telemetry after power up and telemetry appeared to keep working.

On all the days I get a VFR Low warning soon after launch. In the logs the VFR value is always NULL for one record.

I had an RSSI critical value of 25 at 12:51:35.450. I don't believe this should have happened, the glider was about 100m almost above me.

Note also RX changing to 1 and staying there.

Ng-2m-2024-05-17-12-38-44.csv.zip

[lthole]

On May 17 I did this second test:

Main Rx = Archer SR8 Pro on 2.1.14 - bound as rx1, telemetry port = Sport Slave Rx = Archer RS on 2.1.10 (also tried 2.1.9) - bound as rx2, telemetry port = Sport Vari ADV variometer daisy chained via Sport to both receivers Radio X20 Pro on Ethos 1.5.7

I powered up and disabled RS telemetry, but left the Sport connection connected.

In the logs at 13:53:39.030 the VFR value is 49 for 2 records.

Note also RX changing to 1 and staying there. The RS telemetry was disabled, so why did RX switch to 1?

Ng-2m-2024-05-17-13-50-10.csv.zip

[lthole]

On previous receivers you could test redundancy by binding the main receiver to a different receiver ID. On Archer this does not work.

[SmartTommy]

On April 26 I was using an Archer SR8 Pro when a failsafe occurred on turn to final about 50m away 10m high. The problem started at 12:50:45:400. During the failsafe the RX sensor switched from 0 to 1 and even 2! at some points, see below. I was not using a redundant receiver! What does this mean?

On subsequent days I had different problems, I will post each one in a separate comment.

The Tx does not know how many receivers be connected, Tx aways polling between Rx0、Rx1、Rx2 untill get stable telemetry connect.

[SmartTommy]

On May 14 I did this test:

Main Rx = Archer SR8 Pro on 2.1.14 - bound as rx1, telemetry port = FBUS Slave Rx = Archer RS on 2.1.10 (also tried 2.1.9) - bound as rx2, telemetry port = FBUS Vari ADV variometer daisy chained via FBUS to both receivers Radio X20 Pro on Ethos 1.5.7

I am unable to connect FBUS to Vari ADV, Archer SR8 Pro and slave Archer RS via daisy chain. Works fine with RS FBUS disconnected, both Altitude and VSpeed are reported. As soon as I connect the RS FBUS, I start getting sensor lost messages. This should work under the FrSky tri-control telemetry system where you can daisy chain up to 3 receivers plus sensors.

On all the days I get a VFR Low warning soon after launch. In the logs the VFR value is always NULL for one record.

I had an RSSI critical value of 22 at 12:56:11.620. I don't believe this should have happened, the glider was about 100m almost above me.

Note also RX changing.

Ng-2m-2024-05-14-12-53-26.csv.zip

These lines cannot be connected together when use FBUS, but SPORT works(only a portion of the receivers can, please refer to the product manual for details).

[lthole]

Yes I suspected that you cannot use FBUS, that is why I did the two tests with SPort on May 17. While both receivers had telemetry enabled, I got sensor conflict messages.

On the 2nd test the RS has telemetry disabled, but then I don’t understand the log because telemetry was being received while RX was = 1.

[lthole]

For comparison, here is a log of different glider with an RX6R receiver and no redundant receiver. RX stays 0 all the time, and VFR is much better. This was flown in the same place and height as the previous logs shown above.

[SmartTommy]

For comparison, here is a log of different glider with an RX6R receiver and no redundant receiver. RX stays 0 all the time, and VFR is much better. This was flown in the same place and height as the previous logs shown above.

which mode the RX6R works in? ACCST or ACCESS?

[lthole]

The RX6R is using ACCESS.

[SmartTommy]

For comparison, here is a log of different glider with an RX6R receiver and no redundant receiver. RX stays 0 all the time, and VFR is much better. This was flown in the same place and height as the previous logs shown above.

Based on the log data you provided, the RX6R seems to perform better. Telemetry has maintained a stable connection and there has been no continuous frame loss, so it did not switch to another receiver.

[lthole]

Can you please explain for the 2nd test on May 17, RX changing to 1 and staying there. The RS telemetry was disabled, so why did RX switch to 1?

[npirkes]

I opened this issue back in 2021 FrSkyRC/RF_Feedback_Group#30. It was marked as "Not a bug in Ethos". However, after using the SR8 Pro receiver without an additional 2.4 receiver, I didn't face this issue any more.

[SmartTommy]

Can you please explain for the 2nd test on May 17, RX changing to 1 and staying there. The RS telemetry was disabled, so why did RX switch to 1?

I understand what you mean now, and we will fix this issue as soon as possible.

[lthole]

Unresolved, so needs to stay open, and be moved to an RF Issues repo for FrSky R&D to deal with.