error=Unknown data-rate on EU868 with Coding Rate 4/7

ChirpStack (v4)
#1

Hey,

I just tried to switch from v3 to v4. But I always get the following error for some of my sensors:

ERROR chirpstack::uplink: Deduplication error error=Unknown data-rate: Lora(LoraDataRate { spreading_factor: 7, bandwidth: 125000, coding_rate: “4/7” })

I am using the EU868.
The json uplink from the gateway (unfortunately I had to extract it per hand from the gateway as the live “LoRaWAN frames” tab doesn’t show anything, although Chirpstack tags it as online)

{"rxpk":[{"tmst":31760588,"time":"2023-03-07T16:04:04.881020Z","chan":5,"rfch":0,"freq":867.500000,"stat":1,"modu":"LORA","datr":"SF7BW125","codr":"4/7","lsnr":7.5,"rssi":-60,"size":34,"data":"QAACAYIABQABlbEhyeSbQXK/LMKIACHPlXnB9Ctc7prEeg=="}]}

Thanks in advance,
Max

#2

So the problem was the coding_rate. As ChatGPT told me the coding rate of 4/7 is not beeing used in EU868 normally. Flashed the device to use 4/5 fixed it. But I would really love to hear if there is a chance to get also data from devices who are sending cr of 4/7 like it was possible in Chirpstack 3.

Thanks,
Max

#3

There will not be such option. Please note that (as far as I know), a different coding-rate also implies a different airtime (because of the added / removed redundancy). This would mean different max-payload sizes than specified. Please see also:

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2 Likes
#4

Hello! Have you solved the problem with displaying data in “LoRaWAN frames” tab? I have this problem too. But i see statistics from station also )

#5

i have changed back marshaller to “protobuf” in chirpstack-gateway-bridge.toml and LoRaWAN frames appears ))

#6

And also my logs become clear at all (except network errors)

#7

Hey @NikitaK ,
I found out that it has to do with gRPC Streams and my AntiVirus (Sophos) see here: Events or the LoRaWAN frames tabs empty due to antivirus · Issue #44 · chirpstack/chirpstack (github.com)

I couldnt solve it though…
@brocaar all right, I think our intern made a wrong decission there, we will have to flash all devices manually to the right coding rate… thanks anyways :slight_smile: