LoRa climate module ChirpStack - UPLINK_FCNT_RETRANSMISSION error


I’m running LoRa climate module with Mikrotik GW and ChirpStack server for some months (since december 2020) without any problem. Today though I started to see UPLINK_FCNT_RETRANSMISSION error on device in ChirpStack, I!m not aware of any changes on CirpStack side and also I didn’t touch LoRa climate module long time.
What I see in ChirpStack:

Any idea what could happened or where could be a problem?

Well, this is strange, it starts to operate normally again.


Hi, I’ve asked colleagues and we did not see this error in TOWER - Chirpstack networks.
Weird that it recovered.
I suspected for example the power reset which could interfere with frame counter but in your payload I see battery voltage 2.9V so there is no reason to power reset. And it recovered itself.

Let us know if the issue repeats and give us information how many packets were fine, errored, what the crame counter was fCnt in each packet and check the voltage in message.

Which firmware do you use? Is it lora climate ? Did you compiled firmware yourself and did you any changes to it? For example if you enabled confirmed LoRa message?

Its also hard to say where the issue really was, was it device, was it packet formwarder, network server…

Hi @hub.martin,
Which firmware do you use? - device I have received recently from you, didn’t check the version, when it is time I’ll check it.
Is it lora climate ? - yes, as stated in then name of this blog post
Did you compiled firmware yourself and did you any changes to it? - No

Device sends one up-link correctly and then twice same attempt subsequently. What drives device to send these up-links without incrementing counter? Could it be some GW “echo”, i.e. these error up-links come from different GW? … just guessing.
These error messages went several hours. One message ok and two errors and repeat.
When it appears again I’ll try to find out what you suggesting.


just small update, yesterday I switched to another GW. LoRa climate module joined to this GW but started sending data irregularly (should it send every 15 min) and after a while above mentioned error started to occur:

Will continue observation.