Single LORAWAN FRAME generates 2 DEVICE DATA entries - one OK, one ERROR

ChirpStack Network Server
1

I’m deploying Dragino LDS02 door switches and have noticed often (not always) they generate a normal device data entry quickly followed by an entry flagging an error: “frame-counter did not increment”.

Here’s an example of what is happening:

LoRaWAN frame:

image
image1501×708 124 KB

Resulting Device Data:

image
image1501×1140 154 KB

And the second related Device Data that comes right after above:

image
image1501×292 39.3 KB

Would appreciate some help. Thanks.

DM

1 Like
2

Without a doubt, ADR is enabled and the door-switch mote has been configured by the server to nbRep > 1 - meaning uplinks are repeated, up to a total of 3 times. ChirpStack intentionally ignores repeated uplinks (there’s a DoS consideration there) and instead logs an error for repeated frame-counter.

It’s not really an error. If you pay attention to the ADR DLs, you can intuit some idea of link quality from how many of the nbRep frames are reported as errors. But you can mostly ignore them and let ADR figure things out in most cases.

3

Thanks for your reply, very helpful!

1 Like