Class-B devices stays at deviceClassEnabled: CLASS_A

Question

Hello!

Current Configuration on both sensor and Chirpstack:
Class-B Confirmed Donlink tiemout: 0
Class-B-ping-slot-datat-rate: 0
Class-B-ping-slot-periodicity: 16 seconds
Freq: 869525000(Hz)

Eventhough I've configured it as a Class-B sensor, chirpstack keeps returning 'deviceClassEnabled:"CLASS_A"'. Does anyone know why?

It works perfectly with downlinks, but an hour after configuring the sensor it stops responding to downlinks in queue.

Orne Brocaar · Answer

Even if the device is configured as Class-B device within ChirpStack, it remains in Class-A until the device has aquired a Class-B beacon lock.

This often works as follows:

The device activates
It requests the time (e.g. DeviceTimeReq)
Using that time, it knows (with some error margin) when the next Class-B beacon is sent
Once it receives the Class-B beacon, it has aquired a more precise time
On the next uplink, it will set the Class-B bit, indicating to the network that is now able to receive Class-B downlinks

Erik · Answer

I see. Though it doesn't change after a while either. After configuring the device it just gives up after a while and stops sending uplinks to the platform as if it's a Class A sensor, which it displays in the uplinks. I've had the same problem with multicast-downlinks.

The idea is to have a presence-sensor report it's status to chirpstack which makes the display show presence-status through downlinks changing between template 1 and 2 to display respective presence status.

Class-B devices stays at deviceClassEnabled: CLASS_A

2 Answers