RAK 3172 Class B

I’m trying to get a RAK3172 connected in class B and am running into difficulties. Here is the sequence of commands I am using:

[13:35:20:559] RAKwireless RAK3172-E Example
[13:35:20:561] ------------------------------------------------------
[13:35:20:574] Current Work Mode: LoRaWAN.
[13:35:28:570] AT+CLASS=B
[13:35:28:572] OK
[13:35:34:924] AT+JOIN=1:0:8:8
[13:35:34:954] OK
[13:35:41:377] +EVT:JOIN_FAILED_RX_TIMEOUT
[13:35:54:875] +EVT:JOINED
[13:36:50:076] AT+CLASS=?
[13:36:50:087] AT+CLASS=B:S0
[13:36:50:087] OK
[13:37:00:014] AT+TIMEREQ=1
[13:37:00:040] OK
[13:37:03:702] AT+SEND=2:12345678
[13:37:03:718] OK
[13:37:05:169] +EVT:TIMEREQ_OK
[13:37:12:687] AT+CLASS=?
[13:37:12:689] AT+CLASS=B:S1
[13:37:12:689] OK
[13:37:39:667] +BC:FAILED


Here are some of the pertinent settings:

[13:42:48:783] AT+BFREQ=?
[13:42:48:785] AT_NO_CLASSB_ENABLE
[13:42:54:956] AT+CLASS=?
[13:42:54:986] AT+CLASS=B:S3
[13:42:54:986] OK
[13:43:26:489] AT+PGSLOT=?
[13:43:26:489] AT+PGSLOT=7
[13:43:26:489] OK
[13:43:36:285] AT+VER=?
[13:43:36:285] AT+VER=RUI_4.0.1_RAK3172-E
[13:43:36:285] OK

I typically get see the +BC:FAILED message although sometimes the module seems to hang out in the S1 state indefinitely.

Is there something I’m missing? I’m running against a Chirpstack server, RSSI is ~ -60db

Any help would be appreciated.

Hi @randall ,

You to have a beacon lock which is B:S2.

B:S1 - Beacon search
B:S3 - Beacon fail

I personally have no experience with Chirpstack but do you have an end-node already operating in class B on your Chirpstack? Also, does the gateway has GPS?

Another thing is that you must be successfully joined first to establish the device in class B. Then I suggest wait for around two minutes (128seconds) to see if your device can see a beacon downlink coming from the Network Server (via your gateway). Without the beacon lock, the device will keep on S1 state or S3.

Thanks for the reply @carlrowan . I do not have another end-node. The GW I am using does have GPS and has fix on the satellites. I can successfully join the network but I don’t ever see beacon lock even after letting it sit for over an hour. Is there an example of the setup for class b somewhere? The GW I’m using is currently under development so I’m trying to remove as many variables as possible to test things.

Hi @rbelk ,

I cannot same much about your gateway and your configuration on Chirpstack. However, I can probably make a guide using RAK3172 and WisGate Edge for class B then put it in our knowledge hub.

Btw, your sequence is correct. You configure to class B, join the network, send uplinks and wait for successful lock.