Problem to receive more than 11 bytes

[Winner Martins]

Hi Everyone!

I am starting to develop in LoRaWAN, I already had developed something using Chirpstack with ht-m02 Gateway. But now I am using the Multitech Conduit – MTCDT-L4N1-246A to receive LoRaWAN Packets from a node developed using Heltech’s Board.

Looking to the payload received using Node-RED my payload was trimmed in a 4 bytes string, so I’ve found where I change this limit on the Heltec’s Library. When I changed it to 11 bytes it worked (with DR2). Using Default DR as 4 I just received 8 bytes.

But when I changed it to 12+ bytes I only got “(undefined)” as a Payload.

There is some configuration that needs to be done in the Gateway to increase the maximum data size?

Thank You!

Best Regards,

Winner Martins

[Jason Reiss]

Using Default DR as 4

Are you sure default is not DR0 (SF10BW125)? This is limited to 11 bytes payload minus any MAC commands that need to be sent.

When the network sends commands to the end-device it will expect answers in the header of the next packet. This can impact the number of payload bytes that can be sent in the packet.

I expect the issue to be with the end-device and not the gateway. I would not expect the payload to be truncated by the device, unless there is a built in protocol to fragment the payload into multiple packets.

Packets exceeding the LoRaWAN regional payload limits may not be reported by the network server.

[Winner Martins]

Jason,
Thank You for your quick response.

Now it worked I returned to a previous version of the library of the board.

For some reason it was only transmitting on the SF10BW125, I don’t know why. But now it is working 🙂

[Author]

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