Articles on: Eastron

Switching the relays on the Eastron SDM320-LoRa

To identify, connect and decode data from the SDM320-LoRa see this article

Getting the current state of the relay

To get the current state of the relay, the following downlink can be sent on fPort 1.

01 03 FC B0 00 01 B5 BD

An uplink similar to the following should be received shortly after the downlink is sent.

01 03 02 00 00 B8 44

Bytes 3-4 (0-based) of the received uplink can be decoded identically to when the relay state is received periodically. 00 00 indicates the relay is Open and 00 FF indicates the relay is Closed. In the above example all relays are closed.

Switching the relay state

The relay can be closed using the following command.

01 10 FD 00 00 01 02 FF 00 CB 6F

The relay can be opened using the following command.

01 10 FD 00 00 01 02 00 00 8A 9F

Updated on: 18/03/2026

Was this article helpful?

Thank you!