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Wireless Data Acquisition System - LoRa Gateway BL280
5. If password is correct but command is wrong, gateway will return message” wrong command
format, please confirm”, then please check the spelling, letter format and other details
6. If password is wrong, there will be return message
7. If there’s no return message from gateway once it receives SMS command, please check
whether password is correct and signal is normal.
6 Communication Protocol
Gateway BL280 support Modbus TCP, Modbus RTU and MQTT. It can be connected to Alibaba
Cloud, HUAWEI Cloud, King Pigeon Cloud, SCADA an other host computers through cellular and
Ethernet network.
It has various nodes for collecting different data. Below is the diagram of node and register
mapping relationship (For node collecting sequence, please refer to
Address
)
6.1 Modbus RTU Protocol
(1) Function code 04H(0x04): read input register (read node WT107, data is air temperature,
humidity, light intensity, CO2, TVOC and soil temp & humi)
Message format sent from master server station:
Content
Byte QTY Data Sent Remark
Device Address
1
01H
Device 01, range: 1-247, same as the set
address
Function Code
1
04H
Read input register
Register Starting Address 2
9C 40H
Range: 9C40H-9C46 (40000-40006) refer
to below note for address relations. Data
sending sequence
:
high byte will be in
front of low byte, for example 0010,
sequence is 00 10