Outdoor LoRa Data Logger
52
0x84
–
Set Value:
0x84
Total length Device ID
Data length Datavalue[]
…
Checksum
1 byte
1 byte
1 byte
1 byte
1 byte * n
1 byte
Command: 0x84
Purpose: A network server is asking for the LoRa node to set the value (data) of specific enabled output port.
Device ID: Identifier for each outout port. Only those enabled output port will appear in the payload.
Modbus-1
0x50
Modbus-2
0x51
Modbus-3
0x52
DO-1
0x70
Data Length: the data length of the corresponding output port.
Data Value: the data of the corresponding output port.
For a Modbus type port, the data format is composed of
Slave ID
Function call
Start Address
Data Length
Data
1 byte
1 byte
2 bytes
2 bytes
<50 bytes
Example1, the packet
“
8405700101F1” is composed of
Command byte – 0x84
Total Length – 0x05
Device ID – 0x70 /* Port DO-1 */
Data Length – 0x01
Data Value – 0x01
Checksum - 0xF1
Example2, the packet
“
840B500711050001000101CD” is composed of
Command byte – 0x84
Total Length – 0x0B
Device ID – 0x50 /* Port Modbus-1 */; Data Length – 0x07, Data Value – 0x11050001000101, where
Slave ID=0x11, Function Call=0x05, Start Address=0x0001, Length=0x0001, Data=0x01
Checksum - 0xCD
