Page
32 of 52
King Pigeon Communication Co., Ltd.
www.iot-solution.com
Wireless Data Acquisition System - LoRa Gateway BL280
Device Address
1
01H
Device 01, range: 1-247, same as set
address
Function Code
1
01
Read coil register
Starting
Address
of
Register
2
00 00H
Read 2 digital output status of WT102 with
ID 1. More details can be viewed from
below remark.
Qty of Read Register
10
00 0AH
Range: 0000H-0009H, read 2 digital output
status of WT102 with ID 1-5
Remark: Maximum 100 registers of digital output can be read each time. If more than 100
registers,it will be invalid. Each WT102 has 2 digital outputs. The corresponding Modbus address is
(ID-1)*2, for example, the starting address of WT102 with ID 1 is 0, then the starting address of
WT102 with ID 2
Return Message Format
Content
Byte Qty Data Sent Remark
Command Counter
1
00 00H
Same as data sent
Command Counter
1
Fixed Character
1
00H
Fixed format, fixed character
Fixed Character
1
00H
Fixed format, fixed character
Following Message Size 1
00 05H
Same as following message byte size
Following Message Size 1
01H
Device 01, same as data sent
Device Address
1
Function Code
1
01H
Read coil register
Return Byte Size
1
02H
Data: 2N, N is the qty of register to be
inquired
Return Data
2
01 00H
Every 8 bits form 1 byte. Low byte is in
front.
(3) Function code 02H(0x02): read discrete input status (read node WT101 with 4 digital inputs)
Message Format Sent from server master station:
Content
Byte Qty Data Sent Remark
Command Counter
1
00 00H
Every time a data package is sent, the
counter value will be added by 1
Command Counter
1
Fixed Character
1
00H
Fixed format, fixed character
Fixed Character
1
00H
Fixed format, fixed character
Following Message Size
1
00 06H
Same as following message byte size
Following Message Size
1
Device Address
1
01H
Device 01, range 1-247, same as set
address
Function Code
1
02
Read discrete input status
Starting
Address
of
Register
2
00 00H
Read 4 digital input status of WT101 with
ID 1. More details can be viewed from
below remark.
Qty of Read Register
10
00 08H
Range: 0000H-0007H, read 4 digital input
status of WT101 with ID 1&2
Note: Maximum 200 registers of digital inputs can be read each time. If more than that, it’s invalid.
Each WT101 has 4 digital inputs. The corresponding Modbus address is (ID-1)*4, for example, if the
starting address of WT101 with ID 1 is 0, then the starting address of WT101 with ID 2 is 4