RLE Technologies LD5100, User Manual

Page: 58 / 72

www.rletech.com 58 970.484.6510
8 Modbus Communication
8.3. RTU Framing
The example below shows a typical Query/Response from the LD5100 module.
Slave address 2 responds to Function Code 4 with 6 bytes of hexadecimal data and ends with
CRC16 checksum
Register Values:
40001 = 0000 (hex)
40002 = 0000 (hex)
40003 = 0001 (hex)
Table 8.12 Query Sample
Slave
Address
Function
Code
Starting
Register
“Msb”
Starting
Register
“Lsb”
Numbers
of
Registers
“Lsb”
Number of
Registers
“Lsb”
CRC 16
“Lsb”
CRC
“Msb”
02 04 00 00 00 03 B5 A3
Table 8.13 Response Sample
Slave
Address
Function
Code
Count
Bytes of
Data
Register
Data
Msb Lsb
Register
Data
Msb Lsb
Register
Data
Msb Lsb
CRC 16
“Lsb”
CRC 16
“Msb”
02 04 06 00 00 00 00 00 01 B5 A3