Communication
133
Read Holding Registers
Description: reading register blocks of holding register type (block R/W limited to 125 registers).
Function code: 03
Query
Response
Field
Hex Byte Field
Hex Byte
Slave address
01
Slave
01
Function
03
Function
03
Start address Hi
00
Byte count
02
Start address Lo
01
Data Hi
01
No of registers
00
Data Lo
2C
No of registers
L
01
CRC Lo
B8
CRC Lo
D5
CRC Hi
09
CRC Hi
CA
Write Single Register
Description: writing in a single register of the holding type.
Function code: 06
Query
Response
Field
Hex Byte
Field
Hex Byte
Slave address
01
Slave
01
Function
06
Function
06
Address Hi
00
Address Hi 02
Address Lo
0C
Address Lo 0C
Data Hi
00
Data Hi
00
Data Lo
09
Data Lo
09
CRC Lo
48
CRC Lo
88
CRC Hi
0C
CRC Hi
77