MODBUS function code 0x10: write multiple registers
This function code is used to write continuous registers to remote devices (1... 123 registers) block
that specifies the value of the registers written in the request data frame. Data is packaged in two
bytes per register. Response frame return function code, start address and number of registers
written.
Request
N = Register number
Figure11:Write multiple register request frames
Response
N = Register number
Figure 12: write multiple register response frames
The request frame and response frame are illustrated below in two registers that write the values
0x000A and 0x0102 to the start address of 2.
15
Function code
Start Address
Number of input registers
number of bytes
Register values
1 byte
2 byte
2 byte
1 byte
N×2 byte
0x10
2 byte
2 byte
1 byte
N×2 byte
Request Frame
Number Systems
Function code
Start address (high byte)
Start address (low byte)
Input register number (high bytes)
Input register number (low bytes)
number of bytes
Register value (high byte)
Register value (low byte)
Register value (high byte)
Register value (low byte)
(Hexadecimal)
0x10
0x00
0x01
0x00
0x02
0x04
0x00
0x0A
0x01
0x02
Response Frame
Number Systems
Function code
Start address (high byte)
Start address (low byte)
Input register number (high bytes)
Input register number (low bytes)
(Hexadecimal)
0x10
0x00
0x01
0x00
0x02
Function code
Start Address
Register number
1 byte
2 byte
2 byte
0x10
0x0000….0xffff
1…123(0x7B)
Figure 13: Examples of writing multiple register request and response frames
