WAGO-I/O-SYSTEM 750 XTR
Fieldbus Communication 165
750-352/040-000 FC ETHERNET G3 XTR
Manual
Version 1.3.0
Exception
Table 96: Exception of Function Code FC15
Byte
Field name
Example
...
Byte 7
MODBUS function code
0x8F
Byte 8
Exception code
0x01 or 0x02
11.2.3.9 Function Code FC16 (Write Multiple Registers)
This function writes a sequence of registers in a slave device in word format.
Request
The Request specifies the reference number (starting register), the word count
(number of registers to write), and the register data . The data is sent as 2 bytes
per register. The registers are zero-based; therefore, the first output is at address
0.
Example: Set data in registers 0 and 1
Table 97: Request of Function Code FC16
Byte
Field name
Example
Byte 0, 1
Transaction identifier
0x0000
Byte 2, 3
Protocol identifier
0x0000
Byte 4, 5
Length field
0x000B
Byte 6
Unit identifier
0x01 not used
Byte 7
MODBUS function code
0x10
Byte 8, 9
Reference number
0x0000
Byte 10, 11
Word count
0x0002
Byte 12
Byte count
0x04
Byte 13, 14
Register value 1
0x1234
Byte 15, 16
Register value 2
0x2345
Response
Table 98: Response of Function Code FC16
Byte
Field name
Example
...
Byte 7
MODBUS function code
0x10
Byte 8, 9
Reference number
0x0000
Byte 10, 11
Word count
0x0002
