Function Code Fc7 (Read Exception Status) - WAGO 750 Series Manual

4.2.3.7 Function code FC7 (Read Exception Status)

This function reads the first 8 bits of the process output image.
Request
Byte
Byte 0, 1
Byte 2, 3
Byte 4, 5
Byte 6
Byte 7
Response
Byte
...
Byte 7
Byte 8
Exception
Byte
...
Byte 7
Byte 8
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
Field name
Transaction identifier
protocol identifier
length field
unit identifier
MODBUS function code
Field name
MODBUS function code
Reference number
Field name
MODBUS function code
Exception code
Fieldbus Communication
MODBUS Functions
Example
0x0000
0x0000
0x0002
0x01 not used
0x07
Example
0x07
0x00
Example
0x85
0x01 or 0x02
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