Table 76: Response Of Function Code Fc2; Table 77: Assignment Of Inputs; Table 78: Exception Of Function Code Fc2 - WAGO -I/O-SYSTEM 750 XTR Manual

158 Fieldbus Communication
Response
The current value of the requested bits are packed into the data field. A binary 1
corresponds to the ON status and a 0 the OFF status. The lowest value bit of the
first data byte contains the first bit of the inquiry. The others follow in an
ascending order. If the number of inputs is not a multiple of 8, the remaining bits
of the last data byte are filled with zeroes (truncated).

Table 76: Response of Function Code FC2

Byte
...
Byte 7
Byte 8
Byte 9
The status of the inputs 7 to 0 is shown as a byte value 0x12 or binary 0001
0010. Input 7 is the bit having the highest significance of this byte and input 0 the
lowest value. The assignment is thus made from 7 to 0 as follows:

Table 77: Assignment of Inputs

OFF
Bit
Coil
Exception

Table 78: Exception of Function Code FC2

Byte
...
Byte 7
Byte 8
Manual
Version 1.3.0
Field name
MODBUS function code
Byte count
Bit values
OFF OFF ON
0 0 0 1
7 6 5 4
Field name
MODBUS function code
Exception code
WAGO-I/O-SYSTEM 750 XTR
750-352/040-000 FC ETHERNET G3 XTR
Example
0x02
0x01
0x12
OFF OFF ON OFF
0 0 1 0
3 2 1 0
Example
0x82
0x01 or 0x02