WAGO 750 Series Manual page 102

96 • Fieldbus Communication
MODBUS Functions
For each basic data type one or more „FunctionCodes" are defined.
These functions allow digital or analog input and output data, and internal
variables to be set or directly read out of the fieldbus node.
Function code
FC1:
FC2:
FC3:
FC4:
FC5:
FC6:
FC7:
FC 11:
FC 15:
FC 16:
FC 23:
Tab. 4-3: List of the MODBUS Functions in the Fieldbus Coupler
To execute a desired function, specify the respective function code and the
address of the selected input or output data.
Attention
The examples listed use the hexadecimal system (i.e.: 0x000) as their
numerical format. Addressing begins with 0.
The format and beginning of the addressing may vary according to the
software and the control system. All addresses then need to be converted
accordingly.
Function
hexadec.
0x01 Read Coils
0x02 Read Input
Discretes
0x03 Read Multiple
Registers
0x04 Read Input
Registers
0x05 Write Coil
0x06 Write Single
Register
0x07 Read
Exception
Status
0x0B Get Comm
Event Counters
0x0F Force Multiple
Coils
0x0010 Write Multiple
Registers
0x0017 Read/Write
Registers
Access method
and description
Reading of several R: Process image
single input bits
Reading of several R: Process image
input bits
Reading of several R: Process image, internal variables
input registers
Reading of several R: Process image, internal variables
input registers
Writing of an W: Process image
individual output
bit
Writing of an W: Process image, internal variables
individual output
register
R: Process image
Reading of the first
input bits
Communication R: None
event counter
Writing of several W: Process image
output bits
Writing of several W: Process image, internal variables
output registers
Reading and
R/W:
writing of several
output registers
Access to resources
image
Process
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