WAGO 750-830 Manual page 217

4.3.3 Description of the MODBUS Functions
All MODBUS functions are executed as follows:
A MODBUS TCP master (e.g., a PC) makes a request to the WAGO fieldbus
node using a specific function code based on the desired operation. The
WAGO fieldbus node receives the datagram and then responds to the master
with the proper data, which is based on the master's request.
If the WAGO fieldbus node receives an incorrect request, it sends an error
datagram (Exception) to the master.
The exception code contained in the exception has the following meaning:
Exception
Code
0x01
0x02
0x03
0x04
0x05
0x06
0x08
0x0A
0x0B
The following chapters describe the datagram architecture of request, response
and exception with examples for each function code.
Note
In the case of the read functions (FC1 – FC4) the outputs can be additionally
written and read back by adding an offset of 200
addresses in the range of [0
MODBUS addresses in the range of [6000
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
Meaning
Illegal Function
Illegal Data Address
Illegal Data Value
Slave Device Failure
Acknowledge
Server Busy
Memory Parity Error
Gateway Path Unavailable
Gateway Target Device Failed To Respond
- FF ] and an offset of 1000
hex hex
Fieldbus Communication
MODBUS Functions
(0x0200) to the MODBUS
hex
(0x01000) to the
hex
- 62FC ].
hex hex
• 217