Modbus functions
160
FP Web-Server V2.810 EN
Detailed information:
For more information on Modbus-TCP server settings and the respective
server functions, please refer to the online help under the keyword
"Modbus-TCP server Settings".
This function uses the configurable Modbus to PLC address translation
table.
The gateway function routes all Modbus function requests.
The Modbus-TCP server can handle UDP broadcast messages (FP-WEB2
does not generate a response message).
An integrated setup wizard helps you configure the Modbus-TCP server.
NumberMaxOfServerTransactions = 6
SO-RCVBUF, SO-SNDBUF = 4kB with TCP and 2kB with UDP (other IP
stack parameters can be defined)
17.3 Modbus-TCP client of the FP Web-Servers in general
Either the PLC, the data logging function of the FP Web-Server, or a
Modbus RTU master unit can control the Modbus-TCP client functions of the
FP Web-Server.
For PLC control, a shared buffer in the PLC's memory is used. The PLC
program places either the server IP address or the server URL name
and Modbus commands in this buffer. The FP Web-Server reads the
buffer and executes the commands. Additionally, the PLC can also
access a Modbus RTU slave unit via the 9-pin RS232C interface. When
URL names are used, a default URL has to be defined.