Table of Contents
Advertisement
Chapter 17
17.1 Overview over Modbus-TCP functions of the FP Web-Server
General information on Modbus-TCP
FP Web-Server specific implementation
FP Web-Server V2.810 EN
The Modbus-TCP is a standard global communication protocol (IAONA,
Modbus-IDA) and is used to connect the PLC to third-party PLC
equipment, SCADA systems, OPC servers, and Modbus RTU gateways.
A Modbus-TCP server waits for an incoming connect from a Modbus-TCP
client. Hence:
A Modbus-TCP server (Ethernet) is comparable to a Modbus RTU slave
(serial).
A Modbus-TCP client (Ethernet) is comparable to a Modbus RTU master
(serial).
A Modbus-TCP server is addressed with a unique IP address and a port
number (default 502). Using a unit ID address in the Modbus-TCP data
packet, various interfaces of the Modbus-TCP server can be addressed. The
unit ID is comparable to the slave address in Modbus RTU communication.
Modbus communication is based on a number of specified function codes
which can address different data types. Which function codes and data
types are supported depends on the unit implementation.
The FP Web Configurator Tool allows you to configure the FP Web-Server
(as an interface to the PLC) with the following Modbus-TCP server and
client functions.
Modbus functions
Modbus functions
157
Advertisement
Table of Contents
