User Documentation

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1. Introduction
Welcome to the Weidmüller Modbus TCP/RTU gateways. All models feature easy integration of
Modbus TCP to Modbus RTU/ASCII and feature RS-232/422/485 ports for Modbus serial
communication.
1.1 Overview Modbus TCP/RTU Gateway
The Weidmüller Modbus TCP/RTU Gateways provides users with
Seamless integration of Ethernet and serial Modbus devices
Powerful operation modes to handle almost any Modbus application
Windows utility for easy setup and traffic monitoring
Seamless integration of Ethernet and serial Modbus devices
Modbus is one of the most popular automation protocols in the world, supporting traditional
RS-232/422/485 devices and recently developed Ethernet devices. Many industrial devices, such as
PLCs, DCSs, HMIs, instruments, and meters, use Modbus as their communication standard. However,
the Ethernet-based Modbus protocol is different from the original serial-based protocols that a
communication gateway is needed as a bridge for integration.
In order to integrate Modbus networks, the Modbus TCP/RTU Gateway includes an Ethernet interface
and a serial port that supports RS-232, RS-422 and RS-485 communication. It automatically and
intelligently translates between Modbus TCP (Ethernet) and Modbus ASCII/RTU (serial) protocols,
allowing Ethernet-based controllers to communicate with instruments over RS-485 without additional
programming or any other software-based adaptions.
Powerful operation modes to handle almost any Modbus application
With the Modbus protocol, devices must be clearly defined as either masters or slaves. The Modbus
Gateway can be configured to operate as master or slave mode at the serial port. In the slave mode it
is possible that several Ethernet masters control serial slaves simultaneously, in the Master mode a
serial master can control multiple Ethernet slaves.
Extra address mapping and exception parameters are provided to ensure that most situations can be
handled.
Windows utility for easy setup and traffic monitoring
Alternatively to the Web-based configuration of the Gateway the Windows utility Modbus Gateway
Administrator can be used for device configuration. This utility has an integrated search function to
detect the IP addresses of LAN-connected Modbus Gateways. This is very helpful if the IP address of
a Modbus TCP/RTU Gateway is unknown. Additionally traffic monitoring functions help you
troubleshoot Modbus communication problems by tracking items such as connection status and
address translation errors.