Weidmüller IE-GW-MB-2TX-1RS232/485 User manual

Modbus TCP / RTU Gateway
Manual
for models
IE-GW-MB-2TX-1RS232/485
IE-GWT-MB-2TX-1RS232/485
First Edition, May 2014
1536320000/00/05.14

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Modbus TCP / RTU Gateway
Manual
IE-GW-MB-2TX-1RS232/485
IE-GWT-MB-2TX-1RS232/485
The software described in this manual is furnished under a license agreement and may be used only in
accordance with the terms of that agreement.
Copyright Notice
Copyright 2014 Weidmüller Interface GmbH &Co. KG.
All rights reserved.
Reproduction without permission is prohibited.
Disclaimer
Information in this document is subject to change without notice and does not represent a commitment
on the part of Weidmüller.
Weidmüller provides this document 
including, but not limited to, its particular purpose. Weidmüller reserves the right to make
improvements and/or changes to this manual, or to the products and/or the programs described in this
manual, at any time.
Information provided in this manual is intended to be accurate and reliable. However, Weidmüller
assumes no responsibility for its use, or for any infringements on the rights of third parties that may
result from its use.
This product might include unintentional technical or typographical errors. Changes are periodically
made to the information herein to correct such errors, and these changes are incorporated into new
editions of the publication.

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Contact Information
Weidmüller Interface GmbH & Co. KG
Postbox 3030
32760 Detmold
Klingenbergstraße 16
32758 Detmold
Germany
Phone: [phone]
Fax:[phone]
E-Mail [email protected]
Internet www.weidmueller.com

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Contents
1. INTRODUCTION ....................................................................................................5
1.1 Overview Modbus TCP/RTU Gateway ...........................................................................................5
1.2 Modbus Basics ................................................................................................................................ 6
2. PACKAGE CHECKLIST ........................................................................................8
3. OVERVIEW PRODUCT FEATURES......................................................................8
4. HARDWARE DESCRIPTION.................................................................................9
4.1 Panel Layout ....................................................................................................................................9
4.2 LED Indicators .................................................................................................................................9
4.3 Dimensions ....................................................................................................................................10
4.4 Jumpers..........................................................................................................................................11
4.5 DIN-Rail, Wall Mounting................................................................................................................12
4.6 Pin Assignments............................................................................................................................13
4.6.1 DB9 male connector (RS232)...................................................................................................13
4.6.2 Terminal Block (RS-422, RS-485) ............................................................................................13
4.6.3 Power Input, Relay Output........................................................................................................13
5. SPECIFICATIONS................................................................................................ 14
6. GETTING STARTED............................................................................................ 16
6.1 Reset to factory default values by external Reset button ............................................................16
6.2 Connecting Power........................................................................................................................16
6.3 Connecting Serial Devices...........................................................................................................16
6.4 Connecting to a Host or Network.................................................................................................16
7. DEVICE CONFIGURATION ................................................................................. 17
7.1 Device configuration by Web-Interface.......................................................................................17
 .....................................................................................................18
 ..............................................................................................23
 .........................................................................................30
 ..................................................................................................................33
7.2 Configuration and Monitoring via PC-based tool Modbus Gateway Administrator...............34
8. TYPICAL APPLICATIONS................................................................................... 51
8.1 Ethernet Master (TCP) with multiple serial Slaves (RTU).......................................................51
8.2 Serial Master (RTU) with serial Slaves (RTU) and Ethernet Slaves (TCP)............................52
8.3 Serial Master (RTU) with multiple serial Slaves (RTU) over Ethernet ....................................53

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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.

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1.2 Modbus Basics
Introduction
Modbus is one of the most popular automation protocols in the world. It supports both serial and
Ethernet devices. Many industrial devices, such as PLCs, DCSs, HMIs, instruments, meters, motors,
and drivers use Modbus as their communication standard.
Devices are either Masters or Slaves
All Modbus devices are classified as either a master or a slave. Masters initiate all communication with
slaves and do not communicate to other masters. Slaves are completely passive and communicate
only 
Slaves are identified by ID
Each Modbus slave in a system is assigned a unique ID between 1 and 247. Whenever a master
sends a request, the request must include the ID of the intended recipient. Master devices themselves
have no ID.
 0 Broadcast address
1-247 Slave individual address
258-255 Reserved
Communication is done by Request and Response
Modbus communication generally is running by request and response. A master sends a request and
an addressed 
the next request. For broadcast commands no response is expected. This is illustrated by three
scenarios as follows:
Normal communication (Peer-to-Peer)
The master sends a request to the slave. The slave sends a response with the requested information.

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Exception
The master sends a request to the slave. The slave may not support the command or an error is
detected. As result the slave sends an exception to the master.
Broadcast
The master sends a broadcast command, such as a reset command. Every slave on the network
accepts the command. No response is sent to the master.
Requests Need a Time Limit Response timeout
The original Modbus protocol was not designed for simultaneous requests or simultaneous masters,
so only one request on the network can be handled at a time. When a master sends a request to a
slave, no other communication may be initiated until the slave responds. The Modbus protocol
specifies that masters use a response timeout function to identify when a slave is nonresponsive due
to device or communication failure. This function allows a master to discard a request if no response is
received timely.
To integrate a wide range of devices (with different baudrates or line conditions) into a Modbus
communication a limit for a response time is not set and can be determined by the manufacturers.
However, this also makes it difficult for system integrators to know what response timeout value to use
during configuration, especially with older or proprietary devices.
The Weidmüller Modbus Gateway provides a speciual function that tests all attached devices and
recommends a response timeout value. This function saves considerable time and effort for system
integrators, and results in more accurate timeout settings.

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2. Package Checklist
All models of Weidmüller Modbus TCP/RTU Gateways are shipped with the following items:
1 Modbus Gateway
Hardware Installation Guide (includes Download-Links for this user manual and firmware
updates)
3. Overview Product Features
Integration of Modbus TCP and Modbus RTU/ASCII networks
Up to 31 Modbus RTU/ASCII slaves can be connected to the serial port (RS-485)
Up to 32 Modbus TCP slaves can be connected to a Modbus RTU/ASCII master
Up to 16 Modbus TCP masters can control Modbus RTU/ASCII slaves simultaneously
Configuration via Web interface, Telnet or Windows utility Modbus TCP/RTU Gateway
Administrator
2 RJ45 Ethernet ports 10/100 (TX)
1 high speed serial interface (SubD connector for RS232, Terminal block for RS422/485)
Software-selectable RS-232/485/422 communication
High speed serial interface supporting baud rates up to 921.6 Kbps
ProCOM: Virtual Serial Port for flexible Modbus to Modbus TCP communication

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4. Hardware description
The hardware information is valid for models
IE-GW-MB-2TX-1RS232/485 Standard Temperature range model (0 to 55°C)
and IE-GWT-MB-2TX-1RS232/485 Extended Temperature range model (-40 to 75°C)
4.1 Panel Layout
4.2 LED Indicators
Name
Color
Function
PWR1
Red
Power is being supplied to the power input.
PWR2
Red
Power is being supplied to the power input.
RDY
Red
Steady on: Power is on and unit is booting up.
Blinking: Indicates an IP conflict, or DHCP or BOOTP server is not
responding properly.
Green
Steady on: Power is on and unit is running properly.
Blinking: Unit is responding to software function Locate.
Off
Power is off or power error condition exists.
Ethernet
Orange
10 Mbps Ethernet connection.
Green
100 Mbps Ethernet connection.
Off
Ethernet cable is disconnected, or has a short.

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P1
Orange
Serial port is receiving data.
Green
Serial port is transmitting data.
Off
No data is being transmitted or received through the serial port.
4.3 Dimensions