MGate MB3000 Modbus Gateway User Manual Sixth Edition, July 2012 www.moxa.com/product 2012 Moxa Inc. All rights reserved.
MGate MB3000 Modbus Gateway User’s Manual 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 2012 Moxa Inc. All rights reserved. Reproduction without permission is prohibited. Trademarks MOXA is a registered trademark of Moxa Inc. All other trademarks or registered marks in this manual belong to their respective manufacturers.
Table of Contents Chapter 1 Introduction ..............................................................................................1-1 Overview .............................................................................................................................. 1-2 Package Checklist ................................................................................................................. 1-3 Product Features ...............................................................................
Terminal Block (RS-422, RS-485) ............................................................................... 6-5 Power Input, Relay Output ........................................................................................... 6-6 DIN-Rail, Wall Mounting ..................................................................................................... 6-6 Specifications .......................................................................................................................
Introduction .........................................................................................................................11-2 Replace Serial Masters with Ethernet Master(s), Slave IDs are Configurable ....................11-2 Replace Serial Masters with Ethernet Master(s), Slave IDs are Fixed ................................11-3 Keep Serial Master and Add Ethernet Master(s) .................................................................
1 Chapter 1 Introduction Welcome to the MGate MB3000 line of Modbus gateways. All models feature easy integration of Modbus TCP to Modbus RTU/ASCII and feature RS-232/422/485 ports for Modbus serial communication. One, two, and four-port models are available.
MGate MB3000 User’s Manual Hardware Reference: MB3270, MB3270I Overview The MGate MB3000 is a line of protocol gateways that provides users with seamless integration of Ethernet and serial Modbus devices powerful operation modes to handle almost any Modbus application Windows utilities 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
MGate MB3000 User’s Manual Hardware Reference: MB3270, MB3270I Package Checklist All models in the MGate MB3000 line are shipped with the following items: Standard Accessories 1 MGate MB3000 Modbus gateway Document & software CD Quick Installation Guide Power adaptor (MB3180 only) Product warranty statement Optional Accessories DK-35A: DIN-rail mounting kit (35 mm) DR-4524: 45W/2A DIN-rail 24 VDC power supply with universal 85 to 264 VAC input DR-75-24: 75W/3.
2 Chapter 2 Getting Started This chapter provides basic instructions for installing the MGate MB3000.
MGate MB3000 User’s Manual Getting Started Connecting Power The unit can be powered using the AC adaptor or by connecting a power source to the terminal block, depending on the model. The following instructions are for the AC adaptor: 1. Plug the connector of the power adapter into the DC-IN jack on the back of the unit. 2. Plug the power adapter into an electrical outlet. 3. Follow these instructions to connect a power source to the terminal block: 4. Loosen or remove the screws on the terminal block. 5.
MGate MB3000 User’s Manual Getting Started RS-485 Termination and Pull High/Low Resistors In some critical RS-485 environments, you may need to add termination resistors to prevent the reflection of serial signals. When using termination resistors, it is important to set the pull high/low resistors correctly so that the electrical signal is not corrupted. For each serial port, DIP switches or jumper settings are used to set the pull high/low resistor values.
3 Chapter 3 Hardware: MB3180 This chapter provides hardware information for the MGate MB3180.
MGate MB3000 User’s Manual Hardware: MB3180 Panel Layout LED Indicators Name Color Function Steady on: Power is on and unit is booting up. Red Ready Green Off Ethernet Steady on: Power is on and unit is functioning normally. Blinking: Unit is responding to software Locate function. Power is off, or power error condition exists. Orange 10 Mbps Ethernet connection. Green 100 Mbps Ethernet connection.
MGate MB3000 User’s Manual Hardware: MB3180 Dimensions 3-3
MGate MB3000 User’s Manual Hardware: MB3180 Jumpers To set the pull high/low resistors to 150 KΩ, leave jumpers JP3 and JP4 open (not shorted). This is the default setting. To set the pull high/low resistors to 1 KΩ, short jumpers JP3 and JP4 with jumper caps. ATTENTION Do not use the 1 KΩ pull high/low setting on the MGate MB3000 when using the RS-232 interface. Doing so will degrade the RS-232 signals and reduce the effective communication distance.
MGate MB3000 User’s Manual Hardware: MB3180 Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3180 Specifications LAN Ethernet Protection Serial Interface 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Interface RS-232/422/485 No.
4 Chapter 4 Hardware: MB3280 This chapter provides hardware information for the MGate MB3280.
MGate MB3000 User’s Manual Hardware: MB3280 Panel Layout LED Indicators Name Color Function Steady on: Power is on and unit is booting up. Red Ready Green Off Ethernet Steady on: Power is on and unit is functioning normally. Blinking: Unit is responding to software Locate function. Power is off, or power error condition exists. Orange 10 Mbps Ethernet connection. Green 100 Mbps Ethernet connection.
MGate MB3000 User’s Manual Hardware: MB3280 Dimensions 4-3
MGate MB3000 User’s Manual Hardware: MB3280 Jumpers To add a 120 Ω termination resistor, set switch 3 on the port’s assigned DIP switch to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to OFF. This is the default setting. To set the pull high/low resistors to 1 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to ON.
MGate MB3000 User’s Manual Hardware: MB3280 Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3280 Specifications LAN Ethernet Protection Serial Interface 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Interface RS-232/422/485 No.
5 Chapter 5 Hardware: MB3480 This chapter provides hardware information for the MGate MB3480.
MGate MB3000 User’s Manual Hardware: MB3480 Panel Layout LED Indicators Name Color Function Steady on: Power is on and unit is booting up. Red Ready Green Off Ethernet Steady on: Power is on and unit is functioning normally. Blinking: Unit is responding to software Locate function. Power is off, or power error condition exists. Orange 10 Mbps Ethernet connection. Green 100 Mbps Ethernet connection.
MGate MB3000 User’s Manual Hardware: MB3480 Dimensions 5-3
MGate MB3000 User’s Manual Hardware: MB3480 Jumpers To add a 120 Ω termination resistor, set switch 3 on the port’s assigned DIP switch to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to OFF. This is the default setting. To set the pull high/low resistors to 1 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to ON.
MGate MB3000 User’s Manual Hardware: MB3480 Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3480 DIN-Rail, Wall Mounting Mounting on a DIN-rail: You will first need to attach the mounting plates (included) to the unit. Attach the DIN-rail accessories to the mounting plates and latch the unit onto the DIN-rail as shown. The DIN-rail kit is ordered separately. Mounting on the wall: You will first need to attach the mounting plates to the unit. Place four screws in the wall and slide the unit onto the screws as shown.
MGate MB3000 User’s Manual Hardware: MB3480 Specifications LAN Ethernet Protection Serial Interface 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Interface RS-232/422/485 No.
6 Chapter 6 Hardware: MB3170, MB3170I This chapter provides hardware information for the MGate MB3170 and MB3170I.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Panel Layout LED Indicators Name PWR1 Color Red Function Power is being supplied to the power input. PWR2 Red Power is being supplied to the power input. Steady on: Power is on and unit is booting up. Red RDY Green Off Ethernet Steady on: Power is on and unit is functioning normally. Blinking: Unit is responding to software Locate function. Power is off, or power error condition exists. Orange 10 Mbps Ethernet connection.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Dimensions 6-3
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Jumpers The DIP switches are located beneath the DIP switch panel on the side of the unit. To add a 120 Ω termination resistor, set switch 3 to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 to OFF. This is the default setting. To set the pull high/low resistors to 1 KΩ, set switches 1 and 2 to ON.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Pin Assignments DB9 (Male) The MGate MB3170 and MB3170I use a DB9 (male) serial port for RS-232 connections to Modbus RTU or ASCII devices. Pin RS-232 1 2 3 4 5 6 7 8 DCD RxD TxD DTR GND DSR RTS CTS Terminal Block (RS-422, RS-485) The MGate MB3170 and MB3170I use a terminal block connector for RS-422 and RS-485 connections to Modbus RTU or ASCII devices.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Power Input, Relay Output Shielded Ground V2+ DC Power Input 1 V2DC Power Input 1 Relay Output Relay Output V1+ DC Power Input 2 V1DC Power Input 2 DIN-Rail, Wall Mounting There are two sliders on the back of the unit for DIN-rail and wall mounting. Mounting on a DIN-rail: Pull out the bottom slider, latch the unit onto the DIN-rail, and push the slider back in.
MGate MB3000 User’s Manual Hardware: MB3170, MB3170I Specifications LAN Ethernet Protection Serial Interface 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Interface RS-232/422/485 No.
7 Chapter 7 Hardware: MB3270, MB3270I This chapter provides hardware information for the MGate MB3270 and MB3270I.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Panel Layout LED Indicators Name PWR1 Color Red Function Power is being supplied to the power input. PWR2 Red Power is being supplied to the power input. Steady on: Power is on and unit is booting up. Red RDY Green Off Ethernet Steady on: Power is on and unit is functioning normally. Blinking: Unit is responding to software Locate function. Power is off, or power error condition exists. Orange 10 Mbps Ethernet connection.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Dimensions 7-3
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Jumpers The DIP switches are located beneath the DIP switch panel on the side of the unit. To add a 120 Ω termination resistor, set switch 3 on the port’s assigned DIP switch to ON; set switch 3 to OFF (the default setting) to disable the termination resistor. To set the pull high/low resistors to 150 KΩ, set switches 1 and 2 on the port’s assigned DIP switch to OFF. This is the default setting.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I DIN-Rail, Wall Mounting There are two sliders on the back of the unit for DIN-rail and wall mounting. Mounting on a DIN-rail: Pull out the bottom slider, latch the unit onto the DIN-rail, and push the slider back in. Mounting on the wall: Pull out both the top and bottom sliders and align the screws accordingly.
MGate MB3000 User’s Manual Hardware: MB3270, MB3270I Specifications LAN Ethernet Protection Serial Interface 10/100 Mbps, RJ45, Auto MDI/MDIX Built-in 1.5 KV magnetic isolation Interface RS-232/422/485 No.
8 Chapter 8 Typical Applications In this chapter, we introduce four typical Modbus applications.
MGate MB3000 User’s Manual Typical Applications Ethernet Masters with Multiple Serial Slaves Connect all Modbus devices over an Ethernet network Most modern PLCs and host computers support Modbus TCP over Ethernet. In order to access discrete Modbus RTU/ASCII devices for data collection and control, they can rely on the MGate MB3000 Modbus gateway. The MGate MB3000 supports Modbus TCP with up to 16 simultaneous connections.
MGate MB3000 User’s Manual Typical Applications Modbus TCP Masters with ASCII and RTU Slaves Link TCP master devices with both ASCII and RTU serial devices simultaneously When integrating Modbus networks, you may encounter different Modbus serial networks that use different baudrates or a different protocol. Modbus ASCII might be used by some devices, while Modbus RTU is used by other devices.
9 Chapter 9 Configuring the Modbus Gateway We discuss the following topics in this chapter: Installing the Software Starting MGate Manager Change Language Setting Connecting to the Unit Broadcast Search Specify by IP Address Modifying the Configuration Configure Serial Port for RTU or ASCII, Master or Slave Configure IP Address and Other Network Settings Configure Serial Communication Parameters Set up Slave ID Mapping (Smart Routing) Customize Modbus Settings Set Up P
MGate MB3000 User’s Manual Configuring the Modbus Gateway Installing the Software The following instructions explain how to install MGate Manager, a utility for configuring and monitoring MGate MB3000 units over the network. 1. Insert the Document and Software CD into the CD-ROM drive. Locate and run the following setup program to begin the installation process: MGM_Setup_[Version]_Build_[DateTime].exe The latest version might be named MGM_Setup_Ver1.1.0_Build_xxxxxxxx.exe, for example: 2.
MGate MB3000 User’s Manual Configuring the Modbus Gateway 4. When the Select Additional Tasks window appears, click Next to continue. You may select Create a desktop icon if you would like a shortcut to MGate Manager on your desktop. 5. Click Next to start copying the software files. 6. A progress bar will appear. The procedure should take only a few seconds to complete.
MGate MB3000 User’s Manual Configuring the Modbus Gateway 7. A message will indicate that MGate Manager is successfully installed. You may choose to run it immediately by selecting Launch MGate Manager. 8. You may also open MGate Manager through Start Programs MGate Manager MGate Manager, as shown below.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Starting MGate Manager MGate Manager is a Windows-based utility that is used to configure the MGate MB3000. Before running MGate Manager, make sure that your PC and the MGate MB3000 are connected to the same network. Alternatively, the MGate MB3000 may be connected directly to the PC for configuration purposes. Please refer to Chapter 2 for more details.
MGate MB3000 User’s Manual Configuring the Modbus Gateway When you click OK, MGate Manager will immediately reflect your chosen language. ATTENTION Use “Default Language” before contacting Moxa Technical Support. With support for multiple languages, MGate Manager is more user-friendly and accessible. However, if you need assistance from Moxa Technical Support, please change the language to “Default Language”.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Broadcast Search Click Broadcast Search to begin searching the LAN for all MGate MB3000 units. When the search is complete, every MGate MB3000 that is found on the LAN will appear in the window with MAC address and IP address. Simply select the one that you wish to configure.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Specify by IP Address Click Specify by IP Address if you know the IP address of the unit and wish to connect to it directly. A dialog box will appear. Enter the unit’s IP address and click OK. If the search is successful, the unit will be listed in MGate Manager. Click the unit to begin configuration.
MGate MB3000 User’s Manual Configuring the Modbus Gateway ATTENTION If Search by IP Address fails to locate the MGate MB3000, the IP address that you entered might be incorrect. Try doing the search again and re-entering the IP address carefully. Another possibility is that the MGate MB3000 is located on the same LAN as your PC, but on a different subnet. In this case, you can modify your PC’s IP address and/or netmask so that it is on the same subnet as the MGate MB3000.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Configure Serial Port for RTU or ASCII, Master or Slave The Mode tab is where each serial port’s operation mode is configured. The operation mode determines whether the device(s) that are connected to the serial port will operate as a master or a slave, and whether the Modbus RTU or Modbus ASCII protocol will be used.
MGate MB3000 User’s Manual Configuring the Modbus Gateway What is ProCOM? ProCOM is a Moxa proprietary function that creates virtual serial ports on the MGate MB3000 Series to make Fieldbus gateway communications more versatile. This intelligent Fieldbus gateway mimics the behavior of a native serial port when transmitting data to the desired destination.
MGate MB3000 User’s Manual Configuring the Modbus Gateway On the ProCOM mapping dialog box, you can map up to four ProCOM functions for each Modbus gateway to your PC’s COM ports. The driver will generate virtaul COM ports on your PC to connect to the selected MGate MB3000s over the network.
MGate MB3000 User’s Manual Configuring the Modbus Gateway If you would like to change the COM port numbers, double click on the items as follows: 9-13
MGate MB3000 User’s Manual Configuring the Modbus Gateway Configure IP Address and Other Network Settings The Network tab is where the unit’s network settings are configured. You can modify the Name, Network Configuration, IP Address, Netmask, Default Gateway, and DNS. You may also select a Password to protect the unit from unauthorized access.
MGate MB3000 User’s Manual Parameter Name Network Configuration IP Address Netmask Gateway DNS1 DNS2 Password Confirm password Configuring the Modbus Gateway Value Notes You can enter a name to help you identify the (an alphanumeric string) unit, such as the location, function, etc. Select “Static IP” if you are using a fixed IP Static IP, DHCP, BootP, or address. Select one of the other options if the IP DHCP/BootP address is set dynamically. The IP (Internet Protocol) address identifies the 192.168.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Configure Serial Communication Parameters The Serial tab is where each serial port’s communication parameters are configured. You can configure Baud Rate, Parity, Stop Bit, Flow Control, FIFO, and Interface Mode.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Set up Slave ID Mapping (Smart Routing) The Slave ID Map tab is where slave IDs are managed. The definitions on this tab determine how requests will be routed by the unit.
MGate MB3000 User’s Manual Configuring the Modbus Gateway How Slave IDs are Mapped on the MGate MB3000 When a Modbus master requests information from a Modbus slave, the request is addressed to the desired slave's ID, which must be unique on the network. When Modbus networks are integrated by a Modbus gateway, complications can arise if the same slave ID is being used on different networks.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Slave ID Map Example Suppose you have two ASCII slave devices on port 1 assigned to slave IDs 3 and 5. The MGate will automatically create a virtual ID range for port 1, which you will need to modify. If slave IDs 3 and 5 are already in use by TCP slaves, the virtual ID range should be set to IDs that are not in use, such as 20 through 22.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Slave Channel and Response Timeout According to the Modbus standard, the time that it takes for a slave device to respond to a request is defined by the device manufacturer (please refer to Appendix A for details). Based on this response time, a master can be configured to wait a certain amount of time for a slave’s response. If no response is received within the specified time, the master will disregard the request and continue operation.
MGate MB3000 User’s Manual Configuring the Modbus Gateway ATTENTION Please note the following regarding automatic calibration of response timeouts: When automatically detecting the response timeout, the MGate will use the slave ID map to determine which ports and which IDs to search. Make sure that you have defined the slave ID map for your system before clicking “Auto Detection”. The automatic calibration will take some time to complete.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Priority control is designed for requests that are sent to Modbus RTU/ASCII slaves. Since Modbus RTU/ASCII slaves cannot handle multiple requests, the Modbus gateway must send each request individually and wait for the response before sending the next request. As requests stack up, the response time can suffer. This can cause problems for certain critical requests that require an immediate response.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Disable this function by clearing the “Enable the accessible IP list” checkbox.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Miscellaneous Setup This page identifies options that were not mentioned previously: Auto Relay Warning, Reset Button Protect, Web Console, and Telnet Console. Auto Relay Warning will be triggered in the event of a power failure or when Ethernet links are disconnected. When a checked trigger condition occurs, the EIP3000 will open the circuit of the relay output and trigger the Fault LED to start blinking.
MGate MB3000 User’s Manual Configuring the Modbus Gateway ATTENTION Currently the MGate MB3180 does not support Web Console. The MGate MB3180/3280/3480 do not have relay outputs, and consequently do not support Auto Relay Warning. Verifying the Location of the Unit If you are managing multiple MGate units, you may wonder if you are configuring the correct unit in MGate Manager. You can select a unit in MGate Manager and click Locate to make that unit’s “Ready” LED blink for a few seconds.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Monitoring Modbus Activity For troubleshooting or management purposes, you can monitor the data passing through any MGate MB3000 on the network. Data events will be logged as they pass through the gateway. Rather than simply echoing the data, MGate Manager presents the data in an intelligent, easily-understood format, with clearly designated fields including source, type, destination, contents, and more.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Open Traffic Monitor Window Select the unit that you wish to monitor and click Monitor to open the Traffic Monitor window. In the Traffic Monitor window, click Start to begin live monitoring of the data passing through the selected MGate MB3000 unit.
MGate MB3000 User’s Manual Configuring the Modbus Gateway To stop capturing the log, press the Stop button. Filter Traffic Information By default, all events are displayed in the traffic monitor window. MGate Manager also allows the data to be filtered so only the relevant information is displayed. The filter is selected using the radio buttons and customized using the “Filter info” field, as follows: Filter All Exception only Customization VSID=< virtual slave ID> (e.g.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Save Log to File To save the data log to a file, click Save. You may retrieve a saved log by clicking Load.
MGate MB3000 User’s Manual Configuring the Modbus Gateway Upgrading Firmware Firmware updates for the MGate MB3000 are located at www.moxa.com. After you have downloaded the new firmware onto your PC, you can use MGate Manager to write it onto your MGate MB3000. Select the desired unit from the list in MGate Manager and click Upgrade Firmware to begin the process. The dialog boxes will guide you through the process. You will need to browse your PC for the firmware file.
10 Chapter 10 We discuss the following topics in this chapter: DB9 (Male) Terminal Block (RS-422, RS-485) Power Input, Relay Output Pin Assignments
MGate MB3000 User’s Manual Pin Assignments DB9 (Male) The MGate MB3000 uses DB9 (male) serial ports to connect Modbus RTU or ASCII devices. Each port supports three serial interfaces: RS-232, RS-422, and RS-485 (both 2 and 4-wire).
MGate MB3000 User’s Manual Pin Assignments Terminal Block (RS-422, RS-485) The MB3170 and MB3170I have a terminal block connector for RS-422 and RS-485 signals.
11 Chapter 11 Case Studies We discuss the following topics in this chapter: Introduction Replace Serial Masters with Ethernet Master(s), Slave IDs are Configurable Replace Serial Masters with Ethernet Master(s), Slave IDs are Fixed Keep Serial Master and Add Ethernet Master(s) Integrate Modbus RTU, ASCII, and TCP at the Same Time
MGate MB3000 User’s Manual Case Studies Introduction There are many reasons a Modbus gateway might be used to integrate Modbus networks. However, every situation has its own requirements and difficulties. Users may wonder how the gateway can help or even if the gateway is suitable for the system. This chapter presents some case studies to help guide. If you can not find the case the same as yours, it does not mean the MGate MB3000 is not suitable with you.
MGate MB3000 User’s Manual Case Studies Replace Serial Masters with Ethernet Master(s), Slave IDs are Fixed Some legacy Modbus slave devices have fixed IDs that cannot be changed. In order to integrate the devices into a Modbus TCP network, a multiport MGate model (MB3280, MB3270, or MB3480) can be used to assign virtual slave IDs. For more information about virtual slave IDs, please refer to Chapter 9.
MGate MB3000 User’s Manual Case Studies An advanced multiport MGate model (MB3270) can be inserted into the serial system, with the slaves connected to one serial port and the master to another serial port. The advanced gateway allows Ethernet masters to communicate with the serial slaves, and it also provides a serial redirector function that simultaneously allows the serial master to continue controlling the slaves.
A Appendi x A Modbus Overview 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.
MGate MB3000 User’s Manual Modbus Overview Communication is by Request and Response All Modbus communication is by request and response. A master sends a request and a slave sends a response. The master will wait for the slave’s response before sending the next request. For broadcast commands, no response is expected. This is illustrated by three scenarios as follows: Normal The master sends a request to the slave. The slave sends a response with the requested information.
MGate MB3000 User’s Manual Modbus Overview To allow for a wide range of devices, baudrates, and line conditions, actual response timeout values are left open for manufacturers to determine. This allows the Modbus protocol to accommodate a wide range of devices and systems. 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.
B Appendi x B Declaration of Conformity Manufacturer’s Name: Moxa Technologies Co., Ltd. Fl.4, No.135, Lane 235, Pao-Chiao Rd., Shing Tien City, Manufacturer’s Taipei, Taiwan, R.O.C.
