MGate MB3170 & MB3270

1 and 2-port advanced serial-to-Ethernet Modbus gateways

Logotyp DNV -GL godkännandeLogotype CE certifikatLogotyp FCC certifikat

Features and Benefits

  • Supports Auto Device Routing for easy configuration
    Supports route by TCP port or IP address for flexible deployment
    Connects up to 32 Modbus TCP servers
    Connects up to 31 or 62 Modbus RTU/ASCII slaves
    Accessed by up to 32 Modbus TCP clients (retains 32 Modbus requests for each Master)
    Supports Modbus serial master to Modbus serial slave communications
    Built-in Ethernet cascading for easy wiring
    10/100BaseTX (RJ45) or 100BaseFX (single mode or multi-mode with SC/ST connector)
    Emergency request tunnels ensure QoS control
    Embedded Modbus traffic monitoring for easy troubleshooting
    Serial port with 2 kV isolation protection (for “-I” models)
    -40 to 75°C wide operating temperature models available
    Supports redundant dual DC power inputs and 1 relay output
MGate MB3170/3270 Modbus gateway has received Taiwan Excellence and Good Design awards.


The MGate MB3170 and MB3270 are 1 and 2-port Modbus gateways, respectively, that convert between Modbus TCP, ASCII, and RTU communications protocols. The gateways provide both serial-to-Ethernet communication and serial (master) to serial (slave) communications. In addition, the gateways support simultaneously connecting serial and Ethernet masters with serial Modbus devices. The MGate MB3170 and MB3270 Series gateways can be accessed by up to 32 TCP master/clients or connect to up to 32 TCP slave/servers. Routing through the serial ports can be controlled by IP address, TCP port number, or ID mapping. A featured priority control function allows urgent commands to obtain an immediate response. All models are rugged, DIN-rail mountable, and offer optional built-in optical isolation for serial signals.

Integration of TCP masters without alteration to Modbus RTU/ASCII network or software

The MB3270 can integrate Modbus TCP with Modbus RTU/ASCII,without modifying the existing Modbus RTU/ASCII architecture or software. With the serial redirector function, a serial master can maintain direct access to serial slave devices through a specially mapped serial port. This allows the serial and TCP masters to access serial slaves simultaneously.

Cascading Ethernet ports for easy wiring

Advanced models of the MGate™ MB3000 series have two Ethernet ports to make network wiring easier. Dual Ethernet ports allow users to string multiple Modbus gateways together using standard RJ45 Ethernet cables, eliminating the need for a separate Ethernet switch.

Redundant power inputs

Advanced models of the MB3000 series have dual power inputs for greater reliability. The power inputs allow simultaneous connections to two live DC power sources, so that continuous operation is provided even if one power source fails. The higher level of reliability makes these advanced Modbus gateways ideal for demanding industrial applications.

Optical Fiber for Ethernet Communication

The MGate MB3170 Series includes 100BaseFX fiber models that support transmission distances up to 4 km for multi-mode models, and up to 40 km for single-mode models. Optical fiber is well-suited for industrial applications because it is immune to electromagnetic noise and interference. For environments that experience high ground loop voltages, fiber provides the best isolation protection, and because there is no danger of sparking, optical fiber is safer than copper wire to use in hazardous environments.

Warning by relay output

A relay output is provided for the Ethernet link and power input status. The relay output gives maintenance engineers an additional tool for troubleshooting and maintenance.

Priority control for urgent commands (Patented)

As Modbus networks increase in size and complexity, the lag time between commands and responses becomes a major concern. Advanced models of the MB3000 series provide a priority control function for urgent commands, allowing users to force certain commands to get an immediate response. Depending on your system’s requirements, different methods are available to define which commands receive priority.


Ethernet Interface
Number of Ports 2 (1 IP)
Speed 10/100 Mbps, Auto MDI/MDIX
Connector 8-pin RJ45
Magnetic Isolation Protection 1.5 KV built-in
Serial Interface
Number of Ports MB3170/3170I: 1MB3270/3270I: 2
Serial Standards RS-232/422/485, software selectable
Connectors MB3170/3170I: DB9 male for RS-232, Terminal block for RS-422/485MB3270/3270I: DB9 male x 2
ESD Protection 15 KV for all signals
RS-485 Data Direction Control ADDC® (automatic data direction control)
Pull High/Low Resistor for RS-485 1 KΩ, 150 KΩ
Terminator for RS-485 120 Ω
Serial Communication Parameters
Data Bits 7, 8
Stop Bits 1, 2
Parity None, Even, Odd, Space, Mark
Flow Control RTS/CTS, DTR/DSR (RS-232 only)
Baudrate 50 bps to 921.6 Kbps
Serial Signals
RS-422 Tx+, Tx-, Rx+, Rx-, GND
RS-485-4w Tx+, Tx-, Rx+, Rx-, GND
RS-485-2w Data+, Data-, GND
Operation Modes RTU Slave, RTU Master, ASCII Slave, ASCII Master
Configuration Options Web Console, Serial Console, Telnet Console, Windows Utility
Utilities MGate Manager for Windows 98/ME/NT/2000, Windows XP/2003/Vista/2008/7 x86/x64
Multi-master and Multi-drop Master mode: 32 TCP slavesSlave mode: 16 TCP masters (request queue 32-deep for each master)
Bonus Features Smart Routing, Serial Redirection, Priority Control
Physical Characteristics
Housing Plastic
Weight MGate MB3170: 360 gMGate MB3270: 380 g
Dimensions Without ears: 29 x 89.2 x 118.5 mm (1.14 x 3.51 x 4.67 in)With ears extended: 29 x 89.2 x 124.5 mm (1.14 x 3.51 x 4.90 in)
Environmental Limits
Operating Temperature Standard Models: 0 to 55°C (32 to 131°F)Wide Temp. Models: -40 to 75°C (-40 to 167°F)
Storage Temperature -40 to 85°C (-40 to 185°F)
Ambient Relative Humidity 5 to 95% (non-condensing)
Power Requirements
Input Voltage 12 to 48 VDC
Power Connector Terminal block
Power Consumption MGate MB3170: 435 mA (max.)MGate MB3170I: 555 mA (max.)MGate MB3270: 435 mA (max.)MGate MB3270I: 510 mA (max.)
Relay Output 1 Digital relay output to alarm (normal close): Current carying capacity1 A @ 30 VDC
Standards and Certifications
Safety UL 60950-1, EN 60950-1
Hazardous Location UL/cUL Class I Division 2 Groups A/B/C/D, ATEX Zone 2, IECEx (for -IEX models)
EMI EN 55022 Class A, FCC Part 15 Subpart B Class A

EN 55024,EN 61000-4-2 (ESD) Level 3,EN 61000-4-3 (RS) Level 3,EN 61000-4-4 (EFT) Level 4,EN 61000-4-5 (Surge) Level 3,

EN 61000-4-6 (CS) Level 3,

EN 61000-4-8,

EN 61000-4-11,

EN 61000-4-12

Marine DNV
Shock IEC 60068-2-27
Freefall IEC 60068-2-32
Vibration IEC 60068-2-6
MTBF (mean time between failures) MGate MB3170: 210,794 hrsMGate MB3270: 125,234 hrs
Warranty Period 5 years
Details See Warranty @ Moxa