MOXA MGATE MB3270 Modbus Gateway

Overview

MOXA MGATE MB3270 is a 2-port industrial Modbus protocol gateway manufactured by Moxa, designed for bidirectional conversion between Modbus TCP and Modbus RTU/ASCII. It features two serial ports supporting RS-232/422/485 and dual 10/100Mbps Ethernet ports, enabling seamless integration of legacy serial Modbus instruments into Ethernet-based PLC, SCADA and energy management systems. It supports up to 32 Modbus TCP client connections and can connect up to 62 serial Modbus slaves, with priority control for critical commands. The upgraded G2 version is available as successor, while the original MB3270 remains widely stocked as spare for industrial, marine and power automation retrofits.

Features

MOXA MGATE MB3270 supports automatic device routing, with access rules configurable by IP address, TCP port or Modbus ID mapping. The Modbus Gateway allows serial master and Ethernet master to access serial slave devices simultaneously. It provides dual power input and relay alarm output for power failure notification. The optional optical isolation variant protects serial circuits against ground loop surge. It has built-in diagnostic LEDs for power, run and serial port status, supports firmware upgrade and communication debugging via web console. It complies with CE, FCC, UL and industrial EMC standards. MOXA MGATE MB3270 works with flow meters, temperature transmitters, frequency converters and protection relays to unify Modbus network architecture.

Specs

MOXA MGATE MB3270 Modbus gateway. The Modbus Gateway model: MGate MB3270. Brand: MOXA. Serial ports: 2 x RS-232/422/485. Ethernet ports: 2 x 10/100Base-TX RJ45. Protocol: Modbus TCP, Modbus RTU, Modbus ASCII. Max TCP clients: 32. Max serial slaves: 62. Power input: 12–48 VDC, dual redundant power. Mounting: DIN rail mount. Protection class: IP30. Lifecycle: legacy product, successor MB3270-G2 available. It is stocked as industrial Modbus communication spare.

Operating Parameters

MOXA MGATE MB3270 ambient operating temperature: 0℃ ~ +60℃, wide temperature variant -40℃ ~ +75℃. The Modbus Gateway relative humidity: 5%~95% non-condensing. EMC: comply with IEC 61000 industrial automation standards.

Principle

MOXA MGATE MB3270 receives Modbus requests from Ethernet TCP masters and translates them into serial RTU/ASCII frames. The Modbus Gateway forwards serial response data back to Ethernet clients, and also supports reverse conversion from serial master to Modbus TCP slave. It manages command queue and priority scheduling to avoid bus collision. Serial port damage, network link failure or parameter configuration error will cause MOXA MGATE MB3270 protocol conversion interruption and data loss.

Applications

MOXA MGATE MB3270 is widely deployed in power distribution, water treatment, HVAC, oil & gas and marine automation panels. The Modbus Gateway bridges serial field devices and Ethernet control systems, cooperating with PLC, HMI and supervisory platforms. MOXA MGATE MB3270 is a preferred spare for legacy Modbus network maintenance and upgrade.