General
Data bits	7, 8
Stop bits	1, 2

The Moxa MGate MB3170 is an industrial 1-port Modbus gateway that enables communication between serial Modbus devices (RTU/ASCII) and Ethernet-based Modbus TCP networks. It is specifically designed for industrial automation environments where reliable, flexible, and powerful integration of legacy devices into modern networks is required. The device serves as a bridge between older serial devices and modern Ethernet infrastructures, enabling data transmission in SCADA systems, remote maintenance systems, or higher-level control systems.

Applications

The MGate MB3170 is suitable for applications in industrial automation, particularly in environments where serial devices such as sensors, frequency converters, measuring instruments, or controllers communicate via Modbus RTU/ASCII but need to be integrated into an Ethernet network. Support for up to 62 serial Modbus slaves and simultaneous access by up to 32 Modbus TCP clients makes it suitable for decentralized control systems where multiple devices are monitored and controlled over a central network. Features such as Auto Device Routing and emergency request tunneling simplify configuration and enhance communication availability.

Functions and Equipment in Detail

The gateway features a serial interface that can be switched via software between RS-232, RS-422, and RS-485. The baud rate is selectable from 50 bps to 921.6 kbps, with configurable data bits (7 or 8), parity (none, even, odd, Space, Mark), and stop bits (1 or 2). Flow control is supported via DTR/DSR, RTS/CTS, or RTS-Toggle. The serial interface also supports 2-wire and 4-wire mode for RS-485, with integrated pull-high/low resistors (1 kΩ / 150 kΩ) and a 120 Ω terminator. The serial communication can operate in master-slave mode, allowing the gateway to also function as a Modbus master.

Technology Explained Simply

The device features two Ethernet ports (10/100BaseT(X) RJ45) with Auto MDI/MDI-X, enabling flexible network integration. Magnetic isolation of 1.5 kV protects against interference and voltage surges in the network. Protocol support includes Modbus TCP Client/Server, Modbus RTU/ASCII Master/Slave, and Modbus Transparent mode. Integrated protocol monitoring enables diagnosis of communication errors.

Compatibility and Accessories

The gateway is compatible with Modbus standard protocols and can be integrated into existing Ethernet networks. It supports configuration via a web interface (HTTP/HTTPS), Telnet, DSU, MGate Manager, and MCC Tool. Authentication is performed via a local database, with encryption via HTTPS (TLS 1.2), AES-128/256, and SHA-256. Network management is supported via SNMPv1/v2c/v3, NTP, and HTTPS. The devices are designed for industrial environments and comply with EMC standards EN 55032/35 and FCC Part 15B, as well as EMS standards IEC 61000-4-2/-3/-4/-5/-6/-8/-11. Safety certifications include UL 60950-1, UL 508, and EN 62368-1. Certifications for hazardous areas are available according to ATEX, IECEx, and DNV.

Mounting and Installation

The device is housed in a plastic housing with protection rating IP30. Dimensions are 29 x 89.2 x 124.5 mm (with brackets) or 29 x 89.2 x 118.5 mm (without brackets). Mounting is done via brackets suitable for securing to control panels or enclosures. Power supply is via a 7-pin terminal block in the range of 12 to 48 VDC. Power consumption is 435 mA at 12 VDC for standard models. An integrated relay output (1 A @ 30 VDC, resistive load) enables control of external loads.

Advantages in Operation

The MTBF (Mean Time Between Failures) for the MB3170 model is 1,662,526 hours according to Telcordia SR332, indicating high operational reliability and longevity. The operating temperature ranges from 0 to 60 °C (standard) or -40 to 75 °C (wide-range models), making the device suitable for use in harsh environments. Humidity tolerance of 5 to 95 % (non-condensing) allows use in humid or dry rooms. The 5-year manufacturer’s warranty underscores the product’s reliability.

Scope of Delivery

The scope of delivery includes the MGate MB3170 gateway, a quick start guide, and a warranty card.