Serial to Cellular Modem

MGT551 Serial to LTE Cat-4 Cellular Modem
  • 1*RS232/485/422 Port, 1 *SIM Card Slot
Features and Benefits
  • Support the host computer to configure/query device parameters through the serial port AT command
  • Support remote configuration/inquiry of device parameters through the Maiwei cloud platform
  • Support multiple working modes: simple transparent transmission, Ali MQTT, China Mobile OneNET MQTT protocol, Modbus
  • Simple transparent transmission mode supports TCP Client, UDP Client, SSL
  • Feature automatic reconnection in case of network disconnection
  • Support network data reception timeout disconnect and reconnection functionality
  • Independent hardware watchdog design to prevent system crashes
  • Overview
  • Specifications
  • Downloads
  • Models
Product Description

MGT551 industrial wireless 4G serial to cellular modem is a terminal device for wireless data transmission based on the mobile, Unicom, and telecommunications networks. It provides an wireless data transmission channel with TCP/IP network protocol for industrial users. It can offer a fully transparent data channel for bidirectional data transmission from serial ports to the network, enabling wireless data communication between on-site RS232/485/422 bus devices and central control systems. This makes industrial communication smoother, more reliable, and faster, meeting the customer's continuous innovation needs for improving value-added applications.


4G serial to cellular modem provides a wide range of DC power inputs. In terms of installation, the MGT551 industrial 4G serial to cellular modem uses wall-mounted installation. In terms of core components, the product adopts an industrial-grade quality design scheme, with many advantages such as wide network coverage, flexible and fast networking, and low operating costs. It can be used in industries such as power systems, industrial monitoring, traffic management, meteorology, water treatment, environmental monitoring, finance and securities, coal mining, petroleum, etc. It is used for remote on-site data collection, remote monitoring, on-site control, and is an indispensable industrial communication product for the development of the industrial Internet of Things.

Features and Benefits

-Embedded 4G serial to cellular modem, compatible with RS232/485/422 bus

-Allow the upper computer to configure/query device parameters through serial AT commands

-Support remote configuration/query of device parameters through the Maiwe Cloud platform

-Support TCP/UDP Server and TCP/UDP Client functionality

-Support SSL encryption (available only in firmware versions V1.5.xx)

-Support ICMP detection, PPP layer heartbeat, TCP/IP layer heartbeat, and ping functionality (available only in firmware versions V2.0.xx and above)

-Support 2 socket connections

-TCP/IP layer network heartbeat

-Support heartbeat and registration packet functions, including ICCID, IMEI, user-defined data types

-Feature automatic reconnection in case of network disconnection

-Support network data reception timeout disconnect and reconnection functionality

-Support transparent transmission, Maiwe Cloud communication protocol, Alibaba MQTT, China Mobile OneNET MQTT, Modbus, DDP/DC

-Support RS232/485/422 standard buses

-Support serial data packaging based on length and time

-Support SMS functionality in both Chinese and English

-Support FTP remote upgrades


Network Protocol


User Configuration

AT Commands

Operation Mode

Simple Transparent Transmission, Alibaba MQTT, China Mobile OneNET MQTT, Modbus, DDP/DC Protocol

Simple Transparent Transmission

TCP/UDP Server, TCP/UDP Client


Alibaba MQTT / China Mobile OneNet MQTT


Supports SMS in Chinese and English

Registration Package/Heartbeat Package

Types include ICCID, IMEI, user-defined data, etc. User-defined data types support hexadecimal and string formats

Serial Port Data Packaging

Time and length can be configured. Packaging length: 1~1000 bytes, packaging time: 10~60000ms (Different software versions may have variations in the packaging mechanism; you can inquire with our customer service for specific details.)

Network Cache

Send: 1 Kbyte; Receive: 1 Kbyte

Serial Port Cache

Send: 1 Kbyte; Receive: 1 Kbyte

Remote Configuration


Supporting Software

DTU Configuration Tool

4G Cellular Network


MGT551-E (European Version)

Working Frequency

LTE- FDD: B1/B3/B5/B8

LTE-TDD: B34/B38/B39/B40/B41


GSM: 900/1800MHz

LTE-FDD: B1/B3/B7/B8/B20/B28A

TDD: B38/B40/B41


GSM: 900/1800MHz


Antenna Connector

1*antenna connector, using SMA-K (external thread, internal hole)

Serial Port

Serial Port : 1*RS232/485/422 port

Connection Method: RS485/422 uses 5-pin 3.81mm pitch terminal blocks, RS232 uses DB9M

Baud Rate: 600bps~460800bps

Data Bits: 7 bits, 8 bits

Stop Bits: 1 bit, 2 bits

Parity: None, Odd, Even

SIM Card Slot

1 *SIM card slot


One-button restart or factory reset button

Status LED

Power indicator, Status Indicator, NET indicator, LINK A/B indicators, Serial port transmit and receive data indicators

Power Supply

Input Voltage

DC 9~36V, reverse polarity protection

Working Current

MGT551: Average 68mA@DC12V, Maximum 230mA@DC12V

MGT551-E: Average 60mA@DC12V, Maximum 200mA@DC12V


2* 5.08mm pitch terminal blocks

Physical Characteristics


96×90×26 mm (including mounting brackets)


Wall mount

IP Code


Working Environment

Operating Temp


Storage Temp


Relative Humidity

5%~95% (non-condensing)

Industry Standard


IEC 61000-4-2 (ESD): Contact Discharge ±8kV, Air Discharge ±15kV

IEC 61000-4-5 (Surge): Power Lines: Common Mode ±4kV, Differential Mode ±2kV;RS485/422: Common Mode ±4kV, Differential Mode ±2kV

IEC 61000-4-4 (EFT): Power Lines: ±4kV; Communication Ports: ±2kV






MGT551 User Manual

Version 1.1

Standard Model


4G Antenna

Input Voltage





MGT551-E (European Version)



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