Analysis of the Internal Structure of LTE Modem, Explores Its Function, Performance and Reliability

ANALYSIS OF THE INTERNAL STRUCTURE OF THE LTE modem

The full name of Lte modem is the data terminal unit, which is like a Protocol converter. The interconnection and intercommunication between the industrial equipment serial port and the Ethernet/wireless network can be realized. In its small shell, it integrates a serial port module, Ethernet module, wireless communication module, and so on. Through these modules and interfaces, a 4G LTE modem can be connected to various sensors, actuators, and drivers. Realize the function of receiving and transmitting data.

1. Serial port module: it supports industrial standard serial ports such as RS232, RS422, and RS485, and is used for data interaction with field equipment.

2. Ethernet Module: Provides a standard RJ45 interface that allows an Lte modem to be plugged directly into an Ethernet network to communicate with other devices on the network.

3. Wireless communication module: built-in WiFi, 2G/3G/4G, and other wireless modules to achieve wireless transmission.

4. MCU module: responsible for operation control, data processing, and other functions of each module.

5. Power module: provide stable working voltage.

Lte modem is like an industrial equipment data processing and conversion station, which is responsible for collecting equipment data and converting protocols. And transmit that data to a monitoring center through a wired/wireless network. This configuration is ideal for use in complex industrial environments.

LIST OF INTERFACES PROVIDED BY LTE MODEM

LTE modem can easily connect various sensors, executes, and controllers through its various standard interfaces. Build the industrial Internet of Things. The main interfaces are as follows:

1. RS232/RS485 serial port: This is the most basic interface of the LTE modem, which is used to connect field serial devices, such as PLC, sensor, etc.

2. RJ45 Ethernet port: connect to the IP network through the standard Ethernet port to realize the networking of remote devices.

3. WIFI/4G antenna interface: Wireless transmission makes the device more flexible.

4. USB interface: used for device configuration and auxiliary function interface.

5. DC power supply interface: input stable industrial power supply to ensure stable operation of LTE modem.

6. Binary input/output interface: connect digital input and output signals.

7. Analog input interface: connect the analog sensor and collect analog data.

It can be seen that the modem basically covers all the important interface forms needed for industrial interconnection, which can be described as a complete interface and flexible connection.

COMMUNICATION PROTOCOLS SUPPORTED BY LTE MODEM

There are many industrial communication protocols in the industrial Internet of Things, and Lte modem is equivalent to a protocol converter. It can support a variety of industrial communication protocols and convert them into standard IP data for network transmission. Major agreements such as:

1. Modbus: industrial serial communication protocol, widely used.

2. DF1: AB PLC specific communication protocol.

3. CANopen: Universal Serial Bus communication protocol.

4. OPC: Industrial Data Exchange Standard Protocol.

5. TCP/IP: Internet standard protocol.

6. MQTT: Internet of Things Application Layer Communication Protocol.

It can be seen that multi-protocol support is an important function and advantage of DTU. In the industrial Internet of Things system, devices from different manufacturers use different communication protocols, and DTU can effectively connect them. This greatly simplifies the system integration process and reduces the cost of interoperability.

LTE MODEM'S ROLE IN THE INDUSTRIAL INTERNET OF THINGS

LTE modem plays an important role as a "connector" in the industrial Internet of Things system, mainly for the following purposes:

1. Industrial equipment interconnection: connect the industrial equipment using serial communication to the IP network.

2. Data collection: collect field equipment parameters, status data, etc.

3. Remote equipment monitoring: realize remote monitoring of field equipment.

4. Remote control of equipment: send control instructions to the site and remotely control the equipment.

5. Data preprocessing: Before the data is sent to the cloud platform, data filtering, format conversion, and other processing can be performed in the DTU.

6. Data cache: Data can be temporarily stored in the DTU when the network is interrupted.

7. Protocol conversion: implement protocol conversion between devices from different manufacturers.

8. Security control: LTE modem can perform data security verification to ensure the security of data transmission.

Through the above introduction, we can see that the LTE modem plays a key role as a bridge in the industrial Internet of Things system. It realizes the connection from the old serial port equipment to the modern Internet of Things, and makes the traditional industrial equipment really have the ability of "Internet of Things". It greatly reduces the difficulty of industrial interconnection and promotes the transformation and upgrading of industrial equipment to IoT.

LTE MODEM PRODUCT RECOMMENDATION

According to the above introduction, the principle and function of the LTE modem have been fully understood. Finally, we recommend an LTE modem with excellent cost performance.

LTE modem USR-G786 adopts an industrial design, equipped with a high-performance MCU and powerful communication module, which fully meets the needs of industrial applications. The main features are as follows:

USR-G786 is an LTE Cat 4 Modem with low latency, high reliability, and high real-time characteristics. The product has a fast transmission rate, with an uplink peak rate of 50Mbps and a downlink peak rate of 150Mbps. USR-G786-G supports the frequency bands of major operators all over the world, USR-G786-EUX in Europe, and USR-G786-AUX in Australia and Latin America. The product supports TCP/UDP transparent transmission, SMS transparent transmission, HTTP transparent transmission, and mutual conversion between Modbus TCP and RTU. The product has rich functions, is simple to use, and supports customization. It can realize functions such as MQTT to meet more functional needs of customers.

● DC 9-36V wide input voltage range power supply

● 4G LTE， fallback to 3G/2G

● Two-way Transparent transmission

● TCP/UDP, HTTP, SMS, Modbus, MQTT

● SMS, NET, Serial AT command configuration

● FTP Upgrade and FOTA self-upgrade

● Socket Distribution Protocol

● Rich interfaces: 1 RS485 serial port, 1 RJ45 port.

● Multi-protocol support: Modbus, CANopen, and other protocols.

● High speed: Serial port supports 921600bps, and the transmission speed is fast.

● High reliability: wide operating temperature range, -40~85℃, suitable for complex working conditions.

● Security verification: support VPN and other security verification to ensure data security.

● Portable design: Compact handheld size, easy to install.

● Price advantage: similar products have the highest neutral cost performance.

LTE modem is an excellent choice for industrial Internet of Things applications in terms of function, performance, and reliability.