The serial server is a serial port to Ethernet module plus a shell, which has the function of electromagnetic isolation.

The serial port server provides the serial port to network function, which can convert the RS-232/485/422 serial port into a TCP/IP network interface, and realize two-way transparent data transmission between the RS-232/485/422 serial port and the TCP/IP network interface. The serial device can immediately have the function of TCP/IP network interface, connect the network for data communication, a···

The LoRa module has an open transmission distance of more than 5000 meters, which can solve the problem that low power consumption and long distance cannot have both. It is suitable for projects that require wireless meter reading and industrial control.

LoRa mainly operates in free frequency bands around the world (ie, unlicensed frequency bands), including 433, 868, 915 MHz, etc. LoRa network is mainly composed of terminal (built-in LoRa module), gateway (or base station), server and cloud.

NB-IoT refers to Narrow Band-Internet of Things technology. Focusing on the Low Power Wide Coverage (LPWA) Internet of Things (IoT) market, NB-IOT is an emerging technology that can be widely used around the world. NB-IOT uses the license frequency band, and can be deployed in three ways: in-band, guard band, or independent carrier to coexist with the existing network.

In the context of low-power wide-area network technologies such as NB-IoT/eMTC/LoRa, a "complementary effect" is formed in scenarios dominated by short-range technologies such as WiFi, Bluetooth, and Zigbee. What is the relationship between lora and bluetooth?

Generally, DTU can only transmit standard 232 and 485 data, while RTU can only convert analog data into serial port data after collection. DTU is a data transmission device, and RTU is a data acquisition device. The division of labor between the two is clear and easy to distinguish.

DTU is a wireless terminal device that uses the operator's 2G/3G/4G network to convert serial data into IP data or convert IP data into serial data. The following is an introduction to the rankings of DTU application fields.

NB-IoT technology has four major advantages:One is: wide coverage, the coverage of NB-IoT is 20 db better than the traditional GSM network, and one base station can provide 10 times the area coverage;

Narrow Band Internet of Things (NB-IoT) has become an important branch of the Internet of Everything. NB-IoT is widely popular for its strong coverage and long communication distance. So how big is NB-IoT's coverage and how to measure its coverage