What is a serial to the cellular modem?
The cellular modem(also called IP modem, DTU) is designed to provide internet connectivity across a broad range of M2M and IoT applications. A cellular modem is a wireless terminal device used to convert serial data into IP data or IP data to serial data through a wireless communication network. Also, it can be used as an SMS modem and Modbus RTU to Modbus TCP converter. Featuring LTE CAT 1/CAT 4, this modem is widely used in meteorology, hydrology and water conservancy, geology, smart grid, intelligent transportation, finance, mobile POS terminal, supply chain automation, industrial automation, intelligent building, fire protection, public safety, environmental protection, digital medical treatment, remote sensing survey, agriculture, forestry Industry, coal, petrochemical and other fields. They allow Internet connectivity via serial port such as RS232/RS485 to PLCs, meters, instruments. They help to transport data from any industrial device to data control servers over the LTE cellular network, allowing businesses to benefit from real-time data monitoring and acquisition, device management, and control.
The USR IOT range of industrial modem solutions is a family of cellular-enabled modems which have been designed to an industrial specification to allow an easy connection for remote devices over the internet. The USR IOT modems move away from the traditional approach of TCP/UDP connection built and maintenance using a set of AT commands which require a high skill level to implement correctly and reliably. Instead, set up and management are all achieved using the modern configuration utility which makes deployment a simple task.
How does modem work?
The GSM/GPRS/3G/4G IOT M2M Modem with a dynamic IP address will create the connection to the Server to build the tunnel, so the server can communicate to the GSM/GPRS/4G IOT M2M Modem. The GSM/GPRS/3G/4G IOT M2M Modem with the heartbeat can keep the connection tunnel online all the time. Once the connection disconnected, the GSM/GPRS/3G/4G IOT M2M Modem will auto redial to create the connection. The server must with a static IP address or DNS.
Under TCP/UDP mode, when the data length exceeds a fixed length or within the fixed time no new data received, the GSM/GPRS/3G/4G IOT M2M Modem will start to process the received data, packing the data then send to the specified IP address and Port or DNS and Port. Or unpack the data packets from the internet then transfer them to the com port according to the baud rate.