The full name of Modem (Data Transfer unit) is data transmission unit, which uses GPRS network to convert serial port data into IP data or convert IP data into serial port data to communicate through GPRS network, and is suitable for use in unattended stations. The Modem I use is the Industry 1300-60 of Shanghai Jingshuo, which collects data online for 24 hours. The Industry 1300-60 has the function of automatically diagnosing whether the GPRS uplink data is smooth, which can avoid the TCP false connection data transmission is not smooth. The effect is good, and the GPRS traffic cost is saved.
If you want to understand Modem in depth, it is better to start from practical application cases.
1. Charging pile data network transmission
When the charging pile is working, the data can be quickly uploaded to the cloud server through the 4G Modem connected to the charging pile.
2. Data acquisition of distribution box
Some 4G modems with small size and rail installation can be centrally installed in the low-voltage distribution cabinet to quickly send data to the relevant control platform.
3. Remote networking alarm
4G Modem can respond quickly and upload the alarm data to the corresponding monitoring platform at the first time.
4. Smart factory data acquisition
When the Modem device with edge computing function is applied in the factory environment, it can be connected with the Modbus device, and at the same time, the device data can be collected by means of cloud collection or edge collection.
Although the industry of application is different, the principle of application is the same. The main function of Modem is to transmit the data of remote equipment back to the background center. To complete the data transmission, we need to establish a complete set of data transmission system.
With the increasing development of the Internet of Things, the use of Modem has provided great help for the integration of information and industry among various industries, and has gradually developed into the core technology of the Internet of Things application.
1) Data communication: TCP/IP protocol stack is integrated inside the Modem, which supports Modbus RTU to Modbus TCP; the public GSM/SMS/GPRS/3G/4G wireless network is used to provide users with wireless long-distance stable and reliable SMS and data transmission functions. Support SMS and data transmission; AT Command is supported.
2) Data acquisition: collect data of serial equipment, such as serial instrument, collector, PLC, SCADA, etc.
3) Support permanent online: Modem includes multiple online modes such as digital displacement trigger or pulse counting event trigger, timer trigger, voice incoming trigger and short message trigger; Built-in powerful timer function, supporting timing automatic reporting, timing online, timing offline, timing restart and other functions; The device supports always online.
4) Support master-slave: Support master-slave servers, which can be DNS or IP addresses.
5) Remote management: support remote SMS to restart the device and configure device parameters; Support remote program upgrade and remote SMS configuration parameter query.
6) Programmable: powerful programmable function, support custom handshake protocol, heartbeat packet content and offline protocol.