What is a Cellular modem

  First of all, what is the industrial Cellular modem? Cellular modem itself is a kind of intermediate equipment, which is responsible for wireless/wired information transmission. It is divided into WIFI/4G/Ethernet. They use different means of communication for information interaction. The concept of the Internet of Things lies in overall planning and management, and in the interaction between servers and points. But for many equipment companies, They may not be good at information exchange, and Cellular modem is the solution to this situation.

  Equipment companies can use Cellular modem as communication middleware, which can simplify the difficulty of information interaction between end equipment and server, so that users can only consider the development of end equipment and the application of server logic, and no longer need to consider complex interaction means. Whether it is wireless WIFI/4G or wired Ethernet, the docking server can easily exchange information in the form of TCP, UDP, HTTP or MQTT.

  Cellular modem application scenario

  Cellular modem equipment does not only exist in the concept, now there are many scenarios, cellular modem has been used, such as the automatic switch of the 4G base station, operators will monitor the communication pressure of the 4G base station, when it is late at night, the network is less used, operators will remotely turn off the power of the base station. The way to shut down is to send modbus commands directly through Cellular modem to save energy.

  Not only that, turning on and off the base station is just a kind of transmission of information, you can exchange any information through the Cellular modem, for example, you can send instructions to query the current power usage of the base station, and the returned results will also return data to the server through the Cellular modem. Allows the server to monitor the operation of the device in real time.

  Not only in the application environment of people's livelihood, Cellular modem can show its strength. The emergence of Cellular modem is in fact a change in control thinking, which adds a way to the control of equipment. For the original equipment, data acquisition, data processing, equipment action and so on are all completed on the equipment. When the operator is not in the field, our control over the equipment is very poor.

  With the vigorous development of the Internet of Things, the concept of server has been brought more clearly, and the interconnection of all things is not empty talk. People expect a more centralized system to monitor and control the equipment, but in fact, the two biggest problems brought by this change are communication and server side, how to send the data monitored by the equipment to the server, how to process, store and analyze the data by the server are all problems.

  Therefore, many Internet of Things platforms have come one after another. Aliyun, Baidu, Tencent and China Mobile have launched their own related Internet of Things platforms to make samples for many Internet of Things enterprises. So the current pattern is that large Internet of Things applications or enterprises will use their own Internet of Things platforms to control devices, while small Internet of Things applications or enterprises will flock to the embrace of these large payment platforms. The data generated by these devices will finally have a home, and they will be sent to the background of these servers for processing.

  So when the problem of server direction is solved step by step, the problem of data transmission is also synchronized. Large applications or devices will have their own communication units, but small and medium-sized enterprises do not have the ability to independently complete the transmission of device information. This scenario is very suitable for Cellular modem. Cellular modem is actually an application product in the direction of the Internet of Things, a kind of communication middleware, which does not exist unilaterally for a certain device.

  Application of modbus

  As mentioned above, the new era has brought a new idea of the Internet of Things. The concept of emphasizing the server is to simplify the deployment of the device side, and to get rid of the independence of the end device more thoroughly. People want to deprive the brain of the end device, so that they no longer have their own thoughts, because there is a risk of problems with logical processing, and it is also a trouble to develop these logics.

  Take the simplest street lamp system for example, its light sensor will detect the surrounding lighting conditions. When the street lamp can be turned on in low light (at night), the light sensor is the detection device, and the switch of the lamp it controls is the control device. The simplest execution logic is to monitor the value of the light sensor all the time to decide whether to turn on the lamp.So you need a processor to execute this logic all the time. This is the simplest control system. In practice, the control system will have many detectors and controllers. People just want to deprive the value of the existence of this processor, because it costs manpower and material resources, and the failure of this processor will lead to the failure of the whole system.

  This is the value of modbus. Modbus is the kind of universal protocol that people expect to control the device. If the device itself supports modbus, it can be controlled and interacted directly through modbus instructions. Take the simplest street lamp system above. If the light sensor and the switching device of the lamp support modbus command control, the server acts as a control processor,Thousands of street lamps can be monitored at the same time, the server can issue a modbus instruction to query the value of the optical sensor, and then analyze whether it is necessary to issue a modbus instruction to control the switch of the street lamp, when the information is collected, the action of the equipment is realized by the modbus instruction as a carrier, and then all the control logic is moved to the server. We can really simplify the end devices and centralize the control system.

  Network IO

  As mentioned above, we have talked about Cellular modem, the increasingly serious server idea, modbus, and the application of Cellular modem plus modbus. Network IO is actually a gateway with a trade-off effect. Although all the sensors and controllers supporting modbus are combined,The control system can be realized by interacting the data with the server through the Cellular modem. However, the devices supporting modbus are generally more expensive, and the network IO appears to save costs. They are also Cellular modems that can transmit information. But at the same time, it can also be directly used as a control device to execute the opening and closing of the switch, the acquisition of the switch value and the acquisition of the analog value.Increase the functionality of the Cellular modem to simplify the overall system overhead.