Modem itself is a kind of intermediate networking equipment, responsible for wireless/wired information transmission, divided into Wi-Fi/4G/Ethernet, they use different means of communication for information interaction, the concept of the Internet of Things lies in overall planning and management, lies in the interaction between servers and points, but for many equipment companies. Formal communication and information exchange is what they need, and Modem is the solution to this situation.
Equipment companies can use Modem as a communication intermediate device, which can simplify the difficulty of information interaction between end devices and servers, so that users can only consider the development of end devices and the application of server logic, and no longer need to consider complex means of interaction, whether it is wireless Wi-Fi/4G or wired Ethernet. The docking server, whether in the form of TCP, UDP, HTTP or MQTT, can easily exchange information.
Modem does not only exist in the concept, now there are many scenarios, has used Modem, such as the automatic switch of 5G base station, operators will monitor the communication pressure of 5G base station, when it is late at night, the network is less used, operators will remotely turn off the base station power, the way to turn off is to send Modbus directly through Modem. O as to achieve the purpose of saving energy.
Not only that, turning on and off the base station is only a kind of information transmission. You can exchange any information through the Modem. For example, you can send instructions to query the current power usage of the base station, and the returned results will also return the data to the server through the Modem, so that the server can monitor the operation of the equipment in real time.
Not only in the people's livelihood application environment, Modem can show its strength. The emergence of 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 on the spot, our controllability of the equipment is very poor.
Increasingly heavy server thinking
With the vigorous development of the Internet of Things, it is not empty talk to promote the landing of networking more clearly. It is expected that a more centralized system for monitoring and controlling equipment will emerge. In fact, the two biggest problems brought about by this change are communication and server side. How to send the data monitored by the device to the server, and how the server processes, stores and analyzes the data are all problems.
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.
Therefore, 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 Modem to play. Therefore, Modem is actually an application product in the direction of the Internet of Things, a kind of communication middleware, which does not exist unilaterally in a certain device.
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, which is the kind of universal protocol that people expect to control devices. If the device itself supports Modbus, the control interaction can be performed directly through Modbus commands.
Take the simplest street lamp system above as an example, if the light sensor and the switch device of the lamp support Modbus command control, then the server, as a control processor, can monitor thousands of street lamps at the same time. The server can issue Modbus commands to query the value of the light sensor, and then analyze whether it is necessary to issue Modbus commands to control the street lamp switch. When the information is collected, the action of the equipment is realized by Modbus instructions as a carrier.By moving all the control logic to the server, we can really simplify the end-to-end equipment and centralize the control system.
As mentioned above, we have talked about Modem, the increasingly serious server idea, Modbus, and the application of Modem plus Modbus. As for network IO, it is actually a gateway with a trade-off effect.
Although the control system can be realized by combining all the sensors and controllers supporting Modbus and interacting the data with the server through the Modem, the equipment supporting Modbus is generally more expensive, and the network IO appears to save costs, and it is also a Modem 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, and increase the function of the Modem, thereby simplifying the expenditure of the whole system.