Recently, the rise of the Internet of Things (IoT) trend and the emergence of a large number of low-cost sensing and control elements have led to the rapid development of smart homes. Various home devices have begun to join the networking and intelligent functions. This shift will also allow automation control applications to gradually enter the general public's home from the larger factories, commercial buildings or public places. Before the advent of the concept of Internet of Things (IoT), automation had a long history of development, from factories, office buildings, ancillary facilities to homes, all of which are automatically controlled applications. Early related components, building costs, hardware and software integration technology has a higher threshold, most of the automatic control only appears in factories, large commercial buildings or facilities and other places, has been unable to popularize for home applications. In recent years, with the emergence of low-cost sensing and control elements, the vigorous development of network capture technologies, and the rapid popularization of various smart devices, the concept of IoT has been put forward. Not only is the popularization of smart home showing the dawn, for the entire field of automatic control There are also new opportunities. But this should be the same strain of automatic control and IoT areas, sometimes observed there is a "generation gap", this article will be from the automatic control, IoT application requirements, to explore related technologies, solutions for the development trend. Automatic control gradually move closer to the IP network Those who believe early in the field of building automation should be familiar to the Modbus protocol, and the Modobus Modbus protocol, proposed in 1979, became a common standard for early control networks because of its easy-to-understand data format. Early control networks, including Modbus, are wired standard cabling using Serial Communication at the physical layer. Commonly used are RS422 and RS485. There are quite a few issues to be aware of in this type of serial communication, such as the Baud-rate, Parity, Stop Bit, and Inter-Message Interval, Wire material, length, stranded specifications, series connection, interference isolation and termination resistance, may affect the communication quality. These factors also make the traditional serial communication control network has a higher fabricating, maintenance costs and the implementation of technology threshold. With the development of computer networks, TCP / IP has gradually become the common protocol structure of communications on computer networks. Some traditional control networks have also evolved into TCP / IP-based architectures. In response to this trend, the Modbus protocol has also evolved from Modbus RTUs that used serial communications in the past to Modbus TCP that uses the Ethernet with TCP / IP protocol architecture and uses the Transmission Control Protocol (TCP) transport layer protocol to carry the original serial communications. Thanks to the simplicity of the Ethernet architecture, the low maintenance cost and the large number of applications in computer networks, Modbus TCP does not have to worry about the complexity of serial communication signals and wire specifications compared with the old architecture, making the construction and maintenance costs , A lot of technical thresholds are reduced. Because of the use of the TCP / IP protocol architecture, network layer IP protocol can be used for addressing and routing. Modbus TCP also has a wider range of addressing space and the ability to support larger domains. When used with a network bridge, it can also be transmitted over network types such as wireless, power lines, and optical fibers to make Modbus TCP suitable for more complex network environments (Figure 1). Figure 1 The traditional automatic control network to TCP / IP protocol architecture closer to the computer network, other IoT network integration, to create a more diverse applications. On the other hand, as electronic components are mass-produced, the cost is reduced, various types of computers closer to the computer network, and advertised that the sensors, controllers and related integrated architecture that are easy to develop are inexpensive and easy to develop have sprung up. Such as various miniature sensors using ZigBee, Bluetooth Low Energy (BLE), Arduino, Raspberry Pi, among others. Such solutions are extensive use of wireless transmission, easy to compatible with the computer network, and under the banner of IoT, has become a new military strategist. Internet of Things leads to automatic control of software / hardware modernization It is necessary to construct a network that can be used for living around and connecting various devices in series because it is impossible to avoid the need to consider the reliability and energy efficiency in order to provide a stable service for a long time. Has been widely used in the field of automatic control of various types of industrial specifications controllers, sensors, because the structure is simple and after a long product development, reliability and energy efficiency are good performance. Into the IoT era, due to a larger number of communications needs, more diversified communications content, mode and function of applications, making reliability and energy efficiency are facing new challenges. Building a standardized, support-rich architecture may be a good way to see some hardware / software vendors now actively moving in this direction, such as HomeKit from Apple, Google-led Thread Group, and Intel OCT IoTivity and AllSeen AllJoyn led by Qualcomm are all integrated service framework solutions for the IoT Protocol Stack and Application Runtime, Part of the commercialization. There are integrated service architecture solutions, the most convenient than software development and product integration. Software developers can develop applications based on the application programming interfaces (APIs) they provide, with the added benefit of ensuring reliability and information security, with little thought of integration issues. Equipment manufacturers only need in the sensor, the controller belongs to the appropriate service architecture and to meet the relevant norms, you can make the product has good compatibility. In the part of product integration, it is compatible with the indication of a certain service structure, and it is more convenient for the personnel to select the products for deployment or even to purchase. In addition to the integration of service architecture, but also to the hardware level, is the controller, the sensor used by the micro-operating system. Most of the early products were developed by vendors themselves, or closed micro-operating systems developed by software vendors. In recent years, some open source micro-operating systems based on UNIX-like, POSIX operating system architectures have emerged, such as Mbed, Contiki, FreeRTOS and so on.