Compared with system integration and intelligent building, weak current engineering is a relatively perfect unit in construction engineering. With the continuous development of technology, weak current engineering can not be replaced in construction engineering. For example, in the residential construction, the subsystems of weak current engineering are also gradually expanding. In addition to the traditional cable TV and broadband network, many subsystems such as building access control, video monitoring, intrusion alarm, optical fiber into the home, three meter remote transmission, property management and so on are added. The concepts of green building and intelligent building have gradually taken root in the hearts of the people, and have been gradually promoted in construction projects. The integration of household appliances and the combination of indoor information network switches and servers have brought a more intelligent service experience. All functions need the support of weak current engineering. Most projects need weak current system, but there is not much demand for system integration and intelligent building. When investing in the weak current part of the construction project, it is necessary to consider the investment according to the actual situation of the project.

System integration is an important technical means for centralized control of relevant systems (such as security, central air conditioning, water supply and drainage, fire fighting, lighting, electromechanical and other professional subsystems) in the building. It can realize the centralized control of each relatively independent operation system, including weak electronic system and important operation projects in buildings, as well as information sharing among individual buildings. The centralized management system replaces the traditional management mode, so as to realize the systematization and integration of management. Due to the large number of equipment, software and hardware involved in this process and lack of unity, in order to achieve the purpose of unified allocation and management, it is necessary to use certain technical means for resource integration, data processing and system compatibility, that is, system integration, which is much more complicated than several separate weak current projects. In addition to the powerful control function of the integrated system, various key software technologies, supported hardware configuration, and information transmission and sharing between independent systems are important foundations for the normal operation of the integrated system.

3. Intelligent building
The intelligent building mode needs to be realized on the basis of system integration, which can integrate a variety of relevant factors, multiple objective optimization and multiple disciplines, so as to realize the high sharing of all information resources. Thus, the operation efficiency of all equipment is greatly improved, the safe operation of the building is ensured, and the operation cost can be reduced to achieve the comprehensive purpose once and for all.

Although intelligent building needs to be based on system integration, it does not mean that intelligent building and system integration can be equated. There are still differences between them. Because the application of intelligent building is very extensive, involving many aspects and strong comprehensiveness, we should carefully deal with the preliminary work, especially the key links. Systematic and comprehensive analysis shall be carried out for each building's own function and management mode, and targeted investigation and demonstration shall be carried out; Deepen the research and development of software through the analysis of relevant integrated software, especially the software of property management; Through comprehensive analysis, the perfect and applicable software is applied to each subsystem for comprehensive integrated management.