【正文】 The saving machine can deposit the data that the I/O input in the saving machine, and in work adjusting to bee tired to add the machine and |10s to connect, saving machine separately saving machine RAM of the procedure saving machine ROM and datas, the ROM can can do deposit of the data permanence in the saving machine, but RAM only for the CPU putes the temporary calculation usage of hour of buffer space. The PLC anti interference is very and excellent, our root need not concern its service life and the work situation bad, these all problems have already no longer bee the topic that we fail, but stay to our is a concern to e to internal resources of make use of the PLC to strengthen the control ability of the equipments for us, make our equipments more gentle. the trapezoid diagram that the adoption is original after the electric appliances to control, make the electrical engineering teacher while weaving to write the procedure very easy prehended the PLC language, and a lot of non electricity professional also very quickly know and go deep into to the PLC. Application of PLC in the Elevator Control System of Intelligence Building In 1980s the first intelligence mansion had been pleted in America, then intelligence building has been a broadly taken attentions by the whole world. The concept of intelligence building has been put different meanings along with the development of society. The early stage intelligence building had been thought that it is equal to the intelligence mansion, but now the intelligence building not only includes the intelligence mansions but also involves intelligence residential districts. This paper mainly discusses one subsystem of intelligence building system: the elevator control system. In intelligence residential districts the enterprise’s information managing system mainly takes charge of the things which related to the daily life, for example supervising the district equipments, managing vehicles, disposing critical situations and so elevator supervising and control system is also necessary to the intelligence residential districts. How to make people feel safe, stable and fortable and how to save energy resources and protect environments and so on are the basic requirements to the elevator control system. PLC is a mon industry control device. It is a special industry control puter which has the perfect function and simple frame. The PLC strong ability in interference and so on makes the elevator industry one after another to apply the PLC to the elevator control s ystem, in order to replace the relay being used in traditional elevator control system. The Application of PLC in the elevator control system reduces the breakdown rate and efficiently improves the operating reliability of the elevator with safety. This paper mainly discusses the elevator control system’s working principles, the system’s software and hardware realization methods and so on. The Working Principles of Elevator Control System are stated as follows: The spot control information is send into the PLC from the customer input devices firstly, then the PLC control cabi is required to send out the control signal to drive the equipments according to the system demands. The elevator can then perform the homologous action according to the control request. There are velocity feedback devices in system, which adopt measure velocity generators to provide the elevator velocities and generally are installed in the tail of tow motors. So this is a feedback control system, which can improve the system’s control precision. It is not necessary to do interface circuit in the elevator’s PLC control system. What we should do is to send the signals to PLC digital input terminals. The signals include inside and outside calling signals, floor location inspecting signals, limiting location signals, opening and shutdown the elevator door signals etc. The DC power which is provided to PLC can be used as indicator light power. The PLC output points can be directly used to control transducers for the purpose of electrical motor’s positive turn and reverse, stop and control each segment velocity and so on. Moreover, input and output devices are needed in elevator control system, besides the PLC, system’s major control device. The control cabi is the control center, from which we can send out various control mands. The control cabi often was installed in the elevator room. The electric devices and signal systems, for example the contactors, relays, capacitances, resistors, rectifiers and transformers etc, are centralized in the control cabi. The Power of the control cabi was imported from the chief power of the elevator room. This power was also introduced into control panel by soft cables and was linked with each control buttons. The power lines which was derived from control cabi was delivered to tow electric motors. Others control lines and signal lines