1、PDF外文：http:/ of PLC in the Elevator Control System of Intelligence Building Abstract: The paper mainly discusses one subsystem of intelligence building system: the elevator control system. The PLC strong ability in interference and so on makes the elevator industry one after another to apply t
2、he PLC to the elevator control system 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 .The structure of sys
3、tem is also simple and tightly packed.The working principle of the elevator control system is: The spot control information is send into the from the customer input devices firstly, then the PLC control cabinet is required to send out the control signal to drive the equipments according to the
4、 system demands. The elevator can then proceed the homologous action according to the control request .The paper selects companys 200HE series PLC, introducing parts of signal hookup of the elevator control system and explaining the function of the control cabinet. Lastly the automation progra
5、mming is introduced. Simulated experiments enunciates that the design method is viable. It can make the personnel of the industry management center to long-distance monitor and control the elevator in control center, to connect the elevator control system with intelligence building industry manageme
6、nt system by Ethernet or special-purpose network such as Lon Works.The elevator working state can also be timely watched.These not only can realize scientific centralized management of the elevator, but also can lower the elevator maintenance cost etc. It is one of the developing direction of intell
7、igence building elevator control system. Keywords: PLC； intelligence building； elevator control system； working principle； program design . Introduction In 1980s The first intelligence mansion had been completed in America, then intelligence building has been abroadly taken attent
8、ions 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 intelligent mansion, but now the intelligence building not only includes the intelligence
9、 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 enterprises information managing system mainly takes charge of the things which rela
10、ted to the daily life, for example supervising the district equipments, managing vehicles, disposing critical situations and so on.The elevator supervising and control system is also necessary to the intelligence residential districts.How to make people feel safe ,stable and comfortable and how to s
11、ave energy resources and protect environments and so on are the basic requirements to the elevator control system. PLC is a common industry control device.It is a special industry control computer which has the perfect function and simple frame. The PLC strong ability in interference and so on
12、 makes the elevator industry one after another to apply the PLC to the elevator control system, 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 rel
13、iability of the elevator with safety. This paper mainly discusses the elevator control systems working principles, the systems software and hardware realization methods and so on. . The Working Principle of Elevator Control System In Fig. 1 the Hardware Structure Graph of Elevator Contr
14、ol System is presented. Fig. 1 The Hardware Structure Graph of Elevator Control System 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 cabinet is required to
15、 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 ge
16、nerally are installed in the tail of tow motors .So this is a feedback control system, which can improve the systems control precision. . The Hardware Configuration of Control System It is not necessary to do interface circuit in the elevators PLC control system.What we should do is to
17、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 P
18、LC output points can be directly used to control transducers for the purpose of electrical motors positive turn and reverse ,stop and control each segment velocity and so on . companys 200HE series PLC has been selected as major control configuration according to the input/output points and th
19、e length of users program. On the other hand we also consider that the systems function can be expanded in the future . 200HE series PLC ,whose perfect function and strong reliability, can meet these demands at present. Moreover, input and output devices are needed in elevator control system,
20、besides the PLC, systems major control device. Part of signal hookups of the elevator electric control system is shown in Fig.2. The control cabinet is the control center, from which we can send out various control commands. The control cabinet often was installed in the elevator room .T
21、he electric devices and signal systems, for example the contactors, relays, capacitances, resistors, rectifiers and transformers etc., are centralized in the control cabinet. The Power of the control cabinet was imported from the chief power of the elevator room. This power was also introduced into
22、control panel by soft cables and was linked with each control buttons. The power lines which was derived from control cabinet was delivered to tow electric motors. Others control lines and signal lines were separately sent to each floor junction . Program design The design includes two
23、parts: hardware and software.The hardware design is the base of software. Considering that the control demands are relatively complex, we design the programs separately according to the control function. Furthermore, we follow the principle as follows: When the elevator is ascending, the ascending d
24、emands are prior to other demands； When the elevator is descending, the descending demands are prior to other demands. The Sequential Function Chart (SFC) is adopted during the boxes to form elevators executive circuitry design. It is a method specially used in industrial sequential control. The SFC method can describe the systems working procedure in great detail. For example there is a three layers intelligence building. A subprogram, the calling from the third floor as elevator in the first floor, is shown in Fig. 3 with SFC.
