The Design Of Remote Elevator Supervisory Control System Based On PLC

A remote elevator supervisory control system based on PLC was introducedin this paper. This paper is mainly referred to hardware design and softwaredesign about the elevator control system.The elevator structure consists ofmachine room, shaft, landing door, car and etc. The elevator have the function ofwhich is not only automatic leveling, automatic switch door, forward responsingto the call landing signal from car inside and outside, laying a course andelevator safety protections but also other special functions including stop,emergency stop, overhaul, lighting and ventilation.The elevator hardware system mainly consists of maindrivergear,tractionsystem,locating device,guide rail,guide shoe,counter-weight,door machineinstitutions,safety device and etc. safety device includes speed limiter,catchblock,dashpot,overweight alarm.The elevator control system adopts Siemens PLC series of S7-200CPU226CN and uses VVVF frequency conversion elevator host to control speedfrom slow, medium and fast. It also adopts Siemens AS-I （Actuator SensorInterface）bus technology. CP243-2is able to complete the AS-I master,which isresponsible for communication from slavers to control center. The control centerconsists of the CPU226CN and CPU243-2into enough.The control center istransferred from the machine room to the top of the car, and signals located inthe elevator car can be passed directly to the control center,while other signalslocated in the well room and shaft are connected to the slave. Slavers must behave communication to PLC only through the AS-I master. The dispersed slaversare mounted within the shaft and room, responsible for handling with the callbox signal and control of frequency converter. Deviding the power into twoparts, strong power and weak power, the system enhances the anti-jammingcapability, greatly saves the PLC input and output points so that the systemdesign is no longer subject to restrictions because of the number of input and output points of PLC. It also Greatly greatly reduced reduces quantity incable theincable quantity connected to the actuator and sensor and computer aswellimproves the reliability of the system.The use of free port mode can help complete the remote communication withthe connection between the CPU226CN port485and the modem access totelephone lines, then the connection of the modem and computer is completed inthe control room. The elevator monitor on the spot can be done well throughdial-up Internet access. To sum up, we can make use of SiemensSTEP-7MicroWIN programming software for remote monitoring.