Design And Realization Of Remote Elevator Monitoring System Based Of Field Bus

Remote Elevator Monitor System (REMS) acts as a very important role for thesafety and reliability of elevator, which appeared with the development ofcontemporary advanced technology. The emphasis of this paper is put on the structureof REMS, especially the realization of its data-acquisition module. CAN Bus was applied in this study on REMS as the main method of datatransferring, on the basis of which the data acquisition of elevator state was realized.At the same time the author analyzed the protocol of applied layer of CAN Bus,designed the circuits and completed the protocol of applied layer by using computerlanguage C51 due to the specification of CANopen. Several new design schemes were presented according to the deference of styleof communication between data-acquisition module and monitor station. By usingRS232 Bus, the data module for the conversion of CAN Bus to RS232 Bus wasdesigned. Then the communication between the data-acquisition module and monitorstation was fulfilled. This kind of scheme has simple circuits, concise programmingsoftware and low cost. However, the performance of monitor system was limited forthe low data transferring velocity of RS232. In order to tackle this problem, thedata-acquisition module for the conversion of CAN Bus to USB was designed. TheUSB module was designed using the chip of PDIUSBD12 produced by PHILIPSCompany, which greatly improved the performance of real-time monitoring andincreased the number of elevators monitored for USB Bus was provided with thecombination of convenience, flexibility of connection and high data transferringvelocity. CAN Bus repeater was designed with the function of conversion betweenRS422/485 and CAN Bus, which can extend the transmission distance, improve theflexibility and compatibility of the system, as well as make the system monitor theelevator based on RS485 Bus. The structure of two MCUs sharing one Dual-Port RAM is used for the design ofall the circuits used in this paper. The two MCUs are used for data transferring,protocol conversion, fault diagnosis and communication of station and all the data istransferred between the two MCUs through Dual-Port RAM. By using this kind ofstructure, the real-time performance is apparently improved. Finally, the REMS designed in this paper are validated applying deferentmodules, which are based on the testing platform built in our lab. The REMS systemusing data acquisition module for converting CAN Bus to RS232 Bus has stablyworked for a long time and produced good result.