Design Of Sin/Cos To The RS422 Signal Converter

With the rapid development of economy and population explosion in urban areas, tall buildings have become the inevitable choice. As the vertical transportation or vehicle of the modern tall buildings, the elevator is closely related with people's lives. With the highly demand for elevator, it will certainly develop with high speed. The elevator control system decides the development of the entire elevator industry since it determines the speed, comfort, safety and other performances of elevators. The reliability and anti-interference capability of Sin/Cos to the RS422 signal converter, as the signal conversion equipment, plays a decisive role on the safety and reliability of the entire elevator system.Firstly, this paper reviews the development history of the elevator industry and states the significance of project development. Then the circuit designs are made to each module according to the goal of design and further researches are made on the type selection of components. Finally, design the PCB and the signal integrity. The key part of the entire project design is for the software design of CPLD of Sin/Cos to RS422 signal convertor. The design of CPLD include anti- interference filtering processing, frequency division and phase demodulation and is proceeding analog simulation to procedure code by ModelSim design. The result proves the conformance of design. After finishing the design of Sin/Cos to RS422 signal convertor, the hardware debug system is built according to the project demands. And then debug the samples of Sin/Cos to RS422 signal convertor which the result will correspond with the design demand. Comparing with the same products in the market, the project in this project will have higher cost performance. And then its safety and reliability are greatly increased.At the last, this paper designed the testing circuit board. It is used to test the product percent of pass quickly. Because encoder has six terminals in debug system, it is necessary to connect one by one to Sin/Cos to RS422 signal convertor. It is not convenient to test the percent of pass. The testing circuit board can solve above problems to increase the production efficiency and benefit. Nowadays, the design of Sin/Cos to RS422 signal convertor has been put into operation in the elevator system, which performs well.