Pharmacy store control system design based on microcontrollers

LU Hong-chao， GAO Zhi-hui， WEI Lai
（School of Mechanical Engineering， Beijing University of Aeronautics and Astronautics， Beijing 100191， China）

Abstract： Aiming at the disadvantages of programmable logic controller （PLC） control system traditionally used in pharmacy store such as the complexity of programming， poor scalability， high cost and so on， a small distributed control systems （DCS） was designed， which used AT89C51 as the core and PC as the position machine. Then system hardware and software were presented to control several actuators motion as normal-reverse transfer， high and low speed， start and stop and display the number of drugs delivered by actuators. At the same time the communication process was introduced and RS232 serial port was adopted to realize one-on-one communication between PC and microchips. At last， a test running 1 000 different prescriptions randomly was done between the PLC control system and the DCS control system based on microchips and the efficiency delivering drugs and system stability were analyzed on different control methods. The results indicate that the time DCS control system used is 4.5 s less than that the PLC control system used and error rates is less than 0.2%. The control system based on microchips solves the deficiencies of traditional PLC control， improves efficiency and system stability，and has good scalability.
Key words： pharmacy store； PLC； microcontroller； distributed control systems （DCS）； serial communication