Abstract: This paper designs a concentrating surveillance-control system about tobacco baking based on RS485 bus.The upper machine and lower machine all employ microcontroller.The upper machine can monitor and control the data of lower machines from afar.The lower machines utilize  real time chip X1228 as its time system and E2PROM,and employ digital temperature sensor DS18B20 collecting temperature and humidity.The lower machines have multiple curves and self-study functions,and are suitable for multiple requirements of tobacco in different areas and different seasons.

Key words: RS485 bus, tobacco baking, concentrating surveillance-control, microcontroller, real time clock X1228