Serial communication between PC and multi microcontroller in Windows condition

This paper introduces how to realize multi point serial communication with 51 series microcontrollers in Windows operation system.It explains the serial communication of the PC as the master and microcontrollers as the dominated.On the other hand,it narrates the certain problem that the author has come into contact with when using API.Further more, it brings forward the solution of the very problem.The communication program introduced here has worked smoothly in practice application and the paper supplies a solution approach of analogy problems.