文章介绍了ＲＳ４８５与ＲＳ２３２之间的电平转换问题，实际设计了一个ＲＳ４８５与ＲＳ２３２的转换卡，讨论了ＶＣ＋＋５．０版中有关串行通信的ＡｃｔｉｖｅＸ控件的使用方法，实现了串行输出数据采集芯片ＰＳ２００３与ＰＣ之间的串口通信。 This article introduces the problem of level conversion between RS485 and RS232, and actually design a conversion card of RS485 and RS232, and discusses the use of ActiveX control in VC ++ version 5.0 for serial communication , To achieve a serial output data acquisition chip PS2003 serial communication between the PC.