【摘要】 设计了一种智能电动推柜系统,该系统采用具有双串口的P89C669单片机设计通信主板和控制板。主板利用P89C669的UART0构造了RS-485总线,与各个控制板通信;采用GM8123将P89C669的UART1扩展为3个串口(RS232-1,RS232-2,RS232-3),用来解决与多个设备通信的问题。同时控制板利用双串口还可以与其他设备(如读卡机)通信。更多还原

【Abstract】 An intelligent electric bookshelf system was designed; P89C669 which had two COMs was adopted to design the mainboard and control board. UART0 of P89C669 was used to construct RS- 485, which communicated with control board; UART1 of P89C669 was expanded to three COMs by GM8132, and the problem of communicating with several equipments was solved. At the same time, the control panels could communicate with other equipments (card reader) by using the two COMs.更多还原