使用RS-485数据接口系统有许多好处,其中之一就是它能实现多站通信网络。这是RS-485系统与RS-232系统的不同之处。多站通信网络通常传送9位数据字,其中第9位(奇偶校验位)作为地址或数据来识别每一个数据字。当在没有硬件UART的情况下使用很小的微控制器,如图1中的IC_1时,设计人员必须做出抉择:是增加一个外部硬件UART,还是在软件中配置一个UART。外部的UART曾使电路板面积、复杂性和成本 There are many benefits to using the RS-485 data interface system, and one of them is that it enables multi-site communication networks. This is the difference between the RS-485 system and the RS-232 system. A multi-station communication network typically transmits 9 data words, of which 9 (parity) identifies each data word as an address or data. When using a tiny microcontroller, such as IC_1 in Figure 1, without a hardware UART, the designer must decide whether to add an external hardware UART or configure a UART in the software. The external UART once made the board area, complexity and cost