RS-232 to RS-485/422 Converter schematic. It can support RS-422 and RS-485 to change only two jumppers. And it used general devices. 75176 can be replaced max485, 65LBC184 etc.

485通讯资料 485通讯中一个串口可以控制多少个设备的问题是与该485网络中的电气特性和协议特性所决定的。 -485 serial data 485 can be controlled in a number of equipment problems with the 485 network and protocol characteristics of the electrical properties determined.

现场总线CANbus与RS-485之间透明转换的实现-can and 485 convert

：利用RS485数据两线的硬件基础上，以较少的总线控制命令，实现RS485数据总线的时分复用功能，使总线上每一个节点均能平等地 发送数据，在软件设计上信号灯状态切换的时间同步不紊乱，通讯消息的收发有序不冲突以及通讯数据包的完整性-: Using hardware-based two-wire RS485 data on the bus with less control commands to achieve RS485 data bus time-division multiplexing