RS485通信程序，主机和从机都有了，现成的东西可以直接应用在你的开发中，PC程序用VB编写，485多机通讯是ASM的。-RS485 communication procedures, and from the host machine has a ready-made things can be directly used in your development, the PC using VB preparation procedures, more than 485 machine com

使用RS485 协议 使VB 和 单片机进行通信，控制步进马达，含原理图-RS485 agreement to use VB and MCU to communicate, control stepper motor, including schematic diagram

基于上位机用vb写的，和51单片机的集散系统设计。采用了rs232转rs485！-Based on the upper machine written in vb, and 51 SCM distribution system design. Using rs232 switch rs485!