485 serial interface is the electronic industries association (electronic industries alliance, EIA) in the late 1970 s introduced digital communications electrical standards, it makes up for the 232 serial interface communication distance is short, low rate of less than. This standard has the network connection is convenient, good anti-interference performance and long transmission distance, etc. 485 serial interface transceiver using balance send and difference, thus has the ability of restrain common mode interference, plus a transceiver apparatus has high sensitivity, can detect the voltage of low of 200 my reliable communication transmission distance can reach thousands of meters. Use 485 serial interface bus network, just a pair of twisted-pair constitute a distributed system can realize the system network, simple equipment, low cost, long distance communication. Maximum transmission rate 10 Mb/s, maximum transmission distance is 1200 m, the RS - 485 to half duplex. Standard electric property of the interface only regulation, connectors, cable and communication protocol is not stated, but by the user based on the high-level communication protocol.

Keywords:   multi-motor      485 serial port     half-duplex

1 绪论 1

1.1 永磁交流伺服系统的现状和趋势 1

1.2 多电机协同控制的背景、现状和特点 3

1.3 本论文的主要研究内容 4

1.4 本章小结 4

2 系统的工作原理 5

2.1 485串口通信原理 5

2.2 485布线组网原理 7

   2.3本章小结 9

3 硬件设计 10

3.1 AVR128单片机芯片的简介及总体设计 10

3.2 各部分电路设计 11

3.2.2 串口电路的设计 .12

3.2.3数码管显示的电路设计 .13

       3.2.4按钮电路的设计 .14

3.3 本章小结 16

4 软件设计 17

4.1 软件的功能 17

4.2 主程序设计 17

4.3 串口程序设计 17

4.4 按钮程序设计 20

4.5 数码管程序设计 20

4.6 本章小结 21

5 系统和程序调试 22

    5.1程序的调试 22

5.2系统调试简介 23

5.1.1 静态调试 24

5.1.2 联机仿真调试 24

5.3 实验设备及实验系统硬件组成 24

5.4 实验结果 27

5.5 本章小结 28

6 结论 29

6.1 工作总结 29

6.2 研究展望 30

致    谢 31

参考文献 32

附   录A