中文摘要：

设计了一种基于局域网和SPI总线的分布式实验系统，现场控制单元及各子系统都单独使用一片单片机为核心控制器件，使各子系统之间“各司其职”，互不影响．现场控制单元通过SPI总线实现对各子系统（数据采集系统、开关量检测系统、模拟量控制系统、开关量控制系统）的数据信息采集与控制，上位PC机通过RS232或局域网与现场控制单元实现数据信息的交换与控制．

英文摘要：

A distributed experimental system based on LAN and SPI bus has been designed. Field control unit and every subsystems use respective single chip microcomputer as core control device, which makes every subsystem carry out their duties with no interaction. Implementation of each subsystem （ data acquisition system, switch value detection system, analog value control system and switch value control system） data information acquisition and control has been made by the SPI bus for the field control unit. The host computer, via RS232 or LAN and field control unit achieves the exchange and control of data information.