在实时通信中对TTCAN的改进  

Improvement of TTCAN in Real-time Communication

作　　者：冯治宝[1] 萧伟[1] 周美娇[1] 应启戛[1] 

机构地区：[1]上海理工大学光学与电子信息工程学院,上海200093

出　　处：《自动化仪表》2009年第2期21-23,共3页Process Automation Instrumentation

摘　　要：TTCAN是工业领域中被广泛应用的现场总线协议。根据TTCAN协议的主要特点和存在的不足,提出了主/从模式的网络结构,主节点根据同步报文的特点在系统正在运行的情况下生成下一个计划调度表,在下一个周期开始时包含有同步报文传输信息的触发报文将被发送给所有的从节点,解决了调度表在线修改的问题。在同步报文和异步报文之间插入空闲时间,使二者实现时间隔离,避免了事件触发报文对时间触发报文的干扰。TTCAN is one of the fieldbus protocols that have been widely used in process industries. In accordance with the main features and shortcomings of TrCAN, the master-slave mode network strueture is proposed. In master node, the next planning scheduling table is created un- der normal operation of the system based on the characteristics of synchronous messages ; the trigging messages including synchronous messages transmission information are transmitted to all the slave nodes. Thus the problem of online modification of scheduling table is resolved. Idle time is inserted between synchronous messages and asynchronous messages to realize temporal isolation. It avoids the interference from event-triggered messages to time-triggered messages.

关 键 词：TTCAN计划调度 动态调度 时间触发 事件触发 时间隔离 

分 类 号：TP336[自动化与计算机技术—计算机系统结构]