摘要
不同媒体访问控制MAC协议直接导致了现场总线标准的多样化,这对现场总线的理解和应用造成了困难。具体分析了现场总线网络的特殊性,描述了目前使用的各种MAC协议及其优缺点,其中包括面向连接的协议、探询协议、TDMA、令牌环、令牌总线、虚拟令牌传递、隐性令牌传递、CSMA/CD、CSMA/CA和集总帧,进而揭示了这些MAC协议与现场总线标准之间的关系,有助于科研人员和用户选择适合需要的现场总线标准。
The differences of various MAC protocols directly result in diversification of fieldbus standards. It also brings difficulty for people to understand and use fieldbus. The specific characteristics of fieldbus network are analyzed concretely; various MAC protocols presently in use and their merits, demerits are described. These include connection-oriented protocol, polling protocol, TDMA, token ring, token bus, virtual token passing, implicit token passing, CSMA/CD, CSMA/CA and total frame protocols. Thus the relation between these MAC protocols and fieldbus standards is revealed for helping researchers and users to select suitable fieldbus standards.
出处
《自动化仪表》
CAS
北大核心
2009年第7期1-6,共6页
Process Automation Instrumentation
关键词
MAC
现场总线
标准
实时
协议
Media access control ( MAC) Fieldbus Standard Real-time Protocol