流程加工CAN测控网络的应用层协议研究

为提高CAN测控网络的适应性和通信效率,以CAN2.0A技术规范为基础,针对流程加工测控网络的特点,设计面向流程加工领域的CAN总线应用层协议ProCAN。在明确流程加工概念及范围的基础上,分析流程加工测控系统结构模型的特征,提出通信报文的类型,定义标准数据帧仲裁域与数据域的编码格式,并讨论ProCAN协议的通信模式、通信状态、通信异常及长报文误帧重传控制。利用OPNET网络仿真软件进行实验,结果表明,ProCAN协议能实现报文通信,并且具有延时短、实时性强、可靠性高的特点,尤其当网络负载较大时,效果更为明显。

Research on Application Layer Protocol of CAN Measurement and Control Network for Process Machining

In order to improve the adaptability and the communicative efficiency of CAN control network,the ProCAN in the field of process industry is designed,which is based on the technical specification of CAN2.0A and the features of machining process control network. This paper analyzes the features of machining process control system structure model,and proposes the types of communication messages,defines the coding of the standard data frame arbitration field and data field. Meanwhile,the communication model,the control of communication state network,the abnormal communication and the long packets retransmission of error frames for ProCAN protocol are discussed. By using OPNET network simulation software,simulation experiments show that the ProCAN protocol is able to achieve message communication with characteristics of low time delay,strong real-time capacity,high reliability,especially when the network is overload.