低压配电系统中CAN通信适配器设计

Design of CAN Communication Adapter of Low-Voltage Distribution Systems

针对异构网络不能互联互通及CAN总线传输数据量小,高速传输分包数据丢包等问题,提出一种基于透明传输和分包重组规则且适用于低压配电系统的CAN通信适配器。通过采用分包重组规则使CAN可发送数据达378 B,采用透明传输理论实现遵从Modbus协议的智能低压电器通过CAN总线简单、实时集中监控;通过研究不同波特率下适配器发送数据的延时时间,采用软件实时修正的方法避免高速发送分包数据时数据丢包。利用该适配器组建小型智能系统进行测试,结果表明,测控数据传输准确无误,实时性高,满足智能低压配电的需要。

In order to solve the problems such as interconnection on heterogeneous network, small data quantity of CAN, data loss in high-speed transmission of data and so on, a kind of CAN communication adapter based on transparent transmission and packet division and reassembly is proposed for low voltage distribution system. 378 B data can be sent by the rule of packet division and reassembly on CAN. By using transparent transmission theory, the intelligent low-voltage electrical apparatus complied with Modbus protocol can be monitored by CAN in simple, real-time centralized way. By studying delay time of data sending of adapter in different baud rates, data loss in high-speed data-sending would be avoided by the way of real-time correction of software. The re- suits of the test which sets up a small intelligent systems with this adapter shows that the measurement data transmission is accurate and high real-time, and it meets the needs of intelligent low-voltage distribution.