基于CAN总线的多品牌小型PLC监控系统的设计与实现

发布时间：2018-02-20 22:15

本文关键词： CAN总线 PLC 现场监控 MC68HC908GZ60 上位机通信　出处：《苏州大学》2008年硕士论文　论文类型：学位论文

【摘要】： 现场管理信息化已成为中小企业保持其竞争力的必然趋势。本课题针对中小企业现场自动化设备的特点,利用CAN总线技术和设备上的小型PLC自带的通信协议,成功实现PC机与几种品牌的小型PLC通信,在不改变设备现状的情况下,完成设备运行过程的监控,达到低成本实现现场管理信息化的目标。监控系统的硬件部分以Freescale公司的MC68HC908GZ60微控制器为核心,包含RS232C串行通信接口、CAN总线接口等。设计过程中,采用了硬件防干扰技术来保证系统中的信号稳定。系统的软件部分包括MCU方软件与PC方软件两个部分组成。MCU方软件又分为主控节点和监控节点两部分,遵循嵌入式软件编程规范进行设计,完成了系统初始化、CAN总线通信、主控节点与PC的串口通信以及监控节点与PLC的上位机协议通信;PC方软件按照面向对象软件设计方法进行设计,完成了与主控节点通信、参数设置、实时监控、历史记录与查询等模块的设计,并对应这些模块设计出相关操作界面。在完成系统的软硬件设计及测试等工作后,到苏州某小企业进行初步现场调试,监控效果较好,得到了企业的肯定。本课题的主要应用创新点有:针对中小企业的设备特点和各品牌PLC不开放的现状,利用CAN总线技术和上位机协议,对多种品牌的PLC在一个系统内实现通信做了有益尝试,验证了系统的可行性,为中小企业的设备升级节约成本;通信系统中使用自定义的上层协议,提高了信息传输的有效性和稳定性。
[Abstract]:Field management information has become an inevitable trend for small and medium-sized enterprises to maintain their competitiveness. This paper aims at the characteristics of field automation equipment in small and medium-sized enterprises, and makes use of the CAN bus technology and the communication protocol of small PLC. The communication between PC and several brands of small PLC is realized successfully. Without changing the status quo of the equipment, the monitoring of the running process of the equipment is completed, and the goal of field management information is achieved at low cost. The hardware part of the monitoring system is based on the MC68HC908GZ60 microcontroller of Freescale Company, including the RS232C serial communication interface and can bus interface, etc. In the design process, the hardware anti-jamming technology is adopted to ensure the signal stability in the system. The software part of the system consists of two parts: MCU software and PC software. The software is divided into two parts: the main control node and the monitoring node. The system is designed according to the embedded software programming specification, and the system initialization can bus communication is completed. The serial port communication between the main control node and PC and the communication between the monitor node and the host computer protocol of PLC are designed according to the object-oriented software design method. The communication with the main control node, parameter setting and real-time monitoring are completed. History record and query module design, and corresponding to these modules designed a related operation interface. After completing the software and hardware design and testing of the system, a small enterprise in Suzhou was initially debugged on the spot, and the monitoring effect was good. The main application innovations of this topic are: according to the characteristics of the equipment of small and medium-sized enterprises and the current situation that the PLC of each brand is not open, using the CAN bus technology and the host computer protocol, This paper makes a beneficial attempt to realize communication in one system by PLC of many brands, verifies the feasibility of the system and saves the cost for the equipment upgrade of small and medium-sized enterprises, and uses the custom upper layer protocol in the communication system. The efficiency and stability of information transmission are improved.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：TP277

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