数据采集节点的CAN通信接口研究__外文翻译

南京工程学院南京工程学院 毕业设计毕业设计 论文论文 外文资料翻译外文资料翻译 原原 文文 题题 目 目 Distributed Building Temperature Control System Based on CAN Bus 原原 文文 来来 源 源 Journal of Zhejiang Wanli University 1671 2250 2008 05 0075 04 学学 生生 姓姓 名名 周 盈 庆 学学 号 号 201080448 所在院所在院 系系 部 部 机械工程学院 专专 业业 名名 称 称 机械电子工程 第 0 页 毕毕业业设设计计外外文文原原文文 Distributed Building temperature control system based on can bus Abstract This paper proposed a kind of distributed building temperature control system based on CAN Bus and has produced the system of hardware structure design the software design can examine the building temperature and control the exceptional on the real time be indicated through experiment that system is reliable and save energy 1 Introduction Gradually climbs along with the temperature electric power industry welcomed has used electricity once year most seasons the electric power welcomes a peak summer Since 2003 the power supplied has become more and more serious in China And more and more people appeal for building energy conservation Air conditioning s energy conservation is one of the most important components of building energy conservation Many public buildings air condition is one of highest energy consumption sources in China Take Beijing as the example in 2005 although the Beijing large scale public building only accounts for the whole city civil constructing total area 5 4 but whole year the total power consumption actually achieved 3 3bullion kilowatts approach all inhabitants to live use electricity one half according to the preliminary understanding Beijing s public building generally can achieved to energy saving for 30 to 50 through technology transformation One of most important method is through the real time examination building interior temperature to control building in air conditioning 2 The principle of system structure and hardware design 第 1 页 Regarding the different building its internal room distributes and constructs is different in order to realize the system construct conveniently the system uses the distributional structure Based on the SJA1000 CAN communications platform in order to realize various pitch points reliable communication In this foundation the console set each pitch point temperature value setting for every room and realize the entire building temperature real time examination by the LCD demonstration examination result the unusual situation is reported by the warning through speech property by the signal and controlled through the gate of air conditioning s system realization energy conservation goal The system design goal is measure and control point is temperature in a building each room because measured the temperate point and control dispersion therefore system uses the distributional structure The console is connected each part control pitch point distributing building through the CAN Bus 2 1 The console hardware design The AT89C52 MCU is the primarily controller in console It connects with the warning module the memory module the clock calendar electric circuit and the keyboard module Its structure drawing see figure The control pitch point also is controlled by the MCU connected temperature examination module and CAN Bus interface module The system has used the AT89C52 it is a section low power chip that is produced by ATMEL Corporation has 4KB in system programmable FLASH memory integrated The scene programming debugging and the system function changing is much 第 2 页 conveniently flexible using AT89C52 to take the system the master controller When system normal work The console send a definite control temperature value to a designate pitch point Distributed in the building through the CAN Bus The pitch point receive the console s orders and read the temperature detector DS18B20 temperature value distributed in each room through 1 Wire bus transmits each room temperature data and the number of room to the console through the CAN Bus According to the definite temperature value which receives from console control the air gate of air conditioning system in each room After receive the data a pitch point send to the console reads the time from real time clock calendar chip PCF8563 through the I2C Bus with the data which just received store to the memory AT24C128 then process each room temperature value When then value achieve the data which is established from keyboard in advance the console output warring to the alarm circuit on reports the alarm Meanwhile the room number the time and the temperature value delivers the LED display Every room alarm temperature value is established through the keyboard input module the console process value and stores in the memory corresponding the input 2 2 The CAN Bus interface design The CAN Bus corresponds high as 1Mb s the most long distance range many reach 10 km The CAN Bus corresponds using the short frame structure Spends the data transmission time shortly so the probability which disturbed is low and the CAN Bus has good error detecting measures therefore it can be increased deleted in the network each pitch point has an address any pitch point theoretically can be increased deleted in the network based on CAN Bus In the practical application the CAN Bus network most access 110 pitch point The network communication method may for the point to point way or for the broadcast way May be the single host way or many hosts way Therefore the CAN Bus correspondence has the suitable flexibility The transmission correspondence information frame can establish the different priority based on the CAN Bus and higher priority information frame can be transmitted first 第 3 页 an promptly through the Bus information arbitration mechanism This increase more Bus network suits the commercial processing monitor equipments by its remarkable characteristic the inexpensive price the extremely high reliability and the nimble structure The pitch point core component is CAN controller SJA1000 which is PHILIPS Corporation produced and CAN driver PCA82C250 SJA1000 is the integrated independent CAN controller is completely compatible with PHLIPS early CAN controller PCA82C200 It responsibly completes the CAN Bus correspondence protocol function of the physical layer and the data link layer SJA1000internal has the control register orders the register the condition register the interrupt register and receives sends the register and so on the MCU realizes SJA1000 control through read write these registers The Chip of SJA1000 pins TX0 TX1 RX0 RX1 use to connect with the CAN Bus PCA82C250 is 8 feet chip specially uses to drive receiving and dispatching in CAN Bus The SJA1000 pins of TXD RXD separately receive and send signal after the drive the twisted pair wire coaxial cable transmits the medium separately to meet to the chip of PCA82C250 pins CHNH CANL Considered the scene has various disturbance the high speed light isolation components are added between the CAN controller SJA1000 and the PCA82C250 2 3 The pitch point hardware design The pitch point mainly includes the CAN Bus interface the control module of the air gate of air conditioning system and temperature sensor DS18B20 the system structure like figure 3 shows The DS18B20 is DALLS Semiconductor Corporation s newest 1 Wire Bus digital temperature sensor Its volume is smaller suitable voltage is wider and more economical 1 Wire Bus is unique moreover the economical characteristic The user can set up the sensor network with ease The q Wire Bus directly transmits scene digital temperature and greatly enhanced the system anti disturbance ability It supports the voltage of 3V 5 5V The system can be designed nimbly and conveniently The ROM in the DS18B20 has stored 64 bits 第 4 页 serial number It was written with the laser before leaved the plants it can be regarded as each DS18B20 address serial number The 64 bits serial number arrangement is the first 8 bits is the product type marking the DA18B20 product series code is fixed is 28H After that 48bits are this DS18B20 own sequence numbers and these 48sequences number is only one in the whole world finally 8 bits are the front 56 cyclical redundancy check code So use the 64 bits serial number we can divide each DS18B20 and we can meet many temperature sensors of DS18B20 on one 1 Wire Bus According to DALLAS Semiconductor Corporation s material on each 1 Wire Bus can connect mostly 248 1 Wire components But we discovered it was not so in practical When one 1 Wire Bus meets more than 8 DS18B20 sensors the system must to solve the question that MCU drive 1 Wire Bus otherwise the MCU cannot correctly read and write to DS18B20 through 1 Wire Bus Simultaneously the fastest 1 Wire Bus length which connect DS18B20 sensor in system is also limited In full scale test when uses the ordinary signal electric cable as the 1 Wire Bus to measure the length surpasses 50m it take mistake that the MUC reads DS18B20 sensors in one 1 Wire bus and the bus is no more than 150m with the twisted pair cable with belt shielded The system design like this is make sure the MCU can drive the 1 Wire bus and can be satisfy with the communication and stability 3 The system software design The pitch point receives the data frame from console though the CAN Bus From these data frame the pitch point obtains each room temperature limit which control The pitch point reads temperature value the pitch point will control the gate of air conditioning system if the value surpass the limit value And report the room number and the temperature value through the CAN Bus to the console According to the DS18B20 communication protocol that the MCU of pitch point controls DS18B20 to achieve the temperature transmission must include three steps First the MCU must be reset the sensor DS18B20 before each read write Then after successfully reset the MCU send a ROM 第 5 页 instruction finally the MCU transmits the RAM instruction AS this the MCU can carry on the operation to DS18B20 which prearranges It must be attention that the MCU should put down the 1 Wire bus for 500 m at last to carry out reset Then pull on to release the bus After the DS18B20 receives the signal to wait for about 17 60 m the MCU indicate reposition successfully after receiving this signal 4 Conclusion After the field test this system can realize the building temperature examination and control effectively And this system can be applied to other equipments testing and control in order to realize building intelligent management While CAN bus is an effective support for distributed industrial control serial communication network the system can also be widely applied to other needs real time multi point measurement and control areas 第 6 页 毕毕业业设设计计外外文文翻翻译译 基于 CAN 总线的楼宇温度控制系统设计 摘要 文章提出了一种基于 CAN 总线的楼宇温度控制系统 并给出了系统硬件和软件的设 计方案 分析了控制台和分布在楼宇中的控制节点之间的通信问题 从而实现对楼宇温 度实时检测 并对异常情况进行报警和控制 试验表明该系统可靠 能实现节能目的 1 引言 随着人们生活水平的提高 电力工业每年都会面临用电最多的季节 电力顶峰度夏 2003 年以来 我国供电形势从缓和转为全面吃紧 建筑节能成为热点问题 其中空调节 能是最突出的 公共建筑的空调是高能耗的源头之一 以北京为例 公共建筑尽管只占全市民用建 筑总面积的 5 4 但公共建筑全年总耗电量却达到 33 亿千瓦 接近所有居民生活用电的 一半 据初步了解 北京市的公共建筑普遍存在着 30 50 的节能空间 2 系统结构原理与硬件设计 不同的楼宇 其内部空间分布和结构是不同的 为实现系统的构建 笔者提出一种 基于 SJA1000 的 CAN 通信平台来实现各节点的可靠通信 在此基础上 由主控制器实现 对各检测节点的温度设定 实时检测整幢楼宇温度 并由 LCD 显示结果 对异常情况进 行语音报警和控制 以实现节能目的 系统的设计目的是为了测量和控制分布在一栋建 筑物内各个房间的温度 而测温和控制节点是分散的 所以要通过 CAN 总线实现控制台 和分布在建筑物的各个部分的控制节点相连 每个控制节点可以控制多个房间的温度 2 1 主控台和硬件设计 控制台是单片机 为主控制器 连接报警模块 存储模块 时钟 日历电路和人机接 口电路 其结构如图所示 第 7 页 系统采用的 STC89C51 单片机是新一代的超强抗干扰 低功耗 高速工业级单片机 指令代码完全兼容传统的 8051 单片机 用户应用程序空间最大可以达到 64KB 支持在系 统可编程和在应用可编程 使得系统现场程序调试和系统功能修改变得很方便 同时该 芯片内部集成了 4KB 数据 FLASH 控制节点的硬件设计中就无需再外接用于控制温度设定 值的存储芯片 在系统正常工作时 控制台接收从键盘输入的房间号和温度报警设定值并保存到存 储芯片 AT24C128 中 控制台根据房间号确定控制节点地址 并将房间号和温度报警设定 值发送给该控制节点 在异常时 控制台通过 CAN 总线在接收到控制节点发来的数据后 通过 I2C 总线读取实时时钟 日历芯片 PCF8563 的时间 连同接收到的数据写入存储器 AT24C128 并作相应处理 区分出是房间的温度超过设定值还是温度传感器 DB18B20 接 触不良 发出报警信号 同时将房间号 时间 报警原因等信息传送至 LCD 进行显示 2 2 CAN 总线接口设计 总线通信的波特率高达 1Mb s 最远通信距离可达 10km CAN 总线通信采用短帧结构 使得数据 CAN 传输的时间短 受干扰的概率低 并且 CAN 总线协议有良好的检错措施 因此 CAN 总线通信的可靠性较高 可以应用于有较强干扰的环境 CAN 总线定义网络中的 每一节点对应一地址 在实际应用中 CAN 总线最多可挂 110 个节点 基于 CAN 总线通信 对于传送的信息帧可以设定不同的优先级 并通过总线仲裁机制使高优先级的信息能够 被优先 及时地传送 保证了更重要的信息能及时地被传送 从而增加了 CAN 总线通信 的实时性 CAN 总线接口采用 PHILIPS 公司生产的 CAN 控制器 SJA1000 和 CAN 驱动器 PCA82C250 SJA1000 是集成的独立 CAN 控制器 与 PHILIPS 早期的 CAN 控制器 PCA82C200 完全兼容 负责完成 CAN 总线通信协议的物理层和数据链路层的功能 5 SJA1000 内置 第 8 页 控制寄存器 命令寄存器 状态寄存器 中断寄存器和收 发寄存器等 单片机就是通 过读写这些寄存器来实现对 SJA1000 的控制 芯片的 TX0 RX 引脚用于与 CAN 总线收发 驱动芯片相连 PCA82C250 是专门用于 CAN 总线收发驱动的 8 脚芯片 TXD RXD 引脚分 别接收和发送 CAN 总线控制器的信号 双绞线 同轴电缆 传输介质分别接至 CANH CANL 引脚考虑到使用现场可能有各种各样的干扰 在 CAN 控制器和驱动器之间增加高速光耦 隔离器件 6N137 2 3 节点硬件设计 控制节点的主要功能是和控制台通信并接受控制台的温度控制设定值 检测分布在 每个房间的温度控制点 如果有异常 则向控制台报警并控制该房间的空调风门 控制 节点主要包括 CAN 总线接口 控制模块和温度传感器 DS18B20 分散在建筑物