外文翻譯--基于lwip協(xié)議的海洋數(shù)據(jù)采集與傳輸系統(tǒng)研究

1、<p>　　中文3350字，2000英文單詞，10500英文字符</p><p>　　文獻(xiàn)出處：Wang H, Zhou Q, Zhang X, et al. A marine data collection and transmission system based on LwIP[J]. Application of Electronic Technique, 2012:346 - 349.<

2、/p><p>　　畢業(yè)設(shè)計(jì)（論文）外文文獻(xiàn)翻譯</p><p><b>　　原文：</b></p><p>　　Research on Marine Data Collection and Transmission System based on Lwip Protocol</p><p><b>　　Hui Wa

3、ng</b></p><p>　　zjwh.good@163.com</p><p><b>　　Wenyu Cai</b></p><p>　　dreampp2000@163.com</p><p>　　Abstract—Due to the status quo that serial data tran

4、smission capacity cannot meet the demand of marine environment real-time detection in the marine data acquisition system. This paper designs and implements a faster Ethernet data transmission system, which can be connect

5、ed with each other by Interconnection device. For the system based on single node, it consists of sensor modules, processing board. The latter constitutes of STM32F107VC processor, a lightweight LwIP protocol stack based

6、 on it. </p><p>　　Keywords-Data Collection; LwIP ; TCP/IP; Data Transmission.</p><p>　　I INTRODUCTION</p><p>　　In recent years, Marine data collection and transmission system (MDC

7、ATS) regarding seafloor observatory nodes as the carrier can realize the real-time, automatic acquisition of water environmental monitoring data below sea level. It consists of various sensors, CPU controller, data trans

8、ferring interface, and remote monitoring platform. At the same time, it could provide a wealth of information on ocean exploration and monitoring. From the beginning of developing marine data acquisition and moni</p&g

9、t;<p>　　According to the requirement of transferring rate based on data acquisition and transmission system, this paper puts forward aEthernet transmission solution, which uses Floating ball as single MDCATS node,

10、 the whole network diagram is shown in Fig. 1. When considering single node, we use Lwip as Ethernet protocol stack, by completing the transplantation of Lwip TCP/IP protocol stack on STM32FI07VC and using UDP transferri

11、ng form to open the different sensors and set the sample interval for them </p><p>　　II PRINCIPAL FEATURES OF THE SYSTEM</p><p>　　In consideration of consistency for every node in MDCATS Networ

12、ks, this paper emphasizes on analyzing single MDCATS. The overall structure of MDCATS is shown in Fig. 2. The part with bold black box is the main components of the design and implementation in this system. This paper fo

13、cuses on MDCATS which includes varieties of sensors, data acquisition boards and user remote detection terminals. It chiefly fulfills storage data from sensors and detects them with real-time monitoring. In order to e<

14、;/p><p>　　The operating principal of MDCATS can be described as: When sensors underwater detect data coming in, they instantly pass them to data acquisition board through serial port. Once received data, the bo

15、ard immediately takes over samples via Ethernet and executes SD card storage operations. At this point, by means of UDP transmission with the help of net lines that they can pass real-time data to user's remote compu

16、ter terminals. After the data reception, sensors continue to perform data collection</p><p>　　All the sensors above, CTD sensor 1, 2, 3 and 4 are general sensor with RS232 interface. While coupled sensors 1,

17、 2 and 99 are self-contained sensors, when connecting into circuit, they need to add the modem module.</p><p>　　III DESIGN OF THE SYSTEM</p><p>　　A. Communication Manner</p><p>　　A

18、t present, there are three ways of data transition between sensor serial data and Ethernet data. Such as: (1) use a dedicated network processing chips; (2) use high-end embedded system to process; (3) use both microcontr

19、oller and network control chip. By comparison, it is clearly that the first one has a higher costs and need to re-design the interface; the cost of second one is also high, and the resource of chips cannot be used very w

20、ell if only using them as communication interface. Compared</p><p>　　B. CPU and Communication Module</p><p>　　This paper selected STM32F107VC as the main controller; the Core of CPU is based on

21、ARM 32-bit Cortex?-M3, and is up to 72MRZ high performance processor. Due to owning 10/100M Ethernet MAC With dedicated DMA and SRAM (4Kbyte). It is dedicated to network embedded device. At the same time, it has varietie

22、s of serial resources, 5 USART channels, which make it not only supports the physical connection of modem module and sensor, but also provides redundant ports that could connect more equipment thr</p><p>　　T

23、his paper chooses DP83848C as Ethernet physical layer transceiver chip. It is embedded IEEE 802.3-compliant 10/100 Ethernet MAC and supports MIl, RMII, SNI these three connections. Also integrated within the data transce

24、iver and filtering. When in full-duplex mode, the maximum speed can reach 100Mbit/s in theory.</p><p>　　As it is shown in Fig. 3, we adopt RMII connection mode between micro-controller and Ethernet transceiv

25、er chip [3]. By this means, it reduces the connection pins of the PHY under the premise of maintaining the existing characteristics of the physical layer device. Meanwhile, it reduces the cost of system design when keepi

26、ng all the features relating to IEEE802.3 specification.</p><p>　　C. Transplanting Lwip Stack</p><p>　　Lwip is an open source TCP/IP protocol stack which was developed by Adam Dunkles from Compu

27、ter Science in Switzerland [4]. The emphasis of implementation is to reduce RAM usage on the basis of maintaining the TCP functions. It can run only with tens of bytes of RAM and 40KB ROM, which makes it suitable for app

28、lication in low-end embedded systems.</p><p>　　There are two common implementation ways towards Embedded TCP/IP stack. The first one is regarding each protocol in the protocol family as a separate process, a

29、nd specifying communication points in the process. The other one is putting protocol stack into the kernel of operating system, and making connections with protocol stack by application calling. In all, the strong points

30、 of the first one are that its code is easy to understand and occupying fewer system resources, last but not least, it d</p><p>　　D. Design of Software on Data Acquisition Board</p><p>　　This sy

31、stem consists of two parts: obtaining sensor data, transferring data programs and real-time monitoring procedures. Among them, programs on data acquisition board compile and test under KEIL uVision4, programs of remote m

32、onitoring compile and test under Visual Studio 2008.</p><p>　　The program on board mainly consists of 4 steps: (1) System initialization. Including system clock, RTC real-time clock. Lwip protocol stack, gen

33、eral I/O initialization. (2) Serial port configuration and communication. (3) Listening to the command of remote terminal. struct udp __pcb includes the minimum transmission unit of Ethernet data, address of IP, subnet m

34、ask, gateway, local port number, destination port number. When creating udp_pcb, then we call udp API operating function udp _recv to b</p><p>　　E. Design of Software on Remote Monitoring Terminal</p>

35、<p>　　The program of remote user control terminal is mainly to realize real-time monitoring for sampling data on board and status of sensors. Control port searches our devices in the form of filtering IP address, a

36、nd creates virtual link with underwater acquisition board. Afterwards, terminal on ground sends the signal of starting sensors with the help of UDP communication via Ethernet [6]. After transmitting all these commands, e

37、veryone second, control port intermittently sends commands of getting da</p><p>　　F. System Measurement</p><p>　　In the environment of laboratory, we connect 5 serial ports on board with modem”

38、CTD sensor 1, 2, 3, 4, MAC interface connects with MAC interface of PC via net lines. At the same time, we set the number of UDP listening port is 5000, the subnet mask is 255.255.255.0, and the gateway is 192.168.1.1, u

39、ltimately, set local IP is 192.168.1.101 and board with 192.168.1.220. When system powers on, Opening the software of remote terminal, finding the data acquisition board by searching device with spec</p><p>

40、　　In the basis of statement above, then we choose different lengths of data as the approximate data length of sensors, at the same time, we also take 3 transmission methods for comparison in our measurements. As a notice

41、, all the measurements are on the condition of running for 10 minutes. Through Fig. 6, there is no denying the fact that transmission with Ethernet is speedier than the other ways regardless of different amounts of data.

42、</p><p>　　IV CONCLUSIONS</p><p>　　In this paper, we proposed a fast marine data collection and transmission system based on Lwip protocol stack. In the premise of stability of data transmission

43、, in order to take real-time into account tremendously, we improve transmission rate as much as possible from hardware selection to software design. By Ethernet transmission, we not only improve real-time of system, but

44、also provide a more convenient way for Data Interchange. Meanwhile, it is easy for expansion or network by joining interw</p><p>　　ACKNOWLEDGMENT</p><p>　　This paper is funded by Zhejiang Provin

45、ce as a project of technology innovative team (2010R5001 0), which is concentrating on researching on intelligent identification and application of technology and the Open Foundation of the Zhejiang Most Important Subjec

46、ts - Circuits and System.</p><p>　　REFERENCES</p><p>　　1. Yan Xia Zhuang, Yun Qiang Sun, Ai Qin Yao. Real-Time Data Transmission System Based on CAN-BUS [J]. Data collection and Processing, 2006

47、,(21):222-225.</p><p>　　2. Jing Qian Chen, Zhi Wei He, Wen Ze Liu. Design of Protocol Conversion Unit between RS232 and CAN BUS[J].Electronics Engineer,2004,30(4):63-66.</p><p>　　3. Xing Song, Y

48、ong Guo, Xing Hong Xie. Application of Ethernet PHY Chip DP83848C Based on RMII Mode[J].Microconctrollers & Embedded Systems. 2010,(8).</p><p>　　4. Adam Dunkels. Lwip source code [DB/OL] . http://www.sic

49、s.se/~adam/lwip/.</p><p>　　5. Yong Hong Wang, Wei Xu, Li Ping Hao. The principals and p ractice of STM32 based on Cortex-M3 microcontroller[M].2008:366-368.</p><p>　　6. Geroge Thomas.A TCP/UDP t

50、ransmission method used for controlling[J]. Integration of mechanics and electrics in home and abroad.2001,6(4):9-11.</p><p><b>　　譯文：</b></p><p>　　基于LwIP協(xié)議的海洋數(shù)據(jù)采集與傳輸系統(tǒng)研究</p>&

51、lt;p>　　摘要：由于串行數(shù)據(jù)傳輸能力不能滿足海洋環(huán)境的實(shí)時(shí)檢測在海洋數(shù)據(jù)采集系統(tǒng)的需求現(xiàn)狀，本文設(shè)計(jì)并實(shí)現(xiàn)了一種可以通過互連裝置連接的更快的以太網(wǎng)數(shù)據(jù)傳輸系統(tǒng)。這個(gè)系統(tǒng)以單個(gè)節(jié)點(diǎn)為基礎(chǔ)的系統(tǒng)，它包括傳感器模塊，處理板。后者由STM32F107VC處理器，基于它的輕量級(jí)LwIP協(xié)議棧構(gòu)成。通過向處理器移植LwIP協(xié)議棧，我們在應(yīng)用層上實(shí)現(xiàn)了在串行數(shù)據(jù)和以太網(wǎng)數(shù)據(jù)之間的雙向數(shù)據(jù)傳輸系統(tǒng)。在我們的測試中，我們選擇從100到500字節(jié)

52、不同幀長度的變量;通過比較，我們發(fā)現(xiàn)從100字節(jié)到500字節(jié)，通過以太網(wǎng)傳輸?shù)乃俾蕛?yōu)于RS232 、RS485 、CAN總線的傳輸速率，滿足設(shè)計(jì)要求。 </p><p>　　關(guān)鍵詞：數(shù)據(jù)采集; LwIP; TCP / IP;數(shù)據(jù)傳輸。</p><p><b>　　一． 簡介</b></p><p>　　近年來，以海洋數(shù)據(jù)收集和海底觀測節(jié)點(diǎn)作為載

53、體的傳輸系統(tǒng)（MUDCATS），可實(shí)現(xiàn)實(shí)時(shí)、自動(dòng)地采集海平面以下的水環(huán)境監(jiān)測數(shù)據(jù)。它包括各種傳感器，CPU控制器，數(shù)據(jù)傳輸接口，以及遠(yuǎn)程監(jiān)控平臺(tái)。同時(shí)，它可以提供海洋勘探和監(jiān)測的豐富信息。從發(fā)展海洋數(shù)據(jù)采集與監(jiān)控系統(tǒng)開始到現(xiàn)在，傳輸?shù)念愋涂梢允嵌鄻拥腫1]，如RS232，RS485，CAN總線等。而每一個(gè)傳輸方法都有自己的優(yōu)點(diǎn)和缺點(diǎn)。RS232支持全雙工通信，并提供了與各種設(shè)備直接連接的通道，但它的工作距離短，傳輸率低，抗干擾能力差。

54、485只支持半雙工通信，并具有較高的抗噪聲能力，比RS232更遠(yuǎn)的傳輸距離，但是它的傳輸速率也低。 CAN總線只支持半雙工通信，并具備更遠(yuǎn)的傳輸距離和較強(qiáng)的抗干擾能力，但它的傳輸速率仍然是有限的[2]。</p><p>　　根據(jù)數(shù)據(jù)采集和傳輸系統(tǒng)傳送速率的要求，本文提出了一種以太網(wǎng)傳輸?shù)慕鉀Q方案，它采用浮動(dòng)球作為單一MDCATS節(jié)點(diǎn)，整個(gè)網(wǎng)絡(luò)示意圖示于圖1，當(dāng)考慮單個(gè)節(jié)點(diǎn)時(shí)，我們使用Lwip作為以太網(wǎng)協(xié)議棧。我們

55、通過完成Lwip TCP / IP協(xié)議棧在STM32FI07VC上的移植，并使用UDP傳送的形式來開啟不同的傳感器、為它們設(shè)置采樣間隔及實(shí)現(xiàn)實(shí)時(shí)監(jiān)測采集的數(shù)據(jù)。以這種方式，它可以大大提高遠(yuǎn)程控制臺(tái)系統(tǒng)的實(shí)時(shí)性和可操作性。</p><p><b>　　二． 系統(tǒng)主要特點(diǎn)</b></p><p>　　考慮到在MUDCATS網(wǎng)絡(luò)中每一個(gè)節(jié)點(diǎn)的一致性，本文重點(diǎn)分析單個(gè)MUDC

56、ATS。 MDCATS的總體結(jié)構(gòu)示于圖2。粗黑框中的一部分是設(shè)計(jì)和實(shí)現(xiàn)該系統(tǒng)的主要組件。本文重點(diǎn)介紹MDCATS，其中包括多種傳感器，數(shù)據(jù)采集板和用戶遠(yuǎn)程檢測終端。它主要是從傳感器獲取存儲(chǔ)數(shù)據(jù)，并對他們進(jìn)行實(shí)時(shí)檢測監(jiān)控。為了在水下延長傳感器工作時(shí)間，我們提供了外部電源引腳，以便可以進(jìn)行長期的檢測。</p><p>　　MDCATS的工作原理可描述為：當(dāng)感應(yīng)器探測到水下的數(shù)據(jù)時(shí)，它們立即通過串口將數(shù)據(jù)傳送到數(shù)據(jù)采集

57、板。一旦接收到數(shù)據(jù)，數(shù)據(jù)采集板會(huì)立即通過以太網(wǎng)和執(zhí)行SD卡存儲(chǔ)操作進(jìn)行處理。這個(gè)時(shí)候，它們以網(wǎng)線為介質(zhì)通過UDP實(shí)時(shí)傳輸數(shù)據(jù)到用戶的遠(yuǎn)程計(jì)算機(jī)終端。在數(shù)據(jù)接收后，傳感器繼續(xù)進(jìn)行數(shù)據(jù)收集。同時(shí)，遠(yuǎn)程計(jì)算機(jī)終端通過網(wǎng)絡(luò)發(fā)送控制命令;這些數(shù)據(jù)信號(hào)通過網(wǎng)絡(luò)傳送到數(shù)據(jù)采集板CPU之后，CPU控制器對命令進(jìn)行解析，針對不同的分析結(jié)果發(fā)出相應(yīng)的不同指令，使傳感器開啟，進(jìn)行采樣，實(shí)現(xiàn)實(shí)時(shí)控制能力。 </p><p>　　以上所有

58、的傳感器，CTD傳感器1、2、3和4是用采用RS232接口的常用傳感器。但是耦合傳感器1、2和99是自包含的傳感器，當(dāng)連接到電路時(shí)，他們需要添加調(diào)制解調(diào)器模塊。</p><p><b>　　三． 系統(tǒng)的設(shè)計(jì)</b></p><p><b>　　A：通信方式 </b></p><p>　　目前，傳感器串行數(shù)據(jù)和以太網(wǎng)數(shù)據(jù)之間

59、有三種傳輸手段。如：（1）使用專用網(wǎng)絡(luò)處理芯片; （2）使用高端嵌入式系統(tǒng)處理; （3）同時(shí)使用微控制器和網(wǎng)絡(luò)控制芯片。通過比較，很明顯，第一個(gè)方案需要更高的成本并且需要重新設(shè)計(jì)接口;第二個(gè)的成本也很高，如果僅將它們用作通信接口，就不能非常好地使用芯片的資源。與前兩種方法相比，包括成本與應(yīng)用場合，第三個(gè)方案是易于實(shí)現(xiàn)的，并可以根據(jù)實(shí)際需要進(jìn)行擴(kuò)展。因此，我們采取的最后方案。</p><p>　　B. CPU和通訊

60、模塊 </p><p>　　本文選取STM32F107VC作為主控制器; 其CPU核心是基于ARM32位Cortex?-M3的高達(dá)72MHZ的高性能處理器。由于擁有10/ 100M以太網(wǎng)MAC專用的DMA和SRAM（4字節(jié)），它是專門為嵌入式網(wǎng)絡(luò)設(shè)備而設(shè)計(jì)的。同時(shí)，它有多個(gè)串行資源，5 USART通道，這使得它不僅支持調(diào)制解調(diào)器模塊和傳感器的物理連接，而且還提供了可以連接更多設(shè)備的冗余串行端口。 </p&g

61、t;<p>　　本文選擇DP83848C作為以太網(wǎng)物理層收發(fā)器芯片。它內(nèi)建IEEE802.3兼容10/100以太網(wǎng)MAC，支持MIL，RMII，SNI這三種連接。其內(nèi)部還集成數(shù)據(jù)收發(fā)器和過濾器。當(dāng)在全雙工模式下，理論上其最高傳輸速率可以達(dá)到100Mbps/秒。</p><p>　　如圖3，我們采用RMII連接方式連接微控制器和以太網(wǎng)收發(fā)器芯片[3]。通過這種方法，在保持物理層設(shè)備現(xiàn)有特征的前提下減少

62、了PHY的連接開銷。同時(shí)，它減少了保持所有與IEEE802.3規(guī)格相關(guān)的功能時(shí)系統(tǒng)的設(shè)計(jì)成本。 </p><p>　　C.移植LWIP協(xié)議棧 </p><p>　　LWIP是由Adam Dunkles在瑞士計(jì)算機(jī)科學(xué)院開發(fā)的一個(gè)開源的TCP/ IP協(xié)議棧[4]。其現(xiàn)的重點(diǎn)是在保持TCP主要功能的基礎(chǔ)上，減少對RAM的占用。它只需十幾KB的RAM和40K左右的ROM就可以運(yùn)行，這使LwIP協(xié)

63、議棧適合在低端的嵌入式系統(tǒng)中使用 。 </p><p>　　有兩種常見的方式實(shí)現(xiàn)嵌入式TCP/ IP協(xié)議棧。第一個(gè)是將協(xié)議簇的每個(gè)協(xié)議作為一個(gè)單獨(dú)的過程，并在此過程中指定通信點(diǎn)。另一種是將協(xié)議棧嵌入到操作系統(tǒng)的內(nèi)核，并通過應(yīng)用程序的調(diào)用與協(xié)議棧連接。總之，第一個(gè)的優(yōu)點(diǎn)是它的代碼很容易理解并且占用更少的系統(tǒng)資源，調(diào)試方便。而后者則占用較多內(nèi)存和系統(tǒng)的ROM，且不能很好地支持在MDK中進(jìn)行斷點(diǎn)的調(diào)試[5]。最后，我們

64、選擇第一個(gè)。</p><p>　　D.數(shù)據(jù)采集板軟件設(shè)計(jì)</p><p>　　該系統(tǒng)由兩部分組成：傳感器數(shù)據(jù)獲取、傳輸代碼和實(shí)時(shí)監(jiān)控程序。其中，數(shù)據(jù)采集程序在KEIL uVision4上進(jìn)行編譯和測試，遠(yuǎn)程監(jiān)控程序在Visual Studio 2008上進(jìn)行編譯和測試。</p><p>　　板上的程序主要包括4個(gè)部分：（1）系統(tǒng)初始化。包括系統(tǒng)時(shí)鐘、RTC實(shí)時(shí)時(shí)鐘、

65、LWIP協(xié)議棧、通用I / O初始化。（2）串行端口配置和通信。（3）遠(yuǎn)程終端命令的接收。結(jié)構(gòu)體udp_pcb包括以太網(wǎng)數(shù)據(jù)、IP地址、子網(wǎng)掩碼、網(wǎng)關(guān)、本地端口號(hào)、目的端口號(hào)構(gòu)成的最小傳輸單元。當(dāng)創(chuàng)建udp_pcb時(shí)，調(diào)用API操作函數(shù)udp_recv使UDP數(shù)據(jù)單元的屬性生效。對于以太網(wǎng)數(shù)據(jù)的讀取或?qū)懭?，設(shè)置以太網(wǎng)超時(shí)是非常重要的，同時(shí)，LwIP_Periodic_Handle函數(shù)很好地支持了這種功能。構(gòu)造UDP參數(shù)后，使用udp_r

66、ecv函數(shù)來啟用數(shù)據(jù)回調(diào)函數(shù)，通過回調(diào)函數(shù)體中的第二個(gè)參數(shù)建立偵聽線程。在沒有阻塞過程中，一旦接收到的遠(yuǎn)程數(shù)據(jù)報(bào)，我們將調(diào)用udp_send來寫入數(shù)據(jù)。水下的遠(yuǎn)程監(jiān)控是通過udp_echoserver_receive_callback函數(shù)來實(shí)現(xiàn)的。從遠(yuǎn)程終端發(fā)送的命令被反饋到板上的CPU上; 根據(jù)命令的差異，CPU執(zhí)行開啟或關(guān)閉傳感器。（4）集成數(shù)據(jù)幀。 CPU微處理器根據(jù)不同類型傳感器的數(shù)據(jù)幀對數(shù)據(jù)進(jìn)行排序和整合，最后，通過以太網(wǎng)將它

67、們發(fā)送到遠(yuǎn)程監(jiān)控端。板上的流程圖示于圖4。</p><p>　　E.遠(yuǎn)程監(jiān)控終端軟件的設(shè)計(jì)</p><p>　　遠(yuǎn)程用戶控制終端的設(shè)計(jì)主要是為了實(shí)現(xiàn)實(shí)時(shí)監(jiān)控板上的采樣數(shù)據(jù)和傳感器的狀態(tài)?？刂贫丝谝赃^濾IP地址的形式搜索我們的設(shè)備，并在水下采集板上創(chuàng)建了虛擬鏈路。隨后，地面終端將以以太網(wǎng)為媒介，通過UDP通信發(fā)送啟動(dòng)傳感器的信號(hào)[6]。發(fā)送所有這些命令之后，控制端口通過以太網(wǎng)每隔一秒間歇地發(fā)

68、送獲取數(shù)據(jù)命令，以完成數(shù)據(jù)的更新。如果采集板已經(jīng)獲取傳感器采集的數(shù)據(jù)，在這一刻，數(shù)據(jù)采集板再次通過以太網(wǎng)發(fā)送數(shù)據(jù)幀到遠(yuǎn)程控制臺(tái)。在終端接收全部數(shù)據(jù)幀后，主機(jī)通過分析先前的通信協(xié)議并分離數(shù)據(jù)幀，進(jìn)行數(shù)據(jù)包的處理。最后，將它們顯示在用戶圖形界面上。遠(yuǎn)程監(jiān)視終端的流程圖示于圖5。</p><p><b>　　F.系統(tǒng)測量 </b></p><p>　　在實(shí)驗(yàn)室的環(huán)境下，我們

69、連接上5個(gè)串行端口調(diào)制解調(diào)器的、CTD傳感器1、2、3、4，MAC接口與PC機(jī)的MAC接口通過網(wǎng)線連接。與此同時(shí)，我們設(shè)置UDP監(jiān)聽端口號(hào)為5000，子網(wǎng)掩碼為255.255.255.0，網(wǎng)關(guān)為192.168.1.1，最終，設(shè)置本地IP是192.168.1.101和采集板IP為192.168.1.220。當(dāng)系統(tǒng)啟動(dòng)時(shí)，打開遠(yuǎn)程終端的軟件，通過搜索指定IP地址的設(shè)備查找數(shù)據(jù)采集板。現(xiàn)在，主板和PC控制臺(tái)在成功握手后建立通信。按照設(shè)置的采樣

70、時(shí)間間隔，采樣板將數(shù)據(jù)存儲(chǔ)在SD卡中。 </p><p>　　在上面的基礎(chǔ)上，我們選擇不同長度的數(shù)據(jù)作為傳感器的數(shù)據(jù)長度，同時(shí)，我們也需要拿3種傳輸方法的測量結(jié)果進(jìn)行比較。作為一個(gè)通知，所有的測量是在運(yùn)行10分鐘的基礎(chǔ)上進(jìn)行的。如圖6所示，不可否認(rèn)，不同數(shù)量的數(shù)據(jù)通過以太網(wǎng)傳輸比其他方式更快。</p><p><b>　　四． 結(jié)論</b></p>&l

71、t;p>　　在本文中，我們提出了一種基于Lwip協(xié)議棧的海洋數(shù)據(jù)快速采集和傳輸系統(tǒng)。在數(shù)據(jù)傳輸穩(wěn)定的前提下，為了極大地提高實(shí)時(shí)性，我們從硬件選擇到軟件設(shè)計(jì)都盡可能地提高傳輸速率。通過以太網(wǎng)傳輸，我們不僅提高了系統(tǒng)的實(shí)時(shí)性，同時(shí)也提供了更便捷的方式進(jìn)行數(shù)據(jù)交換。同時(shí)，此系統(tǒng)很容易進(jìn)行擴(kuò)展或通過網(wǎng)絡(luò)連接互通設(shè)備。該系統(tǒng)滿足實(shí)時(shí)數(shù)據(jù)傳輸?shù)男枰?，達(dá)到了在同一傳輸條件下優(yōu)于RS232、RS485、CAN總線的目標(biāo)。 </p>

72、<p><b>　　致謝 </b></p><p>　　本文由浙江省出資，為技術(shù)創(chuàng)新團(tuán)隊(duì)項(xiàng)目（2010R50010），這是專注于智能識(shí)別和應(yīng)用技術(shù)及浙江最重要的科目開放基金的研究 - 電路與系統(tǒng)。</p><p>　　REFERENCES</p><p>　　1. Yan Xia Zhuang, Yun Qiang Sun, Ai Q

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