自動化資料擷取與監控發展簡介 蔡 明 忠 國立台灣科技大學 工程技術研究所 自動化及控制學程/自動化及控制中心 副教授

Presentation on theme: "自動化資料擷取與監控發展簡介 蔡 明 忠 國立台灣科技大學 工程技術研究所 自動化及控制學程/自動化及控制中心 副教授"— Presentation transcript:

1 自動化資料擷取與監控發展簡介 蔡 明 忠 國立台灣科技大學 工程技術研究所 自動化及控制學程/自動化及控制中心 副教授
TEL: FAX:

2 Development of sensing and control
Centralization control DCS, PLC, Remote I/O Communication, network Distributed, Open architecture,Intelligent, Smart I/O Communication, network

3

4 傳統分散式控制架構

5 以個人電腦及控制網路為基礎之控制架構

6 Remote Data Acquisition
. Intelligent sensor to controller / computer . Built-in RS-232/RS-485 . Built-in Microprocessor . Programmable I/O . Wireless - Radio modem module . Network - Ethernet, control area network(CAN), Lonwork, . Open architecture - . Friendly MMI (HMI: Human Machine Interface)

7 OPEN I/O Architecture

8 Open_Control is a programmable controller which is designed based on the LonWorks communication technology.

9 Field Bus systems in open network
1.ARCNET(Attached Resource Computer Network) 2.PROFILBUS(PROcess Field Bus) 3.Interbus S (EN50254) 4.SERCOS (Serial Realtime Communication System)- 5.CAN(Control Area Network) – 6.IEEE1394(Firewire) - 7.Industrial Ethernet – 8.EIB (European Installation Bus) 9. Lon work(Local Operating Network) 10.others - Controlnet, WorldFIP, AS-interface

10 Future Development .Powerful  faster host CPU and accessories
.Friendly  MMI(HMI), PC-based, Window-based .Opened  Communication , Network , shared database .Reliability  Hardware/ software .Low cost  competitive, compatibility .Smarter  intelligence( Intelligent ) I/O, DSP, distributed .Smaller  Micro sensor, Micro-mechatronics

11 智慧型I/O簡介 智慧型I/O與傳統I/O最大的區分，在於它具有類似控制系統 之運算、控制及通訊功能以及處理能力，而非只是結合了
驅動器及感測器或是結合多種感測器在一起的轉換器。

12 A smart sensor module

13 資料擷取系統簡介 1.何謂資料擷取系統？ 2.資料擷取系統的發展歷史 3.資料擷取基本原理 4.資料擷取軟硬體系統
6.PC-based Control Net

14 資料擷取系統簡介 廣義的資料擷取系統：量度、控制與通訊
量度系統：將感測器送來的信號作轉換及前置處理 ，化作類比數位轉換電路所能處理且解析度最佳的信號， 透過電腦運算出量度物理量的數值， 透過人機介面或輸出介面送出訊息。 控制系統： 可能接收到的是反饋信號，除了與量度系統同樣進行感測之外，電腦的軟體還必須負責控制器的功能，決定適當的輸出，驅動致動器來進行控制。

15 資料擷取用途 資料擷取是為量測真實訊號(物理現象)，如透過電壓將訊息帶入電腦中來處理、分析、儲存或者做其他處置。
物理現象:如速度、溫度、濕度、壓力、流速、酸鹼值、啟動停止、放射能、光度等 轉換器與感測器:物理現象->電子訊號，如熱電偶為一轉換器，將溫度轉換呈電壓大小，即可以類比-數位轉換器量測，或如應變錶、流速儀與壓力錶等轉換器，分別可以量測力量、流速與壓力。

16 資料擷取系統與時代潮流 過去的量測元件原理限於機械電磁的運作，整體的 量測必須在獨立的儀器上進行
數位技術發展，除了使儀器上能進行分析外，在整合 性上也有了很好的進步，產生了儀器與儀器或電腦 相連接的自動化量測系統（如RS232或GPIB） 後來則有AD/DA 卡為中心的量測控制系統，而更進 步的資料擷取系統，則是如 VXI的高級量測系統作 為代表。

17 Evolution of Instrumentation
50 100 25 75 VI PC Scope(Digital) IC/ASIC Flexibility CRT TV Electronic Transistor Radio Page 1-2: The slide above shows the evolution of instrumentation over the last 100 years. Notice that instruments have evolved by leveraging off of widely used technology. In the 19th century, the jeweled movement of the clock was used to build analog meters. In the 1930s, the variable capacitor, the variable resistor, and the vacuum tube from the radio were used to build the first electronic instruments. Display technology from the television contributed to modern oscilloscopes and analyzers. Today, you can use the high-performance computation and display capabilities of the modern PC to create virtual instruments. Some advantages of using modern PCs include: High-performance instrumentation. High-level user interfaces. Flexibility. (For example, the PC can act as the meter or the oscilloscope for your test and measurement application.) Analog Vaccum tube Clock Time

18 以下為各時代的資料擷取特色： 1.類比儀器（所有功能在單一機體） 2.IEEE 488介面及可擴充的儀器（數位化、儀器之間的通訊、資料傳輸） 3.AD/DA 、GPIB卡加上電腦軟體 4.VXI系統（儀器插卡化、電腦本身規格的提昇、免去連線的問題、通訊速率的提昇）

19 資料擷取基本原理 類比到數位的轉換中有兩個重要的參數： 解析度（Resolution）及取樣率(Sampling Rate) 。 解析度 :
即為經過數位轉換後所造成的量化誤差，因為在電腦中紀錄資料的位元組是 有限的，以MIO卡的類比／數位轉換埠而言，如10V的輸入電壓可以12Bits來紀 錄，意即它的精確度的極限是： 10/212=0.224mV

20 資料擷取基本原理 與解析度相關的前置處理是放大倍數，通常會將輸入信號放大轉換區間，如信號大小為0.1V，而類比／數位轉換埠最大輸入為10V，則可放大100倍，以減少誤差(提高解析度)。 取樣率： （信號的頻率）×（點數/一週期波形）＝取樣率 Nyquist Theorem :取樣率至少為信號頻率大小兩倍.

21 Sampling Rate • Determines how fast A/D conversions take place
• Signals must be sampled fast enough to properly reproduce the signal • Aliasing – signal is undersampled Page 3-2: Discuss the criteria for choosing a proper sampling rate. Sampling Rate—Determines how often the A/D conversions take place. Nyquist Theorem: Fsampling > 2 * Fsignal max. Nyquist Frequency: Half Fsampling. A faster sampling rate forms a better representation of the signal. Discuss the following sampling rate example: If the input signal changes at about 1 kHz, the Nyquist Theorem requires a sampling rate much greater than 2 kHz. If the sampling rate is 10 kHz (10 times larger than the frequency of the signal), the Nyquist frequency is 5 kHz. Aliased due to undersampling Adequately sampled

22 Simultaneous Sampling
For applications where the time relationship between signals is important Instrumentation amplifier and sample-and-hold circuitry for each channel Mux connects channels to the ADC Example – Four 50 kHz signals sampled at 200 kHz ADC S/H Inst Amp Analog Mux Channel 1 Channel 2 Page 3-10: Continue discussing how to sample multiple channels. Simultaneous scanning: Each channel includes a sample and hold circuitry. Explain the sampling example on page 3-10 showing a 270° phase shift in a round-robin scanning system. The 50 kHz input signal completes a cycle (360°) every 20 µs. The time shift between the first and the last channel scanned is 15 µs. The phase difference between the first and the last channel is 270° (15 µs/20 µs * 360°). Simultaneous scanning prevents significant phase shift when sampling multiple channels. Channel 1 Channel 4 Channel 3 Channel 2 Simultaneous Sampling 15 ns (0.09o phase shift) between Ch 1 & 4 (SC-2040 or SCXI-1140) Round Robin Sampling 15 ms (270o phase shift) between Ch 1 & 4

23 High speed sampling rate
Some digitizing oscilloscopes can use equivalent-time sampling to capture very fast repeating signals. Equivalent-time sampling constructs a picture of a repetitive signal by capturing a little bit of information from each repetition 1G Hz * 1/1000 = 1MHz。 即1MHz取樣率可擷取 1G Hz 訊號(週期性訊號)

24 High speed sampling rate

25 Elements of an Instrumentation System

26 Signal Classification

27

28

29

30 資料擷取系統- Signal Conditioning

31 Signal Conditioning • Amplification
– Maximizes use of ADC range and increases accuracy – Increases SNR Signal Voltage S.C.* Amplification Noise in Lead Wires DAQ Board Digitized SNR Amplify only at .01 V None .001 V x100 1.1 V 10 Amplify at S.C.* and DAQ Board x10 1.01 V 100 1.001 V 1000 Pages 1-18 and 1-19: Mention the different types of signal conditioning and point out the advantages of amplification: Increases the DAQ system resolution. Increases the signal-to-noise ratio (SNR). Refer to the SNR table and explain how amplification can have different effects, depending on where it is applied in the system. Stress that amplifying is most effective when applied at the signal source.

32 Common Types of Signal Conditioning
Transducers/Signals Signal Conditioning Thermocouples Amplification, Linearization, and Cold-Junction Compensation Current Excitation, Four Wire and Three Wire Configuration, Linearization RTDs Strain Gauges Voltage Excitation, Bridge Configuration, and Linearization DAQ-STC Common Mode or High Voltages Isolation Amplifiers (Optical Isolation) Page 1–18: The electrical signals that transducers produce are often not well conditioned for DAQ board measurements. Some cases where you need signal conditioning peripherals to condition signals include: If signals are too small, they need amplification. If they are too big, they need attenuation. RTDs and strain gauges need excitation. If the electrical output is not proportional to the physical variable, the signals need linearization. If the DAQ board load is lower than the transducer output, the signals need isolation. If the system is in a noisy environment, the signals need filtering or averaging. Ask students what types of signal conditioning they may need. DAQ Board Loads Requiring AC Switching or Large Current Flow Electromechanical Relays or Solid-State Relays Signals with High Frequency Noise Lowpass Filters

33 Signal Conditioning Transducer Excitation
External voltage or current applied to transducer Provided by signal conditioning hardware Linearization Most transducers are not linear Can be done in hardware or software Isolation Protects hardware from high voltages Used in systems with high common-mode voltages Filtering Remove noise or unwanted signals 4 Hz filter (SCXI-1121) optimum for removing 60 Hz AC noise from slowly sampled signals Antialiasing filters Pages 1-20 and 1-21: Continue discussing the types of signal conditioning and point out the following advantages of each type: Excitation: Makes additional power supplies unnecessary. Linearization: Simplifies the scaling conversion techniques. Software can perform this conditioning. Isolation: Protects the computer from the rest of the system. Filtering: Rejects unwanted signals. Common questions: Without using filtering, what can I do to reject regular or 60 Hz noise from my signals? Use averaging. Averages of 100 thermocouple readings are valid for AMUX-64T applications. What type of signal conditioning should I use for high-impedance transducers? Use isolated preamplifiers.

34 Signal Grounding and Measuring Techniques
Signal Sources and Measurement Systems Rs Differential Referenced Single-Ended(RSE) Non-Referenced Single-Ended (NRSE) Grounded Floating + Measurement System Vs Vm - Grounded Signal Source • Plug-in instruments with non-isolated inputs Pages 1-22 to 1-24: To produce accurate and noise-free measurements, you need to know the nature of the signal source, a suitable ground configuration for the DAQ board and signal conditioning hardware, and the appropriate cable scheme. Discuss the following signal source types: Grounded signals—voltage is referenced to the building ground. Floating signals—voltage is not referenced to the building ground. Floating Signal Source • Thermocouples • Signal conditioning with isolated outputs • Battery-powered devices

35 ? Signal Connections Differential Grounded RSE NRSE Floating
Page 1-28 (cont.): Discuss how to select the measurement system for each type of signal source. Common questions: Which system should I try if I have mixed signals? A differential system fits all signals and has high SNR. What is wrong when my input signal is in range, but the channel reading is saturated? Bias current can move the voltage out of range. Use bias resistors to solve this problem. Why does my AC signal resemble the other channels? Why do I see “ghosts”? The channels may be DC coupled. Tie some references to AIGND. What should I do when my readings are incorrect, noisy, or do not follow my input signal changes? You have a reference problem. Check the grounds, the AIGND, the AISENSE, and V+ and V- connections. Floating

36 Measuring Grounded Sources
Best method – differential Can also use NRSE (uses fewer channels) Both methods avoid ground loops* Incorrect Correct + + + + + + + - Vs Vs + - Vs = Vs = - - + - - + - < DVg > DVg - DVg - - < DVg > Vm = Vs + DVg Vm = (Vs + DVg) - (DVg) = Vs Grounded signal source Pages 1-29 and 1-30: Discuss the methods of measuring grounded signal sources: With differential or NRSE measurement systems, the potential difference between the references of the source and the DAQ board appears as common-mode voltage (voltage not measured) and also avoids ground loops. Ground referenced measurement system Grounded signal source Nonreferenced or differential measurement system Source Ground Measurement System Ground * Ground loops: – Difference in potential between source ground and measurement system ground – Often appears as 60 Hz noise

37 Measuring Floating Signal Sources
Measure with differential, RSE or NRSE Differential or NRSE Use bias resistors (10 kW to 100 kW) Ensure common-mode voltage does not exceed board limits RSE or NRSE Use when signals are high and noise is low All signals should be commonly grounded at the source + - R1 R2 Bias current injected into system by the instrumentation amp Pages 1-30 and 1-31: Discuss the methods of measuring floating signal sources: With differential systems, make sure that the common-mode voltage of the signal is within the range of the DAQ board. With differential and NRSE systems, bias current can move the signal voltage out of the DAQ board voltage range. Although you can use bias resistors to solve this problem, you will then need to consider factors such as AC and DC coupling, and high and low source impedance. Explain that, because of its noise rejection, a differential mode is usually the preferred mode. Consider using a single-ended mode when: All signals are greater than 1 V. All input signals can share the same ground. You use short cables in a noise-free environment. Summarize the different combinations by referring the students to Figure 1-30 on page 1-33. Resistors (10 kW < R < 100 kW) provide a return path to ground for instrumentation amplifier input bias currents. Only R2 is required for DC-coupled signal sources. For AC-coupled sources, R1 = R2.

38

39

40

41 資料擷取提高效率要訣 1.使用高效能界面硬體/驅動程式 2.使用個人電腦/標準的作業環境 4. 使用具彈性的儀控架構 5. 與資訊網路結合
3. 使用適當的儀控軟體 4. 使用具彈性的儀控架構 5. 與資訊網路結合 This seminar will focus on five key strategies to leverage the latest technology using off-the-shelf components for a corporate-wide test strategy. 1. Align with the personal computer - Technology in the general-purpose computer industry is improving at an all-time high. Companies like Microsoft and Intel are pushing the limits of desktop computing to meet higher-end application areas, such as games, financial transactions, large database sytems, and the internet. These improvements are making standard, low-cost PCs more appropriate for more advanced test systems. 2. Align with a standard test management environment - Test management software, such as a test executive, frees your developers from focusing on the mundane software tasks, such as operator interfaces, report generation, and test sequence execution. Instead, they can focus on test. 3. Align with virtual instrumentation test software standards - Using the latest software tools for test can lead to significant development productivity. 4. Align with scalable instrumentation - Many instrumentation approaches can be realized in multiple form factors, from plug-in boards, to VXI instruments. Scalable instrumentation allows you to apply the best solution to each situation without sacrificing code development or reusability. 5. Integrate with corporate information systems - Any system should easily be able to present and share data through standard corporate reporting and archiving tools.

42 模組化的軟體架構 重覆使用率 80% 50% 90% SQL Test Management Services 報表 SPC 程序
Exec 儀器驅動程式 80% 50% As we’ve discussed throughout this seminar, the key to new productivity in production test is adopting a modular test software architecture that can scale to meet the needs of many departments throughout the product development cycle. By building your architecture with flexible off-the-shelf components and tools, you can maximize code reusability to minimize development time and system maintenance. Today, instrument drivers have become the domain of the instrument vendors and tool suppliers. Almost all of the code you will use in your systems for controlling instruments will be reusable code. By choosing a flexible, off-the-shelf test executive, you can again reuse a large portion of code, yet still customize various components as needed to meet the needs of your particular application. The key here is that you can customize a solution without having to write all of the code yourself. Obviously, your individual test programs will require the most custom coding by your engineers. However, by standardizing on scalable instrumentation and building reusable software components, you can easily leverage much of your test development with previous efforts to gain a significant measure of reusability. 90%

43 DAQ系統實現 LabViEW可以控制DAQ卡讀取類比輸入訊號，讀取或送出數位訊號和安排內建計時器來量測頻率、產生脈衝等，對於類比輸入訊號而言，來自感應器的電壓資料透過即插式DAQ卡將訊息帶入電腦中來處理、儲存或做其他處置。

44 Unit to be Tested/ measured
PC-based DAQ架構 控制及應用軟體 硬體及驅動程式 PC or Workstation Application Software DAQ Products Process- sensor, Actuators The second basic strategy to building modular test systems uses industry standard components as the fundamental building blocks of a test system. Whether you use GPIB, VXI, Serial, or PC data acquisition plug-in boards, specifying as many industry standard components allows you to immediately take advantage of the rapidly evolving computer industry. Lower component costs, higher performance, and reduced development and maintenance costs are the results of this strategy. Industry standard technologies such as PCI increases VXI and GPIB controller performance. Plug-in PCI data acquisition boards benefit from a higher speed connection to the CPU and system memory. Virtual Instrumentation Systems are centered around the personal computer. Equipped with standard hardware interfaces, computers serve as an ideal platform to mix and match a variety of different instrumentation hardware within a given system. The power and flexibility of virtual instrumentation is delivered with modern software tools and leverage the ever-increasing performance and decreasing costs of the computer industry and associated tools. Serial Instruments GPIB Instruments Unit to be Tested/ measured VXI Instruments

45 DAQ solution 軟體支援 Data In/Out PCI/ISA Application Software
LabVIEW LabWindows/CVI MATLAB Visual Basic C/C++... Application Software Interface Software Driver(NI-DAQ) Mac, DOS, Win 95/98/ NT Interface software provides the link between application software and the hardware. NI-DAQ works with a variety of programming languages including: LabVIEW, LabWindows/CVI, ComponentWorks, Visual Basic, and many C/C++ versions. It is the interface software that knows the hardware details, how to communicate with different boards, and makes hardware functionality easily accessible to the user. Data In/Out DAQ Board PCI/ISA

46 量測自動化利器 IEEE 488.2 電腦控制量測儀器 簡化儀控流程(儀器驅動程式) 數據收集及測試決策可同時進行 人機
Remote Access Digital Scope Plant Device GPIB GPIB instruments offer test and manufacturing engineers the widest selection of vendors and instruments for general purpose to specialized vertical market test applications. GPIB instruments have traditionally been used as standalone benchtop intruments where measurements are taken by hand. Many GPIB instruments that are used today are still used in this fashion. To increase productivity and reduce overall test times, engineers are now taking computer control of their GPIB instruments so they can acquire and process more measurement data and make quick decisions both in the lab and on the production floor. Computer control automates the process of taking a measurment from a GPIB instrument. You use instrument drivers to easily access the functionality of the instrument through LabVIEW, LabWindows/CVI, C/C++, or Visual Basic and write test applications that take multiple measurments in a short amount of time. These measurements can be quickly formatted and analyzed to generate reports and ultimately make decisions on whether the unit under test (UUT) adheres to the quality specifications required for that particular component or product. You can use computers with PCI, PCMCIA, ISA Plug and Play, ISA, NuBus, Sbus, Serial, Parallel and Ethernet interfaces to develop high performance desktop, portable, wireless, and distributed (using Ethernet) applications that automate taking measurements from GPIB instruments. You use the NI software under Windows NT/95/3.1, Mac OS, and many flavors of Unix. Because NI is consistent across these operaing systems, you can easily port applications to other platforms with little to no souce code modification. Ethernet Desktop PCI ISA MAC SUN Portable PCMCIA Parallel Serial Wireless

47 選擇DAQ卡考慮項目 Test & Measurement World Survey
硬體可靠度 準確度 軟體可靠度 使用容易 整合性 技術支援t 先進技術 價格 價值 長期成本 廠牌 產品選擇性 What are the requirements for new DAQ systems? Test & Measurement World surveyed you, the user, for the answers. The following conclusions can be drawn from the survey: Measurement Accuracy is extremely important. Reliability is crucial. The operating system must be stable regardless of the application stability. Complex applications require more data, faster, without compromising data integrity. Improved productivity is desired. Faster design to production cycle time is required. In order to give you what you need to be successful in your DAQ application, DAQ hardware must be designed to deliver these requirements. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% Test & Measurement World 1995 PC-Based Test Market Insight Study

48 資料擷取與電腦技術發展 CPU MITE 硬體 軟體 網路 LANs Internet

49 Case Study: Ford In-Vehicle Field Prototype Testing
需求：可攜帶牢固、耐溫的測試系統 挑戰：需要以多種儀表清楚顯示數據 方案：工業級可攜帶電腦、 LabVIEW軟體及資料擷取介面卡 Ford engineers wanted a better way to test their vehicles during field test trials in the heat of Arizona. The previous system wedged test drivers into a automobile packed with data logger, strip chart recorders, gauges, and display units. Ford wanted a faster way to collect and analyze the data, while leaving more room for the test drivers. National Instrumentation Engineering (NIE), an Alliance member, developed an in-vehicle test system using LabVIEW and E-Series DAQ boards in a ruggedized PC mounted in the trunk of the test vehicle. All of the data is acquired and automatically displayed through a small laptop disply unit in the driver seat, as well as accessible remotely through a cellular modem. Once the new instrumentation system was complete, Ford engineers were able to acquire data throughout hour test periods in the hot Arizona sun. In addtion, Ford engineers were able to add tests and make minor modifications as their needs changed. For more information on this User Solution, please refer to the Appendix.

50 Case Study: Design Verification 用影像量測半導體溫度變化
需求：要達到 micron 解析度的溫度量測 挑戰：非接觸式量測半導體零件溫度分部 方案： LabVIEW-based 液晶感測系統加上 IMAQ PCI-1408 影像擷取卡及辨識軟體 Semiconductor designers must be able to track the thermal characteristics of their designs and detect faults in this devices as they become more and more complex. Image Therm Engineering has developed a LabVIEW-based semiconductor thermal mapping system that uses PC-based image acquisition technology. The system integrates with Temptronic Liquid Crystal Thermal Analysis kit and ThermoSocket precision temperature control products. With this system, semiconductor desginers can quickly view the thermal characteristics of their designs and detect faults, saving thousands of dollars in redesign time and effort. For more information on this User Solution, please refer to the Appendix.

51 Case Study: Traulsen NSF 規格冷凍庫測試
方案： LabVIEW資料擷取介面卡， SCXI 前端處理硬體 Traulsen sells more reach-in refrigerators and freezers to the restaraunt business than any other company in the world. Their customers include McDonald’s, Outback Steakhouse, Denny’s Marriot, and Kmart. To make the “preferred vendor” lists for each of these customers, Traulsen must ensure that every refrigerator and freezer meets the standards set forth by the National Sanitation Foundation (NSF). To test units for guideline adherence, Traulsen needed a PC-based instrumentation system to montor and control four rooms containing eight test stands at their site in Grand Prairie Texas. G Systems, an Alliance member, built a LabVIEW-based test system that uses SCXI to monitor all eight test stands. The system replaced an older, DOS-based system that was “ancient and unworkable.” With the new system, Traulsen was able to eliminate a number of standalone, paper data loggers. Now, they can acquire the data directly and import the information directly into Excel in real-time for further analysis without interrupting the operation of the tests. For more information on this User Solution, please refer to the Appendix.

52 Reference (1.) “次世代自動化技術趨勢與應用”, 中華民國自動化協會 研討會, Feb. 1997
(2.)    . 蔡明忠,” Automated Sensing and remote control”,1997生產自動化與控制之教學與訓練研討會, 國立台灣科技大學自動化及控制中心, 03/1997 (3.)    .“新世代PC-based控制技術發展研討會”, 中華民國自動化協會 研討會, 05/1998 (4.)    Lonworks seminar, Echelon, 知業科技, 1996 (5.)    ANCO Inc. (OPEN AUTOMATION),”OPEN-IO introduction” ; (6.)    葉文彬, “整合控制網路與智慧型I/O在非集中式控制系統之開發研究”,國立台灣科技大學 工程研究所 自動化及控制學程碩士論文, 06/1998. (7.) NI day 19 98