虛擬數(shù)字存儲示波器外文翻譯

1、<p><b>　　附錄2 外文翻譯</b></p><p>　　Virtual-digital storage oscilloscope</p><p>　　Virtual digital storage oscilloscope-the structure and composition：Virtual digital oscilloscope PXI

2、bus from a multi-functional data acquisition card and the corresponding software. They will be installed on a PC running Windows, constitutes a powerful can store digital oscilloscope.</p><p>　　Data Acquisit

3、ion</p><p>　　The design of NI is used by the company's multi-purpose data acquisitioncardPXI-6670E, its main functions are as follows: 64-way single-ended / 32-way differential analog input; 12 accuracy;

4、 1.25 MSPS sampling speed; 1.25 MSPS disk write speed ; ± 0.05 ~ ± 10V input range; two-way 12 analog outputs; eight digital I/O.two-way 24 counter /timer.</p><p>　　Functional equipment</p>

5、<p>　　In this case virtual digital oscilloscope with real-time data acquisition, spectralanalysis and window treatment and filtering capabilities. In the virtual digital oscilloscope main panel on data collection an

6、d analysis of the spectrum, and window processing, filtering and other function keys, according to the corresponding button we can enter into the appropriate sub-panel.</p><p>　　Software Design and Implement

7、ation</p><p>　　Virtual digital oscilloscope software design based on the use of C-language programming environment LabWindows / CVI. LabWindows / CVI support numerical type, Boolean, and the string of text,

8、and other data types, but the biggest advantage is through dialog forms of interactive operations generate standard C code. In addition LabWindows / CVI provides a very rich debug tools, including single-step, breakpoint

9、s, variable view, monitor window, and so on, these features make the adjustment process </p><p>　　The main function modules</p><p>　　Virtual digital oscilloscope mainly by the software control s

10、ignals the completion of the acquisition and display processing, data collection in the main panel to complete the following features: Setting up access, set up sampling frequency, set up a manner that waveform, data col

11、lection in the main panel to complete the following Features: Acquisition of real-time signal and the signal on its own spectrum analysis, see lines, and other functions, and window panels dealing with the acquisition o&

12、lt;/p><p>　　The source files generated when the control panel to complete the set, you can have a function of the code of procedure. Specific methods for: to have completed the panel as a response to the curren

13、t state of the [Code] menu, select [Generate] in the [All Code], in the pop-up dialog function selected in the main panel and withdraw from the function , And the user interface will be able to produce documents relative

14、 to the framework of the code function.</p><p>　　Add the code generated automatically step on the corresponding control is a function of the framework, to make certain controls to complete the function, we m

15、ust add code to control the controls. One main () function is the entrance procedures, it is the function of initialization procedures, loading the user and display panels, such as to complete other functions required to

16、 add code. Following the code for data acquisition functions, data acquisition process by calling the callback function bu</p><p>　　Software development environment: virtual digital oscilloscope software des

17、ign based on the use of C-language programming environment LabWindows / CVI. LabWindows / CVI support numerical type, Boolean, and the string of text, and other data types, but the biggest advantage is through dialog for

18、ms of interactive operations generate standard C code. In addition LabWindows / CVI provides a very rich debug tools, including single-step, breakpoints, variable view, monitor window, and so on, these fea</p><

19、;p>　　Have the function</p><p>　　★ function with real-time display: Acquisition Acquisition signal to the input signal and real-time display in a PC terminal. </p><p>　　★ digital filtering: II

20、R filter on the use of digital signal processing and real-time filtering, at the same time filter can be set up in the best approximation function type, filter type, order, from top to bottom cut-off frequency, and other

21、 parameters.</p><p>　　★ latest wave show: to meet the transient waveform display, but can also be transient waveform to be saved. </p><p>　　★ waveform storage: at any time after the original sig

22、nal or signals to the LVM LabVIEW unique file format stored on the local hard drive, for future analysis or processing. One transient signal to the cut-off wave after BMP format images stored in local hard上供view and anal

23、ysis of the future. </p><p>　　★ significant wave back: to keep the memory of the LVM format waveform re-read the document and then displayed on a PC client. </p><p>　　★ spectrum analysis: After

24、the filter frequency signal respectively corresponding analysis and response analysis of the frequency and wave at the same time to show real-time manner and form.</p><p>　　Basic principles</p><p&

25、gt;　　the use of hardware acquisition card acquisition signals, using software provided by NI DAQmx READ acquisition signals, and then through Waveform Graphs to conduct real-time display. This has a basic oscilloscope, s

26、ignal showed that after using Write To Measurement File waveform will be saved as LVM documents. This realization of the basic "store" function, but through Read To Measurement File can be read LVM, thus comple

27、ting the "echo" feature. As the hardware and the acquisition of PC-card-bas</p><p>　　The main function: </p><p>　　DAQmx Read, Digital IIR Filter, Waveform Graphs, Write To Measurement

28、File, Read To Measurement File, and other major function.</p><p>　　Customizing the Waveform Graph</p><p>　　The waveform graph indicator displays the two signals. To indicate which</p><

29、;p>　　plot is the scaled signal and which is the simulated signal, you customize</p><p>　　the plots. Complete the following steps to customize the appearance of an</p><p>　　indicator on the fr

30、ont panel.</p><p>　　1. Move the cursor over the top of the plot legend on the waveform graph.</p><p>　　Notice that while there are two plots on the graph, the plot legend</p><p>　　d

31、isplays only one plot.</p><p>　　2. When a double-headed arrow appears, shown in Figure 1-11, click and</p><p>　　drag the border of the plot legend until the second plot name appears.</p>

32、<p>　　Figure 1-11. Expanding a Plot Legend</p><p>　　3. Right-click the waveform graph and select Properties from the</p><p>　　shortcut menu to display the Graph Properties dialog box.</p

33、><p>　　4. On the Plots tab, select Sawtooth from the pull-down menu. Click the</p><p>　　Line Color color box to display the color picker. Select a new line</p><p><b>　　color.<

34、/b></p><p>　　5. Select Sawtooth (Scaled) from the pull-down menu.</p><p>　　6. Place a checkmark in the Don’t use waveform names for plot names</p><p><b>　　checkbox.</b&g

35、t;</p><p>　　7. In the Name text box, delete the current label and change the name of</p><p>　　this plot to Scaled Sawtooth.</p><p>　　8. Click the OK button to apply the current conf

36、iguration and close the</p><p>　　Graph Properties dialog box.</p><p>　　Notice how the plot color on the front panel changes.</p><p>　　9. Experiment with other properties of the grap

37、h by using the Graph</p><p>　　Properties dialog box. For example, try disabling the autoscale feature</p><p>　　located on the Scales tab.</p><p>　　10. Click the Cancel button to avo

38、id applying the changes you made while</p><p>　　experimenting. If you want to keep the changes you made, click the</p><p>　　OK button.</p><p>　　11. Save and close this VI.</p>

39、<p>　　Saving Data when Prompted by a User</p><p>　　Complete the following steps to build a VI that logs data to a file when the</p><p>　　user clicks a button on the front panel.</p>

40、<p>　　1. On the block diagram, double-click the Write LabVIEW Measurement</p><p>　　File Express VI to access the Configure Write LabVIEW</p><p>　　Measurement File dialog box.</p>&

41、lt;p>　　2. Change the file name test.lvm to Selected Samples.lvm in the</p><p>　　File name text box to save the data to a different file.</p><p>　　3. Close the Configure Write LabVIEW Measurem

42、ent File</p><p>　　dialog box.</p><p>　　4. Right-click the Signal input of the Write LabVIEW Measurement File</p><p>　　Express VI. Select Insert Input/Output from the shortcut menu t

43、o</p><p>　　insert the Comment input.</p><p>　　5. Right-click the Comment input of the Write LabVIEW Measurement</p><p>　　File Express VI. Select Select Input/Output»Enable from

44、 the</p><p>　　shortcut menu to insert the Enable input.</p><p>　　In the previous exercise you learned to add inputs and outputs by</p><p>　　expanding the Express VI using the down a

45、rrows. Notice that this</p><p>　　method is a different way of displaying and selecting the inputs and</p><p>　　outputs of an Express VI.</p><p>　　The inputs and outputs of an Expres

46、s VI appear in a predetermined</p><p>　　order when you add new inputs and outputs. To select a specific input,</p><p>　　you may need to add an input first, then change the input to the specific&

47、lt;/p><p>　　one you want to use.</p><p>　　6. Move the Write to File terminal to the left of the Write LabVIEW</p><p>　　Measurement File Express VI.</p><p>　　7. Wire the Wr

48、ite to File terminal to the Enable input of the Write</p><p>　　LabVIEW Measurement File Express VI.</p><p>　　The block diagram should appear similar to Figure 2-6.</p><p>　　Figure 2

49、-6. Block Diagram for the Save Data VI</p><p>　　8. Display the front panel and run the VI. Click the Write to File button</p><p>　　several times.</p><p>　　9. Click the STOP button o

50、n the front panel.</p><p>　　10. To view the data you saved, open the Selected Samples.lvm file</p><p>　　with a spreadsheet or word processing application.</p><p>　　Notice how the Se

51、lected Samples.lvm file differs from the</p><p>　　test.lvm file. test.lvm recorded all the data generated by the Save</p><p>　　Data VI, whereas Selected Samples.lvm only recorded the data</p&

52、gt;<p>　　when you pressed the Write to File button.</p><p>　　11. Save and close this VI.</p><p>　　Or to talk about the need to improve the design of the place. The first is efficiency. Wh

53、ether this design is from the original intention of the design or the result of design, are not fully take into account the efficiency of procedures and the efficiency of operation. Only a small number of functions and t

54、he realization of the need to optimize. This design were completed in less than one day of production, coupled with debugging time. Efficiency is not high enough reflected in the following ar</p><p>　　Second

55、, file storage efficiency is not high. LabVIEW provides a wide range of data storage file format, which is the most efficient binary form, followed by the text. The use of this design is unique to the LVM LabVIEW format,

56、 the benefits of doing so is called for, deficiency is not common, other software will not be able to read this document effective waveform information. With the Windows Notepad to open LVM documents found, in fact, LVM

57、is a document essentially a text file, recording a wav</p><p>　　Thirdly, it is part of the process of debugging tests left some function in the design of not deleted, only the former was hidden template proc

58、essing, in fact CPU is still running in this part of the function of consumption of resources. </p><p>　　Fourth is here to the six Waveform Graphs, just in front panel made a stack processing, it is a "

59、screen" In fact, for certain procedures can significantly reduce the optimized use of Waveform Graphs. At the same time because in theory if not need to show that the public can be a "screen”.</p><p&

60、gt;　　This was followed by the human-computer interface design. Ease of operation needs to be raised. In addition to the necessary self-button interface, the button should better. For example, switch interface automatical

61、ly trigger procedures, and omit one of the switch button. In addition to the design of the interface graphics, there are too many forms, the ideal situation is designed to be hidden in control of the state model.</p&g

62、t;<p>　　Once again there is a regret. Can be designed as a dual-channel oscilloscope trace or more will be even more perfect. A high-end oscilloscope usually have two channels, and some have more spectrum for the

63、channel. In fact, the increase in access is not difficult, but also far more than the traditional high-end oscilloscope the two channels.</p><p>　　According to requirements of Title 32 of vertical resolution

64、 / div, oscilloscope, a total of eight grid, that is, divided into 256, the choice of eight A / D. Also because of the level of resolution of 20:00 / div, it corresponds to the third gear scan rate 0.2 s / div, 0.2ms/div

65、, 20us/div the sampling rate is respectively 100 HZ, 100KHZ and 1 MHZ. As follows: a scanning speed of Xs / div, the level of demand for the resolution of 20:00 / div, so every point of sampling interval for X/20s, that

66、</p><p>　　Therefore, when the scanning speed of third gear requirements for 0.2 s / div, 0.2ms/div, 20us/div, corresponding to the third gear sampling frequency are 100 HZ, 100KHZ, 1MHZ. However, the 100 HZ

67、to 100 KHZ the span too great, and not conducive to the middle band signals in the show, so we add a 1 KHZ and 10 KHZ Liangdang scanning speed. As the highest sampling rate to 1 MPS, so ordinary A / D to meet the require

68、ments, so we selected TI's eight COMS ADC TLC5510. The chip single-5 V power supply</p><p>　　The A / D circuit of the dynamic range of input signal for a small 0.59 V ~ 2.59V. In order to be extended to

69、the dynamic range of 0 ~ 10 V, to be in its previous level by adding the following adjustment circuit. In addition to the circuit five times the input signal attenuation, the input signal is still on the superposition of

70、 the 1.5 V DC.</p><p>　　Control circuitry to do the programmable device, the main address cumulative unit, sampling speed option modules and programmable device and MCU interface unit. The address cumulative

71、 unit circuit as follows:</p><p>　　CLK for the system clock, counting from the former first-chfa enter a negative pulse, D flip-flop on the counter and reset, then the clock counting. When the full terms, th

72、e circuit automatically cease to work and produce a low-INT signal to mark the end of counting. Onf signal to latch signal, when it was low, latch the current sampling. </p><p>　　The choice of memory chips a

73、nd real-time considerations: Option 1: a sampling data storage RAM, to put the first post-harvest methods of work. Circuit advantages of this method is simple, control simple, easy to implement. But only in the higher fr

74、equency when the input signal to a more stable output waveform, when the signal is very low, the output waveform update cycle is too long, the lack of real-time, and the output waveform data acquisition can not be carrie

75、d out at the same time, some sig</p><p>　　Option 2: The two RAM, using a RAM storage of data collection, another film RAM output data, that is, two alternate RAM storage and output. The way to resolve some o

76、f the lost information signal, but the rate of mining must be consistent, otherwise the data will inevitably cause conflict. The method for low-frequency signals no meaning, no good solution to the problem of real-time a

77、nd more complex circuits, the occupation of mouth line resources, wastage.</p><p>　　Programme 3: I use one pair of RAM, while mining release. The method simple circuit, the better solution of the problem so

78、the real-time use of the programme. As the highest sampling rate is 1 MPS, it demands the greatest memory access time should be less than 1 us. As the level of demand for the resolution of 20:00 / div, and a total of 10

79、analog oscilloscope grid, that is, every time scanning should have 200 points, Therefore, storage of only 200 units. When the input signal an acquisition, th</p><p>　　Waveform display circuit: a waveform dis

80、play X-Y manner and external trigger mode. However, in order to show the oscilloscope characters must choose X-Y approach. 1) Analysis of the data output rate: As the maximum speed of data acquisition for 1 MHZ, so data

81、playback system scan rate should be more than 1 MHZ, can display real-time data update process. According to the experiment, we selected output frequency to 2 MHZ. In the output frequency, the real-time system better, an

82、d waveform stability</p><p>　　Output data from the address by address accumulator, we address the accumulator after class to join the select level data, by scanning signals into digital data pulse switch cha

83、nnels, you can achieve after the latch or a single wave triggered after the show Mobile level.</p><p>　　Sawtooth formation circuit: It was found that the programmable device EPM7128SLC84-15 counting the inte

84、rnal structures of the circuit is very easy to have a burr so that the output sawtooth instability, thus we have a choice of hardware circuit count sawtooth. Sawtooth clock output from the circuit to provide data to ensu

85、re that the scanning signal and data signals simultaneously. Sawtooth dollars will be upon expiry of the binary pulses output after a delay Larger, gave the Z-axis analog oscill</p><p>　　Trigger circuit: tri

86、gger level by the microcontroller through the D / A (MAX508) output, by comparison with the input signal is compared to be trigger signal. The trigger signals to a microcontroller interrupt, the MCU after launch EPM7128

87、start collecting. Selection of the circuit here is relatively high gain, low noise, low drift Yun-OP37 posed by open-loop. Its output by two diode limiter to be the standard TTL signal.</p><p>　　Two-trace Os

88、cillographic circuit: theoretically strict trace oscilloscope to double two-way signal sampling at the same time, then need two high-speed A / D, and its front-end circuit. But ordinary analog oscilloscope resolution is

89、generally not high, thus has no significance to strictly require the two signals at the same time. Therefore, we used all the way acquisition circuit of the two alternate input signal sampling, data were collected will b

90、e stored in the memory of the odd-even address, </p><p>　　Minimum system circuit: the system to AT89C52 as the core. 20 keys from the keyboard composed by MM74C923 completed its scan. Display System is the D

91、CM-162A, it is character LCD, there are two lines of 16, from 8-bit characters in each line of five, because of its resolution is not high, difficult to display Chinese characters, so we use All English interface. In add

92、ition, the system also has 32 K of RAM (62256) and a 82 C55 port expansion as a backup. Part of the power system for the +5 V, +12 </p><p>　　Frequency Measurement modules: the use of SCM counter to measure t

93、he signal. Because the trigger pulse with the same input signal frequency, so just to trigger a pulse frequency can be measured. When the frequency of less than 5 Khz, the use of the method of measurement weeks, the meas

94、ured signal to the gate for a period of time, the MCU to a machine cycle (1 us) for the benchmark time, that is, in its count cycle.</p><p>　　When the input signal in the 5 K-50K when measured by the frequen

95、cy approach to the measured signal for the time benchmarks for the regular 1 S gate time, a time-count, that is, in frequency. Characters display module.</p><p>　　The level of input in the X-axis scanning si

96、gnal, in Y-axis input field scanning signal, the Z-axis input signal brightness can be formed on the characters in the oscilloscope. The field scanning signals generated by the EPM7128 internal count. Z-axis data exist i

97、n the external ROM. Peak peak measurements: general AD (MAX197) on the importation of high-speed acquisition circuit to signal a longer time of sampling, get input signal to the maximum and minimum, and then their poor V

98、alue prior to pa</p><p>　　AUTO-SCALE function: This feature automatically adjust to achieve the level of sensitivity and vertical sensitivity, so that waveform better be displayed. First, the system through

99、the regular AD (MAX197) read as an input signal level trigger level so that the system is stable trigger. Then, call frequency measurement function, measured the frequency of input signal, because the level of sensitivit

100、y we will be divided into 20 us / div, 0.2ms/div, 2ms/div, 20ms/div, 0.2s/div five stalls, in order</p><p>　　This system of measurement, the function and meet the targets were subject requirements. Completio

101、n of the functions are as follows: the input signal can be a single trigger, the trigger after the show that stability can not change with the input signal changes, the signal of a sampling of up to 2,048 sample points i