Using Waveform Data

introduction getting waveform data panning using markers adjusting display color exporting data saving data

Introduction

Waveforms are the actual time and amplitude data from the instrument. HP BenchLink Scope displays them graphically, and they are internally stored as time/amplitude information.

You can acquire analog as well as logic waveform data on your PC. Once you’ve acquired waveform data, you can use markers to help you study amplitudes and times and the differences between marked amplitudes and times. Your markers will also show you the state of all digital signals that your vertical (time) markers intersect.

Once the waveform data is transferred to the PC, it can be saved in different formats such as .WFX (binary), .CSV (comma-separated time/amplitude data), or .PRN (tab-separated time/amplitude data). These files can be imported as ASCII data or importing as time/amplitude data into spreadsheets for further data analysis.

Waveform data can also be copied to the Windows Clipboard and pasted into other applications.

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Getting Waveform Data
  1. From the menu bar, select Waveform --> New.... The New Waveform dialog box will appear, offering information about waveforms and allowing you the choice of selecting waveform options or canceling the waveform acquisition.
  2. Choose the waveform data source(s) you wish to transfer to the PC, then click the OK button. You may select multiple waveforms for transfer, but you must select waveforms that are currently visible on your instrument’s display.
  3. A new untitled Waveform window will appear with the waveform data displayed.
  4. To enhance the display of complex waveforms, select Waveform --> Connect dots from the menu bar.

    Note
    When a Waveform window contains new or updated data, there will be an asterisk in the title bar. When the window is saved as a .WFX file, the asterisk will disappear.
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Panning
  1. Click the left arrow of the scroll bar to see waveform data that is to the left of your waveform view’s current position.
  2. Click the right arrow of the scroll bar to see waveform data that is to the right of your waveform view’s current position.
  3. You may also click and drag the scroll bar’s scroll box to move through your data.
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Using Markers
  1. Markers can be enabled or disabled through the use of the Show Markers tool bar icon markers icon, or via the Waveform --> Show markers command from the menu bar.
  2. The Source drop-down lists are used to associate each XY pair of markers with a particular analog channel.
  3. The X and Y edit controls next to each Source drop-down list show the current X and Y position of each marker. These values are updated as you graphically click-and-drag the markers on the Waveform window’s graph area. You may also enter values directly into the X and Y edit controls, in order to position the markers manually.
  4. Below the two X and Y fields, DX and DY difference information is displayed. DX shows the difference in X positions between the two markers, and DY shows the Y position difference. The difference fields are not editable. Note that DY values are not displayed if the units differ between the two markers.
  5. If analog waveforms are not present on the Waveform window, Y and DY information is not displayed.
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Adjusting display color
  1. In the Channel Properties dialog box, available by selecting Waveform --> Channel Properties... from the menu bar, select the waveform you want to change in the Channel drop-down list.
  2. Click the Color... button.
  3. When the color dialog appears, select a color, then click OK.
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Exporting data to other applications
  1. Waveform files saved in the time/amplitude (.CSV) format can be imported into spreadsheet applications such as Microsoft® Excel 4.0. The data is displayed in columns of time and amplitude. Microsoft® Excel uses a comma (,) as a delimiter to insert the information into the correct column.
  2. Waveform files saved in the time/amplitude (.PRN) format can be opened in a statistical analysis application such as DADiSP/32-Win. The data is displayed in columns of time and amplitude.
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Saving data
  1. Select File --> Save as... from the menu bar. The File Save As dialog box is displayed.
  2. Enter the desired filename and click the OK button to save the file to disk.

    Note
    If you attempt to exit HP BenchLink Scope without saving the Waveform window, HP BenchLink Scope will automatically prompt you to do so before exiting the application. Your file can only be saved in the waveform (WFX) format from this dialog box.
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Last updated: 8/23/2000
Swarthmore College