Section 1 Establishing an Instrument Connection

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1 Manual for Sweep VI Fall 2011 DO NOT FORGET TO SAVE YOUR DATA TO A NEW LOCATION, OTHER THAN THE TEMP FOLDER ON YOUR LAB STATION COMPUTER! FAILURE TO DO SO WILL RESULT IN LOST DATA WHEN YOU LOG OUT! 1.1. Power on instruments Section 1 Establishing an Instrument Connection Power on both instruments (function generator and digital multimeter) and make sure they are connected to the computers USB ports Start Program Begin by starting the VI. It can be found in the Program Files, under the subfolder Sweep Demo. The file is a standard executable compiled under the LabView runtime environment, so LabView will not start when the file is run Program Controls and Layout When the program starts, a window will appear with the default options shown in the figure below. Descriptions for these controls may be found on the following page. LabView Sweep VI Manual Fall

2 Control Buttons Connect Connect to instruments. Allows user to establish a connection between the instrument panel and the physical instruments. Button is disabled once a successful connection is established. Quit Quit / stop program. This button is always active and allows the user to exit the program. Start Start sweep. This button is only active after a successful connection to the instruments has been established. Stop Stop sweep. This button is only active during an active sweep. Output Disabled / Enabled Enable / disable function generator output. Useful for setting up experiments before sweep is initiated. Export Data To Excel Export sweep data to Excel. This button is only active after a sweep measurement has been completed. Multimeter Controls Multimeter ID Instrument ID for the multimeter. The value Rigol_DMM should be selected. Absolute Resolution Resolution of DMM reading and sampling rate. By default, this is set to 4.5 Rate:Fast Function Measurement function of the DMM. This is set to DC Volts by default. Autorange Does what it says. Allows for auto- ranging of the display and measurement (i.e. milli- volts versus volts) Function Generator Controls Frequency Generator ID Instrument ID for the Function Generator. The value Rigol_FG should be selected. Waveform Waveform to be generated. Sine is selected by default Amplitude Output amplitude of the generated waveform. This is set to 5V by default. DC Offset DC offset of the generated waveform. This is set to 0V by default. Unit Measurement units of the waveform amplitude. This is set to Vpp by default. Start Frequency Start frequency of the sweep. This is set to 100 (Hz) by default. Stop Frequency Stop frequency of the sweep. This is set to (Hz) by default. Step Size Step size (increment) of the sweep measurement. This is set to 100 (Hz) by default. # Data Points Estimate of the number of data points that will be generated (display only). LabView Sweep VI Manual Fall

3 1.4. Select Instrument IDs Before the user can run a sweep, a connection to the instruments must be established. First, select the appropriate instrument IDs under the drop- down boxes labeled Multimeter ID and Frequency Generator ID and pressing the Connect button: The appropriate instrument IDs should appear as Rigol_DMM and Rigol_FG respectively. If these IDs do not appear in the drop- down menu then make sure that the instruments are powered on and connected to the USB ports on the back of the computer Establish Instrument Connection When the Connect button is pressed, it will remain down for a few seconds as the instrument connections are established. The Status box at the right of the window will begin to flash, indicating that instrument initialization is taking place. LabView Sweep VI Manual Fall

4 1.6. Active Control Buttons Once a connection to both instruments has been successfully established, the Connect button and instrument ID boxes will become disabled and inactive. The Start, and Output Disabled button will now be active. The Status box will now indicate that the instrument panel is ready to begin a sweep measurement. The instrument control panel is now set for a sweep measurement to be performed. LabView Sweep VI Manual Fall

5 Section 2 Running a Sweep Measurement Before beginning a sweep measurement, the sweep parameters must be set according to the experiment s requirements. This is outlined below: 2.1. Set Multimeter Controls. First, the options under Multimeter Control must be set: Under Multimeter Control, The Absolute Resolution should be set to 4.5 Rate:Fast and the Function should be set to AC Volts. These options set the multimeter to sample as fast as possible while measuring AC voltage. The Auto Range setting should be left set to Enable Set Function Generator Controls Next, the options for the sweep generation must be set under the Function Generator Control box: The controls should be set as follows: Waveform: Sine Amplitude: 0.1 (0.1V) DC Offset: 0 (0V) Unit: Vpp (Volts peak- to- peak) Start Frequency: 10 (10Hz) Stop Frequency: 100,000 (10kHz) Step Size: 10 (10Hz) Note: The options displayed in the above figure are default and may need to be changed. LabView Sweep VI Manual Fall

6 2.3. Run Sweep Measurement With all sweep and instrument parameters set, you are now ready to run the sweep measurement. Clicking the Start button in the upper right- hand corner of the program window will initiate the sweep: When the sweep starts, the Stop button will become active, allowing the user to stop the sweep at any time. The status box will begin to flash the word Running indicating that a sweep measurement is currently active. Measurements from the DMM will begin to appear in the Sweep Measurement plot area at the bottom of the window. Upon completion of the sweep, a dialgog box will appear indicating that the measurement is finished: Click Ok to continue. The sweep data is now ready for export to Excel. LabView Sweep VI Manual Fall

7 Section 3 Expotring Data to Excel Once the sweep has completed, the Export Data to Excel will become active. This button allows the user to export the data shown in the Sweep Measurement plot direclty to Excel for further manipulation and plotting Export Data After a completed sweep, the program window will appear as shown in the figure below: The Export Data to Excel button is now active. Clicking this button will export the data displayed in the Sweep Measurement plot direclty to Excel. The user will be prompted with the following dialog: Click Ok to continue. LabView Sweep VI Manual Fall

8 A second dialog will appear, instructing the user to save the exported data to a safe location after export. By default, the exported data is stored in a temporary folder under the user s profile, which is emptied every time a user logs out of the computer. If not re- saved, this data will be lost. Click Ok to continue. Excel will now load, with the exported data displayed in the first two columns of the active worksheet, as seen in the figure below. LabView Sweep VI Manual Fall

9 3.2 Insert Scatter (XY) plot. We will now insert a scatter (XY) plot of the acquired data. Select the first two columns of the worksheet (the columns that contain the data from our previous LabView export). At the top of the window, under Insert, select Scatter, under the Charts section of the menu. Select Scatter With Smooth Lines and Markers as the chart type. This may be changed according to individual preference. LabView Sweep VI Manual Fall

10 A chart should now appear in the center of the Excel worksheet: LabView Sweep VI Manual Fall

11 3.3 Format Chart Axes Select the Y axis by left- clicking on the scale. It should appear highilighted as shown below: Now, right click on the highlighted Y axis to bring up a context menu. Select Format Axis LabView Sweep VI Manual Fall

12 The next menu that appears will allow format changes to various options for the Y axis. In this example, we are moving the Horizontal axis down so that it crosses below the plotted data. Copy the chart to your lab report by right clicking anywhere on the chart area and selecting Copy. The chart will be copied to the clipboard and may be pasted in any open document. DO NOT FORGET TO SAVE YOUR DATA TO A NEW LOCATION, OTHER THAN THE TEMP FOLDER ON YOUR LAB STATION COMPUTER! FAILURE TO DO SO WILL RESULT IN LOST DATA WHEN YOU LOG OUT! LabView Sweep VI Manual Fall