INTRODUCTION: The explanation, relevant diagrams and the related links are specified clearly in the Handout for the above lab.
In our Computer Lab 1st floor (AutoCAD back room) there are a set of computers equipped with Data Acquisition hardware: Lab-PC+ DAQ board [I/O Connector], cable, and Demo-box with terminals (3 for analog input, 2 for analog output, 1 for counter, and Ground terminal-center pin in Function Generator area), for your own REAL measurements of your own signal sources (± 5V range Northe row PCs, or 0 to 10 V South row PCs).

PART I: Start up

1. On one of these set of computers switch on the monitor. You will observe a "NOTICE: Only authorized CEET faculty, staff, and students may access this machine. "
2. Click O.K.
3. "Login" Pop-up widow appears
4. Default Name: ACAD & cursor prompting for Password:
5. Click O.K. ( No need for typing Password )

PART II: Configure DAQ board or verify existing configuration
[DAQ Board Configuration Instructions]

NOTE: Verify and record the existing DAQ board configurations, but DO NOT change them because they have to match the jumper and dip-switch settings on the board!

1. Click "Start" button to begin
2. Select Programs
3. Select Lab VIEW or Select NI-DAQ group if available
4. Select NI-DAQ Configuration utility
5. "Niconfig.daq -NI-DAQ Configuration utility" Pop-up widow appears
6. Note down the following information/settings:

• Personal Computer's NIU inventory number (white label with bar-code on the unit with the plug-in DAQ board in it):
• Device # : 1
• Device name: Lab-PC +

1. Click "Configure" button
2. "Configuring Device 1: Lab-PCPlus" Pop-up window appears
3. Note down settings:
• Base Address (do not change)
• Direct Memory Access: usually 3 (may vary with some PCs)
• Interrupt Request: usually 4 (may vary with some PCs)

1. Click "AI" (for Analog Input) in the main menu
2. Note down settings:

• Polarity/Range depends on Jumper settings: ± 5V range North row PCs, or 0 to 10 V South row PCs.
• Mode Referenced Single Ended (reqired for Demo Box)

1. Click "AO" (for Analog Output) in the main menu
2. Note down settings:

• Polarity: Bipolar ( ± 5V range for the North row PCs, or Unipolar (0 to 10 V range for the South row PCs)

1. Click "Accessory" in the main menu
2. Note down settings:

• Accessory: None

1. Click "O.K."  (or "X" Close icon) to close the Pop-up widow

 PART III: Measure a battery voltage

NOTE: The "Front Panel" user interface of 490LVDAQ.llb file is the best viewed if the monitor resolution is set to 1024x768 pixels and "Small font size." Adjust these in the Display Properties' Settings window (right-click anywhere on the screen and choose Properties).

1. Following these steps you can find out the unknown voltage of any source (a 1.5V battery for example) using the DAQ board.
2. Double-click "Demo Lab VIEW-DAQ" icon on the screen, which is a shortcuts to "490LVDAQ-v5.llb" or "I:\Mee390\490LVDAQ.llb" file.
3. "File Dialog" Pop-up widow appears
4. Select "490lvdaq.vi" file (usually the first on the list)
5. Click "O.K."
6. "490lvdaq.vi" a full-screen Pop-up widow appears
7. Connect a battery of known voltage to channel 1 (CH1, for example) & ground (GND) on the DAQ Demo-box terminals and note down the voltage value on the display corresponding to that channel (1, for example, as you have connected your battery to CH1, channel 1 pin).
8. Press " RUN " icon (the right-arrow just below "Edit menu") to run program and perform measurements.
9. Note down the voltage value obtained and compare with battery voltage measured by a multimeter for example.
10. Close all the Pop-up windows

PART IV: Measure a waveform from (Demo box) function generator

1. Double-click "Lab VIEW Demo" icon on the screen
2. "File Dialog" Pop-up widow appears
3. Select "490lvdaq.vi" file
4. Click O.K.
5. "490lvdaq.vi" a full-screen Pop-up widow appears
6. For measuring the minimum frequency of the function generator, turn the function generator knob (see the Figure in handout) in the counter-clock-wise direction to the far end. Connect the square wave (or sign, or triangular-saw waves) pin to any analog input channel (for example 2). The ground is internally connected (inside the box). On the Virtual Scope screen click the "CONTINUES/FINITE switch" to FINITE mode and choose other settings if you like to change the default values. Now depress the" RUN " icon (the right-arrow just below "Edit menu") and obtain a reading. Find out the signal time period from the graph on the display. The minimum frequency of the function generator is obtained by taking the reciprocal of the measured time period.

For the above settings the time-period obtained was 0.00915sec/cycle. Thus the minimum frequency of function generator was 109 Hz.

7. For measuring the maximum frequency of the function generator, turn the function generator knob (see the Figure in handout) in the clock-wise direction to the far end. Connect the square wave (or sign, or triangular-saw waves) pin to any analog input channel (for example 2). The ground is internally connected (inside the box). On the Virtual Scope screen click the "CONTINUES/FINITE switch" to FINITE mode and choose other settings if you like to change the default values. Now depress the" RUN " button (the right-arrow just below "Edit menu") and obtain a reading. Find out the signal time period from the graph on the display. The maximum frequency of the function generator is obtained by taking the reciprocal of the measured time period.

Professor M. Kostic's Web Site: www.kostic.niu.edu *Usage Policy & © Copyright by M. Kostic