Difference between revisions of "CSC270 Tektronix Scope Lab"
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* Connect Probe 2 to Test Point 3 | * Connect Probe 2 to Test Point 3 | ||
* Autoset | * Autoset | ||
| − | * Press on 2 to bring Waveform 2 on the screen. | + | * Press on the ''blue'' '''2''' button to bring Waveform 2 on the screen. |
* Notice that Waveform 1 (yellow) appears very clearly, but Waveform 2 does not. | * Notice that Waveform 1 (yellow) appears very clearly, but Waveform 2 does not. | ||
* This is because Waveform 1 is faster than Waveform 2, and the scope by default synchronizes itself to the signal on Probe 1. | * This is because Waveform 1 is faster than Waveform 2, and the scope by default synchronizes itself to the signal on Probe 1. | ||
| − | == | + | <br /> |
| + | ==Solution for Getting Stable Images of Different Waveforms== | ||
* To get a better picture of what is going on, we need to take ''snapshots'' of the waveforms with the '''single''' button, while playing with the '''Scale''' button. | * To get a better picture of what is going on, we need to take ''snapshots'' of the waveforms with the '''single''' button, while playing with the '''Scale''' button. | ||
* Go ahead, change the scale a bit and press '''Single'''. Repeat a few times until you feel you have captured the repeating nature of both waveforms. | * Go ahead, change the scale a bit and press '''Single'''. Repeat a few times until you feel you have captured the repeating nature of both waveforms. | ||
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Revision as of 13:59, 16 February 2016
--D. Thiebaut (talk) 11:49, 16 February 2016 (EST)
This lab is an introduction to the use of the Tektronix MSO3000/DPO3000 Oscilloscope.
Contents
Reference Material
- You can find annotated copies of the manual on Judy Cardell's site.
- The original manual of the scope can be found here. The good part starts on Page 29!
The Setup
- You need one of the HP signal generator boards.
- Get a couple of probes from the equipment pouch, and connect them to the 1 and 2 inputs of the scope.
- Use colored rings to mark the probes
- Don't forget to connect your scope's AC cord!
Capturing one waveform
- Turn on the scope (bottom left button on face).
- Turn on the board (make sure the battery is fully engaged in its connector) by pressing on the button near the battery. A red LED should turn on.
- Connect Probe 1 to TP 1, and ground it, i.e. connect the alligator clip to the GND connector on the board.
- Press the yellow 1 button right over the probe.
- Press AUTOSET (black button, middle right of face)
- You should get your first waveform, which is referred to as a square wave.
- Move the waveform up and down using the two buttons around the yellow 1 button
- Move the waveform left and right using the large pan button (top middle of the face).
- Scale the waveform and magnify or reduce it with the smaller zoom button, around the pan button.
Measuring waveforms: time and amplitude
- The scope has two horizontal cursors you can move around, as well as two vertical cursors that allow you to measure time differences (horizontally) and voltages (vertically).
- The cursors are turned On/Off by using the small Cursors button (top left of the face).
Time Measurements
- Question
- What is the length of one period of the signal? What is its frequency?
To answer this question:
- Move the 2 vertical cursors to measure a full period of the signal. Report the time you measure.
- Click on Measure (center top), which will bring in a menu at the bottom of the screen.
- Click on Configure Cursors and set the cursor mode to display Hz instead of seconds. Click on Configure Cursors one more time to remove the menus from the screen.
- What is the frequency reported by the scope? Is it 1/period?
Voltage Measurements
- Question
- What is the amplitude of the waveform in Volts?
To answer this question:
- Click on Cursors another time to control both horizontal and vertical cursors
- Use the Select button to switch between horizontal and vertical cursors
- Use the Multipurpose a and Multipurpose b buttons to move the cursors.
- Measure the amplitude, in volts.
- Note that the amplitude is not 5 Volts, but a lower voltage.
Capturing 2 Waveforms
- Connect Probe 2 to Test Point 3
- Autoset
- Press on the blue 2 button to bring Waveform 2 on the screen.
- Notice that Waveform 1 (yellow) appears very clearly, but Waveform 2 does not.
- This is because Waveform 1 is faster than Waveform 2, and the scope by default synchronizes itself to the signal on Probe 1.
Solution for Getting Stable Images of Different Waveforms
- To get a better picture of what is going on, we need to take snapshots of the waveforms with the single button, while playing with the Scale button.
- Go ahead, change the scale a bit and press Single. Repeat a few times until you feel you have captured the repeating nature of both waveforms.
- Question
- What is the frequency of Waveform 2 (in blue)?
Exercises
Practice!
- Get proficient at using the scope and redo the experiments above with two new waveforms: Waveforms 2 and 5.
- In particular, learn how to quickly
- measure the frequency
- measure the time difference between two points
- synchronize the two waveforms, so that you have a clear image of both, without overlapping parts
- capture the image to your USB stick.
Discover!
- Figure out how to save a waveform to your USB stick!
