What is an oscilliscope

An Oscilloscope is a tool that graphs an electrical signal. It’s a very powerful troubleshooting tool to verify that your signal is not getting distorted in your circuit. It is a tool used for monitoring and is also capable of performing operations on your generated waveform, such as waveform math, calculate frequency, rise and fall time, etc. Oscilloscopes graph on an XYZ region with X being time, Y being Voltage, and Z being Intensity of the signal. For a helpful pocket guide check out this document from Tektronix [link].

The particular scopes available in the DAMlab are the Tektronix TDS 3014 (Nickname: Tesla) and TDS 3054 (Nickname: Gauss).    

The TDS 3014 is a 4 channel Digital Phosphor Oscilloscopes (DPOs) released by Tektronix in 1999. The max sample rate is 1.25 GS/s and has a 100MHz minimum bandwidth.

The TDS 3054 is also a 4 channel Digital Phosphor Oscilloscopes (DPOs) released by Tektronix in 1999. The 3054 is the higher end model of the 3014 with a max sample rate of 5GS/s and a 500MHz minimum bandwidth.

On & Operating

To start out connect your probe to the oscilloscope by plugging the probe’s BNC connecter to the channel one (CH1) port on the scope. Ensure the probe is secure.

Power on your scope. Power buttons will typically be found around other buttons that are related to the power supply unit on the scope. If a pop-up menu appears press MENU OFF. Be sure that channel one is the only active channel (The channels are typically color coded on digital scopes).

To remove a channel, press the channel button (CH2, CH3, …) then press the WAVEFORM OFF button.

There you go! With channel one being the only active channel you are a step closer to get to proper measurement. Next, we will compensate the probe to ensure it is not giving bad readings.

Probe Compensation & AUTOSET

1. Attach the probe to either CH1 or CH2 (Keep it on CH1 if you have been following along) and attach the probe ground clip to the other channel BNC connecter ground (see picture). Also be sure the probe setting is set to x1.

2. Attach the probe tip to the PROBE COMP connector.

3. Be sure you are looking at the waveform for the right channel then press the AUTOSET button. You should see a square wave on the screen after that.

4. Set the vertical scale to 1V using the VOLTS/DIV knob.

5. Center the waveform using the vertical POSITION knob.

6. Set the horizontal scale to 200µs using the SEC/DIV knob.

7. Set the trigger coupling to Noise reject (This is typically accessed through the Trigger Menu).

8. Set the vertical bandwidth to Full.

9. Check to make sure the square waves have flat tops and bottoms, if not the probe is not properly compensated (See step 11).

10. With a screwdriver adjust the low frequency compensation adjustment, located on the probe body for the best possible square wave.

After those steps the probe should be properly compensated and have very little room for error, but before we move on we used a rather complex and important button on the scope that deserves explanation, the AUTOSET button.

The AUTOSET is analogous to an autofocus so you can see at least one full cycle of your waveform. If you are connected to a signal that doesn’t seem to have any reading, pressing AUTOSET may reveal the proper setting for that particular waveform.

Getting Measurements

    At this point you can attach the Oscilloscope probe to the signal you wish to take measurements on. Be sure that the probe is set to x10 and place the grounding clip on the ground of your circuit. The main probe can be placed on the node you wish to measure the signal of.

1. Press the ‘Measure’ button found on the top right button panel of the oscilloscope.

2. A menu will appear on the right side of the screen with different types of measurements that can be displayed. Select which measurements you would like to be displayed to the screen by pressing the button corresponding directly to the right.

3. Once you have all of the measurements you want press the ‘Menu Off’ button to return to your signal screen. Your measurements will appear on the right side of the screen.