UNIVERSITY OF CALIFORNIA AT BERKELEY College of Engineering Department of Electrical Engineering and Computer Sciences EE105 Lab Experiments Agilent DSO5014A Oscilloscope Tutorial Contents 1 Introduction 1 2 Quick Notes to get started fast 1 3 Trigger 2 4 Interface Details 4 1 Auto Scale Button 4 2 Analog Section 4 3 Horizontal Section 4 4 Display Button 4 5 Measure Section 4 6 Cursors 5 Examples 5 1 Measuring the Peak to Peak Voltage Vpp 5 2 Measuring Frequency of a Waveform 5 3 Measuring Voltage with Cursors 5 4 Using Averaging 5 5 Measuring a Transfer Characteristic 1 2 2 3 3 4 4 4 of a Waveform 5 5 5 5 6 6 Introduction The Agilent DSO5014A is an oscilloscope and it is used to measure voltages that vary with time There are four independent input channels available on the DSO5014A thus it can be used to simultaneously measure and compare four different waveforms e g input and output waveforms of an amplifier The default mode of the oscilloscope plots time on the horizontal axis and voltage on the vertical The scaling of the axes can then be adjusted for each input signal Scaling can either be done manually or with the Auto Scale button There are other modes of operation for the oscilloscope as well such as the XY mode that plots one channel against the other in a Voltage Voltage plot However in these labs you will primarily use the default mode This tutorial starts with quick notes on the most vital information So if you feel somewhat comfortable using the oscilloscopes you can check over the quick notes and figure out the details on your own Otherwise please also read the later sections which include more detailed descriptions of the Agilent DSO5014A interface as well as examples of common measurement procedures 2 Quick Notes to get started fast After connecting the probes try the Auto Scale button It will generally provide a good axis scaling if the waveform is not too irregular small or at a high frequency 1 3 TRIGGER 2 Each channel has an independent control knob to allow the manual setting of the vertical scale Each channel only has one scale reading which is displayed to the left of the corresponding channel number at the top of the screen To adjust the scale simply turn the knob in the ANALOG section These knobs are located above the numbered buttons there is one vertical scaling knob for each input channel To conduct measurements e g measuring Vpp press the Quick Measure button in the MEASURE section of the panel Notice the softkeys that appear on the bottom of the screen Select the desired source and measurement using the first two menu buttons below the screen e g Source 1 Pk Pk Then initiate the measurement by pressing the third menu button i e Measure Cursors can be activated by pressing the Cursor button Use the menu buttons below the screen to adjust the settings and use the entry knob next to the Cursor button to move the cursors AC coupling will remove any DC bias offset from the measured signal This feature can be selected using the menu button below the screen note that this can only be done in the channel menu Press the corresponding numbered button e g 2 in the ANALOG section to have the channel menu appear on the bottom of the screen The oscilloscope s ground is earth grounded so the black alligator wires on the probes are connected together Since the function generator is also earth grounded the oscilloscope probe grounds are connected to the function generator ground To avoid shorts to ground you should always connect the oscilloscope ground clips to the same node Do not try to use the probes to measure floating signals as you can with the DMM 3 Trigger The Agilent DSO5014A has a TRIGGER section on its interface panel Triggers are used to synchronize the oscilloscope with an external signal so that measurements can be taken at the right moment For example to capture a single voltage pulse one might use a trigger input to signal the oscilloscope to take measurements at the pulse arrival Triggers can also be used with periodic inputs However you will generally not need to use oscilloscope triggering in these labs 4 Interface Details The power button is in the lower left corner of the front panel Press it to turn on the oscilloscope The oscilloscope screen should now display a coordinate system At the top of the screen vertical and horizontal scaling units are displayed The default mode will display vertical scaling for each input in volts div and horizontal scaling in seconds div Note that these units correspond to the respective lines that make up the square grid The buttons below the screen are referred to as menu buttons or context buttons in this tutorial Their functionality changes with the selection of other buttons e g by pushing the Quick Measure button Each button s current function is labeled on the screen by the text immediately above the button These menu buttons are essential to taking measurements and performing more complex functions on the oscilloscope The following sections cover the front interface panel in the general order you would consider them when making waveform measurements At the end of the tutorial there are examples of common measurement procedures Please refer to a photo of the Agilent DSO5014A in Figure 1 this might help in locating the mentioned controls buttons 4 1 Auto Scale Button The Auto Scale button has the oscilloscope guess a good axis scaling based on the input waveform This button is always a good first pass for scaling and often it will be the only scaling that you will need You 4 3 INTERFACE DETAILS Figure 1 Agilent DSO5014A Front Panel can also tune the scaling manually with the ANALOG and HORIZONTAL controls which are described below 4 2 Analog Section The controls of the ANALOG section adjust the vertical scaling and position of each independent channel signal Note that the controls for each channel are aligned vertically with respect to the input port The knobs above the numbered buttons set the vertical scaling vertical zoom on the display The 1 2 3 and 4 numbered buttons toggle showing their respective inputs The position knob is located below the numbered buttons and have up and down arrow markings next to them These knobs control the voltage offset against the display axes The horizontal axis does not represent 0 volts but instead the 0 volt position for each input is designated by a numbered ground symbol on the left side of the screen When you adjust the offset with the position knob you will see the
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