Agilent Technologies 54621D, 24A, 42A, 54621A, 22A, 41A guide

Making Measurements

To reduce the random noise on a signal

To reduce the random noise on a signal

If the signal you are applying to the oscilloscope is noisy, you can set up the oscilloscope to reduce the noise on the displayed waveform. First, you stabilize the displayed waveform by removing the noise from the trigger path. Second, you reduce the noise on the displayed waveform.

1 Connect a signal to the oscilloscope and obtain a stable display.

2Remove the noise from the trigger path by turning on either high-frequency reject or noise reject.

High-frequency reject (HF reject) adds a low-pass filter with the 3-dB point at 50 kHz. You use HF reject to remove high-frequency noise, such as AM or FM broadcast stations, from the trigger path.

0 dB

3 dB down point	Pass
	Band

dc 50 kHz

HF Reject

5-6

Image 174

Agilent Technologies 54621D, 24A, 42A, 54621A, 22A, 41A manual To reduce the random noise on a signal

Contents

Agilent 54621D/22D/41D/42D Mixed-Signal Oscilloscopes Softkeys extend the functionality of command keys Display shows current input signalsHorizontal Controls select sweep speed and delay parameters Utilities This Book Page Contents Contents Trigger Types Using Labels on the Mixed-Signal Oscilloscope Run/Stop/Single/Infinite Persistence Operation Math Functions Saving and Recalling Traces and SetupsCapturing Data Cursor Measurements Utilities Contents-6 Getting Started Getting Started Getting Started Setting up the Oscilloscope To inspect package contents To inspect package contents Package contents for 54620/40-Series Oscilloscopes To inspect options and accessories To inspect options and accessories To inspect options and accessories Accessories available Model Description To inspect options and accessories Power Cords Plug Type Cable Part Number To clean the oscilloscope Disconnect power from the instrumentTo clean the oscilloscope To adjust the handle To adjust the handle To power-on the oscilloscope Press the power switchTo power-on the oscilloscope To adjust the waveform intensity To adjust the waveform intensity To connect the oscilloscope analog probes To connect the oscilloscope analog probes To compensate your analog probe To compensate your analog probePress Autoscale To use the digital probes mixed-signal oscilloscope only To use the digital probes mixed-signal oscilloscope only Connect the clip to a node in the circuit you want to test Signal Lead Ground Lead Clip Signals Ground To connect a printer To connect an RS-232 cableTo connect a printer To verify basic oscilloscope operation Press the Autoscale key on the front panelTo verify basic oscilloscope operation Getting started using the oscilloscope interface To verify basic oscilloscope operation Using Quick Help Getting Started Loading an updated language file from floppy disk Loading an updated language file from floppy diskPage Front-Panel Overview Front-Panel Overview Viewing signal detail with acquire mode Using Single versus Run/StopUsing Auto trigger mode versus Normal trigger mode Important Oscilloscope Considerations Important Oscilloscope Considerations Using Vectors Display menu Delayed Sweep Post Acquisition Processing 54620/40-series Oscilloscope Front Panels 54620/40-series Oscilloscope Front Panels 54624A 4-Channel Oscilloscope Front Panel Entry knob Autoscale key Softkeys Front-Panel Operation 54621D, 54622D D, and 54642D digital channels Interpreting the display Interpreting the display To use analog channels to view a signal To use analog channels to view a signalExample To use digital channels to view a signal To use digital channels to view a signal How Autoscale Works To display signals automatically using AutoscaleTo display signals automatically using Autoscale Undo Autoscale To apply the default factory configuration To apply the default factory configuration To adjust analog channel vertical scaling and position To adjust analog channel vertical scaling and positionCenter the signal on the display using the position knob Measurement Hints To set the vertical expand reference for the analog signal To set analog channel probe attenuation factorExpand About Center To display and rearrange the digital channels To display and rearrange the digital channels Press the Main/Delayed, then press the Vernier softkey To operate the time base controlsTo operate the time base controls To make a single acquisition First set trigger Mode/Coupling Mode softkey to NormalTo start and stop an acquisition To start and stop an acquisition To use delayed sweep To use delayed sweepPress the Delayed softkey Press Main/Delayed To make cursor measurements To make cursor measurements To make automatic measurements Choose what measurement you want on that source by pressingTo make automatic measurements To modify the display grid To print the displayTo modify the display grid Triggering the Oscilloscope Trigger Out connector Triggering the Oscilloscope To select the Mode and Coupling menu Selecting Trigger Modes and Conditions To select a trigger mode Normal, Auto, Auto Level To select a trigger mode Normal, Auto, Auto LevelAuto Level and Auto modes Normal mode To select trigger Coupling To select Noise Reject and HF RejectTo select trigger Coupling To set holdoff To set holdoff To set holdoff Holdoff Operating Hints External Trigger Probe Settings External Trigger InputExternal Trigger Input Previous menu Trigger Types MegaZoom Technology Simplifies Triggering To use Edge triggering Select 1, 2, Ext, or Line as the trigger sourceTo use Edge triggering To use Edge triggering To use Pulse Width triggering To use Pulse Width triggering Press the qualifier softkey to select the time qualifier Qualifiers can be set as follows Qualifier time set softkey To use Pattern triggering To use Pattern triggering Specifying an Edge in a Pattern To use can triggering To use can triggering Press the Baud softkey to set the can signal baud rate Press the Trigger softkey to select the trigger condition To use Duration triggering To use Duration triggering To use Duration triggering When the duration trigger occurs To use I2C triggering To use I2C triggering Ack Data Stop Start Address R/W Condition Frame Start Addr7 Read Ack Data or Condition 26th clock edge To use I2C triggering To use Sequence triggering To use Sequence triggering Sequence Selected Press the Stage softkey and select Find Press the Find softkey and select the Find stage conditionEdge Pattern 1 and Edge Press the Stage softkey and select Trigger on Edge Pattern 2 and Edge Nth Edge Press the Stage softkey and select Reset on Edge 1 or Pattern 1 and Edge Timeout To use Sequence triggering To use SPI triggering To use SPI triggering Resetting all bits in the serial data string to one value Assign source channels to the clock, data, and frame signals To use SPI triggering To use SPI triggering To use TV triggering To use TV triggering Press the Mode softkey to select the TV triggering mode To use TV triggering Provide Correct Matching TV standard Field Alt Field To trigger on a specific line of video Alternate Triggering Line Numbers per Field for Each TV Standard Line Number Represents Count To trigger on all TV line sync pulses To trigger on a specific field of the video signal To trigger on all fields of the video signal To trigger on odd or even fields Holdoff Settings To use USB triggering To use USB triggering To use USB triggering Trigger Out connector MegaZoom Concepts and Oscilloscope Operation MegaZoom Concepts and Oscilloscope Operation MegaZoom Concepts Deep Memory Deep MemoryMemory depth values Oscilloscope Responsiveness Oscilloscope ResponsivenessMegaZoom Technology Display Update Rate Display Update Rate To setup the Analog channels To setup the Analog channelsTurning channels off To setup the Analog channels Press the Imped impedance softkey Press the BW Limit softkey to turn on bandwidth limitingPress the Invert softkey to inverted the selected channel Press the Probe softkey to display the channel probe menu To setup the Horizontal time base To setup the Horizontal time basePress the Main softkey to select Main horizontal mode Main mode Press the Vernier softkey to turn on the time base vernier To setup the Horizontal time base Delayed mode To setup the Horizontal time base Roll mode XY mode Acquisition Modes Press the Acquire key to display the Acquire menuAcquisition Modes All points displayed after Single or Stop Peak Detect Average Mode Smoothing # Avgs=1 or High-resolution mode Realtime Mode Infinite Persistence Display modesPress the Display key to view the Display menu Clear display Vectors On/Off Pan and Zoom Pan and ZoomZoom To pan and zoom a waveform To pan and zoom a waveform Run/Stop/Single/Infinite Persistence Operation Acquiring Data Acquiring DataSingle versus Run/Stop Run/Stop versus Single Memory Depth/Record LengthMemory Depth/Record Length Single Press the Single key To run and stop an acquisitionTo take a single trace To run and stop an acquisition To capture a single event Connect a signal to the oscilloscope Set up the triggerTo capture a single event Operating Hints To use infinite persistence To use infinite persistenceClearing stored infinite persistence waveforms To clear the waveform display Press the Display key, then press the Clear Display softkeyTo clear the waveform display Configuring the Mixed-Signal Oscilloscope To display digital channels using Autoscale Activity indicator Interpreting the digital waveform displayInterpreting the digital waveform display List of stacked channels To turn individual channels on and off To turn individual channels on and off Press the Turn on or Turn off softkey To force all channels on or all channels offTo change the display size of the digital channels Displayed To change the logic threshold for digital channels To change the logic threshold for digital channels Using Digital Channels to Probe Circuits Using Digital Channels to Probe CircuitsInput Impedance High-Frequency Probe Equivalent Circuit Probe Grounding Best Probing Practices Using Labels on the Mixed-Signal Oscilloscope To turn the label display on or off To turn the label display on or off To assign a predefined label to a channel Press the Label keyTo assign a predefined label to a channel Label Assignment Auto-Increment Features To define a new labelTo define a new label To define a new label Label List Management To reset the label library to the factory default To reset the label library to the factory defaultPress the Default Library softkey Defaulting labels without erasing the default library Saving and Recalling Traces and Setups Press the Save/Recall key to display the Save/Recall menuMaking a hardcopy print To Autosave traces and setups To Autosave traces and setups MegaZoom Concepts and Oscilloscope Operation To save traces and setups to a new file on the floppy disk To save traces and setups to a new file on the floppy diskTo create a new file name, press the New File softkey To recall traces and setups To recall traces and setupsRecalling overwrites current settings Saving printing screen images to floppy disk Press the CSV, TIF, or BMP softkeySaving printing screen images to floppy disk Recalling the factory default setup Recalling the factory default setup Making Measurements Making Measurements Concepts about the 54620/40-series Oscilloscopes Main and Delayed Sweep Capturing Data Making Measurements To use delayed sweep To reduce the random noise on a signal To reduce the random noise on a signal LF Reject Use averaging to reduce noise on the displayed waveform Press the Acquire key, then press the Averaging softkey Smoothing # Avgs=1 or High-resolution mode Making Measurements Characterize the glitch with delayed sweep To use the Roll horizontal mode Press the Main/Delayed key, then press the Roll softkeyTo use the Roll horizontal mode To use the XY horizontal mode To use the XY horizontal mode Signal centered on the display Calculate the phase difference using the formula below Signals are 90 out of phase Signals are in phase Math Functions Math Operating Hints Math Scale and Offset Math Scale and OffsetMath Scale and Offset are Set Automatically Multiply Multiply Subtract Subtract Differentiate Differentiate Figure below shows an example of differentiate Integrate Integrate Integrate and Signal Offset FFT Measurement FFT Measurement Aliasing FFT Operation Scale and offset considerations FFT Measurement Hints FFT Measurement FFT Measurement Hints Cursor Measurements To make cursor measurements Select the X and Y softkeys to make a measurement Cursor Examples Cursors measure frequency of pulse ringing Measuring pulse width with cursors Average Amplitude Base Maximum Minimum Peak-to-Peak RMS Top Phase DelayAutomatic Measurements Preshoot Overshoot Making automatic measurements Making automatic measurements FFT measurements Making time measurements automaticallyMaking time measurements automatically Digital channel time measurements Frequency CounterDuty Cycle Period + Width Making time measurements automatically Fall TimeRise Time Width Making time measurements automatically At Min Isolating an event for frequency measurement Delay Making Delay and Phase MeasurementsMaking Delay and Phase Measurements Digital channel measurements Phase Measurement Making voltage measurements automatically Making voltage measurements automaticallyMath Measurements and Units Measurement definitions Using delayed sweep to isolate a pulse for Top measurement Top Making overshoot and preshoot measurements Making overshoot and preshoot measurementsPreshoot Making overshoot and preshoot measurements Overshoot Page Utilities Utilities To configure Quick Help languages To configure Quick Help languages Loading an updated language file from floppy disk Language Info softkey To update your instrument to the latest application software To configure a printer To configure a printerPress the Format softkey to select the print format Gray scale printing CSV lengthScale factors Form feed Deleted files cannot be recovered To use the floppy diskTo use the floppy disk Press the XON DTR softkey to set the RS-232 handshake To set up the I/O port to use a controllerTo set up the I/O port to use a controller Press the Baud softkey to set the RS-232 baud rate Pin Number Signal RS-232 Connections To set the clock To set the clock To set up the screen saver To set up the screen saverPress the Saver softkey to select the screen saver type To set up the screen saver Press Start User Cal to start the routine To perform service functionsTo perform service functions User Cal User Cal Status Self testAbout Oscilloscope To set other options Default Library softkey mixed-signal oscilloscopes onlyTo set other options Expand softkey Performance Characteristics Performance Characteristics Agilent 54620-series Performance Characteristics Acquisition Analog ChannelsAcquisition Digital Channels on 54621D and 54622D only Agilent 54620-series Performance Characteristics Vertical System Analog Channels Vertical System Digital Channels 54621D and 54622D only Accuracy = ±2.0%80 mV + 0.4%80 mV = ±1.92 mV Horizontal Sample rate of 200/400 MSa/s Trigger System Can Analog Channel Triggering Digital D15 D0 Channel Triggering 54621D and 5462 2DExternal EXT Triggering Measurement Features Display System FFT Storage General Characteristics Power RequirementsInstallation categories Agilent 54620-series Performance Characteristics Agilent 54640-series Performance Characteristics Acquisition Digital Channels on 54641D and 54642D only Agilent 54640-series Performance Characteristics Vertical System Digital Channels 54641D and 54642D only Range Ns/div to 50 s/div Resolution Vernier Minimum pulse width setting 2 ns Digital D15 D0 Channel Triggering 54641D and 54642D Display System Window Rectangular, Flattop, Hanning Noise Floor General Characteristics Page Index Numerics Index Missing acknowledge condition, I2C trigger Index-3 Index-4 Declaration of Conformity Product Regulations EMC Declaration of Conformity Product Regulations Safety Document Warranty Agilent Technologies, Inc