Agilent Technologies 54621D, 24A, 42A Press the Vernier softkey to turn on the time base vernier

MegaZoom Concepts and Oscilloscope Operation

To setup the Horizontal time base

4Press the Vernier softkey to turn on the time base vernier.

The Vernier softkey allows you to change the sweep speed in smaller increments with the time/division knob. The sweep speed remains fully calibrated when Vernier is on. The value is displayed in the status line at the top of the display.

When Vernier is turned off, the Horizontal sweep speed knob changes the time base sweep speed in a 1-2-5 step sequence.

5Note the setting of the Time Ref (time reference) softkey.

Time reference is the reference point on the display for delay time. Time reference can be set to one graticule from the left or right edge, or to the center of the display.

A small hollow triangle (∇ ) at the top of the graticule marks the position of the time reference. When delay time is set to zero, the trigger point indicator (▼ ) overlays the time reference indicator.

Turning the Horizontal sweep speed knob will expand or contract the waveform about the time reference point (∇ ). Turning the Horizontal delay time ( )

knob in Main mode will move the trigger point indicator (▼) to the left or right of the time reference point (∇ ).

The time reference position sets the initial position of the trigger event within acquisition memory and on the display, with delay set to 0. The delay setting sets the specific location of the trigger event with respect to the time reference position. The time reference setting affects the delayed sweep as described in the following ways:

•When the horizontal mode is set to Main, the delay positions the main sweep relative to the trigger. This delay is a fixed number. Changing this delay value does not affect the sweep speed.

•When the horizontal mode is set to Delayed, the delay controls the position of the delayed sweep window inside the main sweep display. This delayed delay value is independent of sampling interval and sweep speed.

Changing this delay value does not effect the position of the main window.

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