4-12
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 Vern ier i s turn ed off , the H orizo ntal s weep s peed knob c hange s the t ime
base sweep speed in a 1-2-5 step sequenc e.
5 Note 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 to p of the g raticul e marks the posit ion of th e
time refer ence. W hen delay time is set to ze ro, the t rigger p oint ind icator ()
overlays the time reference indicator.
Turn ing th e H ori zo nt al swe ep sp ee d kn ob wi ll e xp an d o r co nt ra ct the wa ve fo rm
about the time reference point (). Turning the Horizontal delay time ( )
knob in Main mode will move the trigger point indicator () to the left o r righ t
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 t he sp eci fic l ocat ion of th e tri gger eve nt wi th re spe ct to the time refe renc e
position. The time reference setting affects the delayed sweep as de scribed 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.
Chan gin g th is d ela y v alu e do es n ot e ffe ct the pos iti on o f th e ma in win dow .