Tektronix MDO3012, User Manual

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Acquire the Signal
7. Push Delay on the lower menu to select
On when you want to delay the acquisition
relative to the trigger event.
With Delay set to On , turn the Horizontal Position knob counterclockwise to increase the delay. The trigger point will move
to the left and ultimately outside of the acquired waveform. Then you can adjust the Horizontal Scale knob to acquire more
detail around the area of interest at the center of the screen.
When this delay is on, the trigger point separates from the horizontal expansion point. The horizontal expansion point
stays at the center of the screen. The trigger point can move off the screen. When this happens, the trigger marker turns
to point in the direction of the trigger point.
Use the delay feature when you want to acquire waveform detail that is separated from the trigger event by a signi fi cant
interval of time. For example, you can trigger on a sync pulse that occurs once every 10 ms and then look at high-speed
signal characteristics that occur 6 ms after the sync pulse.
When the delay feature is set to Off , the expansion point is tied to the trigger point so that scale changes are centered
around the trigger point.
Using Roll Mode
Roll mode gives a display similar to a strip chart recorder for low-frequency signals. Roll mode lets you see acquired data
points without waiting for the acquisition of a complete waveform record.
Roll mode is enabled when the trigger mode is auto and the horizontal scale is set to 40 ms/div or slower.
Quick Tips
Switching to Envelope or Average acquisition mode, using digital channels, using math waveforms, turning on a bus,
or switching to Normal trigger will disable Roll mode.
Roll mode is disabled when you set the horizontal scale to 40 ms per division or faster.
Push
Run/Stop to halt Roll mode.
64 MDO3000 Series Oscilloscopes User Manual