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GW Instek GDS-800 Series User Manual User Manual

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GDS-800 Series Digital Storage Oscilloscope Operation Manual

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Figure 5-7: Operating the XY display function

These 500 points processed by the oscilloscope under run mode are characteristic

points of real acquired long memory waveform. Due to the hardware limitation of LCD

panel, always 250 points (300 points for side menu off) will be displayed. The way to

explore the real acquired waveform on the oscilloscope’s long memory is stopping

the scope and change the time base. When the scope is stopped, users can observe

any portion or all the waveform memory record by changing the time base or

horizontal trigger position. Decreasing time base expands the waveform and is

referred to as “zooming in”. This feature performs the similar function to the time base

windowing feature. But this feature is available under the real-time acquisition mode

and is only operable when acquisition is stopped.

Users can shift the stopped waveform horizontally on the LCD screen. It is controlled

by the horizontal’s POSITION knob. Increasing “delay trigger indicator” shifts the

waveform to the left and decreasing “delay trigger indicator” shifts the waveform to

the right. By observing the memory bar and viewable area, user can see what portion

of the memory is being displayed.

The memory length is also an important factor because the following formula.