Auto-Magnify - Tektronix MDO4000C User Manual

Analyze waveform or trace data

Auto-magnify

As you adjust the horizontal scale control to faster time/division settings, the MDO4000C Series automatically increases the
sample rate to keep acquiring the same record length in the shorter period of time. Eventually though, the oscilloscope hits the
maximum sample rate. Once the instrument is at its fastest sample rate, further changes to faster timebase settings cause the
oscilloscope to operate in Auto-magnify mode, where the oscilloscope shows the faster desired time/division setting and
continues to acquire the desired record length. The result is that the oscilloscope cannot show all of the acquired points within the
desired time/division setting.
Instead, the oscilloscope shows you only a portion of the entire record in the time-domain graticule. This feature provides you
with a way to magnify a portion of the record without having to use the smaller zoom screen display. This feature gives you the
maximum benefit of the sample rate / record length combination in your oscilloscope. With Auto-magnify, you have access to the
full record length at the maximum sample rate.
NOTE. Auto-magnify only comes on when the zoom feature is turned off.
1. The entire acquisition is indicated by the
horizontal bar in the upper display.
2.
The portion of the acquisition shown in
the time domain graticule is shown within
the part of the upper display defined by
the brackets.
NOTE. If you are using the frequency domain and auto-magnify features at the same time, and if you move the spectrum time
outside of the portion of the acquisition shown in the graticule, then the orange bar in the time-domain display showing the
spectrum time will disappear, as will any activity in the frequency domain display.
140 MDO4000C Series Oscilloscope User Manual