Tektronix TDS5054, User Manual

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Acquiring Waveforms
TDS5000 Series User Manual
3- 31
The oscilloscope acquisition system can process the data as it is acquired,
averaging or enveloping the waveform data to produce enhanced waveform
records. Once the waveform record exists (enhanced or not), you can use the
postprocessing capabilities of the oscilloscope to further process that record:
perform measurements, waveform math, and so on. Refer to
Acquisition Modes
on page 3--21 for a description of the acquisition modes.
While sampling on the input signal provides the data that makes up the
waveform record for any given channel, the oscilloscope builds the waveform
record through use of some common parameters (“common” means they affect
the waveforms in all channels).
Figure 3--11 shows how these common parameters define the waveform record.
They define how much data is taken and from where in the data stream. The
parameters are:
H
Sample Interval: The time between sample points taken during acquisition.
H
Record Length: The number of samples required to fill a waveform record.
H
Trigger Point: The trigger point marks the reference zero time in a waveform
record. All waveform samples are located in time (minus and/or plus) with
respect to the trigger point.
H
Horizontal Position: When horizontal delay is off, the horizontal position is
the time from the first sample taken (first point in the waveform record) to
the trigger point (in percent of samples before the trigger). The trigger point
and the horizontal reference are at the same time in the waveform record.
When horizontal delay is on, the HORIZONTAL POSITION knob controls
the horizontal delay time. The horizontal delay is the time from the trigger
point to the horizontal reference.
Sampling Modes
Waveform Record