Tektronix TDS 684A, TDS 744A, TDS 784A Choosing an Acquisition Mode

Acquiring and Displaying Waveforms

3–16 TDS 684A, TDS 744A, & TDS 784A User Manual

Horizontal Position. To set the horizontal position to specific values in the menu

instead of using the Horizontal POSITION knob:

Press HORIZONTAL MENU ➞ Horiz Pos (main) ➞ Set to 10%, Set to

50%, or Set to 90% (side) to choose how much of the waveform will be

displayed to the left of the display center.

You can also control whether changing the horizontal position setting affects all

displayed waveforms, just the live waveforms, or only the selected waveform.

See Zoom a Waveform, on page 3–38 for the steps to set the horizontal lock feature.

You also can select Delayed Runs After Main or Delayed Triggerable. Use the

main time base for most applications. Use the delayed time base when you want

to delay an acquisition so it captures and displays events that follow other

events. See To Find More Information below.

To perform tutorials that teach selecting, scaling, and positioning of waveforms,

see Example 1: Displaying a Waveform on page 2–13 and Example 2: Displaying

Multiple Waveforms on page 2–15.

To learn how to use delay with waveforms, see Delayed Triggering on

page 3–80. To learn how to magnify waveforms, see Zooming on Waveforms, on

page 3–37.

Choosing an Acquisition Mode

The TDS Oscilloscopes are digital products that can acquire and process your

input signal in a variety of modes. To help you choose the best mode to use for

your signal measurement task, this subsection first describes:

How the oscilloscope samples and digitizes an input signal

How the different acquisition modes (such as interpolation) affect this process

How to select among these modes

Following these descriptions are procedures for selecting the sampling and

acquisition modes, beginning with Checking the Acquisition Readout on page 3–23.

Acquisition is the process of sampling the analog input signal, digitizing it to

convert it into digital data, and assembling it into a waveform record. (See

Figure 3–9.) The oscilloscope creates a digital representation of the input signal

by sampling the voltage level of the signal at regular time intervals. The sampled

and digitized points are stored in memory along with corresponding timing

information. You can use this digital representation of the signal for display,

measurements, or further processing.

To Find More Information