Triggering on Waveforms
TDS 684A, TDS 744A, & TDS 784A User Manual 3–57
Both the trigger point indicator and level bar are displayed from the Display
menu. See Set Display Readout Options on page 3–29 for more information.
The trigger point indicator shows position. It can be positioned horizontally off
screen, especially with long record length settings. The trigger level bar shows
only the trigger level. It remains on screen, regardless of the horizontal position,
as long as the channel providing the trigger source is displayed.
Trigger Status Screen. To see a more comprehensive status listing of the settings
for the main and delayed trigger systems, press SHIFT STATUS ➞ STA-
TUS (main) ➞ Trigger (side).
Each trigger type (edge, logic, and pulse) has its own main trigger menu, which
is described as each type is discussed in this section. To select the trigger type,
press TRIGGER MENU ➞ Type (main) ➞ Edge, Logic, or Pulse (pop-up).
Triggering on a Waveform EdgeThe TDS Oscilloscope can trigger on an edge of a waveform. An edge trigger
event occurs when the trigger source passes through a specified voltage level in a
specified direction (the trigger slope). You will likely use edge triggering for
most of your measurements. This subsection describes how use edge trigger-
ing — how to select edge type, source, coupling, slope, and level. It also details
how to select trigger mode, auto or normal, for all trigger types.
To quickly check if edge triggers are selected, check the Trigger readout. When
edge triggers are selected, the trigger readout displays the trigger source, as well
as the trigger slope and level. (See Figure 3–36.)
Main Time Base
Main Time Base Time/Div Main Trigger
Source = Ch 1 Main Trigger
Slope = Rising Edge
Main Trigger
Level
Figure 3–36: Edge Trigger Readouts