Tektronix TDS 684A, TDS 744A, TDS 784A To State Trigger

Triggering on Waveforms
TDS 684A, TDS 744A, & TDS 784A User Manual 3–67
It compares the times and, if the time TRUE is longer (for TRUE for more
than) or shorter (for TRUE for less than), then it triggers a waveform display
at the point the logic condition became FALSE. This time can be, and usually
is, different from the time set for TRUE for more than or TRUE for less
than.
In Figure 3–41, the delay between the vertical bar cursors is the time the logic
function is TRUE. Since this time is more (216 s) than that set in the TRUE for
more than menu item (150 s), the oscilloscope issues the trigger at that point,
not at the point at which it has been TRUE for 150 s.
Logic Function (AND) Becomes TRUE
Logic Function Becomes FALSE and
Triggers Acquisition
Time Logic Function is TRUE
Time Logic Function Must be TRUE
Figure 3–41: Logic Trigger Menu — Time Qualified TRUE
When you select the logic class State, the oscilloscope uses channel 4 as a clock
and triggers on a logic circuit made from the rest of the channels (pages 3–60
through 3–62 describe how state triggers work). To use state triggering, do the
following procedures.
Select State Triggering. Press TRIGGER MENU ➞ Type (main) ➞ Logic
(pop-up) ➞ Class (main) ➞ State (pop-up).
Define Inputs. To set the logic state for each of the input channels (Ch1, Ch2, ...):
1. Press TRIGGER MENU ➞ Type (main) ➞ Logic (pop-up) ➞
Class (main) ➞ State (pop-up) ➞ Define Inputs (main).
To State Trigger