Tektronix 524A, 540A, 544A, TDS 520A Operations Common to Pattern and State

Logic Triggering
Reference
Table 3-4: Logic Triggers
Pattern State Definition 1,2
AND Clocked AND If all the preconditions selected
for the logic inputs3 are true,
then the oscilloscope triggers.
NAND Clocked NAND If not all of the preconditions se-
lected for the logic inputs3 are
true, then the oscilloscope trig-
gers.
OR Clocked OR If any of the preconditions se-
lected for the logic inputs3 are
true, then the oscilloscope trig-
gers.
NOR Clocked NOR If none of the preconditions se-
lected for the logic inputs3 are
true, then the oscilloscope trig-
gers.
1Note that for State class triggers, the definition must be met at the time the clock input
changes state. See the descriptions for Pattern and State in this section.
2The definitions given here are correct for the Goes True setting in the Trigger When menu.
If that menu is set to Goes False, swap the definition for AND with that for NAND and for OR
with NOR for both pattern and state classes.
3The logic inputs are channels 1, 2, 3, and 4 for the TDS 640A & TDS 644A and 1, 2, Aux 1
and Aux 2 for the TDS 620A & TDS 524A when using Pattern Logic Triggers. For State Logic
Triggers, channel 4 (Aux 2 for the TDS 620A & TDS 524A) becomes the clock input, leaving
the remaining channels as logic inputs.
The Logic Trigger menu (Figure 3-43) lets you select when to trigger (true or
false), set the thresholds for each channel, select the mode (auto or normal),
and adjust the holdoff.
Press TRIGGER MENU ➞ Type (main) ➞ Logic (pop-up) ➞ Class (main) ➞
Pattern or State (pop-up).
Operations Common
to Pattern and State