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State Trigger
A state trigger occurs when the inputs to the logic function cause the function to become True or
False at the time the clock input changes state. When you use a state trigger, you define:
 The precondition for logic input channels 1 through 3 (channel 1 on TDS5000B 2-channel
instruments)
 The direction of the state change for the clock input, channel 4 (channel 2 on the TDS5000B
2-channel instruments)
 The Boolean logic function: AND, NAND, OR, or NOR (not available on the TDS5000B 2-
channel instruments)
 The condition for triggering: the Boolean function becomes True (logic high) or False (logic
low)
State trigger logic conditions are summarized in the following table.
Pattern State Definition
1, 2
AND
Clocked AND
If all the preconditions
selected for the logic
inputs
3
are TRUE, then the
instrument triggers.
NAND
Clocked NAND
If not all of the
preconditions selected for
the logic inputs
3
are TRUE,
then the instrument
triggers.
OR
Clocked OR
If any of the preconditions
selected for the logic
inputs
3
are TRUE, then the
instrument triggers.
NOR
Clocked NOR
If none of the
preconditions selected for
the logic inputs
3
are
TRUE, then the instrument
triggers.
1
For state triggers, the definition must be met at the time the clock input changes state.
2
The 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 types.
3
The logic inputs are channels 1, 2, 3, and 4 when using Pattern triggers. For State triggers,
channel 4 becomes the clock input, leaving the remaining channels as logic inputs. (TDS5000B 2-
channel instruments, channel 2 is the clock.)