Tektronix 545A Instruction Manual page 18

Operating
Instructions
—
Type
545A
Triggering Level
"
Waveforms
Obtained
With The
Triggering
Level Control Set
In
The
+ Region
Trigger
Slope
•a
Sweep
Triggers
On
4
Slope
Trigger Slope
Sweep
Triggers
On
-
Slope
Trigger Slope
a-
Sweep
Triggers
O
n
+ Slope
Trigger Slope
Waveforms Obtained
With The
Triggering
Level Control Set
In
The
-
Region
Triggering
Level
Sweep
T
riggers
On
-
Slope
Fig.
2-8.
Effects
on
the oscilloscope
display produced by
-f-
and
—
settings of the
TRIGGERING
LEVEL
control.
When
the
TRIGGERING
LEVEL
control
is
set
in
the
+
region, the
sweep
is
triggered on the
upper portion of
the input
waveform;
when
it
is
set
in
the
—
region, the
sweep
is
triggered on
the
lower portion
of
the input
waveform. The
TRIGGER SLOPE
control
determines
whether
the
sweep
is
triggered on the
rising
portion or the falling
portion of the input
waveform.
2-8