Tektronix 2247A

Operators Familiarization
NOTE
For
RISE
and
FALL
measurement,
if
the
measurement
channel
is
the
same
as
the
A
Trigger
channel,
the
A
Trigger
level
is
automatically
adjusted
to
try
to
guarantee
that the
measurement
will
trigger
properly,
as
follows:
ItA
Trigger
SLOPE
is
_s-
and
measurement
is
RISE,
A
Trigger
level
is
set
near
the
10%
level
(as
determined
by
the
RISE
measurement's
peak
acquisition)
.
IfA
Trigger
SLOPE
is
~_
and
measurement
is
FALL,
A
Trigger
level
is
set
near
the
90%
level
(as
deter-
mined
by
the
FALL
measurement's
peak
acquisi-
tion).
'fA
Trigger
SLOPE
is
~_
and
measurement
is
RISE
or
if
A
Trigger
SLOPE
Is
~
and
measurement
Is
FALL,
A
Trigger
level
is
set
near
the
50%
level.
if
the
RISE/FALL
measurement's
peak
acquisition
should
set
the
10%
and
90%
levels
incorrectly
(e.g.,
if
the.
signal
being
measured
has
severe
overshoot),
the
A
Trigger
level
may
be
set
incorrectly
as
well,
causing
loss
of
A
sweep.
If
this
happens
when
A
Trigger
MODE
is
AUTO
LEVEL,
the
A
sweep
will
be
regained
but
the
RISE/FALL
measurement
may
not
be
triggering
properly.
In
this
case
(if
the
signal
overshoot
isn't
too
bad),
the
\-
SET
REF
->
function
can
be
selected
to
manually
set
the
0%
and
100%
levels.
NOTE
RISE
and
FALL
time
measurements
may
have
trouble
trig-
gering
on
signals
that
are
around
50
MHz
or
higher.
If
this
happens,
try
changing
A
Trigger
SLOPE
and/or
A
Trigger
LEVEL.
TRIG
10-90
js
the
default
when
RISE
or
FALL
is
first
called
up.
When
selected,
the
C/T
will
set
the
trigger
levels
at
the
10%
and
90%
points
between
the
0%
and
100%
reference
levels.
TRIG
20-80
may
be
selected
after
a
RISE
or
FALL
measurement
has
been
started
up.
When
selected,
the
trigger
levels
are
recomputed
for
the
20%
and
80%
points
between
the
0%
and
100%
reference
levels.
Selecting
elther
TRIG
10-90
or
TRIG
20-80
does
not
cause
another
3-22
2247A
Operators
wv
7
Ea
EG