HP 83480A User Manual

Eye, Mask and Eyeline Mode Measurement Tutorials
Making Eyeline Measurements
(HP 83480A Option 001 only)
4
STOP
5
To continue measurements,press:
4
RUN
5
Eyeline traces are often improved through averaging. To activate averaging,
press:
4
Acquisition
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNN
Averaging on
Whatever the number of averages is set to, this number of waveforms
(complete record lengths) will be measured before a single averaged
eyeline
trace
is displayed.
A tradeo
exists between
throughput and
noise
reduction.
Error
trace
capture
Error
trace
capture
allows
you
to
isolate
the
waveform
that
caused
amask
violation.
Before
starting
error
trace
capture
,
the
following
should
be
considered
in
setting
up
the
measurement
to
ensure
that
the
desired
number
of
bits
is
displayed
in
the
sequence
leading
to
a
mask
violation.
Set
the
time
base
position
to
several
bits
,
or
time
increment,
above
the
lowest
allowable
value
to
ensure
the
full
sequence
is
seen.
F
or
example
,
the
minimum setting at 622 Mbit/sec is 13.7 bits.To view 10 bits, set the position
to greater than 24 bits. Similarly, at 2,488 Mbit/sec, the minimum setting is
54.7 bits, so set it to > 65 bits.
Set up and align the mask. You may need to wait several seconds to generate
enough
waveforms
to
create
an
eye
diagram
suitable
for
mask
alignment.
Note
that
the
mask
is
aligned
to
the
full
eye
closest
to the
left
screen
edge
.
T
o
see
the
sequence
leading
to
a
mask
violation,
the
mask must
be
adjusted
to the right edge of the screen. This is done
by simply reducing the time
base position setting. Unless the mask is intentionally aligned again, it
will
maintain its position in time
.
5-48

HP 83480A Specifications

General

Brand	HP
Model	83480A
Category	Measuring Instruments
Language	English