HP 54645A, Руководство пользователя и сервисное руководство

Страница: 281 / 301

Entered trigger operator is
used in the advanced pattern trigger.
“Entered” means that the trigger
qualifier is satisfied as soon as the in-
put waveforms have transitioned
from a state that does not match the
pattern to a state that does match
the pattern.
Graticule refers to the hash marks
on the display. These marks can be
set to full, frame, or none.
Labels are terms defined or cho-
sen from a predefined list to
associate input channels with their
functions in the system under test.
When you assign a label ending in a
digit, such as D0, the oscilloscope in-
serts the label into the non-volatile
label list, automatically increments
the digit, displays the modified label
in the entry field, and selects the
next channel.
Memory See “Display memory,”
“Setup memory,” or “Trace memory.”
Minimum detectable pattern width
is the minimum time for which an in-
put pattern must remain stable for
the oscilloscope to recognize it as
matching a pattern trigger specifica-
tion. At very fast sweep speeds
(small Time/Div settings), the pat-
tern width is nearly a constant value.
At time base settings of 2
µ
s/div and
slower, this is approximately a con-
stant value plus one sample period.
Minimum duration trigger setting
specifies the shortest duration set-
ting that the oscilloscope can
accurately verify against the incom-
ing pattern. The minimum duration
trigger setting is two sample periods
or 16 ns, whichever is greater.
Negative width is the time for
which a signal is low.
Pattern trigger defines a set of
pattern of highs, lows, and don’t care
inputs that must be recognized
across the input channels during any
given input sample. The pattern may
be combined with one edge on any
input channel to form the complete
trigger specification. The pattern
trigger occurs when the pattern is en-
tered.
Period is calculated by selecting
the first and third transitions from
the left side of the visible display and
measuring the delta time between
these two transitions.
Positive width is the time of a sig-
nal or glitch that is high.
Signal inputs connect the MSO
acquisition system to the probes.
Glossary
Glossary-2