Tektronix 2247A

3-20
Operators Familiarization
(TO RISE/FALL MENU) — selects the rise/fall measurement menu.
In this menu, the top two Items are the actual measurements. Only
one of these two may be selected at a time. When a measurement Is
selected, the peaks of the signal are automatically measured, the
trigger levels are set (as described below), and the measurement
starts.
RISE
FALL
TRIG 10-90
TRIG 20-80
ie SET REF -H
Rise/Fall menu
The next two menu Items determine how the rise/fall trig levels are set;
only one of these two may be selected (underlined when selected).
When TRIG 10-90 Is selected, the rise or fall measurement will trigger
at the 10% and 90% points between the positive and negative peaks of
the waveform. Selecting TRIG 20-80 will cause the measurement to
use the 20% and 80% points.
The I SET REF -4 Item toggles on (underlined) or off each time Its
button Is pushed. When on, the [© 0% and 100%-4 cursors will appear
for manual adjustment of the rise/fall reference levels. When toggled
back off again, the rise/fall measurement will resume, using these new
levels to calculate and set the 10%-90% (or 20%-80%) trigger levels.
RISE measures the rise time of elther CH 1 or CH 2. When this
measurement Is first selected, the peaks of the signal are measured
and stored as the 0% and 100% reference levels. Then the 10% and
90% trigger levels are calculated and set from the reference levels,
and the time interval Is measured and displayed. During RISE/FALL
measurements, all B Trigger mode, source, and coupling LEDs are
turned
off,
and
these
parameters
may
not
be
set.
The
B
Trigger
level
may
not
be
adjusted;
when
A
is
selected,
the
usual
modes,
slopes,
couplings,
and
level
may
be
controlled.
B
Trigger
SLOPE
Js
also
not
settable. B SLOPE LED will be on if doing a RISE measurement and off
If doing a FALL measurement.
2247A Operators