HP 7090A, Руководство оператора, Страница: 63 / 105

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Performing a Direct Recording (Versus-Chan3)
Channel
1
or 2 may be plotted against Channel 3 in the direct recording
mode. The procedure is similar to that for direct versus-time recordings .
However, for versus-chao3 direct recordings that are manually triggered,
the
TOTAL TIME
setting has no affect on the duration of the recording. This
feature allows a continuous, free-running measurement, for which lowering
and lifting of the pen and termination of the measurement are performed
manually_
To perform a versus-chan3 direct recording:
1. Select Channel 1 or 2 as the Y-axis variable. Select
CHANNEL
3
as the
X-axis variable.
2. Prepare an appropriate recording area as follows. (Refer to Chapter 3 for
details.)
a. Position
ZERO
and
FULL SCALE.
h.
Set
RANGE
and
OFFSET
for the selected X- and Y-axis channels.
c. Set
TOTAL TIME
for time-limiting of the recording (external or internal
trigger mode only).
d. Grid the recording area.
TOTAL TIME
settings are ignored for manually· triggered measurements.
For external or internal triggering,
TOTAL TIME
settings of 1 second to
24 hours may be used to select the recording duration. If a total time of
less than
1
second is selected, the HP
7090
will reset
TOTAL TIME
to 1
second and perform a I·second recording when the trigger is received.
3. Select an appropriate pen color using the
PEN SELECT
pushbuttons.
4. Use the
TRIGGER
mode selector to select the desired trigger mode.
For manual, front-panel triggering, select the
MANUAL
mode. The exter­
nal or internal trigger modes may also be selected for direct recordings,
as well as post·trigger time delays. These trigger modes and operations
are described in Chapter
5.
5. Press
RECORD DIRECT
to initiate the trigger search.
The pen holder and paper will move so that the pen is above the record­
ing area's zero point. The HP
7090
will then respond to the X,V input
with the pen raised until the trigger is received, at which time the pen
will lower and draw the plot.
To start recording for the manual trigger mode, press
PEN ON
to latch the
pen in the "down" position. (pressing
PEN UP
will
latch the pen in the
"up" position.) The pen may also
be
controlled remotely using the external·
pen connection described on the following page.
• •
•
Select the )(. alld
Y-Axis V(lfiables
Prepnre the
Recordillg Area
•
Select Ihe
Trigger Mode
•
Initiate the
Trigger Scarrh
Recording
Perfonning Direct and Buffered Recordings 4-3