
Scans by ArtekMedia © 2007
Prepare the
Recording Area
Select
lire
Trigger Mode
IlIitiate the
Trigger Search
Recording
Completed
.
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:...
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,
--
.
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,-,-
2. Prepare an appropriate recording area as follows. (Refer to Chapter
3
for
details.)
a. Position
ZERO
and
FULL SCALE.
b. Set
RANGE
and
OFFSET
for the selected Y·axis channel.
c.
Set
TOTAL TIME
to scale the X-axis.
d. Grid the recording area.
For direct, versus-time recordings,
TOTAL TIME
determines the pen sweep
time. Times settings of
1
second to 24 hours may be used. If a total time
of less than
1
second is selected, the
HP 7090
will reset
TOTAL TIME
to
1
second and perform a l-second recording when the direct recording is
initiated.
3.
Select a pen color appropriate for plotting the selected channel using the
PEN SELECT
push buttons.
4. Use the
TRIGGER
mode selector to select the desired trigger mode.
For manual, front·panel triggering, select the
MANUAL
mode. (The
manual trigger mode is automatically selected during initialization.)
The external 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 will move to the recording area's zero point. The pen remains in
the up position until the selected trigger is received, at which time the
pen lowers to draw the trace.
There is no trigger search for the manual trigger mode - pressing
RECORD DIRECT
triggers the recording immediately (unless a post·trigger
time delay is specified).
For the external and internal trigger modes, the pen is lowered and
plotting begins when the selected trigger is received (unless a post-trigger
time delay is specified).
Status of the trigger search is shown by the
TRIGGER SEARCH
indicator,
which is continuously lit during a trigger search and blinks during a
post-trigger time delay.
The pen is automatically lifted when the recording is completed. Direct
recordings can be stopped in progress by pressing
STOP
-
this will lift
the-pen and terminate the recording.
4·2 Performing Direct and Buffered Recordings