HP 7090A, Operator'S Manual, Page: 67 / 105

Scans by ArtekMedia © 2007
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Performing a Buffered Recording (Versus Time or
Versus Chan3)
The following steps may be used to perform a versus-time or versus-chan3
buffered recording:
I.
2.
Establish the recording area scaling as follows. (Refer to Chapter 3 for
details.)
a. Set
RANGE
and
OFFSET
for all channels to be recorded and plotted. The
Channel 1 and/or 2 (and/or Channel 3 in a versus time measurement)
RANGE
and
OFFSET
settings scale the recording area's Y·axis.
For versus-chan3 recordings, the Channel 3
RANGE
and
OFFSET
set-
tings scale the recording area X·axis.
h.
Set
TOTAL TIME
to establish the recording duration (buffer-fill time)
and sample rate.
For versus-time recordings, the
TOTAL TIME
setting scales the record-
iog area's X-axis.
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, as well as
post- or pre-trigger times. (Trigger modes and operations are detailed in
Chapter
5.)
3. Press
FILL BUFFER
to initiate the trigger search.
4.
For the manual trigger mode, there is no trigger search, and the buffers
begin filling when
FILL BUFFER
is pressed (unless a post-trigger time delay
has been specified).
For the external trigger mode, the buffers begin ftlling when the external­
trigger signal is received. For the internal trigger mode, the buffers begin
filling when the Channel 1 input meets the selected trigger conditions.
Status of the trigger search is shown by the
TRIGGER SEARCH
indicator.
The indicator is continuously lit during a trigger search, and blinks
during a post-trigger time delay.
Status of the buffer-fill process is shown by the
BUFFER FILLED
indicator.
The indicator blinks while the buffers are filling, and remains lit when
the buffers are filled.
Use the upper three
CHANNEL �ELECT
push buttons to select the Y-axis
variable(s).
Use the lower
CHANNEL SELECT
pushbutton to select the X-axis variable.
Select
CHANNEL
3
for versus-chan3 plots; select
TIME
for versus-time plots.
[J
Scale Ihe
Recording Area
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Select IlIe
Trigger Mode
, Initiate the
Trigl-!er S earc h l
Recording
Select th{!
X- and
Y.Axis Variables
Performing Direct and Buffered Recordings 4-7