Table of Contents
Advertisement
AUTO - Selected using button (29).
This mode resembles the NORM mode, except that it automatically
generates an internal trigger and forces a waveform to appear on
the screen whenever the selected trigger is not present for more
than 500 msec. When the 9400A auto-triggers, the display usually
moves in time as the trigger is not time-correlated with the input
signal.
Auto trigger can not be used when the 9400A is in the RIS mode.
When the 9400A is in the Roll mode (> 500 msec/div), it samples
input signals continuously.
In the AUTO mode any valid trigger
will halt data acquisition
once the trigger delay requirements
have been satisfied.
SEO_NCE - Selected using the upper button (29).
Sequence triggering enables the 9400A's acquisition memories to be
partitioned into up to 250 segments.
Possible settings are: 8, 15, 31, 62, 125, or 250 segments.
Waveform acquisition in SEONCE mode is particularly useful in the
case of short-lived or echoed signals, such as those typically
encountered in RADAR, SONAR, LIDAR and NMR.
In this mode, the time base setting determines the total duration
(TIME/DIV x I0) of each segment. Changing the number of required
segments does not change the time base; it only affects the number
of digitized points (record length) per segment. The number
data points per division is shown in the Acquisition Parameters
display, called by pressing Panel STATUS button (2).
The display is only updated after a sufficient number of sweeps
has been acquired. If less than the required number of triggers is
available the SEQNCE acquisition
may be aborted by pushing the
SEQNCE button (29) again.
The 9400A then completes the missing sweeps by auto-triggering a
sufficient
number
of times
while setting
its input coupling
temporarily to GND. Thus the artificially completed sweeps will
appear on the display as GND lines.
Manual Operation
5-10
Advertisement
Table of Contents
