28
Subject to change without notice
new value is shown on the right hand edge of the screen,
while the previously captured data are shifted to the left. The
leftmost value is shifted out of the memory and lost.
The recording can be stopped at any time by selecting the
HOLD [40]
function.
ROLL
mode can only be used with time coefficients from
100s/div to 50ms/div, as lower time coefficients (faster
time base speeds) are impractical.
If the time base is set to values between 20ms/div and
100ns/div and ROLL mode is selected, the time base will
be automatically set to 50ms/div.
41.2 #AV
Pressing and holding the lower STOR. MODE [41]
pushbutton opens the AVERAGE menu.
The actual setting is displayed highlighted. Changes can
be made by the pushbuttons related to the readout
information.
[43] RESET – SINGLE
- Pushbutton with two functions and
associated LED.
STORAGE AND ANALOG MODE
43.1 SINGLE
Pressing and holding this pushbutton switches the
SINGLE
SINGLE
SINGLE
SINGLE
SINGLE event capturing mode on or off. The readout
indicates
SINGLE
in bottom right position by “sgl”.
SINGLE
mode is available in digital as well as in analog
mode and remains unchanged when switching over from
analog to digital mode or vice versa. The main purpose of
SINGLE
is the capture of one time events, but it can also
be used in combination with repetitive signals.
SINGLE
mode automatically selects normal triggering
(
NM
-LED lit). Otherwise the automatic trigger (
AT
) would
occur without an input (trigger) signal.
If the trigger circuit is activated by
RESET
, one time base
sweep (analog mode) or one complete data acquisition
(digital mode) is performed after a suitable signal caused
triggering. Switching over to SINGLE in analog mode
interrupts the time base sweep and blanks the beam.
STORAGE MODE ONLY
The fastest time coefficients where random sampling is
used are not available in combination with “sgl” (SINGLE).
If such time base settings are selected, the time coefficient
setting is automatically changed, and the actual channel
mode is also taken in account.
43.2 RESET
Briefly pressing the RESET – SINGLE pushbutton causes a
reset. The effect depends on the actual signal display mode.
41.1 STOR. MODE
On condition that Yt mode (CH I, CH II, DUAL, ADD) is
present and “hld” (HOLD) is inactive, briefly pressing of
one STOR. MODE pushbutton opens a pulldown menu. It
offers “rfr”, “env”, “avm” and “rol”. The selected mode
is displayed bottom right by the readout.
The following description assumes that the trigger
conditions are met in Refresh (“rfr”) and it`s submodes
Envelope (“env”) and Average (“avm”).
41.1.1 rfr (Refresh mode)
In this mode, as in analog mode, periodically repeating
signals can be captured and displayed.
The signal acquisition is started by triggering the digital
time base. Then the previously captured and displayed
signal will be overwritten with the current signal. This will
be displayed until the digital time base is triggered again.
This is in contrast to analog operation where the screen
remains blank when the time base is not triggered.
In refresh mode, the signal acquisition can be effected
with pre or post triggering when a time base between
20ms/div and 100ns/div is selected. The pre or post
triggering will be automatically switched off (0s), with larger
time coefficients (100s/div to 50ms/div) in order to avoid
excessive waiting times. If it is required to measure with
pre or post trigger in this time base range, one should
select single shot (SINGLE [43]).
41.1.2
env (Envelope mode).
In this mode the minimum and maximum values of the
signal during several signal acquisitions will be determined
and displayed. Except for the display, operation of the
envelope mode is identical to refresh operation.
Changes in the signal are easier to measure and are more
visible in ENVELOPE operation. This is valid not only for
amplitude changes but also for frequency variations (Jitter).
The ENVELOPE evaluation begins anew when the
RESET
- SINGLE [43] pushbutton
is pressed briefly, to actuate
the
RESET (RES)
function.
41.1.3 avm (Average mode)
.
In this case also several signal acquisition scans are
required; hence, it is a submode of “rfr” (Refresh). The
signal is averaged over the several acquisitions so that
amplitude variations ( e.g. noise) and frequency variations
(Jitter) are minimized or eliminated in the display.
The accuracy of the mean value evaluation increases as
the number of signal acquisitions is increased. One can
select the number between 2 and 512 (please note item
“41.2.:
#
AV”). The selected setting is displayed in the
readout. Of course, with increasing accuracy the total
acquisition time also increases.
The AVERAGE calculation begins anew when the
RESET -
SINGLE [43] pushbutton
is pressed briefly, to actuate the
RESET (RES)
function.
41.1.4 rol (ROLL mode)
.
In this mode, the memory contents and thus also the signal
display, are continuously updated. Because signal capture is
untriggered, no idle states arise while waiting for a new trigger
event to start signal capture. With each signal sampling the
Controls and readout
