12
Subject to change without notice
If digital
SINGLE (SGL)
mode has not been chosen, one
of the associated LEDs is lit. The signal capture and
display mode can be selected by pressing one of the
buttons. The mode setting is indicated by one of the LEDs
(
RFR, ENV, AVM
and
ROL
) and also displayed by the
readout. The only exception is in XY storage mode. Then
the
RFR-LED
is lit and the readout displays XY. No other
signal capture and display mode can be chosen in XY
mode. The desired Yt signal capture mode can be selected
by pressing the upper or lower
STOR. MODE
button.
The following description presumes that
HOLD (HLD)
is
not activated and the trigger conditions are met.
(9)
RFR
- stands for refresh operation. 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-triggering or post-triggering when a time base
between 20ms/cm and 1µs/cm is selected. The pre-
triggering or post-triggering will be automatically switched
off (PT0%), with larger time coefficients (100s/cm to
50ms/cm) in order to avoid excessive waiting times. If it
is required to measure with pretrigger or post-trigger in
this time base range, one should select single shot
(SINGLE = SGL)
.
In XY digital mode the
RFR-LED
lights. It indicates a
continuous, trigger independent signal acquisition. The
trigger circuit is switched off.
(9)
ENV
- is the abbreviation for ENVELOPE operation.
In this mode the minimum and maximum values of the
signal during several signal acquisitions will be determined
and displayed. Except for this display, the ENVELOPE
operation is identical to the 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
SIN-
GLE (10)
button is pressed briefly, to actuate the
RESET
(RES)
function.
Attention!
The pretrigger or post-trigger will be automatically
switched off (PT0%) in the time base range from 100s/
cm to 50ms/cm.
(9)
AVM
- indicates Average (mean value) mode.
This operation is effective when the AVM-LED lights up
and the readout displays
AV...
.
In this case also several signal acquisition scans are
required; hence, it is similar to Refresh operation. 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 the number of signal acquisition scans used
for evaluation is increased. One can select the number
between 2 and 512. The selected setting is displayed in
the readout. Of course, with increasing accuracy the
time required for this also increases.
To select a different value briefly press both
STOR. MODE
pushbuttons simultaneously. The
AV...
display in the
readout flashes indicating the setting mode. Now, the
value can be changed by briefly pressing the upper or lower
STOR. MODE
button. The setting mode can be exited by
again briefly pressing the two buttons simultaneously. The
setting mode will also be switched off automatically if none
of the two buttons is actuated during about 10 seconds.
The averaging begins anew after briefly pressing the
SINGLE (10)
pushbutton (RESET-function).
Attention!
The pretrigger or post-trigger will be automatically
switched off (PT0%) in the time base range from 100s/
cm to 50ms/cm.
(9) ROL
- indicates ROLL mode.
In
ROLL
mode the ROL-LED is lit and the readout displays
“ROL”
.
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 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 (7)
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
1µs/div and ROLL mode is selected, the time base will be
automatically set to 50ms/cm. The time deflection
coefficient set previously before switching to ROLL mode
will be internally stored (e.g. 20ms/cm). If ROLL mode
has been selected inadvertently and the
TIME/DIV.
knob
has not been changed, the time base will be automatically
set to the internally stored coefficient when switching
from
ROLL
to
AVERAGE
mode.
(10) SINGLE
- Pushbutton with two functions and associated
LEDs.
SINGLE
Pressing and holding the SINGLE pushbutton switches
between SINGLE and:
1.storage mode Yt (time base) or XY operation or
2.analog mode Yt (time base) operation,
dependent on the actual instrument setting.
Controls and readout
