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Storage Operation
Front-panel controls
All front-panel controls for storage operation are located in
the X-field, surrounded by a frame marking.
STOR. ON pushbutton switches the oscilloscope from real
time to storage mode. Further pressure releases the button
and switches back to real time mode.
Stored signals (in HOLD condition) are retained in the real
time mode; they can be displayed on the screen at any time
by pushing this button. A time coefficient changed in the
meantime has no effect on the stored signals in HOLD con-
dition.
STOR. ON LED: this lamp indicates by shining continuously
that the storage mode is switched on. It also indicates by
flashing if the TIME/DIV. switch is incorrectly set (out of
range). The setting is correct, when, using the storage
mode, the time coefficient is selected inside the range en-
closed by the continuous black line. This range is marked
below the scale with STOR. Fiashing of the lamp is sup-
ported by a 4kHz piezoelectric beeper, which gives an
acoustic warning in the same rhythm.
HOLD | and HOLD I! pushbuttons serve for holding the
memory contents of each channel.
If they are depressed, the memory contents are retained
until the mains voltage is switched off or fails. New storage
is only possible on each channel when the relevant button
is released (out).
SINGLE pushbutton: it switches the digital timebase from
repetitive sweep to single sweep.
Thus single events (such as switching on or off processes,
non-periodic signals} can be displayed and stored as long as
required with constantly uniform screen
intensity. The
single sweep mode is not applicable in analogue oscillo-
scope operation.
RESET pushbutton: brings the digital timebase into the
ready position for single sweep with the single button de-
pressed.
A suitable trigger edge arriving after operation
of the
pushbutton initiates the single sweep.
RESET LED: this lamp indicates storage readiness for
single sweep mode. It goes out after storage Is finished.
TIME/DIV.
rotary switch:
when
the memory
mode
is
switched on, the analog timebase is switched off.
It is replaced by the digitally generated quartz control
timebase. The timebase fine control knob is then out of op-
eration. Because the digital scanning rate is limited to
maximum 0.1 MHz, the smallest adjustable time coefficient
is 1ms/cm, the largest 5s/em. These ranges are framed in
black on the TIME/DIV. scale.
Storage resolution and operating modes
Vertical resolution
Dot density in each operating mode 8 bit = 2° = 256 dots on
9 cm display height (28 dots per cm). However only 8 cm
can be evaluated in the screen graticule.
Horizontal resolution in timebase mode
Channel | alone: Dot density 10 bit = 2'° = 1024 dots on
10 cm display width (100 dots per cm).
Channel Il alone: Dot density 10 bit = 2'° = 1024 dots on
10 cm display width (100 dots per cm).
Channel | and fl(DUAL button depressed): Dot density 10 bit
= 2'° = 1024 dots on 10 cm display width (100 dots per cm).
Sum and difference CHI + CHH (ADD button without/with
one or two INVERT buttons depressed). Dot density 10 bit
= 2" = 1024 dots on 10 cm display width (100 dots per cm).
Horizontal resolution with X-MAG. x10 button
Depressing the X-MAG. x10 button produce no effect on
the stored data; these remain completely unchanged. How-
ever, the display is 10-fold expanded in the X-direction. The
dot density changes from 100 to 10 dots per cm.
Maximum signal frequency in storage mode
The highest frequency which can be evaluated depends upon
resolution, display height adjusted, signal shape and possible
use of the X-MAG. x10 button. [It cannot be strictly defined
and must be assessed according to application. The denser
the dot sequence which simulates the signal shape, the more
accurately the stored display can be evaluated. With sine
shapes the zero-axis crossings are therefore critical and with
the square waves, steep edges. In the vertical direction a
large display
height
setting
is favourable
for accurate
amplitude measurement, but not for waveform assessment,
because the dot density is then small. A too small display
height Is again inaccurate, because scanning in the X and Y di-
rection can fluctuate by +1 dot (statistical scatter). The Y-
bandwidth
in storage mode
is at least 50kHz. So, with
100kHz
scanning
frequency,
a
maximum
theoretical
bandwidth of 50kHz is within reach. However, this requires
special procedures. A 5kHz signal in sine or symmetrical
square wave shape is indeed certainly detectable with the X-
MAG.x10 button depressed, but can be evaluated at best in
its amplitude. Details such as harmonic distortion factor or
edge steepness and interference pulse spikes or glitches
cannot be assessed with any accuracy.
Subject to change without notice
M19 205
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