32
Subject to change without notice
10.4.3
Optimum display
In this display mode, so called “Alias“ signal displays can be
avoided. The signals to be recorded are sampled with a higher
sampling rate than that required by the time coeffi cient and
the display resolution. This is enabled by the 1 M Byte storage
capacity per signal as it enables you to store more data than
actually required. As 1 M Byte data are available although only
2000 can be displayed by the crt, one sample is taken from 500 to
be displayed, the sample with the highest deviation being taken.
So each of the 2000 samples displayed is taken out of 500 (2000
* 500= 1 M). This means that in comparison with 2000 k Byte
memory and 2000 samples display, signal frequencies can be
500 times higher before they could cause aliasing. All samples
are displayed in vector mode as described in item 10.4.2.
STOP
Attention!
Due to “Optimal” display more noise becomes
visible as the minimum and maximum values are
displayed.
10.4.4
Status Acq. (acquisition)
In combination of AUTO, normal and single event capture, the
Pre Trigger time is displayed in % if the waiting time is higher
than 1 second. After 100% has been reached, the waiting time
for the trigger event is displayed. Due to the short pre trigger
time in small time defl ection coeffi cient settings, only the waiting
time for the trigger event may become visible.
10.5 Self Cal
43
This function key leads to the submenu “Settings Self Cal“. If
the oscilloscope inputs are open (no inputs applied), an auto-
matic calibration (adjustment) can be made by pressing “Start“.
The calibration can be aborted by pressing the MENU OFF
43
pushbutton.
The automatic calibration (adjustment) optimises the oscillo-
scope behaviour under the current temperature conditions,
after 30 minutes warm up time.
11
AUTOSET
(pushbutton)
Choosing AUTOSET will cause an automatic instrument setting,
dependent upon the actual input signal, which selects positions,
signal amplitude and time base for a reasonable display (in
FFT mode optimum parameter are set). The choice of analog
or digital mode will not be affected. In component test mode
(available only in analog mode), XY mode, or ADD; dual channel
mode will automatically be selected. If dual channel or CH1 or
CH2 were previously chosen this will remain.
The digital modes Roll, Envelope or Average will be changed
to refresh mode.
AUTOSET will further set the intensity to an average value if it
was set too low. If a menu was opened it will be turned off by
AUTOSET. During the display of HELP texts AUTOSET is not
available. AUTOSET can and should be used during FFT ope-
ration to avoid misadjustment.
12
HELP
Pressing the HELP pushbutton will turn the signal display off
and display the help text. If a menu was opened, the help text will
refer to the menu, special menu or submenu option selected.
If a knob is moved another help text referring to this knob will
appear. Press HELP again to deactivate the text.
13
POSITION 1
(knob)
This knob can assume various functions which depend upon the
operating mode, the functions selected with the CH1/2–CUR-
SOR–MA/REF–ZOOM pushbutton
15
and the menu option
selected.
13.1 Y Position
13.1.1
Y-Position of channel 1 (analog and digital mode)
POSITION 1 is for Y Position CH1 control, if Yt mode (time base
mode) is present and the CH1/2–CURSOR–MA/REF–ZOOM
pushbutton
15
is not lit.
13.1.1.1
Y Position of the FFT display (only in digital mode)
measured with channel 1
Position 1 allows you to move the FFT spectrum display, the
FFT reference indicator (arrow symbol at the left side of the
graticule) and the FFT marker (X Symbol) in vertical direction.
13.1.2
REF (reference) signal position ( digital mode only)
The POSITION 1 control functions as the position control for
the signals stored in the reference memory if these conditions
are fulfilled:
1
st
A reference signal must be on display (SAVE/RECALL
9
>
Reference Display
>
(upper display area) REx (x = number of
memory location, select with INTENS)
>
On (with or without
associated settings).
2
nd
After pressing CH1/2–CURSOR–MA/REF–ZOOM pushbutton
15
>
Math./Ref. was selected, the pushbutton will light up
green.
The POSITION 2 knob can also serve as a Y Position control
for signals stored in the reference memory, if the previously
mentioned conditions are met and ON is set in the lower sector
of “Reference Display“.
13.1.3
Mathematics Signal Position ( digital mode only)
The POSITION 1 control serves as a Y Position control for ma-
thematics signals, if after pressing the MATH pushbutton
7
(?Mathematics
>
Display (upper sector)) an equation (MA1...MA5)
has been chosen by the INTENS knob
2
and “?Math./Ref“ has
been selected (pushbutton light green) after the CH1/2–CUR-
SOR–MA/REF–ZOOM pushbutton
15
has been activated.
POSITION 2 knob can serve as a Y Position control for mathe-
matics signals, if the previously mentioned conditions are met
C o n t r o l s a n d R e a d o u t
INTENS
!
HM1008-2
ANALOG
DIGITAL
OSCILLOSCOPE
1 GSa
·
1 MB
100 MHz
DIGITAL
ANALOG
FOCUS
TRACE
MENU
MATH
SAVE/
RECALL
AUTOSET
ACQUIRE
SETTINGS
HELP
CURSOR
MEASURE
RUN / STOP
POWER
POWER
12
11
10
9
8
7
6
5
4
3
2
1
