38
Subject to change without notice
22
SOURCE
(pushbutton)
Preliminary note!
The pushbuttons MODE
20
, FILTER
21
and SOURCE
22
refer
to the trigger unit. In XY mode these pushbuttons are without
effect as XY displays are untriggered.
Depressing this pushbutton will call various menus depending
on the previously selected MODE
20
: Edge, Video, Logic.
In the ”Trigger SOURCE“ menu the source is selected from
which the trigger signal is to be taken. The options depend on
the actual mode of the scope.
22.1 Edge / Video Trigger
22.1.1
CH1
Conditions: Analog or digital mode, ”Edge“ or ”Video“ selected.
CH1 will then be the trigger source, no matter whether it is
displayed or not. Readout: ”Tr:CH1, (Slope), Filter (TV)“.
22.1.2
CH2
Conditions: Analog or digital mode, ”Edge“ or ”Video“ selected.
CH2 will then be the trigger source, no matter whether it is
displayed or not.
Readout: ”Tr:CH2, (Slope), Filter (TV).“
22.1.3
LC0 ... LC3
Conditions: digital mode, logic probe connected, LC/AUX on
(pushbutton
36
), EDGE.
The logic signal at LC0 ...LC3 will trigger if the level conditions
are fulfilled. The switching level will be indicated in the ”Logic
Chan.“ menu if the pushbutton LC/AUX
36
is depressed and may
then be changed if desired. Readout: ”Tr:logic“.
22.1.4
Alt. 1/2
Conditions: Analog mode, EDGE Triggering.
Alternate triggering with the signals from channels 1 and 2 as
described in the section ”Alternate Trigger“ of chapter ”Trig-
gering and time bases“. Please note that in this trigger mode
the apparent time relationships between the two signals on the
screen are meaningless and misleading, the relative position
of the two signals depends only on their shape and the trigger
level selected.
In dual channel mode (DUAL) alternate triggering is only pos-
sible in conjunction with alternate dual channel operation. If
previously dual trace chopped mode was selected (VERT/XY
32
pushbutton)
>
DUAL chop) it will be automatically changed
to alternate mode when alternate triggering is selected. After
”Alt. 1/2“ is turned off dual trace chopped mode may be selec-
ted again.
Readout: ”Tr:alt, Slope, Filter“.
22.1.5
External
In this mode the trigger signal comes from the AUXILIARY INPUT
(TRIG EXT
38
). Readout: ”Tr:ext, Slope, Filter“.
22.1.6
AC Line
The trigger signal is taken from the line (mains supply) which
feeds the scope. See also the section ”Line triggering“ in the
chapter ”Triggering and time bases“. Readout: ”Tr:alt, Line,
Slope“.
22.2 Logic triggering
Logic triggering is only possible in digital mode. Press MODE
pushbutton
20
to call the TRIGGER menu and select LOGIC.
Press now the SOURCE
22
pushbutton which will present the
LOGIC menu where the following settings may be selected:
LC0 ... LC3, X H L
With the aid of the function key the trigger logic level can be
determined: H = High or L = Low level. X means that both levels
will trigger (don’t care).
23
TRIG’d display
(not in Roll- and XY-mode)
This LED will light up if the time base receives a signal suited
for triggering at the instruments present trigger settings. It
depends upon the trigger signal whether the LED will just blink
or remain illuminated.
24
NORM display
This display will light up provided ”Auto“ triggering was not
selected. The mode can be selected in the ”Trigger“ menu
called by pressing (MODE
20
). The light indicates that the
screen will remain dark as long as there is not sufficient
trigger signal.
25
HOLD OFF display
(analog mode only)
This display will light up if the hold off time was set to
>
0% in
order to indicate that the longer than minimum hold off time
may cause a lower rep rate of the time base and thus a darker
display. Setting the hold off time requires pressing the HOR VAR
pushbutton
30
which calls the menu ”Time base“. Only the time
base A hold off time may be changed.
See the section ”Hold off time setting“ in the chapter ”Triggering
and time bases“.
26
X-POS DELAY
(pushbutton)
(no function in Roll- and FFT-mode)
This pushbutton allows you to change the function of the HO-
RIZONTAL knob
27
.
26.1 Analog mode
The pushbutton signals the actually selected function in accor-
dance with the front panel lettering:
dark:
X position control
green: Delay time control
C o n t r o l s a n d R e a d o u t
FFT-
Marker
VAR
x10
TIME / DIV
SCALE
·
VAR
X-POS
LEVEL A/B
50s
2ns
LC/AUX
FFT
HORIZONTAL
DELAY
MODE
FILTER
SOURCE
TRIG
’
d
NORM
HOLD OFF
TRIGGER
HOR
MAG
POWER
MENU
OFF
19
26
27
20
23
21
24
28
22
25
29
30
