User manual

26
Trigger System
gative pulse on a rising slope. Activate the pulse trigger by
pressing the TYPE key
31
in the TRIGGER section. Press
the FILTER key
36
, then you can select additional settings
for the pulse trigger in the soft menu. There are six diffe-
rent settings:
❙ t
i
> t: The pulse width ti, which will generate the trigger is
greater than the adjustable reference time t.
❙ t
i
< t: The pulse width ti, which will generate the trigger is
less than the adjustable reference time t.
❙ t
i
= t: The pulse width ti, which will generate the trigger
equals the adjustable reference time t. The reference time
is a combination of time t plus the adjustable deviation.
❙ t
i
≠t:The pulse width ti, which will generate the trigger is
unequal to the adjustable reference time t. The reference
time is a combination of time t plus the adjustable
deviation.
❙ t
1
<t
i
<t
2
: The pulse width ti which will generate the trigger
is less than the adjustable reference time t
2
and greater
than the adjustable reference time t
1
.
❙ not(t
1
<t
i
<t
2
): The pulse width which will generate the
trigger is greater than the adjustable reference time t
2
and
less than the adjustable reference time t
1
.
The time resp. the variation (tolerance zone) can be se-
lected via universal knob or KEYPAD key in the CURSOR/
MENU section. Selecting the corresponding soft menu
item allows you to set any of these settings for positively
(POS.) or negatively polarized pulses (NEG.). For the asso-
ciatedpositivepulse,youdenethewidthfromrisingto
falling slopes, and accordingly for the associated negative
pulse from falling to rising slopes. As is consistent with the
principle, triggering always occurs on the second slope of
the pulse.
6.3.3 Logic Trigger
Selecting the LOGIC trigger in the soft menu after pres-
sing the TYPE key
31
will switch the trigger source to the
digital inputs. Pressing the SOURCE key
32
after selecting
this trigger type displays a soft menu for additional set-
tings and a window to list these settings. The soft menu
You may test all settings in the logic trigger without any active
logic probes R&S®HO3508 connected.
Fig. 6.4: Pulse trigger menu
key LOGIC CHANNEL enables you to select a logic channel
for which you wish to determine the trigger condition. Use
the universal knob in the CURSOR/MENU section for this
purpose. In the general menu, the selected digital input is
markedwithabluebackground.Intheeld,thetrigger le-
vel is marked as High (H), Low (L) or (X). Use the corres-
ponding soft menu key to select the trigger level. The soft
menu item COMBINATION allows the logic combination of
the digital channels. They can be combined by logic AND
or OR. If AND is selected, the set conditions of all channels
must be met simultaneously for the input signal so that the
combination produces a logic High (H) as a result. If OR is
selected,atleastoneofthedenedlevelconditionsmust
be met. The last item in this menu is the option TRIGGER
ON. Use the soft menu key to select TRUE or FALSE. This
allows you to preselect whether the trigger will be genera-
ted at the beginning (TRUE) or the end of the logic condi-
tion (FALSE).
After selecting the desired set of conditions, you can use
the FILTER key
36
for additional settings. A soft menu will
open allowing you to add a time limit to the TRIGGER ON
option (this menu shows the condition selected in the
SOURCE menu). Press the top soft menu key DURATION
to add a time limit. This option compares the duration of
the output signal for the combination of the logic condi-
tions to the set duration ti. If the duration is identical or not
identical,youcansetthedeviation∆t.Iftiswithinthese
parameters, the trigger condition has been met. The menu
eldbelowallowstheselectionofthecomparisoncriteria.
The following criteria are available:
❙ t
i
≠t: The duration of the applied bit pattern which will
generate the trigger is unequal to the adjustable reference
time.
❙ t
i
= t: The duration of the applied bit pattern which will
generate the trigger is equal to the adjustable reference
time.
❙ t
i
< t: The duration of the applied bit pattern which will
generate the trigger is less than the adjustable reference
time
❙ t
i
> t: The duration of the applied bit pattern which will
generate the trigger is greater than the adjustable
reference time.
Fig. 6.5: Logic trigger menu