Triggers
R&S
®
RTM20xx
36
User Manual 1317.4726.02 ─ 01
3 Triggers
3.1 Basics of Triggering
Triggering means to capture the interesting part of the relevant waveforms. Choosing the
right trigger type and configuring all trigger settings correctly allows you to detect various
incidents in analog, digital, and logic signals.
Trigger
A trigger occurs if the complete set of trigger conditions is satisfied simultaneously. It
establishes the time-zero point in the waveform record. The instrument acquires contin-
uously and keeps the sample points to fill the pretrigger part of the waveform record.
When the trigger occurs, the instrument continues acquisition until the posttrigger part of
the waveform record is filled. Then it stops acquiring and displays the waveform. When
a trigger is recognized, the the instrument will not accept another trigger until the acqui-
sition is complete.
Trigger conditions
A simple set of trigger conditions includes:
●
Source of the trigger signal
●
Trigger type and and its setup
●
Horizontal position of the trigger: trigger position and reference point
●
Trigger mode
The R&S
RTM provides various trigger types for troubleshooting and signal analysis, for
example, edge trigger, width trigger, pattern trigger, and specific triggers like video and
bus triggers.
More complex trigger conditions are also available: you can setup a trigger sequence to
join two edge triggers with an optional delay time or event count. Similar setups are also
known as multi-step trigger or A/B trigger.
Furthermore, hysteresis avoids unwanted trigger events caused by noise.
Trigger event
In particular for the A/B trigger sequence, it is important to distinguish between the trigger
and the event. An event is the fulfillment of the event conditions, but an event may not
be the trigger. The trigger occurs only if the conditions of all events - the A event and the
B event - in a trigger sequence and all further trigger conditions are all fulfilled.
Trigger information
Information on the most important trigger settings are shown in the information bar. The
label shows:
●
Trigger source and level
●
Trigger coupling and filters
Basics of Triggering
