User manual

Triggers
R&S
®
RTO
53User Manual 1316.0827.02 ─ 06
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. It establishes the
time-zero point in the waveform record. The instrument acquires continuously and keeps
the sample points to fill the pre-trigger part of the waveform record. When the trigger
occurs, the instrument continues acquisition until the post-trigger part of the waveform
record is filled. Then it stops acquiring and waits for the next trigger. When a trigger is
recognized, the instrument will not accept another trigger until the acquisition is complete
and the holdoff time has expired.
Trigger conditions
A simple set of trigger conditions includes:
●
Source of the trigger signal, its coupling and filtering
●
Trigger type and its setup
●
Horizontal position of the trigger: trigger offset and reference point
●
Trigger mode
The R&S RTO provides various trigger types for troubleshooting and signal analysis, for
example, edge trigger, glitch trigger, interval trigger, slew rate trigger, and pattern trigger.
For complex tasks like verifying and debugging designs, advanced trigger settings are
available:
●
Hysteresis, that is the rejection of noise to avoid unwanted trigger events caused by
noise
●
Holdoff to define exactly which trigger event will cause the trigger
●
Qualification to consider the states of digital signals on other input channels and their
logical combination
●
Trigger sequences to combine two events
Trigger event
In particular for advanced trigger settings, 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. Only if the additional criteria are met - hysteresis, holdoff, and/or additional
events in a trigger sequence - the trigger occurs.
Event-specific conditions are:
●
Trigger source
Basics of Triggering