Rohde & Schwarz R&S UPP, User Manual

Page: 452 / 938

Instrument Functions
R&S
®
UPP
436 User Manual 1411.1055.32 ─ 10
The pretrigger memory is filled from the start of the measurement and always contains
the latest samples of the time frame selected as the pretrigger, before triggering
occurs. For so long as the pretrigger is not completely full, triggering remains locked. It
is only armed when the pretrigger memory is full and is at least one sample below the
trigger threshold.
The pretrigger memory is filled from the front in the manner of a shift register, so that
the older samples move back one position as each new sample is added:
●
If the pretrigger time is longer than the total trace length, triggering takes place
when the trace length is reached. The pretrigger memory (which is only partially
full) is then displayed.
●
If the desired pretrigger interval has expired, the older samples in the back part are
replaced by newer samples.
The trigger point is always t = 0.0 s; the pretrigger time is given as a negative time.
Note: The total length of the waveform trace is 480000 samples and is entered under
Trace Length. If the pretrigger is used, the recording duration for the triggered section
of the signal is reduced.
Remote command:
SENSe7:TRIGger:PRE
on page 767
Autotrigger
For activating the autotrigger, that is, forced triggering, when the trigger condition is not
fulfilled ("true") within the time selected as "Trace Length".
"deactivated" Autotrigger off
The triggering of waveform recording – and thus the termination of a
single measurement that has been started – occurs only when the
trigger event has occurred (i.e. has changed to "true").
If an unfavorable trigger condition is chosen (e.g. the trigger level is
too high) the measurement continues indefinitely and must be inter-
rupted manually (STOP key).
This setting is recommended if the waveform is to be displayed only if
the trigger condition is fulfilled.
"activated" Autotrigger on
When the trace length has expired, forced triggering occurs, that is,
the waveform is then displayed untriggered, as in the case of manual
triggering.
This setting is recommended if you wish to ensure that the measure-
ment terminates, or in the case of an unknown signal trace.
Remote command:
SENSe7:TRIGger:AUTO
on page 767
5.30.2 Delay Measurement
The delay measurement function is used to measure signal delays in a DUT (e.g.
between the input and the output). For this purpose, a known signal is applied to the
Analysis in the Time Domain