User Manual

The Spectrum Application (RF Measurements)
R&S
®
FPL1000
332User Manual 1178.3370.02 ─ 09
cases you can define a trigger for the measurement. In FFT sweep mode, the trigger
defines when the data acquisition starts for the FFT conversion.
An "Offset" can be defined to delay the measurement after the trigger event, or to
include data before the actual trigger event in time domain measurements (pre-trigger
offset).
For complex tasks, advanced trigger settings are available:
●
Hysteresis to avoid unwanted trigger events caused by noise
●
Holdoff to define exactly which trigger event will cause the trigger in a jittering sig-
nal
● Trigger Source...................................................................................................... 332
● Trigger Offset........................................................................................................ 332
● Trigger Hysteresis................................................................................................. 332
● Trigger Drop-Out Time.......................................................................................... 333
● Trigger Holdoff.......................................................................................................334
Trigger Source
The trigger source defines which source must fulfill the condition that triggers the mea-
surement. Basically, this can be:
●
Time: the measurement is repeated in a regular interval
●
Power: an input signal is checked for a defined power level
The trigger signal can be any of the following:
– The input signal at one of various stages in the signal analysis process - before
or after the input mixer, after the video filter etc.
– A signal from an external device via one of the TRIGGER INPUT / OUTPUT
connectors on the instrument
For details on the available trigger sources see "Trigger Source" on page 336.
Trigger Offset
An offset can be defined to delay the measurement after the trigger event, or to include
data before the actual trigger event in time domain measurements (pre-trigger offset).
Pre-trigger offsets are possible because the R&S FPL1000 captures data continuously
in the time domain, even before the trigger occurs.
See "Trigger Offset" on page 338.
Trigger Hysteresis
Setting a hysteresis for the trigger helps avoid unwanted trigger events caused by
noise, for example. The hysteresis is a threshold to the trigger level that the signal
must fall below on a rising slope or rise above on a falling slope before another trigger
event occurs.
Trigger and Gate Configuration