Spectrum Analyzer Mode
R&S
®
Spectrum Rider FPH
174
User Manual 1321.1011.02 ─ 06.00
6.2.5.3
Working with Trigger Functionality
If you have to perform measurements according to certain signal conditions, you can
use a trigger. A trigger responds to certain events. If a trigger is active, the R&S Spec-
trum Rider starts to measure if the trigger conditions are met. The trigger can be gener-
ated either externally or internally. The R&S Spectrum Rider provides the following trig-
ger functions
Selecting the trigger source
1. Press the [SWEEP] key.
2. Select the "Trigger" softkey.
The R&S Spectrum Rider opens a submenu to select the trigger source.
3. Select the trigger source you need.
The R&S Spectrum Rider activates the trigger.
The R&S Spectrum Rider provides the following trigger functions.
●
Free Run
A new sweep starts on completion of the previous sweep. This sweep mode is the
default state of the R&S Spectrum Rider.
●
Video Trigger
A sweep starts when the video voltage exceeds a particular level. The video trigger
is available only in the time domain (span = 0).
In the frequency domain, the R&S Spectrum Rider would never start a measure-
ment with the video trigger because there is no guarantee that there is a signal that
generates video voltage present at the start frequency.
●
External Trigger
(rising or falling slope)
A sweep starts on the rising edge (RISE) or on the falling edge (FALL) of an exter-
nal trigger signal. The external trigger signal is fed in via the BNC connector "Ext
Trigger". See details of connector in
Chapter 3.2.2.2, "BNC Connector"
,
on page 33. The switching threshold is 1.4 V, i.e. a TTL signal level.
●
Gated Trigger
When the gated trigger is active, a gate signal that is applied to the R&S Spectrum
Rider trigger input controls the sweep. The R&S Spectrum Rider starts measuring
when the applied gate signal becomes active and the set gate delay has expired,
and it interrupts the measurement as soon as the defined gate length is reached.
With the gate signal becoming active the next time the measurement is resumed
etc.
Pulsed signals can be measured by this method, if the gate delay and gate length
are selected in a way that the measurement is only performed while the pulse is
active. Gated measurements are possible in the frequency domain (span > 0) and
the time domain (span = 0).
Including a Delay Time
When you are using a video trigger in the time domain or an external trigger, you can
delay the start of the measurement with respect to the trigger event by entering a delay
Configuring Spectrum Measurements
