Setting the Sweep R&S FSH3
Trigger
To respond to events, the R&S FSH3 has a variety of trigger functions. The trigger can either be
external or generated internally.
• FREE RUN A new sweep starts on completion of the previous sweep. This is the
default setting for the R&S FSH3.
• VIDEO A sweep starts when the video voltage exceeds a settable value.
Video triggering is only available when span = 0 Hz. When a
frequency spectrum is being displayed, (span ≥ 10 kHz), there is no
guarantee that a signal to generate a video voltage is present at the
start frequency. Under these circumstances, the R&S FSH3 would
never perform a sweep.
• EXTERN and EXTERN The sweep is started on the rising edge () or on the falling edge ()
of an external trigger signal. The external trigger signal is fed in via
the BNC connector EXT TRIGGER. The switching threshold is
1.4 V, i.e. a TTL signal level.
When a video trigger or an external trigger is selected, the start of measurement can be delayed with
respect to the trigger event by entering a delay (DELAY). In this way, time differences between the
trigger event and the measurement can be allowed for.
The current trigger setting is displayed centrally at the top of the screen
(e.g. Trig: Free).
Operating sequence:
¾ Press the SWEEP key.
¾ Press the TRIGGER softkey.
The submenu for setting the trigger opens. If the
default setting is selected, FREE RUN is highlighted in
red. If span = 0 Hz, any setting can be selected;
otherwise the settings VIDEO... and DELAY... are in
darker labelling to show that they are not available.
¾ Select the setting you want with the cursor keys or
the rotary knob and terminate the entry with the
ENTER key or with the TRIGGER softkey.
The "Trig:" box at the center of the top of the screen
indicates the setting that has been selected.
If the VIDEO... trigger setting has been selected, the trigger level and any trigger delay (DELAY...) must
be entered. The trigger level is expressed as a percentage (%) of the reference level. 100 % means that
the trigger level equals the reference level, 50 % that the trigger level is in the middle of the y axis on
the measurement diagram (default setting). The position of the video trigger on the level axis is shown
by a ">".
1145.5973.12 4.16 E-6
To Next Page
Loading...
