Operating Manual 1302.6163.12 - 03 4.63
R&S ESU Instrument Functions
Receiver Mode
CONT AT HOLD With  the  CONT AT HOLD softkey the scan is continued where it was interrupted.
The scan is always continued with the settings in the scan table.
Remote command: --
STOP SCAN The STOP SCAN softkey stops the scan. Upon restart, scanning starts at the begin-
ning. The results of the performed measurements are lost.
Remote command: :ABOR
4.5.6 Triggering the Scan – TRIG Key 
The  TRIG key opens a menu for selection of the trigger sources and the trigger
polarity. The active trigger mode is indicated by highlighting the corresponding soft-
key.
To indicate that a trigger mode other than FREE RUN has been set, the enhance-
ment label TRG is displayed on the screen. If two windows are displayed, TRG
appears next to the appropriate window.
TRIG
FREE RUN 
The FREE RUN softkey activates the free-run sweep mode, i.e. start of a scan is not
triggered. Once a measurement is completed, another is started immediately.
FREE RUN is the default setting of R&S ESU.
Remote command: TRIG:SOUR IMM 
VIDEO 
The VIDEO softkey activates triggering via the displayed voltage.
For the video triggering mode, a level line showing the trigger threshold is displayed.
Using the level line, the threshold can be adjusted between 0% and100% of the dia-
gram height.
Remote command: TRIG:SOUR VID
TRIG:LEV:VID 50 PCT
EXTERN 
The  EXTERN softkey activates triggering via a TTL signal at the input connector
EXT TRIGGER/GATE on the rear panel.
Remote command: TRIG:SOUR EXT
POLARITY
POS | NEG 
The POLARITY POS/NEG softkey selects the polarity of the trigger source. 
The scan starts after a positive or negative edge of the trigger signal. The selected
setting is highlighted. 
The selection is valid for all trigger modes with the exception of FREE RUN.
The default setting is POLARITY POS.
Remote command: TRIG:SLOP POS
FREE RUN
VIDEO
EXTERN
POLARITY POS | NEG