Rohde & Schwarz R&S UPP, User Manual

Page: 367 / 938

Instrument Functions
R&S
®
UPP
351 User Manual 1411.1055.32 ─ 10
The sweep x-axis is always predefined by the external sweep, even if it is the internal
generator that generates the sweep signal.
The start and stop values determine the sweep direction for external sweeps: If the
start value is less than the stop value, an upward sweep is performed, otherwise a
downward sweep will be performed.
Signal changes counter to the sweep direction affect continuous mode and single
mode differently:
●
If an external continuous sweep was started using [START ] any significant change
of frequency in the stop to start direction causes the sweep to restart.
●
If an external single sweep was started using [SINGLE ], changes in the stop to
start direction are interpreted as interference and ignored. A measured value
beyond the stop value terminates the sweep.
Though using the internal generator for level-controlled measured value triggering
is not actually prohibited, in most cases it gives no advantage.
In the case of edge-sensitive triggering , the triggering edge is defined by the start
and stop values: If the start value is less than the stop value, triggering occurs on a
positive edge, that is, at the exact moment when a value below "Start" is followed by a
value above "Start."
Min Volt
This is used to enter a minimum level for external frequency sweeps. If the signal is
below this threshold, no triggering occurs.
It prevents triggering at pauses in the signal. An excessively low minimum level would
cause even frequency values measured in the noise to be used for triggering.
Remote command:
ARM:LEVel:MIN
on page 735
Start
This is used to enter the start value for the recording interval (in the case of external
sweeps) or for the trigger range (in the case of level triggering).
The start value should be selected so that the first value to be recorded lies within the
start/stop interval even for measurement uncertainties.
If the start value is less than the stop value, the external sweep runs as an upward
sweep; in the case of edge triggering the system awaits a positive edge. Measured val-
ues that are lower than "Start" are ignored.
External Sweeps and Level-Controlled Measured value Triggering