Rohde & Schwarz SMC100A, Руководство по эксплуатации

Страница: 140 / 363

Instrument Function
R&S
®
SMC100A
123 Operating Manual 1411.4060.32 ─ 04
The setting of the RF OFF mode is not affected by an instrument preset (PRESET key),
*RST
and the "Save/Recall" function. This parameter is influenced only by the
​
Factory
Preset .
"Unchanged" Freezes the setting of the attenuator when RF is switched off. The
attenuator is only activated when RF is switched on.
This setting recommended if a constant VSWR (
V oltage S tanding W ave
R atio) is required.
"Full Attenu-
ated" Sets attenuation to maximum when the RF signal is switched off. This
setting is recommended for applications that require a high level of
noise suppression.
SCPI command:
​
[:
​
SOURce<hw>]:
​
POWer:
​
ATTenuation:
​
RFOFf:
​
MODE
​
on page 276
User Variation
If the level is set using the rotary knob, the step width is defined in the "User Variation"
section.
Variation Active - RF Level
Activates the user-defined step width used when varying the level value with the rotary
knob.
"ON"
The level value set with the rotary knob is varied using the user-defined
step width which is entered under "Variation Step".
"OFF" The level value set with the rotary knob is varied in steps of one unit at
the cursor position (standard operating mode).
SCPI command:
​
[:
​
SOURce<hw>]:
​
POWer:
​
STEP:
​
MODE
​
on page 282
Variation Step - RF Level
Sets the user-defined step width for entering the RF level using the rotary knob. Level
variation with this step width must also be activated with "Variation Active".
SCPI command:
​
[:
​
SOURce<hw>]:
​
POWer:
​
STEP[:
​
INCRement]
​
on page 281
Reverse Power Protection
The reverse power protection prevents against overload by an external signal applied to
the RF output of the R&S Signal Generator.
The reverse power protection is tripped when the power of the external signal becomes
too high. A relay opens and interrupts the internal connection to the RF output. This
condition is indicated in the display header by the "OVERLOAD" status message.
Overload
If an "Overload" status message is indicated in the display header, reset the overload
protection by pressing the RF ON/OFF key.
RF Signal - RF Block