Rohde & Schwarz SMC100A - Page 147

Instrument Function
R&S
®
SMC100A
132Operating Manual 1411.4060.32 ─ 09
"Fixed"
When this operating mode is switched on, the attenuator and the
relays are fixed in their current positions to provide level settings with-
out interruption. The resulting variation range is defined and dis-
played under "Attenuator Fixed Range".
Note: The function is effective when automatic level control is activa-
ted ("ALC State = On").
If the normal variation range is overranged or underranged, level
errors increase considerably and the warning "Level under/over-
range" appears in the info line. The spectral purity of the output signal
decreases with high attenuation.
Remote command:
:OUTPut<hw>:AMODe on page 266
Fixed Range (PEP) In
Displays the level range in which the level is set without interruption for the "Attenuator
Mode fixed" setting.
Remote command:
:OUTPut<hw>:AFIXed:RANGe:UPPer? on page 265
:OUTPut<hw>:AFIXed:RANGe:LOWer? on page 265
RF OFF Mode
Selects the attenuator mode, when the RF signal is switched off.
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 is recommended if a constant VSWR (Voltage Standing
Wave Ratio) is required.
"Full Attenuation"
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.
Remote command:
[:SOURce<hw>]:POWer:ATTenuation:RFOFf:MODE on page 314
User Variation
If the level is set using the rotary knob, the step width is defined in the "User Variation"
section.
Variation Active
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).
RF Block