Real Time

4. ALC

Instrument: 1 2 3 4 5 6 7 8 9        

The following figure is a composite of all supported instruments, so some parameters may not apply to your instrument.

4. ALC: ALC Trigger Source bus (M9381A)

4. ALC: ALC Mode (M9381A)

ALC

Choice: Off | On

Default: On

Double-click or use the drop-down menu to enable or disable the automatic level control.

On – The ALC circuit constantly monitors and controls the output power level.

Off – No automatic leveling occurs.

ALC Bandwidth

Choice: Auto | 100.00 Hz | 1.00 kHz | 10.00 kHz | 100.00 kHz

Default: Auto

Double-click or use the drop-down menu to select an ALC bandwidth.

This parameter is not available for all instrument model numbers and may be grayed out.

Power Search Reference

Choice: Fixed | Modulation | RMS

Default: Modulation

Double-click or use the drop-down menu to select a fixed or modulated reference signal when doing a power search. This feature is important to get a fast response to amplitude changes when switching between different waveforms.

Fixed – Power search uses a fixed 0.5 V reference.

Modulated – Power search uses the RMS value of the current I/Q modulation as the reference.

RMS – Power Search uses an RMS value reference.

Set ALC to Off to enable this parameter.

This parameter is not available for all instrument models and may be greyed out or not shown in GUI.

RF During Power Search

Choice: Normal | Minimum

Default: Normal

Double-click or use the drop-down menu to select the level of the output power control during a power search routine.

Normal – Performs power searches without setting the internal step attenuator to its maximum setting. Glitches and power changes may be present during the search.

Minimum – Sets the signal generator's step attenuator to its maximum setting during power search to protect sensitive circuits.

Set ALC to Off to enable this parameter.

ALC Trigger Source bus (M9381A)

Choice: AUTO | PXI0 | .. | PXI7

Default: None

Double-click or use the drop-down menu to select a bus for ALC hold signal path on PXI backplane. This parameter is only available when connected to the M9381A.

This parameter is only available when Minor Enhancement Update (MEU) Option U01 or greater is valid. Refer to Licenses for more information.

ALC Mode (M9381A)

Choice: : Off | HOLD | TRACK

Default: Off

Double-click or use the drop-down menu to select ALC mode. This parameter is only available when connected to the M9381A.

This parameter is only available when Minor Enhancement Update (MEU) Option U01 or greater is valid. Refer to Licenses for more information.