Stores whether the signal generator's LO signal can be shared on request by the RFmx driver. It is recommended to use Automatic sharing of local oscillator (LO) in test setups that use a vector signal transceiver (VST) with the NI-RFSG to generate a signal at the DUT's input and the RFmx driver to measure the signal at the DUT's output.

Syntax

Namespace: NationalInstruments.ModularInstruments.NIRfsgPlayback

public static int StoreAutomaticSGSASharedLO(IntPtr rfsgSession, string channelName, RfsgPlaybackAutomaticSGSASharedLO automaticSGSASharedLO)

Remarks

When using instruments that do not have LO with excellent phase noise, to minimize the contribution of the instrument's phase noise affecting your measurement, it is recommended to share the LO between the signal generator (SG) and signal analyzer (SA).
To enable sharing signal generator's LO with signal analyzer automatically, setup the device specific physical connections as mentioned in the following table and follow the steps in the mentioned order.

PXIe-5840/5841/5842

SG LO is shared with SA via an external path. Hence you must connect RF Out LO Out to RF In LO In using a cable.

PXIe-5830/5831/5832

SG LO is shared with SA via an internal path. Hence the external cable connection is not required.

  1. Enable Automatic SG SA Shared LO on NI-RFSG Playback Library

  2. Set the LOSource method to Automatic_SG_SA_Shared in RFmx

  3. Configure other required settings on NI-RFSG and RFmx, including selecting waveforms

  4. Initiate NI-RFSG

  5. Initiate RFmx

Note

Measurement results might get affected while performing measurements in the RFmx driver if the signal analyzer measurement frequency span is wide enough to capture signal generator LO. In these cases, it is recommended to configure the NIRfsgPlaybackLOOffsetMode parameter to NoOffset.

Parameters

NameTypeDescription
rfsgSessionIntPtr

Identifies the instrument session. The rfsgSession handle is obtained from the NIRfsg.DangerousGetInstrumentHandle method.

channelNamestring

This parameter is reserved for future use.

automaticSGSASharedLORfsgPlaybackAutomaticSGSASharedLO

Specifies the access control of SG LO.

Returns

Returns the status code of this method. The status code either indicates success or describes a warning condition.