RFmxInstrMX.GetDownconverterFrequencyOffset Method
- Updated2024-07-17
- 2 minute(s) read
RFmx
Gets an offset from the center frequency value for the downconverter. Use this method to offset the measurement away from the LO leakage or DC Offset of analyzers that use a direct conversion architecture. You must set this method to half the bandwidth or span of the measurement + guardband. The guardband is needed to ensure that the LO leakage is not inside the analog or digital filter rolloffs. This value is expressed in Hz.
Namespace: NationalInstruments.RFmx.InstrMX
Assembly: NationalInstruments.RFmx.InstrMX.Fx40 (in NationalInstruments.RFmx.InstrMX.Fx40.dll) Version: 24.5.0.49285 (24.5.0.49285)
Syntax
public int GetDownconverterFrequencyOffset( string channelName, out double value )
Public Function GetDownconverterFrequencyOffset ( channelName As String, <OutAttribute> ByRef value As Double ) As Integer
Parameters
- channelName String
- Pass an empty string.
- value Double
- Upon return, contains an offset from the center frequency value for the downconverter. Use this method to offset the measurement away from the LO leakage or DC Offset of analyzers that use a direct conversion architecture. You must set this method to half the bandwidth or span of the measurement + guardband. The guardband is needed to ensure that the LO leakage is not inside the analog or digital filter rolloffs. This value is expressed in Hz.
Return Value
Int32Returns the status code of this method. The status code either indicates success or describes a warning condition.
Remarks
This method gets the value of DownconverterFrequencyOffset attribute.Default values: For spectrum acquisition types, RFmx automatically calculates the default value to avoid residual LO power. For I/Q acquisition types, the default value is 0 Hz. If the center frequency is set to a non-multiple of LO Frequency Step Size property, this property is set to compensate for the difference. Supported Devices: PXIe-5644/5645/5646, PXIe-5830/5831/5832/5840/5841/5842. The following valid values correspond to their respective devices:PXIe-5646-100 MHz to +100 MHz PXIe-5830/5831/5832/5840/5841/5842-500 MHz to +500 MHz Other devices-42 MHz to +42 MHz