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Configures the specified reference level.

This node performs the following actions to configure the specified reference level:

  • Configures the Rx front end attenuators and filters
  • Returns the I/Q impairment correction data, which you can use to correct I/Q impairments
  • Returns the resulting vertical range that you can use to scale binary data retrieved from the device.
  • Sets the RF filter to the specified frequency

Input Parameters

  • Register Bus—The Register Bus object created by the ni579x Open node and used as the session handle for the NI-579x Configuration nodes.
  • scope—Specifies which channel to configure.
  • reference level [dBm]—Specifies the maximum power, in dBm, of the signals expected at the input terminal of the device. The RF signal path of the device is configured to maximize the dynamic range of the measurement relative to this power level.
  • frequency [Hz]—Specifies the frequency the LO is tuned to for the measurement.
  • headroom [dB]—Specifies the amount of headroom to leave in the range of the ADC if the signal input to the device is at the reference level power. Leave enough headroom to avoid clipping or over range errors and DSP overflows.
  • correct IQ imbalance?—Specifies whether to calculate the I/Q impairment correction values. Set this parameter to FALSE if you are not using the I/Q impairment correction DSP blocks in the FPGA.
  • characterization data—A set of data that describes the characteristics of this device that allow the node to calculate the proper attenuation and I/Q imbalance correction settings for the specified frequency. This data is stored in the EEPROM and can be retrieved using the ni579x Load Characterization Data (Single Channel) node. For the NI 5791, the Rx data is index 0 in the array of characterization data returned by the ni579x Load Characterization Data (Single Channel) node.

Output Parameters

  • Register Bus (out)—The Register Bus object created by the ni579x Open node and used as the session handle for the NI-579x Configuration nodes.
  • coerced reference level [dBm]—The actual reference level the device is configured to. This value is the maximum power level that can be input to the device without exceeding the vertical range of the ADCs.
  • coerced vertical range [Vpp]—The peak-to-peak vertical range, in volts, of the device. You can use this value to scale binary data retrieved from the device to volts. This value assumes that the I/Q impairment correction values returned by this node are applied to the signal using the I/Q Impairment Correction DSP block in the FPGA.
  • IQ impairment correction—The values to apply to the I/Q Impairment Correction DSP block in the FPGA to correct gain and phase imbalances in the mixer.
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Installed By: LabVIEW Communications System Design Suite (introduced in 1.0)

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported