RFmxSpecAn SEM Fetch Upper Offset Margin VI
- Updated2025-10-13
- 4 minute(s) read
Returns the measurement status and margin from the limit line measured in the upper offset segment.
Use "offset<n>" as the selector string to read parameters from this VI.

Inputs/Outputs
Selector String
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Selector String specifies a selector string comprising of the signal name, result name, and offset number. If you do not specify the signal name, the default signal instance is used. If you do not specify the result name, the default result instance is used. Example: "offset0" "signal::sig1/offset0" "result::r1/offset0" "signal::sig1/result::r1/offset0" You can use the RFmxSpecAn Build Offset String2 VI to build the selector string.
Instrument Handle In
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Instrument Handle In specifies the RFmx session refnum. Instrument Handle In is obtained from the RFmxInstr Initialize NIRFSA VI.
Timeout (s)
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Timeout specifies the timeout, in seconds, for fetching the specified measurement. Set this value to an appropriate time, longer than expected for fetching the measurement. A value of -1 specifies that the VI waits until the measurement is complete. The default value is 10.
error in (no error)
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error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
Margin Relative Power (dB)
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Margin Relative Power returns the power, in dB, at which the margin occurred in the upper (positive) offset segment relative to the integrated or peak power of the reference carrier.
Margin Absolute Power (dBm or dBm/Hz)
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Margin Absolute Power returns the power, in dBm or dBm/Hz, at which the margin occurred in the upper (positive) offset segment. The power is measured in dBm when you set the SEM Power Units property to dBm, and in dBm/Hz when you set the SEM Power Units property to dBm/Hz.
Instrument Handle Out
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Instrument Handle Out passes a reference of your RFmx session to the next VI.
Measurement Status
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Measurement Status indicates the upper offset measurement status based on measurement limits and the fail criteria that you specify in the SEM Offset Seg Limit Fail Mask property.
Margin (dB)
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Margin returns the margin, in dB, from the limit mask value that you set in the SEM Offset Seg Limit Fail Mask property. Margin is defined as the maximum difference between the spectrum and the limit mask. When you set the SEM Offset Seg Limit Fail Mask property to Absolute, the margin is with reference to the absolute limit mask. When you set the SEM Offset Seg Limit Fail Mask property to Relative, the margin is with reference to the relative limit mask. When you set the SEM Offset Seg Limit Fail Mask property to Abs AND Rel, the margin is the maximum of the margins referenced to the absolute and relative limit masks. When you set the SEM Offset Seg Limit Fail Mask property to Abs OR Rel, the margin is the minimum of the margins referenced to the absolute and relative limit masks.
Margin Frequency (Hz)
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Margin Frequency returns the frequency, in Hz, at which the margin occurred in the upper (positive) offset.
error out
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error out contains error information. This output provides standard error out functionality. |
Selector String
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Instrument Handle In
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Timeout (s)
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error in (no error)
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Margin Relative Power (dB)
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Instrument Handle Out
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Measurement Status
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error out
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