RFmxSpecAn_SEMFetchUpperOffsetMargin
- Updated2025-10-13
- 3 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 function.
Syntax
int32 __stdcall RFmxSpecAn_SEMFetchUpperOffsetMargin(niRFmxInstrHandle instrumentHandle, char selectorString[], float64 timeout, int32 *measurementStatus, float64 *margin, float64 *marginFrequency, float64 *marginAbsolutePower, float64 *marginRelativePower)
Parameters
| Name | Direction | Type | Description | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| instrumentHandle | [in] | niRFmxInstrHandle | This parameter specifies the RFmx session refnum. Instrument Handle In is obtained from the RFmxInstr_Initialize function. | |||||||||
| selectorString | [in] | char[] | This parameter 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_BuildOffsetString2 function to build the selector string. | |||||||||
| timeout | [in] | float64 | This parameter 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 function waits until the measurement is complete. The default value is 10. | |||||||||
| measurementStatus | [out] | int32 * | This parameter indicates the upper offset measurement status based on measurement limits and the fail criteria that you specify in the RFMXSPECAN_ATTR_SEM_OFFSET_LIMIT_FAIL_MASK attribute.
| |||||||||
| margin | [out] | float64 * | This parameter returns the margin, in dB, from the limit mask value that you set in the RFMXSPECAN_ATTR_SEM_OFFSET_LIMIT_FAIL_MASK attribute. Margin is defined as the maximum difference between the spectrum and the limit mask. When you set the SEM Offset Seg Limit Fail Mask attribute to Absolute, the margin is with reference to the absolute limit mask. When you set the SEM Offset Seg Limit Fail Mask attribute to Relative, the margin is with reference to the relative limit mask. When you set the SEM Offset Seg Limit Fail Mask attribute 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 attribute to Abs OR Rel, the margin is the minimum of the margins referenced to the absolute and relative limit masks. | |||||||||
| marginFrequency | [out] | float64 * | This parameter returns the frequency, in Hz, at which the margin occurred in the upper (positive) offset. | |||||||||
| marginAbsolutePower | [out] | float64 * | This parameter 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 RFMXSPECAN_ATTR_SEM_POWER_UNITS attribute to dBm, and in dBm/Hz when you set the SEM Power Units attribute to dBm/Hz. | |||||||||
| marginRelativePower | [out] | float64 * | This parameter 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. |
Returns
Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred.
To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError function.
The general meaning of the status code is as follows:
Value | Meaning |
|---|---|
0 | Success |
Positive Values | Warnings |
Negative Values | Errors |