Returns the occupied bandwidth (OBW) measurement.

Syntax

int32 __stdcall RFmxSpecAn_OBWFetchMeasurement(niRFmxInstrHandle instrumentHandle, char selectorString[], float64 timeout, float64 *occupiedBandwidth, float64 *averagePower, float64 *frequencyResolution, float64 *startFrequency, float64 *stopFrequency)

Parameters

NameDirectionTypeDescription
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 and result name. 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. The default value is "" (empty string).
Example:
""
"signal::sig1"
"result::r1"
"signal::sig1/result::r1"
You can use the RFmxSpecAn_BuildSignalString 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.

occupiedBandwidth[out]float64 *

This parameter returns the occupied bandwidth, in Hz.

averagePower[out]float64 *

This parameter returns the total integrated power of the averaged spectrum acquired by the OBW measurement when you set the RFMXSPECAN_ATTR_OBW_POWER_UNITS attribute to dBm. This function returns the power spectral density when you set the OBW Power Units attribute to dBm/Hz.

frequencyResolution[out]float64 *

This parameter returns the frequency bin spacing, in Hz, of the spectrum acquired by the measurement.

startFrequency[out]float64 *

This parameter returns the start frequency, in Hz, of the OBW. The OBW is calculated using the following formula: OBW = stop frequency - start frequency

stopFrequency[out]float64 *

This parameter returns the stop frequency, in Hz, of the OBW.

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