Fetches the spectrum used for channel power (CHP) measurement.

Syntax

int32 __stdcall RFmxSpecAn_CHPFetchSpectrum(niRFmxInstrHandle instrumentHandle, char selectorString[], float64 timeout, float64 *x0, float64 *dx, float32 spectrum[], int32 arraySize, int32 *actualArraySize)

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.

x0[out]float64 *

This parameter returns the start frequency. This value is expressed in Hz.

dx[out]float64 *

This parameter returns the frequency bin spacing. This value is expressed in Hz.

spectrum[out]float32

This parameter returns the spectrum trace values.

arraySize[in]int32

Specifies the size of the array. Set the arraySize parameter to 0 to get the size of all the arrays in the actualArraySize parameter.

actualArraySize[out]int32 *

Returns the actual size of the array, if you pass NULL to all output array parameters, and set the arraySize parameter to 0.

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