niBTSA_RFSAAutoLevel
- Updated2023-02-21
- 2 minute(s) read
int32 __stdcall niBTSA_RFSAAutoLevel (ViSession RFSAHandle, char hwChannelString[], double bandwidth, double measurementInterval, int32 maxNumberOfIterations, double *resultantReferenceLevel);
Purpose
Examines the incoming signal to calculate the peak power level. This function then returns the estimated peak power level in the resultantReferenceLevel parameter.
Use this function if you need help calculating an approximate setting for the power level for I/Q measurements. This function queries the NIRFSA_ATTR_REFERENCE_LEVEL attribute and uses this value as the starting point for auto level calculations. Set the NIRFSA_ATTR_REFERENCE_LEVEL attribute to the highest expected power level of the signal for faster convergence. For example, if the device under test (DUT) generates the signal with the average power of x dBm, set the NIRFSA_ATTR_REFERENCE_LEVEL attribute to x + expected peak-to-average power ratio (PAPR) of the signal.
Parameters
| Input | ||
| Name | Type | Description |
| RFSAHandle | ViSession | Identifies the instrument session. The toolkit obtains this value from the niRFSA_init function or the niRFSA_InitWithOptions function. |
| hwChannelString | char[] | Specifies the NI RF vector signal analyzer device channel. Set this parameter to "" (empty string) or NULL. |
| bandwidth | double | Specifies the bandwidth of the signal to be analyzed. This value is expressed in Hz. |
| measurementInterval | double | Specifies the acquisition length, in seconds. The toolkit uses this value to compute the number of samples to acquire from the NI RF vector signal analyzer. The default value is 10m. |
| maxNumberOfIterations | int32 | Specifies the maximum number of iterations to perform when computing the reference level to set on the NI RF vector signal analyzer. The default value is 5. |
| Output | ||
| Name | Type | Description |
| resultantReferenceLevel | double* | Returns the estimated peak power level of the input signal. This value is expressed in dBm. |
Return Value
| Name | Type | Description | ||||||||
| status | int32 | Returns the status code of this operation. The status code either indicates success or describes an error or warning. Examine the status code from each call to an niBT SA 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 niBTSA_GetErrorString function. The general meaning of the status code is as follows:
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