RFmxWLAN_OFDMModAccFetchChainRMSEVM
- Updated2025-10-13
- 2 minute(s) read
Fetches the chain RMS EVM results.
Syntax
int32 __stdcall RFmxWLAN_OFDMModAccFetchChainRMSEVM(niRFmxInstrHandle instrumentHandle, char selectorString[], float64 timeout, float64 *chainRMSEVMMean, float64 *chainDataRMSEVMMean, float64 *chainPilotRMSEVMMean)
Remarks
Use "segment<n>/chain<k>" as the selector string to read results from this function.
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 or the RFmxInstr_InitializeFromNIRFSASessionArray function. |
| selectorString | [in] | char[] | This parameter specifies a Selector String comprising of the signal name, result name, segment number, and chain 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. The default value is "segment0/chain0". Example: "segment0/chain0" "signal::sig1/segment0/chain0" "signal::sig1/result::r1/segment0/chain0" "result::r1/segment0/chain0" You can use the RFmxWLAN_BuildChainString function to build the selector string. |
| timeout | [in] | float64 | This parameter specifies the timeout 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. This value is expressed in seconds. The default value is 10. |
| chainRMSEVMMean | [out] | float64 * | This parameter returns the chain RMS EVM of all subcarriers in all OFDM symbols. When you set the RFMXWLAN_ATTR_OFDMMODACC_AVERAGING_ENABLED attribute to True, this parameter returns the mean of chain RMS EVM results computed for each averaging count. This value is expressed as a percentage or in dB. |
| chainDataRMSEVMMean | [out] | float64 * | This parameter returns the chain RMS EVM of data subcarriers in all OFDM symbols. When you set the OFDMModAcc Averaging Enabled attribute to True, this parameter returns the mean of data chain RMS EVM results computed for each averaging count. This value is expressed as a percentage or in dB. |
| chainPilotRMSEVMMean | [out] | float64 * | This parameter returns the chain RMS EVM of pilot subcarriers in all OFDM symbols. When you set the OFDMModAcc Averaging Enabled attribute to True, this parameter returns the mean of pilot chain RMS EVM results computed for each averaging count. This value is expressed as a percentage or in dB. |
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 RFmxWLAN_GetError function.
The general meaning of the status code is as follows:
Value | Meaning |
|---|---|
0 | Success |
Positive Values | Warnings |
Negative Values | Errors |