AutoLevel(string, double, double, out double)
- Updated2025-10-13
- 2 minute(s) read
Examines the incoming signal to calculate the peak power level and sets it as the value of the GetReferenceLevel(string, out double) method. Use this method to help calculate an approximate setting for the power level for measurements. When using PXIe-5663, 5665, or 5668R devices, NI recommends that you set an appropriate value for mechanical attenuation before calling the AutoLevel(string, double, double, out double) method. Setting an appropriate value for mechanical attenuation reduces the number of times the attenuator settings are changed by this method, thus reducing wear and tear, and maximizing the life time of the attenuator.
Syntax
Namespace: NationalInstruments.RFmx.SpecAnMX
public int AutoLevel(string selectorString, double bandwidth, double measurementInterval, out double referenceLevel)
Remarks
Resets the mixer level, mixer level offset and IF output power offset.
Sets the starting reference level to the maximum reference level supported by the device based on the current RF attenuation, mechanical attenuation and preamp enabled settings.
Iterates to adjust the reference level based on the input signal peak power.
This method maps to the RFmxSpecAn_AutoLevel() function in C.
Parameters
| Name | Type | Description |
|---|---|---|
| selectorString | string | Pass an empty string. The signal name that is passed when creating the signal configuration is used. |
| bandwidth | double | Specifies the bandwidth, in hertz (Hz), of the signal to be analyzed. |
| measurementInterval | double | Specifies the acquisition length. Use this value to compute the number of samples to acquire from the signal analyzer. This value is expressed in seconds. Auto Level VI does not use any trigger for acquisition. It ignores the user-configured trigger properties. NI recommends that you set a sufficiently high measurement interval to ensure that the acquired waveform is at least as long as one period of the signal. |
| referenceLevel | out double | Upon return, contains the estimated peak power level of the input signal. This value is configured in dBm for RF devices and as Vpk-pk for baseband devices. |
Returns
Returns the status code of this method. The status code either indicates success or describes an error or warning condition.