Performs the user-configured ModAcc measurement on all initialized devices at multiple reference levels relative to the user-configured SetReferenceLevel(string, double) method and configures the reference level corresponding to the lowest GetChainRmsEvmMean(string, out double) result on each device.
This method only measures at the reference levels that do not result in an ADC or OSP overflow when you set the SetAutoLevelAllowOverflow(string, RFmxWlanMXOfdmModAccAutoLevelAllowOverflow) method to False. If you set the OFDMModAcc Auto Level Allow Overflow method to True, this method measures at a few reference levels beyond the overflow.
After calling this method, you need to perform the ModAcc measurement.
Calling this method will also set the Reference Level Headroom method to 0.

Syntax

Namespace: NationalInstruments.RFmx.WlanMX

public int AutoLevel(string selectorString, double timeout)

Remarks

This method expects:

  • A valid OFDMModAcc measurement configuration

  • SetReferenceLevel(string, double) method set to peak power of the signal

  • Repetitive signals at the analyzer's input along with trigger settings that measure the same portion of the waveform every time the measurement is performed

  • No other measurements are running in parallel


Auto level needs to be performed again if the input signal or RFmx configuration changes.
For repeatable results, you must make sure that the OFDMModAcc measurement is repeatable.
This method measures EVM at reference levels starting at an integer at least 1 dB above the value you configure for the Reference Level method, extending upto 12 dB lower when you set the OFDMModAcc Auto Level Allow Overflow method to False, and up to 17 dB lower when you set the OFDMModAcc Auto Level Allow Overflow method to True with a step size of 0.5 dB.
When you use this method with the SetNoiseCompensationEnabled(string, RFmxWlanMXOfdmModAccNoiseCompensationEnabled) method set to True, you need to make sure that valid noise calibration data is available for the above measurements.

Parameters

NameTypeDescription
selectorStringstring

Pass an empty string. The signal name that is passed when creating the signal configuration is used.

timeoutdouble

Specifies the timeout for fetching the EVM results. This value is expressed in seconds. Set this value to an appropriate time, longer than expected for fetching the measurement. A value of -1 specifies that the method waits until the measurement is complete.

Returns

Returns the status code of this method. The status code either indicates success or describes a warning condition.