Limitations of the Limited Configuration Change Property

Limitations of the Limited Configuration Change Property

The following list describes the limitations of the Limited Configuration Change property when you set it to a value other than Disabled.

• When you set the Limited Configuration Change property to Frequency or Freq and Ref Level, you must either set Acquisition Bandwidth Optimization Enabled property to False or ensure that the center frequency is set to the center of the frequency span covered by the channel left edge of the left most carrier and the channel right edge of the right most carrier.  Although this restriction typically applies to signal configurations with multiple carrier channels, it also applies to a single carrier case where the carrier center is offset from the center frequency. The following are the suggested approaches for ensuring that the center frequency is centered within the carrier channels:
  • In WCDMA, set the Carrier at Center Frequency parameter to -1 when calling the RFmx WCDMA Configure Contiguous Carriers VI
  • In LTE contiguous multi-carrier, set the Component Carrier Spacing Type parameter to Nominal or Minimal and set the Component Carrier at Center Frequency parameter to -1 when calling RFmxLTE Configure Component Carrier Spacing VI
• When you set the Limited Configuration Change property to Frequency or Freq and Ref Level then the x0 parameter of spectrum traces will be based on the frequency value at the time of the first Commit and will not be adjusted when the frequency is changed.
• When you set the Limited Configuration Change property to Frequency or Freq and Ref Level, the band specific masks or measurement configurations will not be adjusted when you change the frequency. For example, LTE SEM uses a different SEM mask for frequencies less than or equal to 3 GHz than for frequencies greater than 3 GHz.  NI recommends that you create separate named signal configurations for each frequency set or band that has a different mask or measurement configuration.  Refer to the standard specific concept topics for each measurement to find the properties affected by the measurement configurations.
• Values other than Disabled are not supported for the Limited Configuration Change property when you perform measurements that require multiple acquisitions.  The following measurements or measurement modes are not supported:
  • Spurious Emissions
  • Harmonics
  • Noise Figure 
  • IM Measurement Method set to Dynamic Range or Segmented
  • ACP with Measurement Method set to Dynamic Range
  • PVT with Measurement Method set to Dynamic Range
• When you set the IM Measurement Method set to Normal, you must also set the Frequency Definition parameter to Relative when you call the RFmxSpecAn IM Configure Frequency Definition VI.
• Analysis-Only mode is not supported