Error -1074135024 in niRFSG Multitone Generation

Updated Jun 25, 2019

Reported In

Hardware

  • PXIe-5840

Driver

  • NI-RFSG

Operating System

  • Windows

Issue Details

When using the niRFSG Multitone Generation.vi example in LabVIEW, why can't I set eight tones configured for power levels to produce an average power of 0dBm? Why is there a difference in behavior when this worked for five tones at the same average power level? 

When I set the eight tones to the right power level to create an average power of 0 dBm, I see an error:

Error -1074135024 occurred at niRFSG Initiate.vi
Possible reason(s):

IVI: (Hex 0xBFFA0010) Invalid value for parameter or property. 

Property: Power Level (dBm)

Solution

The LabVIEW shipping example is currently configured to accommodate the peak to average power ratio of tones for center frequencies greater than 120 MHz, where the VST can changes between a low frequency path and a high frequency path , so if you are going to be generating at a center frequency less than 120 MHz, such as 100 MHz, you may need to make some adjustments to the example code in order to run it without this error and successfully, regardless of the 120 MHz threshold. 

These changes include the following, also shown in the below image. 
  1. In the niRFSG property node, change the input of the Power Level Type property from Average Power mode to Peak Power mode. 
  2. Prior to writing the RFSG output and following the Uniform Spacing, normalize the signal, which is required for this mode. 

Additional Information

If aiming to increase the number of tones while maintaining an average power of 0 dBm, it is possible that generation at lower frequencies with the VST will exceed the peak output power limits, as per the RF Output Power Range of the PXIe-5840 specifications, shown below. Reference these parameters when defining the limits of the generation capable for the hardware at certain frequency ranges.