Resolve RFmxSpecAn CHP Fetch Measurement Error -1074135025 on PXIe-5841

Updated Aug 28, 2026

Reported In

Hardware

  • PXIe-5841

Software

  • RFmx SpecAn

Driver

  • NI-RFSA

Issue Details

I am evaluating a PXIe-5841 and using RFmx Spectrum Analyzer measurements together with NI-RFSA functionality in a custom session-management architecture.
After a successful measurement, repeated acquisitions may fail with the following error:
 
 
 
Error -1074135025 occurred at RFmxSpecAn CHP Fetch Measurement.vi
Possible reason(s):
 
IVI: (Hex 0xBFFA000F) Invalid parameter.
Parameter Name: startingRecord
Corresponding Value: 1
Maximum Value: 0
 
 
 
 
I may also observe invalid session or invalid reference errors when using RFmx and NI-RFSA together, particularly when performing resets between measurements. The first acquisition works correctly, but subsequent measurements fail or exhibit inconsistent behavior.

Solution

The observed behavior can occur when RFmx and NI-RFSA are sharing the same underlying analyzer session and the session state is modified by lower-level reset operations.
To resolve the issue:
  1. Initialize RFmx and NI-RFSA using a shared session architecture.
    • Use RFmxInstr Initialize NIRFSA.vi to establish the RFmx session.
    • Use RFmxInstr Get NIRFSA Session.vi when NI-RFSA access is required.
    • Maintain a single owner for the physical PXIe-5841 session whenever possible.
  2. Use a persistent device-level session manager.
    • Initialize the hardware once.
    • Keep the session active for the duration of operation.
    • Prevent multiple independent components from initializing, resetting, or closing the same device session.
  3. Avoid calling niRFSA Reset With Options within the normal measurement loop.
    • This operation can clear driver state expected by RFmx.
    • Repeated measurements may fail even when the session handle remains valid.
  4. Use RFmxSpecAn Reset to Default.vi when a software reset is required.
    • This approach preserves RFmx ownership of the underlying session.
    • Testing showed successful repeated execution after replacing the NI-RFSA reset operation with the RFmx reset method.
  5. Verify record-handling logic when performing repeated measurements.
    • For standard single-record acquisitions, fetch record 0 on each acquisition.
    • Do not advance startingRecord unless a multi-record acquisition has been explicitly configured.
  6. Reapply acquisition settings after any reset operation if repeated measurements are required.
    • Number of Records
    • Number of Samples
    • IQ Rate
    • Trigger configuration
    • Fetch-related settings
  7. Review the application for unintended NI-RFSA acquisition calls.
    • Check for direct IQ acquisition functions such as Fetch IQ, Read IQ, or other helper VIs that may be operating on the same session.
    • Ensure RFmx and NI-RFSA configurations remain synchronized.
Following these recommendations resolved the repeated measurement failures and allowed successful execution of RFmx Spectrum Analyzer measurements without the original error.

Additional Information

Technical observations from the investigation:
  • RFmx and NI-RFSA share the same underlying analyzer session.
  • Direct NI-RFSA reset operations can invalidate or modify state expected by RFmx measurements.
  • A centralized session-management model is recommended when multiple RF personalities or APIs access the same PXIe-5841 device.
  • Replacing niRFSA Reset With Options with RFmxSpecAn Reset to Default.vi resolved the reported issue during testing.
  • Additional validation may be required when operating the Signal Generator and Signal Analyzer simultaneously as independent instruments.

Related Links

RFmxInstr Reset Driver (VI) - NI

RFmxSpecAn Reset to Default (VI) - NI

RFmxInstr Initialize NIRFSA VI - NI

RFmxInstr Get NIRFSA Session (Array) (VI) - NI

Other Support Options

Ask the NI Community

Collaborate with other users in our discussion forums



Request Support from an Engineer

A valid service agreement or active software subscription may be required, and support options vary by country.