A LabVIEW 8.5.1 application using the RsSpecAn driver, an R&S FSP spectrum analyzer, and a GPIB 82357B reports two separate faults: -113 Undefined header while configuring the analyzer and -250 mass storage error while storing a trace. Troubleshoot them independently. The first concerns commands sent to the analyzer; the second concerns the storage operation, its VISA session, and the destination path.
Separate the command and storage faults
| Reported fault | Evidence-supported focus | Verification |
|---|---|---|
-113 Undefined header |
Inspect the exact command generated for the R&S FSP, including the reported :TRAC:MODE MAXH"0" text and other rejected headers. |
Identify the first rejected command and confirm that later errors are not merely downstream results. |
-250 mass storage error |
Check the Store Trace to File function's VISA Resource connection and determine whether its filename refers to analyzer storage or the PC. | Confirm that the function receives the active VISA session and that the selected storage system can access the destination. |
Diagnose the -113 Undefined Header response
The analyzer reportedly rejects :TRAC:MODE MAXH"0" and commands associated with settings such as the 50-ohm input impedance. Record the exact strings written over GPIB rather than diagnosing only from the driver call. In the displayed trace-mode string, MAXH and "0" appear adjacent; determine whether that text is one malformed command, two concatenated arguments, or only the way the error was displayed. Do not change unrelated measurement values until the first rejected header is isolated.
The configured values reported with the application include a reference level of 30.E+0, stop frequency 20E6, start frequency 0, coupling value 4E-3, reference-level offset 50E-3, attenuation 10, input impedance 50, and amplitude unit dbm. These values document the attempted setup, but the evidence does not establish which one generated each rejected header or whether the installed analyzer supports every driver-generated command.
Correct the VISA session path
The Store Trace to File function's VISA Resource input was not actually connected: the visible wire passed underneath the function and continued to the close operation. A nearby wire is not an electrical connection in the block diagram. Without the session input, the storage function cannot reliably operate on the same analyzer session used by the preceding driver calls.
- Trace the VISA Resource wire from the instrument open or initialization function to Store Trace to File.
- Connect the wire directly to the function's VISA Resource terminal, then continue the same session to the close function.
- Run the VI and inspect the error immediately after Store Trace to File, preserving the first error in the chain.
Resolve the -250 mass storage error
The filenames discussed were a:\test.txt and C:\test.txt. The original A: destination raised the practical question of whether that storage device existed and was available. Changing the text to C: does not by itself prove that the analyzer can access the PC's C drive. First establish whether Store Trace to File writes through the analyzer's mass-storage system or creates a file through the PC application.
If it is an analyzer-side store operation, select a destination available to the analyzer and then transfer or read the trace back to the PC separately. If it is a PC-side write operation, verify the LabVIEW path representation and PC destination. The discussion mentions both single and doubled backslashes, but does not identify the string display mode, so judge the actual path value reaching the function rather than its visual slash count alone. Verify success by confirming that the expected text file exists and contains trace data before opening it in a spreadsheet or Excel.
FAQ
Why does the R&S FSP report -113 Undefined header?
The analyzer is rejecting a transmitted command header. Capture the exact command stream and start with the reported :TRAC:MODE MAXH"0" text, checking whether its mode and following argument were incorrectly concatenated.
Why does Store Trace to File return -250 mass storage error?
Check that its VISA Resource terminal is genuinely wired to the active analyzer session, then determine whether the filename must identify analyzer storage or PC storage. A PC path such as C:\test.txt is not sufficient if the operation executes on the analyzer.
How do I verify that the spectrum trace was saved correctly?
Check the error output immediately after Store Trace to File, confirm that the target file exists on the intended storage system, and inspect it for trace data before importing it into a spreadsheet or Excel.