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Error 30559 on a viReadAsync and viWriteAsync Using Measurement Studio and NI-VISA

Primary Software: Measurement Studio>>Enterprise Edition (Full Development System)
Primary Software Version: 6.0
Primary Software Fixed Version: N/A
Secondary Software: Measurement Studio>>Professional Edition (Base Package), Measurement Studio>>Standard Edition (Starter Kit), Driver Software>>NI-VISA

Problem:
I have Measurement Studio 6.0 and I ran the sample program located in C:\Program Files\National Instruments\MeasurementStudio\VB\Samples\Visa\Basic Visa and it returns error 30559 when I try to do ReadAsync or WriteAsync. The regular synchronous read and write work fine.

The error that shows up in NI-Spy is:
0xBFFF003B (VI_ERROR_QUEUE_ERROR) Unable to queue the asynchronous operation.

Solution:
The driver generates that error because the asynchronous operation you called could not be queued. Measurement Studio enables both the event queue and the handler for the same event type on the same session. NI-VISA 3.0 and later does not support that functionality.  Also you should only use the NI-VISA 3.0 driver with Measurement Studio 7.0 or later.

The two options to fix this error are:
  • Upgrade to Measurement Studio 7.0 and keep NI-VISA 3.0, or
  • Keep Measurement Studio 6.0 and use NI-VISA 2.6.
For more information refer to documentation for the viEnableEvent in the NI-VISA Programmer Reference Manuals (linked below).

Related Links:
Manuals: NI-VISA 2.6 Programmer Reference Manual
Manuals: NI-VISA 3.0 Programmer Reference Manual

Attachments:

 






Report Date: 01/06/2004
Last Updated: 11/06/2008
Document ID: 355BAAWH

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