NI-Switch 20.0 Known Issues


This document contains the NI-Switch 20.0 known issues that were discovered before and since the release of NI-Switch 20.0. Known issues are performance issues or technical bugs that NI has acknowledged exist within this version of the product.


Not every issue known to NI appears on this list; it is intended to show the most severe and common issues that you may encounter and provide workarounds when possible. Other technical issues that you may encounter could occur through normal product use or system compatibility issues. You may find more information on these issues in NI’s Product Documentation, Knowledgebase, or Community.

Bug Number

Legacy ID



393016 284305

SCXI-1127 (Rev D and earlier) continuously drives the TTL1 trigger line on the SCXI backplane

Continuously driving the TTL1 trigger line on the SCXI backplane does not allow bus sharing of TTL1 with other SCXI modules. NI-SWITCH returns an error if an SCXI-1127 is in the chassis and if TTL1 is being used for scanning. If using the NI-DAQmx driver for your SCXI system, you get a resource reservation error if you try to perform a switching or signal conditioning operation that requires use of TTL1.


There is currently no known workaround for this issue.

Reported Version:

NI-Switch 1.6

Resolved Version:



Feb 7, 2011

393021 284308

There are known DLL collision issues with the Microsoft Visual Basic debugger and a National Instruments device driver using Traditional NI-DAQ (Legacy)

A support DLL used by NI-SWITCH fails to load if Visual Basic has already loaded another DLL into the same address space.


To change the default address that is used to load the driver DLL, create the following registry key: \\HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\NI-PAL\CurrentVersion\palConfig\Memory\ sharedFixedAddress where the value is a DWORD (0x44000000 generally works). For the change to take effect, you must close and restart all applications after adding the registry key.

Reported Version:

NI-Switch 2.5

Resolved Version:



Feb 7, 2011

Final Time Issue Listed

Issues found in this section will not be listed in future known issues documents for this product.


There are currently no issues to list.

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Glossary of Terms


  • Bug ID - When an issue is reported to NI, you may be given this ID or find it on  You may also find IDs posted by NI on the discussion forums or in KnowledgeBase articles.
  • Legacy ID – An older issue ID that refers to the same issue.  You may instead find this issue ID in older known issues documents.
  • Description - A few sentences which describe the problem. The brief description given does not necessarily describe the problem in full detail.
  • Workaround - Possible ways to work around the problem.
  • Reported Version - The earliest version in which the issue was reported.
  • Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
  • Date Added - The date the issue was added to the document (not the reported date).