Keysight VISA Messages for Users of 32-bit VISA on 64-bit Windows

If you are using 32-bit VISA with 64-bit Windows, when you are in the About box for IO Control, you will see one of the following status messages that describe the discovered condition of VISA32.dll on your machine.

In the section 32-bit VISA information (in the IO Control About box):

  • Keysight VISA: The primary VISA library. - This status indicates that the file “C:\Windows\SysWOW64\visa32.dll”, as installed by Keysight IO Libraries Suite, is the primary VISA as expected. No action is required.

  • Keysight VISA: The secondary VISA library. - This status indicates that the file “C:\Windows\SysWOW64\visa32.dll” already existed at the time of IO Libraries installation, and was not installed/replaced by Keysight. In this case, primary VISA status belongs to the third party VISA, and Keysight VISA is considered secondary.

  • Keysight VISA: Operating as secondary (installed as primary but overwritten) - This status indicates that Keysight VISA was originally installed as primary, but then was renamed during the installation of a third-party .dll, causing the third-party .dll to be primary and causing Keysight VISA to operate as secondary. If you want to restore Keysight VISA to primary, the third party VISA must be uninstalled and Keysight IO Libraries must be repaired/re-installed.

  • Keysight VISA: Installed as primary but 32-bit visa32.dll missing - This status indicates that the .dll for Keysight VISA was installed at one point but is missing. Repair / reinstall to restore Keysight VISA as primary.

  • Keysight VISA: Operating as primary (installed as secondary) - The system was able to detect that Keysight’s VISA was manually installed by a user but not as part of a normal installation process. Action may not be required unless the user needs to repair the installation back to its original state.

  • Keysight VISA: Installed as secondary but 32-bit visa32.dll missing - If the system discovers the condition where another vendor's VISA was installed as primary and that third-party .dll is now missing, it will detect/report this status. Correction of this condition is outside the scope of IO Libraries as it is a third-party or user-generated issue.