A strange behavior of NI VISA-COM if two VISA library are installed

[kozlov]

Hi, all!
I have discovered a strange behavior of NI VISA-COM if two VISA libraries (NI and Agilent) are installed. I have in mind configuration if NI VISA is installed as primary and Agilent VISA is installed as secondry. In that case all NI VISA-COM calls are translated to Agilent VISA library calls. I tested the same program on 3 computers. The program use NI VISA library only if Agilent VISA library is not installed.

Thanks in advance.

[JoshuaP]

Hey Kozlow,

In some versions of Agilent VISA they use the same name for their VISA dll as NI VISA. In these instances you can not have Agilent and NI VISA on the same machine.

http://digital.ni.com/public.nsf/websearch/3B3626D9C1F999218625694200791AD7?OpenDocument

http://digital.ni.com/public.nsf/websearch/3B3626D9C1F999218625694200791AD7?OpenDocument

I believe after Rev K of the Agilent VISA it would allow you to set the installation as a side-by-side installation. In this case you would have to install NI-VISA first. You might want to also perform a repair on the NI-VISA.

I hope this helps out.

JoshuaP
National Instruments