How is instrument interchangability achieved?

[saycoda]

I just swapped out an older instrument of the same type in my test rack(dual channel power meters, Gigatronics vs. HP).Both have associated Instr Drvrs. I found myself changing alot of code to achieve the basic function of reading power. Is there another technique for interchangability, other than many lines of conditional code?

TIA

[Pierre_63]

You can look at the IVI technologie. It's based on Visa. (Tools>>CreateIvi Driver ). It allows you to programm interchangability driver, because you set/get attributes. This settings call a callback function that write the command to the instrument. If yours instruments are interchangable, they have the same attributes.

[Jeremiah Cox]

Hello saycoda,
IVI Drivers have been developed to solve this issue as well as several others. They are instrument drivers that use a defined API for each class of instruments. For example, all IVI drivers for DMMs are required to have the functions defined as Base Capabilities in the IVI DMM Class Specification (they all posses the same interface). If you write your programs using IVI Class drivers, you can interchange devices without even recompiling your code. All that is necessary is that you have the Specific IVI driver for the new instrument installed on your system and that you reconfigure our software (this generally takes 2-10 minutes depending on the instrument). For further information on IVI as well as where you can download drivers, I would direct you to t
he following web sites:
http://www.ivifoundation.org
http://www.ni.com/ivi
http://www.ni.com/idnet

Jeremiah Cox
Applications Engineer
National Instruments
http://www.ni.com/ask