Can any one tell me that whether VISA is a software architecture or an interface standard?

when i was reading tutorials in Instrument control toolbox, i came cross VISA manytimes, some explaining it as an interface and some as an software architecture, is VISA is an interface like GPIB or its differen?. Some are saying VXI,USB are all comes under VISA, I am badly confused with VISA, GPIB,VXI,USB etc..

Any explanation on the above would be really appreciated..

Thanks & Regards Vijith

Answer 1

[Walter Roberson]

http://en.wikipedia.org/wiki/Virtual_Instrument_Software_Architecture

Virtual Instrument Software Architecture, commonly known as VISA, is a widely used I/O API in the test and measurement (T&M) industry for communicating with instruments from a PC. VISA is an industry standard implemented by several T&M companies, such as Rohde & Schwarz, Agilent Technologies, Bustec, National Instruments, Tektronix and Kikusui.

The VISA standard[1] includes specifications for communication with resources (usually, but not always, instruments) over T&M-specific I/O interfaces such as GPIB and VXI. There are also some specifications for T&M-specific protocols over PC-standard I/O, such as HiSLIP[2] or VXI-11[3] (over TCP/IP) and USBTMC[4] (over USB).

[Vijith Natarajan]

Would you please make a classification of interface like a tree model?? So i can understand what comes under what.. I searched in google, but i am not pretty clear with it..

thanks

[Walter Roberson]

Programs call the API. The API knows how to talk to hardware I/O interfaces such as GPIB, and also knows how to talk some interface protocols that are layered on top of other interfaces such as TCP/IP and USB.

If you want classification then you need to indicate which classification scheme you are using. For example, are you using a 5 layer model or a 7 layer OSI model? http://www.gslis.utexas.edu/~l38613dw/readings/NotesOnInterconnection.html