Section 2: General operation
Models 707B and 708B Switching Matrix Reference Manual
2-58
707B-901-01 Rev. A / August 2010
Supplied software
The majority of software applications and all instrument drivers from Keithley Instruments depend on
some, or all, of the following software components:
•
NI-VISA™
•
VISA shared components
•
IVI shared components
•
NI™ CVI™ runtime engine
•
NI™ IVI™ compliance package
•
Keithley instrument driver
These software components are included on the CD-ROMs that came with your instrument, and are
also available for download at the
(http://www.keithley.com/support).
VISA
The Virtual Instrument Software Architecture (VISA) is a standards body that maintains the
specifications for a whole series of software components related to instrument connectivity (I/O). The
VISA specifications, formerly maintained by the VXIplug&play Systems Alliance, are now being
(http://www.ivifoundation.org).
The VISA library (standard VPP-4.3) is a standard for an API to communicate with instruments
connected to the computer communication buses: Ethernet, USB, RS-232, GPIB, and so on. VPP-4.3
is a software API standard — several instrument vendors have implementations of VPP-4.3, including
National Instruments, Agilent Technologies, and Tektronix.
There are three types of programming interfaces to VISA: VISA-C, VISA-COM and VISA .NET.
•
VISA-C is a DLL that has a flat API. The five main message-based functions are viOpenDFLT, viOpen,
viWrite, viRead and viClose.
•
VISA-COM is an ActiveX type interface to VISA that is more suited for the VB6 and .NET environments.
•
VISA.NET is a .NET interface for VISA that the IVI Foundation is currently (July 2010) standardizing on.
VISA shared components
The IVI Foundation provides the VISA shared components, which contain the VISA-COM
components that VISA vendors install with their VISA installations. There are separate entries in the
Add/Remove Programs dialog box for the VISA shared components and the vendor’s VISA.