For a long time, interchangeability has become the goal of many engineers to build test systems. Because in many cases, the instrument hardware is either outdated or needs to be replaced, there is an urgent need for a method to improve the system with new instrument hardware without changing the test program code. In order to solve this problem, IVI (Interchangeable Virtual Instrument) Foundation was established in September, 1998. IVI Foundation is an open alliance composed of end users, system integrators and instrument manufacturers. At present, the organization has formulated specifications for five types of instruments-oscilloscope/digitizer (IVIScope), digital multimeter (IVIDmm), arbitrary waveform generator/function generator (IVIFGen), switch/multiplexer/matrix (IVISwitch) and power supply (IVIPower). As one of the system alliances, NI actively responded to the call and developed the driver library based on the virtual instrument software platform.

Members of IVI Foundation often hold system alliance meetings to discuss instrument specifications and formulate new instrument specifications. In due course, a special working group will be set up to deal with special technical issues, such as:

Establish specifications for new instruments;

Combined with the instrument specification, model the standard of application program (such as setting the file format and help file of standard waveform);

Define the test steps of instrument drive;

Establish fault reporting and distributed update mechanism;

Investigate the industrial standards of computers and formulate the specifications of software communication and software packages.

IVI Foundation is committed to improving the standardization level of instrument drivers from basic interoperability to interchangeability. By formulating the unified specification of instruments, test engineers gain greater hardware independence, reduce the cost of software maintenance and support, shorten the programming time of instruments, and improve operational performance. Using IVI technology can benefit many departments. For example, a transaction processing system using IVI technology can use different tools in its system. When the instrument is out of date or has been upgraded, high-performance or low-cost instruments can be replaced at will without changing the source code of the test program. In telecom and electronic consumer products, when the instrument fails or needs maintenance, it can keep its production line running normally; Various large manufacturing companies can easily reuse and * * enjoy the test code between departments and equipment without forcing the same instrument hardware.