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What is an Instrument Driver?Publish Date: Feb 02, 2012

OverviewAn instrument driver is a set of software routines that control a programmable instrument. Each routine corresponds to a programmatic operation such as configuring, reading from, writing to, andtriggering the instrument. Instrument drivers simplify instrument control and reduce test program development time by eliminating the need to learn the programming protocol for each instrument.

National Instruments provides instrument drivers for a wide variety of instruments; these instrument drivers are written in and/or and use either the Plug and PlayLabVIEW LabWindows/CVIarchitecture or the Interchangeable Virtual Instrument (IVI) architecture.

Both architectures use Virtual Instrumentation Software Architecture (VISA) to provide bus and platform independent instrument communication. The Instrument Driver Network has thousands offree instrument drivers for download.

Table of ContentsPlug and Play Instrument Drivers

Interchangeable Virtual Instrument (IVI) Drivers

Virtual Instrumentation Software Architecture (VISA)

Related Links:

1. Plug and Play Instrument DriversPlug and Play instrument drivers simplify controlling and communicating with your instruments through a standard and straightforward programming model. Using Plug and Play instrument driversmakes interacting with hardware easier than other instrument driver technologies.

The Plug and Play architecture is implemented in both LabVIEW and LabWindows/CVI. Plug and Play instrument drivers provide source code native to the development environment. Withaccess to source code, you can modify, customize, optimize, debug, and add functionality to the instrument driver. Source code also enables Plug and Play instrument drivers to becross-platform, so you can use them in any operating system that works with LabVIEW or LabWindows/CVI software.

For more information on Plug and Play Instrument Drivers see . Types of Instrument Drivers: Plug and Play

2. Interchangeable Virtual Instrument (IVI) DriversIVI drivers are more sophisticated instrument drivers that feature increased performance and flexibility. These drivers are designed for more complex test applications that requireinterchangeability, state caching, or instrument simulation.

IVI drivers implement state-caching to eliminate redundant commands that may be sent to the instruments in your system. This reduction in instrument I/O can provide significant performanceimprovements. IVI drivers can also be configured to run in simulation mode, where the actual instrument and the signal it acquires or generates is simulated in software.

One of the most important features of IVI drivers is their ability to allow instruments to be interchanged in a system without modifying the test application. The IVI Foundation has defined eightclasses of instruments: DC Power Supplies, DMMs, Function Generators, Oscilloscopes/Digitizers, Power Meters, RF Signal Generators, Spectrum Analyzers, and Switches. An instrument thatconforms to one of the IVI Class specifications may be substituted with another instrument of the same class, regardless of manufacturer or bus connection (GPIB, USB, LXI, PXI).

For more information on IVI Instrument Drivers see Interchangeable Virtual Instruments

3. Virtual Instrumentation Software Architecture (VISA)The Virtual Instrumentation Software Architecture (VISA) is a comprehensive package for configuring, programming, and troubleshooting instrumentation systems comprised of VXI, PXI, GPIB,TCP/IP, USB, and/or serial interfaces. It provides a common foundation for the development, delivery, and interoperability of high-level multi-vendor system software components, such asinstrument drivers, soft front panels, and application software.

NI-VISA is the National Instruments implementation of the VISA I/O standard. NI-VISA includes libraries, interactive utilities such as NI I/O Trace and the VISA Interactive Control, and configurationprograms for all your development needs, and is standard across the National Instruments product line.

4. Related Links:NI Instrument Driver NetworkTypes of Instrument DriversInterchangeable Virtual Instruments (IVI) Web PagesNI-VISAHow to Use an Instrument Driver in LabVIEW TutorialIVI FoundationOn-Demand Training: IVI Fundamentals I - What Are IVI Drivers? (SSP required)On-Demand Training: IVI Fundamentals II - Why Use IVI Drivers? (SSP required)