Instrument Control Toolbox

Controlling Instruments Using the VISA Standard

VISA Overview

Virtual Instrument Standard Architecture (VISA) is a standard defined by Agilent Technologies and National Instruments for communicating with instruments regardless of the interface.

The Instrument Control Toolbox supports the GPIB, VXI, GPIB-VXI, and serial port interfaces using the VISA standard. Communication is established through a VISA instrument object, which you create in the MATLAB workspace. For example, a VISA-GPIB object allows you to use the VISA standard to communicate with an instrument that possesses a GPIB interface.

Note    Most features associated with VISA instrument objects are identical to the features associated with GPIB and serial port objects. Therefore, this chapter presents only interface-specific functions and properties. For example, register-based communication is discussed for VISA-VXI objects, but message-based communication is not discussed since this topic is covered elsewhere in this guide.

For many VISA applications, you can communicate with your instrument without detailed knowledge of how the interface works. In this case, you may want to begin with one of these topics:

• The GPIB Interface
• The VXI Interface
• The GPIB-VXI Interface
• The Serial Port Interface

If you want a high-level description of all the steps you are likely to take when communicating with your instrument, refer to Chapter 2, The Instrument Control Session.

Serial Polls

Using Vendor Tools to Identify and Test Your Resources