Using VISA COM I/O API in .NET

.NET and Test & Measurement I/O  

The Microsoft .NET architecture, with its C# and Visual Basic programming languages and the Microsoft Visual Studio development environment, has many features that make it an excellent environment for Test & Measurement programmers. There is only one problem: doing actual instrument communication. Keysight Technologies, Inc. has released the T&M Toolkit, which provides services, applications, and APIs to make instrument programming natural and simple in Visual Studio environments (www.keysight.com/find/toolkit). While the T&M Toolkit provides a simple, easy-to-use programming environment from Visual Studio, savvy Visual Studio users today can fall back on more basic I/O tools such as VISA COM I/O to get their T&M programming tasks done in .NET environments. 

VISA COM I/O and .NET  

The VISA COM I/O API is a programming interface standardized by the IVI Foundation for communicating with instruments over GPIB, LAN, USB, RS-232, or other hardware interfaces. Keysight Technologies has an implementation of the VISA COM I/O standard that works with Keysight I/O hardware as well as the computer-standard I/O interfaces. VISA COM I/O is an update of the older VISA C API to work in and with Microsoft’s COM technology.  

Microsoft has integrated robust support for COM components in the .NET environment. The COM interfaces tend to translate well into .NET equivalents via automated wrapper-generator tools that Microsoft provides. Due to this COM support in .NET, many programmers will find VISA COM to be an excellent choice for instrument communication in .NET. This article describes how to use Keysight’s VISA COM I/O implementation with C# and Visual Basic (VB) examples. 

Table of Contents 

• Getting started 
• The Visual Studio Add Reference dialog 
• Get familiar with the Object Browser 
• Using Keysight VISA COM I/O in Microsoft Visual Studio 
• Advanced VISA COM I/O operations in .NET 
• VISA COM I/O and VB threading