If you are an R&D, manufacturing or test engineer in the electronics industry, chances are you use your test instruments for more than simple benchtop measurements. At some point, most engineers need to program and control test instruments and communicate with them from a PC or laptop.
Until recently, there hasn’t been a quick and easy way to physically connect test instruments to your computer, much less an easy way to get your PC and test equipment to communicate smoothly with each other. If you are like most engineers, you have wasted a lot of time and effort getting your instruments hooked up, dealing with driver issues, and writing code, all in a simple quest to make your test instruments talk to each other and to your PC.
There are some new solutions available to save you time with these connectivity issues so you can have more time to spend on more productive tasks. The purpose of this paper is to walk you through the choices you need to make when you are setting up your automated tests and introduce you to some of the hardware options available that can simplify your connection, communication, and programming tasks.
Making the hardware connection is just the first step in mastering the whole connectivity challenge. For assistance with other aspects of connectivity, register for free information on the Keysight Connectivity at www.keysight.com/ find/IO.
Making the Physical Connection
In the past, RS-232 and GPIB have been the primary interfaces used for connecting instruments to PCs in test and measurement applications. Although RS-232 is a low-cost solution, its low baud rate and connection limitations make it too slow and cumbersome for many of today’s measurement needs.
GPIB technology has provided a high-performance, stable communications solution for more than 25 years. GPIB does have some drawbacks, though. For example, you must install a GPIB card in each PC you want to use to access your test and measurement instruments. Before you can install a GPIB card, you need to have an available I/O slot — a commodity in perennial short supply. Then you must open your PC housing to install the GPIB card, an action many computer users would prefer to avoid. The hassle involved certainly makes it inconvenient to attempt to share a GPIB card among multiple users. The alternative, equipping everyone in your work group with an individual GPIB card, can be expensive.
USB and LAN connections are now built into most of today’s PCs, and standard PC I/O has evolved into an acceptable alternative for automating and controlling test and measurement instruments. Early USB devices, developed for connecting PCs to peripherals such as keyboards and mice, offered limited bandwidth. Today, however, USB 1.1 interfaces offer bandwidths up to 12 Mb/s, and USB 2.0 interfaces offer up to 480 Mb/s bandwidth, adequate for most test and measurement applications. Typical LAN configurations support 10 or 100Mb/sec (10BASE-T/ 100BASE-TX) networks. Data transfer rates, however, are determined by the amount of traffic on the network. To maximize measurement data throughput, you can use a dedicated LAN and achieve higher performance for test systems. New LAN standards go up to 1 GB/s, and before too long, we expect to see LANs migrating to even faster speeds.
Today, the Keysight Technologies, Inc. test and measurement instruments are equipped with USB and LAN connections and use a mixture of interfaces. To support you during your migration to USB and LAN, Keysight offers simple solutions for connecting your legacy GPIB instruments to standard computer I/O.
