Instruments: The New Generation
By Lawrence Loo
We are witnessing the rapid evolution of standalone instruments into something far greater. Local storage and faster processors have created gradual transformations, but now LAN I/O, leveraged from the PC industry?s R&D investments, promises to accelerate the transformation.
LAN was once viewed as a good interface for block transfers, but too slow for the single transactions encountered in test systems. As Ethernet has progressed from 1 Megabit to 10baseT, 100baseT and now Gigabit LAN, latency issues have dropped proportionately. LAN latency now rivals that of GPIB, and the block speed of LAN is substantially greater than that venerable 8-bit parallel bus. With multiple vendors from the T&M industry introducing LAN-based products, it?s easy to see the handwriting on the wall: LAN will become the backplane of next-generation instruments. Notice we said backplane, not just I/O.
The speed and reach of LAN are proving to be useful in bench top instruments. These new instruments are already optimized with smaller footprints, faster speeds and prolonged calibration intervals. Also, remote instrument setup is now made easier via a simple browser. But that?s not all. LAN will present instrument designers with the ultimate flexibility: a single architecture to serve R&D, design validation and manufacturing.
Fitting substantial amounts of instrumentation into a smaller footprint will be done with faceless instruments, running the identical software the standalone instrument runs. These standard rack-sized instruments will sport a small form factor, use LAN as a communication device and have graduated capability for external triggering. The name of this new architecture is LXI.
LAN Extensions for Instruments (LXI) is a new consortium, initiated by Agilent and VXI Technology, and now comprising a stellar line-up of electronic test companies from around the globe (www.lxistandard.org). Agilent believes LXI to be the most efficient platform for test development and for moving hardware and software from one realm to another. The same hardware design can be used for both standalone and faceless instruments, and the measurement science prevalent in rack and stack instruments can now be enjoyed in a smaller form factor, unfettered by cages and racks.
The next step is to carve instruments along logical partition lines, creating building blocks that meld to form one or several instruments, while still realizing the accuracy and repeatability commensurate with standalone instruments. Combine several LXI Synthetic Instrument modules, and you have a complete instrument. Reconfigure the system through a switch, and you have a different set of measurement capability, without increasing the footprint.
The standalone rack and stack instrument has steadily morphed into a system-ready instrument, with a local human interface and local intelligence, in a smaller package and with a LAN interface. The equivalent instrument in a smaller, faceless package, results in the form factor called LXI Type A. Finally, partitioning an LXI instrument into its building blocks gives the engineer an unlimited combination with which to synthesize other instruments.
Combining these hardware changes with industry-standard I/O drivers in the form of IVI-COM and a test and measurement face for Microsoft?s Visual Studio, and you have a multi-language software environment that works where you want to work, combined with R&D-class instrumentation that has the speed and reach of LAN.
Agilent has gone one-step further enabling test engineers to incorporate these innovations in test instruments, their flexible connectivity options, and a software environment of their choice. We call that Agilent OPEN.