A New Modular Instrumentation Platform

Wouldn’t we all like to have test systems that combine the high performance/low price ratio of PCs, the data transfer rates of the PCI bus, and the instrumentation-oriented features of VXI? And wouldn’t we like the test systems to reside in a proven industrial mechanical configuration and conform to standards that ensure multivendor interoperability? Well, such a solution, termed PCI eXtensions for Instrumentation (PXI) now is available.

The concept and pertinent parameters are described in an open specification announced this month. The goal of PXI is to combine the price and performance advantages of mainstream PCs with necessary instrumentation extensions. The form factor is CompactPCI, for which standards have been developed by the PCI Industrial Computer Manufacturers Group (PICMAG).

CompactPCI pairs the electrical specifications of the PCI bus as implemented in today’s desktop PCs with the widely accepted Eurocard-style card and chassis mechanical specifications as outlined in ANSI 310-C, IEC 297, and IEEE 1101.1. A small 3U (100 mm × 160 mm) and a large 6U (233.35 mm × 160 mm) form factor are supported.

CompactPCl provides more space for plug-in cards than is available in a desktop PC and features a dense, but electrically efficient, pin-and-socket connector style (IEC-1076) which also is popular with the telecom industry. Eurocard specifications address issues pertinent to PXI, such as electromagnetic compatibility, mechanical keying, and connector arrangements.

By selecting the PCI bus as a backbone, PXI brings desktop PC technology to test and measurement environments. It offers the same electrical features as PCI, including 132-MB/s data rates and plug-and-play functionality, and defines Microsoft’s Windows NT® and Windows 95® as standard software frameworks.

PXI addresses the needs of test and measurement by adding an integrated trigger bus and reference clock for multiboard synchronization and timing and local buses for slot-to-slot communication between peripherals—features familiar to VXI users. Environmental testing and active cooling are mandated by PXI to ease systems integration and ensure multivendor interoperability.

Most of the following PXI products are available now, but some will be introduced later in 1997 or early 1998.

PXI Mainframes

The PXI-l000 is a 3U mainframe that can house a system controller and up to seven PXI or CompactPCl peripheral modules. The PXI-1000 has integrated, filtered, forced-air cooling in compliance with the PXI specification. The power supply and cooling fans are configured as a single unit, simplifying removal and maintenance. Cost: $1,995.

The PXI-1010 is a combination mainframe that houses up to eight PXI or CompactPCl peripheral modules and up to four signal conditioning and data acquisition (SCXI) modules. SCXI offers analog input, analog output, and digital I/O modules. The PXI-1010 can be rack-mounted and offers integrated, filtered forced-air cooling for both PXI and SCXI modules. Available in Q4. Cost: $2,995

Controllers and Interfaces

The PXI-8150 is a 3U, high-performance, embedded controller for PXI or CompactPCl. It is available with a 166-MHz Pentium with MMX and includes a 2.2-GB hard drive; a 3.5″ floppy drive; 16 MB of RAM; built-in PCI-SVGA with 2 MB VRAM; USB, serial, and parallel ports; standard keyboard and mouse connectors, and preloaded Windows 95. A 233-MHz Pentium processor with MMX and Ethernet and integrated GPIB interfaces are optional. The PXI-8150 requires only one active slot in a 3U PXI system, leaving all other active slots available for PXI or CompactPCl peripherals. Cost: starting at $2,995.

The PXI-8310 is a high-performance IEEE 488 (GPIB) interface. The module includes the TNT4882C ASIC which performs the basic IEEE 488 Talker, Listener, and Controller functions required by IEEE 488.2. Data transfer rates extend to 1.5 MB/s when using the IEEE 488.1 three-wire handshake or to 7.7 MB/s using the high-speed HS488 GPIB protocol. Cost: $495.

The PXI-8320 is a single-slot module that gives PXI and CompactPCl computers control of VXI- or VME-based instrumentation systems by using the Multisystem eXtension Interface bus (MXI-2). The PXI-8320 makes a PXI controller perform as though it were plugged directly into a VXI or VME backplane, giving the PXI computer the capability of an embedded controller. Cost: $1,495.

The VXI-P302 is a single-slot VXI card that accepts up to two PXI peripheral boards. It directly leverages PXI technology into VXI by enabling you to use PXI modules in VXI-based instrumentation systems. Available in Q2 1998. Cost: $1,495.

Data Acquisition Modules

The PXI-6070E is a bus-master, E Series DAQMIO module. It features 16 analog inputs, 12-bit resolution, 1.25-MS/s sampling rate, two 12-bit analog output channels, eight lines of digital I/O, two up/down, 24-bit counter/timers, and analog and digital triggering. Cost: $1,995.

The PXI-6040E also is a member of the DAQMIO family of products and identical to the PXI-6070E except that it features a 250-kS/s sampling rate. Cost: $1,195.

The PXI-6533 plug-in digital I/O interface is part of the DAQDIO family. It performs single-point input and output and high-speed data transfer using a range of handshaking protocols and pattern generation.

With PCI bus mastering, the PXI-6533 performs burst-mode handshaking operations at speeds up to 20 Mwords/s where a word is an 8-, 16-, or 32-bit pattern. Other features include optional wired-OR outputs, edge or pattern detection triggering for pattern generation applications, and six customizable handshaking protocols. Cost: $1,195.

Instrumentation and Image Acquisition Modules

The PXI-5102 is part of the DAQScope™ family of products that delivers digitizing features similar to stand-alone digital oscilloscopes. Features include dual channels with software-selectable AC/DC coupling, an input range of 50 mV to 5,000 V, a 20-MS/s real-time maximum sampling rate, and flexible analog and digital triggers. VirtualBench scope software is provided. Available in Q4. Cost: $1,495.

The PXI-1408 is part of the IMAQ family of products that provides high-accuracy, monochrome image acquisition meeting RS-170, CCIR, NTSC, and PAL video standards from any of four input sources. It acquires frames in real time and transfers them directly to system memory. Cost: $1,395. National Instruments, (800) 258-7022.

Copyright 1997 Nelson Publishing Inc.

September 1997

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