The PXI Express (PXIe) platform combines performance and flexibility to provide cost-effective test solutions to meet complex functional testing requirements in automotive, aerospace and defense, power and energy, and even commercial applications.
PXIe, which consists of a chassis that accommodates a variety of card-based instruments, makes it easy to configure a test system that offers signal-source, digitizer, and other instrumentation functionality.
A key feature of PXIe is a hardware trigger bus that enables synchronization between cards in one chassis. The advantage of a standard modular platform like PXIe is the ability to work with multiple instruments in the same chassis and have them work together as a single system. This includes instruments from multiple vendors.
Multifunction digitizer
A PXIe card that combines signal-source and digitizer functionality along with flexible general-purpose digital I/O capabilities would enable even higher levels of performance, compactness, and functionality, representing a virtual Swiss Army Knife of instrumentation. Such a card’s digitizer could handle fast voltage measurements, and combining its current-source excitation capability combined with the digitizer would enable resistance measurements and allow the calculation of temperature based on resistor-temperature-detector (RTD) measurements, as well.
The ideal card would also offer built-in self-test (BIST) and self-calibration capabilities that can be executed prior to critical tests to meet the needs of today’s dynamic manufacturing and test environments that require reliability, accuracy, repeatability, and minimal downtime. In addition to ensuring its own reliability and functionality, the card would incorporate the intelligence necessary to confirm reliable connections to external transducers and other devices.
32-channel digitizer with two analog outputs
AMETEK Programmable Power’s VTI Instruments brand offers such products with its new EMX-2632 and EMX-2616 PXIe digitizer card. The EMX-2632 features 32 channels of differential analog inputs and incorporates eight 16-bit successive-approximation-register (SAR) analog-to-digital converters (ADCs), which can provide simultaneous sampling on groups of eight input channels at 1.6 MS/s. A 4:1 multiplexer enables scanning across four groups of eight channels each at 400 kS/s, covering all 32 channels. The companion EMX-2616 card offers a similar architecture with a total of 16 channels. Both cards can be thought of as not just digitizers but rather high-channel-count, high-speed DMMs.
Both cards can handle input voltage ranges to 16 V, making them suitable for use in automotive and other applications areas that are increasingly using higher voltages. Other selectable voltage ranges include 2 V and 0.25 V. The EMX-2632 has two output channels at ±10 V or ±20 mA, while the EMX-2616 has a single output channel at the same ratings. In addition, the EMX-2632 and EMX-2616 have 16 and eight general-purpose 3.3-V digital I/O channels, respectively.
When used with AMETEK Programmable Power’s EMX-2500 gigabit Ethernet controller, the EMX-2632 and EMX-2616 enable integration and synchronization with tens to thousands of external instrumentation channels through compliance with the IEEE-1588 v2 PTP standard. An LXI-certified device, the controller adds LXI connectivity to a PXIe chassis and offers an embedded web page for monitoring, control, and identification across a network.
Programming options
Programmability is a key consideration for any automated test application, and the EMX-2632 and EMX-2616 fit smoothly into any software environment. Out of the box, they come with a built-in graphical user interface (GUI), or soft front panel, that lets you access the instruments’ full functionality from a standard web browser. You can use the GUI for configuration as shown in Figure 2, where, for example, channel 1A (CH1A) is selected as a voltage input with a 16-V range.
The GUI also provides detailed views of acquired signals. Figure 3a, for example, shows the fast Fourier transform (FFT) of a signal whose peak frequency component is 0 dB in magnitude at a frequency just above 10 kHz. And Figure 3b shows the time-domain view of a 2-V peak-to-peak, 150-Hz signal.
Figure 3. The EMX-2632’s soft front panel displays an FFT of a signal with a significant peak just above 10 kHz (a) and a time-domain view of a 2-V peak-to-peak, 150-Hz signal (b).
If you or your team write your own test programs, you can take advantage of VTI Instruments’ extensive driver support for Linux, Windows, MathWorks MATLAB, and NI LabVIEW. All of VTI Instruments’ digitizers, including non-PXIe versions such as the EX1402 16-channel isolated high-voltage measurement instrument, use the same drivers, simplifying code development for programmers contending with a variety of instrument form factors.
If you don’t want to program, you can make use of VTI Instruments’ EXLab turnkey solution, which offers easy-to-use spreadsheet configuration, real-time data displays, and data export in multiple formats.
New Swiss Army Knives in the Toolbox
The complete EMX family of products includes the previously mentioned EMX-2500 controller as well as an arbitrary waveform generator, high-performance breakout boxes, programmable resistors, and digital I/O modules. The new EMX-2632 and EMX-2616 add two Swiss Army Knives to the toolbox, enabling the development of flexible, high-performance, and cost-effective test solutions. View the EMX-2632/2616 product page for more information.