Tech Focus: Big things in small packages

Amid increasing demand for smaller form factors and mobility for in-field instruments in electronic test & measurement instruments, the role of USB instruments continues to grow. Whether it’s a USB-based vector network analyzer, RF power meter, data acquisition system, oscilloscope, or digital multimeter, universal serial bus technology enables the creation of cost-effective and compact test solutions. The benefits that the USB standard offers instrumentation include the ability to be placed directly on a connection to be measured, and the ability to be powered only by USB power.

The development of USB technology began in 1994, and its first specification—USB 1.0—was introduced in 1996 with defined data transfer rates of 1.5 Mbit/s low speed and 12 Mbit/s full speed. USB 2.0 was released in 2000 and ratified more than a year later, speeding up to 480 Mbit/s. The USB 3.0 specification was released in November 2008, with subsequent 3.1 and 3.2 specifications published in December 2014 and September 2017, respectively. Most recently, USB 3.2 preserved 3.1’s SuperSpeed (5 Gbit/s) and SuperSpeed+ (10 Gbit/s maximum) transfer modes, while introducing two new SuperSpeed+ transfer modes over the USB-C connector with data rates of 10 and 20 Gbit/s (1250 and 2500 MB/s).

Currently, there are no official proposals for a USB 4.0 specification. But rumors suggest 4.0’s transfer rates would be approximately 10,000 MBps—10 times that of its predecessor. As for when we can expect to see 4.0 introduced, most market experts estimate between 2020-2021. USB 3.0 figures to have staying power for a while, as there are still relatively few devices capable of saturating a 3.0 connection.
Let’s take a look at some recent product innovations in USB instrumentation.

New family of low-cost USB analog modules

This vendor has launched a new family of low-cost USB analog I/O modules—the USB-AIO family. This line of 12- and 16-bit USB modules starts with its flagship model, the USB-AIO16-16F. This high-speed, 16-bit multifunction analog input/output board is suitable for precision measurement, analysis, monitoring, and control in embedded applications. The USB-AIO16-16F can sample inputs at speeds up to 1 MHz for the board’s 16 single-ended or eight differential analog input channels. Standard features in the USB-AIO family include up to four 16-bit analog outputs and 16 high-current digital I/O lines—all packaged in a small, rugged, industrial enclosure. This family of boards also includes models with slower A/D speeds and a group of 12-bit modules for less demanding applications. The USB-AIO family includes a dozen models with list prices ranging from $374 to $879. The boards feature eight standard analog voltage input ranges, two factory current input ranges (4 to 20 mA or 10 to 50 mA), 16 factory pseudo-differential inputs, a data sample buffer, and hardware real-time calibration capability. Access I/O Products

Six-slot modular USB/LXI chassis

Last September, this vendor launched a new six-slot modular USB/LXI chassis that occupies only a small, 1U rack-height form factor, making it suitable for portable and space-restricted rack-mount applications. The 60-106 chassis accepts from one to six Pickering PXI 3U modules; the user can choose from over 1,000 module types including programmable resistors, matrices, multiplexers, general purpose relays, RF switches, and fault insertion units. The chassis is USB 3.0-compatible and features a fully compliant LXI interface with the option of using a Wi-Fi dongle (sold separately). Therefore, remote control via USB or LXI Ethernet is possible—chassis can be controlled through standard interfaces found on most personal computers and tablets that support HTML5. The vendor states possible system configurations include switching matrices up to 3,312 crosspoints or up to 108 channels of programmable resistor/sensor emulation, enabling the system to add the necessary switching and frees up the PXI/PXIe slots for instrumentation. Pickering Interfaces

100 kHz to 18 GHz Compact USB VNA

This vendor recently released its new S5180 Compact USB VNA with frequency range from 100 kHz to 18 GHz, which is as portable as the other VNAs in its Compact product series, but with an expanded frequency range. The S5180 provides a wide dynamic range up to 135 dB, typ. (10 Hz IFBW) and a fast sweep speed. The vendor’s metrology-grade USB VNAs include an RF measurement module and a software application which runs on a Windows PC, laptop, or tablet, connecting to the measurement hardware via USB interface. The user can take advantage of the latest OS, processing power, larger display, and reliable performance of an external PC, as well as lower total cost of ownership and simplified maintenance of the analyzer. The result is a faster, more effective test process that fits into the modern workspace in lab, production, field, and secure testing environments. Copper Mountain Technologies

USB-based power sensors

This vendor’s new CPS2000 series of True Average Connected Power Sensors offer USB, IAN, and PoEconnectivity, and were designed to simplify integration and shorten test times in manufacturing and ATE environments. CPS2000 sensors address the challenges faced by manufacturing test engineers by providing lower cost of test, higher measurement throughput and greater up time, all packaged into a future-proof instrument with a variety of connectivity capabilities. The CPS2000 shortens test times with throughput rates of>100 measurements per second. The wide frequency, 50 MHz to 8 GHz, and measurement, -40 dBm to +20 dBm, ranges provide high performance at a great price and ensures the ability to test a wide variety of cutting-edge devices. The intuitive user interface and powerful programming tools provide easy access to all measurements as well as special features, such as multi-channel measurements, channel-to-channel math and strip chart recording. These product specifications and features position the CPS2000 as an ideal tool for high-volume manufacturing test.Boonton