USB Data Acquisition

Description: The Universal Serial Bus (USB) has become a widely adopted technology for connecting computer peripherals. It is present on nearly every new computer and typically offers a seamless connection method for a variety of consumer electronics devices such as digital cameras, scanners, and printers. This ease of connectivity, along with the high data transfer rate of USB, makes it particularly useful for data acquisition and control units. This document discusses the application of USB data acquisition units in an electromechanical engineering technology laboratory environment, examining the features, advantages, and disadvantages of the hardware. The LabVIEW software tools (virtual instruments) developed for interfacing with the USB devices are also presented, along with examples of sensing and control systems experiments and projects. USB technology has transitioned from consumer electronics to laboratory equipment, providing a convenient connection and relatively high data rates that benefit portable data acquisition units. Numerous affordable options are available from manufacturers such as LabJack, Measurement Computing Corporation, and National Instruments. The LabJack U12, utilized by engineering technology students at Penn State Berks, exemplifies the features typical of current USB devices. These features include multi-channel analog voltage input and output, digital I/O, event counter input, and a +5V power supply output sourced from the host computer via the USB cable. Such capabilities render these devices ideal for various engineering technology educational applications. Integrating USB data acquisition hardware with LabVIEW software results in a powerful and portable measurement and control system for laboratory and classroom experiments, as well as hardware-in-the-loop (HIL) design projects. Unlike traditional ISA or PCI bus plug-in cards, USB devices can be easily transferred between different computers. When used with a laptop, the system becomes fully mobile, expanding application possibilities. The affordability of these USB data acquisition devices also allows students to purchase them for home experimentation, significantly enhancing their learning experience. The LabJack unit interfaces effectively with various transducers, including temperature, position, velocity, and acceleration/tilt sensors. However, some sensors may require analog signal conditioning before connecting to the LabJack to buffer or scale the signals. Further processing of signals from these devices, along with the graphical user interface, is managed using LabVIEW software, where significant creativity in system design occurs. A set of LabVIEW virtual instruments (VI) has been created for the LabJack U12 by the authors for engineering technology students. This document elaborates on the hardware and software features and capabilities of a USB data acquisition system intended for use in engineering technology education, with included examples of experiments and applications. The LabJack U12 is a lightweight USB peripheral housed in a durable plastic case, connected to the controlling computer via a standard detachable USB cable. Power is supplied through the USB cable, eliminating the need for an external power supply. External data acquisition and control signal connections are made through screw terminals on the unit's top (with a screwdriver included) and a 25-pin D connector on the side. The LabJack U12 features eight 12-bit analog voltage inputs.

The USB data acquisition system described offers a versatile platform for engineering education, combining the user-friendly nature of USB connectivity with the advanced capabilities of LabVIEW software. This integration facilitates a wide range of experiments and projects, allowing students to engage in practical applications of theoretical concepts. The multi-channel input and output capabilities of the LabJack U12 enable simultaneous data collection and control, essential for complex experiments involving multiple sensors and actuators. Moreover, the portability of the system enhances its usability in various educational settings, from traditional classrooms to remote laboratories.

In addition to the basic functionalities, the system supports various transducer types, enabling students to explore diverse measurement and control scenarios. The ability to condition analog signals before inputting them into the LabJack ensures accurate data acquisition, vital for experiments requiring precise measurements. The graphical user interface capabilities of LabVIEW further enrich the learning experience, allowing students to visualize data in real-time and develop customized control systems.

The LabJack U12's design, featuring screw terminals and a D connector, simplifies the process of connecting various sensors and actuators, making it accessible for students with varying levels of technical expertise. This ease of use, combined with the affordability of USB data acquisition devices, promotes hands-on learning and experimentation, essential components of engineering education. Overall, the USB data acquisition system represents a significant advancement in educational technology, providing students with the tools needed to thrive in a rapidly evolving field.The Universal Serial Bus (USB) has become a ubiquitous technology for computer peripherals. It is available on virtually every new computer and in most cases provides a seamless connection method for a variety of consumer electronics devices such as digital cameras, scanners and printers. This ease of connection together with the inherent high dat a rate of USB also makes this technology very useful for data acquisition and control units. This paper presents the use of USB data acquisition units in an electromechanical engineering technology laboratory environment. Features, advantages and disadvantages of the hardware are discussed. The LabVIEW software tools (virtual instruments) developed to interface with the USB device are presented.

Examples of sensing and control systems experiments and projects are also given. The Universal Serial Bus (USB) has quickly found its way from consumer electronics (cameras, scanners, printers, cell phones, etc. ) to laboratory equipment. The ease of connection and relatively high data rate of USB makes this technology very useful for portable data acquisition units.

Several units are now available at very reasonable cost from companies such as LabJack, Measurement Computing Corporation and National Instruments. The unit currently used by engineering technology students at Penn State Berks is the LabJack U12. The LabJack U12 features are typical of the USB devices currently available. These features include multi-channel analog voltage input and output, digital I/O, event counter input and +5V power supply output (supplied from the host computer via the USB cable).

This set of features makes these devices ideal for many types of engineering technology education applications. Combining USB data acquisition hardware with the capabilities of LabVIEW software makes a very powerful and portable measurement and control system for laboratory/classroom experiments and hardware-in-the-loop (HIL) design projects.

1 Unlike traditional ISA or PCI bus plug-in cards, the USB devices can be easily moved to different computers. When paired with a laptop computer, the system becomes completely mobile which provides many more application possibilities.

The low cost of these USB data acquisition devices also makes them a viable option for students to purchase on their own for home experimentation. This capability greatly enhances the students` learning process. 2, 3 The LabJack unit provides a very good interface for many types of transducers including temperature, position, velocity and acceleration/tilt sensors.

Some sensors, however, require analog signal conditioning prior to connection to the LabJack to buffer or scale the signals. Further processing of signals acquired from these devices, as well as the graphical user interface is performed with LabVIEW software.

This is where the real creativity of system design takes place. Using LabVIEW software, the range of applications that can be constructed around the USB devices is enormous. A set of LabVIEW virtual instruments (VI) has been developed for the LabJack U12 by the authors for use by engineering technology students.

This paper presents and discusses the hardware and software features and capabilities of a USB data acquisition system for use in the engineering technology education environment. Examples of experiments and applications are also included. The LabJack U12 device is a lightweight USB peripheral device housed in a durable plastic case as shown in Figure 1.

The unit is connected to the controlling computer via a standard detachable USB cable. Power for the U12 is obtained through the USB cable thus no external power supply is needed. Some of the external data acquisition and control signal connections are made through the screw terminals on top of the unit (screwdriver included!) while others are via a 25-pin D connector on the side. 4 The LabJack U12 has eight, 12-bit analog vol