Control Engineering

Products Reflect Data Acquisition Trends

Contec Microelectronics' data acquisition products for USB and Ethernet fit well with industry expectations.

In the January 2004 issue of Control Engineering, the Product Focus feature article concentrates on data acquisition systems and their ability to be used in wide-ranging applications. To compile the data on which the article is based, Control Engineering conducted a survey of its subscribers responsible for evaluating, specifying, recommending, installing, and/or purchasing data acquisition hardware and software.

The survey yielded a range of interesting data points indicating clear trends in the purchase and use of data acquisition (DAQ) systems. Contec Microelectronics USA, a unit of Japan's largest DAQ manufacturer, has chosen to address some of these points as they relate to the company's USB and FIT DAQ modules.

20 years of advancement

Over the last two decades, DAQ technologies have made great strides, especially with regard to increasing measurement resolution and adaptation to a wide variety of platforms and networks. These advances have made DAQ systems a principal player in SCADA use as well as testing and diagnostics for statistical process control and work-in-progress testing in many industries, including utilities, continuous process, discrete, and batching applications.

To adapt to these needs of such applications in various industries, Contec's USB modules were developed to utilize the hot-swappable plug-and-play capability of the interface. USB devices also can be connected via a hub, allowing for up to 127 modules to interface with a single computer. However, the number of units is not restricted to the number of expansion bus slots. These USB modules support two different power sources—from the bus (via the interconnection cable) or from an external source.

FIT data acquisition modules were developed as an integral component of Contec's F&eIT (factory and Ethernet information technology) product line. These modules can be used with the company's FIT I/O controller unit or as add-ons to the USB modules.

The USB and FIT data acquisition products were developed to provide information and machine control outside of a PC. Both are din-rail-mountable and can be connected with other modules via a proprietary stacking bus, thereby eliminating the need for a backplane. USB-controlled units are generally used in environments where the controlling PC is nearby, as is typically the case in laboratories or test environments. The FIT-controlled units are Ethernet-based and suitable for use in settings where information needs to be sent over long distances. These units can also be interconnected with the F&eIT Web system for off-site control.

Contec's USB and FIT modules come with general-purpose drivers (supporting Visual C++) and utility software (for node setting and firmware updating). The FIT units also have available DDE drivers (allowing for seamless communication with third-party SCADA/HMI software).

Both the USB and FIT modules have been on the market for more than two years and are gaining a foothold in the data acquisition market. Their ease of use and discreet size allow for a relatively painless transition to PC-based and Web-accessible control systems.

Elements of Choice

The Control Engineering DAQ Product Focus survey also found that engineering departments now count on vendors to provide products with increased emphasis on certain selection factors. The top five of these factors for DAQ hardware are: ease of use, availability, technical support, price, and wide range of I/O device options.

Contec addresses each of the factors in the following ways:

• Ease of use—features include plug-and-play flexibility, "push-in" type wire connectors, din-rail mounting, and the ability to draw power from the plant floor with ac-dc converters (available in same din-rail-mountable form factor)
• Availability—if modules are not in stock in U.S., they can be easily shipped from manufacturing facilities in Japan
• Technical Support—all units go through exhaustive quality assurance testing in Japan before shipping. On-site technical staff in U.S. is available to address customer questions and concerns.
• Price—both USB and FIT modules are priced competitively in U.S. market.
• Range of I/O options—both versions are available in a variety of analog and digital I/O combinations and with RS-232, GP-IB, and counter/timers. The FIT product line also includes RS-232C-to-Ethernet and RS-422-to-Ethernet media converters and PLC link units.

In three areas of the Product Focus survey in particular, respondents were generally in agreement. Most use 16-bit resolution DAQ products (few use 32-bit); the most common number of variables sampled by DAQ on a per-minute basis tended to be less than 500 (50% of respondents fell into this category, with just 14.6 percent sampling 500-1000 variables and 13.5% sampling 1,001-2000 variables); and 48% do not use wireless technology in DAQ, with 80% of the remainder using it only sparingly.

As a result, Contec has tailored it USB and FIT DAQ modules to meet market demands. Both USB and FIT modules are only available in the 12- to 16-bit resolution range. As with many of the respondents to the Control Engineering survey, most of Contec's large end-users have requested this resolution. The company does, however, expect to upgrade module resolution when requirements increase in a larger sector of the manufacturing community.

With regard to sampling rate, both USB and FIT modules are best suited for sampling fewer than 500 variables per minute. However, the ability of USB to expand the number of accessible units increases the variables (in some instances) to the 500-1,000 variables per minute category.

Although both modules are set up to run on native cabling (USB runs on USB cables and FIT runs on Ethernet), they are designed to interface with Contec's Flexlan wireless systems.

During the advance of DAQ technologies over the past 20 years that brought increased measurement resolution and adaptability to a variety of platforms and networks, something else happened to DAQ. It became an integral part of modern manufacturing operations and a mainstay of automated test data collection. Meanwhile, Contec Microelectronics has been building a long history of providing data acquisition products to the manufacturing sector. Although its market share in the U.S. is still growing, Contec is the largest supplier of data acquisition in Japan. The company's history and experience in working with engineers drives its efforts to make all new versions of its data acquisition products backwards-compatible with older versions. Contec understands that the rip-and-replace mentality is not commonly applied to systems affecting critical plant floor applications. The company also understands the need for flexibility, and has structured its engineering department to work with customers on needed modifications for unique projects.

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