Software and Hardware from a Single Source?

Is it essential, desirable or detrimental to purchase data acquisition software and hardware from the same source? The answer to this question isn’t simple.

Many factors play important roles in a decision of this nature. Along with the availability of in-house expertise on configuring data acquisition systems (DAS), there are end-product requirements to consider plus expected expansion and the multiusage potential of these systems.

PC-based DAS hardware, software and system suppliers provide one or several of these services or products:

· Hardware–These include PC plug-in-based or port-connected signal conditioning, ADC, DAC or DSP boards or modules, which are usually accompanied by software drivers.

· DAS Program Development Software–An environment that enables an engineer to configure an application program to let the selected hardware and ancillary analysis software carry out specific data acquisition tasks.

· Systems–A ready-to-install or turnkey solution based on a definition of the DAS requirements provided by the customer.

Most frequently, DAS design and integration are performed in-house. In this case, selecting the right hardware, drivers and application software products and vendors can be critical. Since some vendors furnish all three products, should one of these software-plus-hardware providers be your preferred source?

For very high-speed or exotic applications, a single vendor may be mandatory. “For subsystems that acquire multichannel data simultaneously at sustained rates in the neighborhood of 16 MHz for many seconds, it is essential to buy hardware and software from the same vendor,” said Dick Boring, Director of Engineering at Analog Digital Technology (ADTEK). “In mission-critical applications, accountability is what matters. Assuring proper operation and customer support requires complete understanding of the hardware/software architecture, interrelationships and functionality.”

Advantages and Disadvantages

A major benefit of buying everything from one vendor is the higher degree of certainty that hardware and software will work together. “The engineer who developed the software is generally in the same building with the engineer who developed the hardware,” said Rick Daniel, Vice President Product Management at Intelligent Instrumentation. “The likelihood that they communicated during the development of the product is much higher than it would be if they worked for different companies.”

If you purchase from different companies, it is probable that, even if the two vendors are genuinely trying to solve a compatibility problem, they are not necessarily well-acquainted with each other’s products. “In this scenario, users may become the principal problem-solver, getting whatever help they can from separate phone calls to the two vendors–a very undesirable situation,” pointed out Robert Galter, President of Alligator Technologies.

“Obviously, the greatest advantage of obtaining hardware and software from the same vendor is compatibility, which minimizes time spent configuring the system,” said Mike Winters, Vice President Sales and Marketing at Corelis. “On the downside, the hardware and software can be nonstandard and nontransportable from one system to another.”

Another potential problem pertains to upgradability. “If the software obtained with the hardware is a proprietary package produced by the hardware manufacturer, it may be difficult to adapt the application to changing needs,” said Ron Gilbert, Marketing Communications Manager at IOtech. “Many proprietary software packages support only their own manufacturer’s hardware.

“While this might not seem like a problem when a system is first installed, future application requirements are difficult to foretell. At some point, the user of such a proprietary software system may find his application seriously handicapped by its limited hardware support.

“However, obtaining hardware and software from the same vendor is a good idea if the software is a widely supported, open applications-development environment, such as Visual Basic. This allows you to keep abreast of technological trends and to add complementary software and hardware to adapt to the changing needs,” Mr. Gilbert concluded.

Some points to consider when purchasing hardware from highly focused software specialists were noted by Jeff Brower, President of Signalogic. “If a vendor who specializes in software adds his own hardware to offer a complete system, the hardware can be limited,” commented Mr. Brower. “We have found that software vendors who support multiple types of hardware often provide better overall solutions.

“When a vendor’s software package supports only his hardware, the underlying design of the software could be limited because the programmers make decisions based on only one hardware type,” Mr. Brower continued. “This can result in slow or nonexistent software upgrades or poor response to customer-reported bugs because:

· The basic software design was tied too closely to the hardware. · The software was not modular or high-level enough to be upgraded easily.”

Another word of caution came from Stuart Streiff, President of PC Instruments. “When you buy hardware and software from the same vendor, the software may have been developed by a group with a limited goal and inward focus. That is, the software supports the company’s hardware, but may fall short when controlling another vendor’s hardware.”

Becoming locked into one vendor may also make changes and upgrades more difficult. “Future hardware may not work with existing hardware,” warned Mike Owens, Product Marketing Manager at Loral. “For instance, trying to time-correlate data collected by different boards may be impossible because the software control may be asynchronous.”

But don’t be overwhelmed by the potential negatives of buying hardware and software from the same vendor. “If you should have a problem, you know whom to call to get problems resolved,” emphasized Mr. Daniel. “There isn’t any finger-pointing between the hardware and software companies. It is clear who has the ball.”

Selecting Separate Sources

Many integrators, especially those with substantial DAS design experience, advocate buying application program development software from one source and hardware from another. And once this purchasing split is decided, another issue must be addressed: which of the two sources will supply the software drivers for the hardware.

The separateness of these sources may be a matter of degree. Many software providers also integrate and furnish third-party hardware and vice versa. “It can be very advantageous to buy from vendors who support third-party products, as long as interoperability has been proven,” noted Robert Gaurie, Design Engineer at Sheldon Instruments.

“Almost every data acquisition hardware manufacturer sells third-party software along with their products,” concurred Don Di Rocco, President of American Data Acquisition Corp. (ADAC). “For example, we resell about 10 packages for data acquisition, test and control applications.

“The most important issue relative to painless hardware/software integration is the interface between the two–the drivers,” Mr. Di Rocco continued. “Since most of the drivers that interface our boards with third-party packages were written at ADAC, we provide the customer with direct support for the hardware/software interface. Determining who wrote the hardware driver and whether the driver supplier will provide support is crucial to a successful installation.”

Hardware and software suppliers and integrators have many reasons why it is advantageous to deal with separate suppliers. Here is a sampling of these reasons and suggestions for avoiding potential pitfalls:

Advantages and Advice

Some companies have developed expertise in hardware and others in software. Although it is not uncommon to find extensive and well-integrated hardware and software expertise in one organization, there are more suppliers to choose from when purchasing hardware and software separately. In some cases, only a few highly focused companies may have the very special or unique product that perfectly fits your requirements.

The advantages provided by PC-based DAS implementations are founded on the vast availability of hardware and software products for the DOS and Windows platforms as well as their standards which encourage openness. “Users can take advantage of this openness and select hardware and software to fit their needs, and not necessarily limit themselves to one manufacturer,” emphasized Mr. Di Rocco.

If you choose hardware and software from different companies, you gain greater flexibility. “Generally, it is best to choose the software first and then look for the lowest-cost hardware that will work with it and still do the job,” said Mr. Daniel. “If the software vendor has hardware as well, it still might be a good idea to consider it.”

Many common data acquisition/PC-based requirements can be readily implemented with off-the-shelf boards. Most of these are intended for multipurpose applications. “Their reusability is greatly enhanced by a comprehensive software package that simplifies configuration changes,” remarked Bob Leonard, Product Marketing Manager at DATEL.

“For reutilization, the board vendor must provide a very high-quality documentation package and board-level software support products. These may include sample programs, Windows-based software and drivers for programs such as LabView, all with source code. Support also must be available,” Mr. Leonard emphasized.

Software Considerations

Here is a compilation of comments from leading suppliers regarding some of the important software aspects:

· When looking at software, consider both your current and future needs. Avoid proprietary software that will limit your choices for hardware and software add-ons to meet future needs–Keithley MetraByte.

· It is important to consider whether you can extend the functionality of the software. It is very frustrating to find that a software package gives you 95% of the functionality you need but does not give you a way to get that last 5%–Intelligent Instrumentation.

· In cases where a software package works with multiple hardware platforms, the software vendor will often support only the subset of functions that is common to all or most of the boards that are supported. If you chose a board because it has a unique feature, it will be very frustrating to learn that the software you have bought does not support it–Intelligent Instrumentation.

· Software drivers that support a variety of software environments or boards typically support the least-common-denominator features, limiting you from taking full advantage of the hardware functionality–National Instruments.

· Obviously, one vendor cannot supply the complete range of products you will need for every application. Therefore, look for application software that has an open architecture so it is possible to integrate specialized hardware into the system. This is typically accomplished through DLLs or DDE under Windows–National Instruments.

· The best quality products–whether software or hardware–come from highly specialized companies. This leads to concerns about compatibility. The latest trend in Windows, however, provides some hope. With Microsoft Windows maturing, it is becoming the umbrella for product compatibility. At least the means are there for vendors to use–Signametrics.

This case in point is provided by Signametrics: In the process of creating a driver for two leading software environments, we, at Signametrics, encountered an interesting phenomena. Creating drivers from a DLL for one vendor software environment went smoothly, while doing the same for a larger, reputable vendor took several days. Other hardware vendors have confirmed this.

When buying a software environment around which to build a data acquisition system, you may find–often too late–that the options for compatible hardware shrink to a fraction of what is available on the market, and usually to the lower-performance products. The acid test of whether or not a software environment product is friendly is to benchmark it against Microsoft’s Visual Basic (VB).

Create a simple VB interface to a hardware vendor’s DLL provided with the hardware. Using the same DLL, try creating a driver for your favorite software environment, such as Geotest’s ATEasy or National Instrument’s LabView. If the effort is not much different, it’s a go.

These companies provided information for this feature:

American Data Acquisition Corp. (800) 648-6589

Alligator Technologies (714) 850-9984

Analog Digital Technology (ADTEK) (818) 597-1578

Corelis, Inc. (310) 926-6727

DATEL, Inc. (508) 339-3000

Intelligent Instrumentation (800) 685-9911

IOtech, Inc. (216) 439-4091

Keithley MetraByte (508) 880-3000

Loral Test & Information Systems (800) 351-8483

National Instruments (512) 794-0100

PC Instruments Inc. (216) 487-0220

Signametrics Co. (206) 524-4074

Copyright 1995 Nelson Publishing Inc.

May 1995

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