Bert Moore

Introduction

It seems almost a step backwards. After years of trying to get the pencils and clipboards out of the manufacturing environment, many companies are now looking at putting pens and clipboards back into it.

Of course, it should be noted that these aren't your typical pens and clipboards...these are pen-based terminals: hand-held computers that use pen-like styluses as an input device.

One of the reasons pen-based systems are so immediately interesting is that they do resemble the clipboards of yore...and some of them allow all the "human" activities that haven't been accommodated by even the most advanced bar code terminals.

Technology

At the heart of any pen-based system is a sophisticated hand-held computer capable of running high level software, typically DOS and Windows® although increasingly Palm-OS applications are showing up. With this kind of processing power, complex data collection programs and routines can easily be developed using standard programming tools.

It's what's on the face of these systems, however, that makes pen-based systems unique: a touch screen.

Touch screens have been around for a number of years and are available using a number of different technical configurations (e.g., inductive, capacitive). In simple terms, the surface is electrically sensitive and touching the screen changes or creates electrical signals sent to the processor. These signals are then translated into X and Y coordinates.

Depending on the system, the range of X and Y coordinates may be relatively coarse (0.10 inch increments or larger) or virtually infinite (individual pixels).

Touching the screen is equivalent to selecting an option through mouse clicks or "highlight and select."

While some of the touch screen technologies register touches even when the operator is wearing heavy work gloves, the stylus permits more precise "touches" and is required for some advanced options.

Applications and Benefits

Pen-based computing opens a new area for data collection on the shop floor and in other mobile applications.

Pen systems are designed primarily to provide a simple input mechanism with pre-defined options.

One typical application would be the replacement of a bar code menu for quality control. Instead of the operator scanning a bar code that represents "accept" or "reject," those choices would be presented on the display. Other selections might then be provided, such as the reason for rejection, rework instructions, and so forth.

Another typical application is filling in of "preprinted" forms, although in this case, the form is electronic. This is particularly useful if "conditional" data is required.

As an example, plant inspection routines could benefit from pen-based systems. An operator would go through the inspection routine according to the form(s) presented on the terminal. Each field might represent a specific piece of equipment or location – and might even be tied into a bar code on the equipment. An operator might scan a bar code on a fire extinguisher cabinet for positive identification. He might then note that the extinguisher is not only "present" but also shows "fully charged." Or perhaps it might be noted that its "inspection date is within 30 days."

Pen-based systems offer tremendous flexibility because they are not dependent on pre-encoded marks (such as bar codes).

Changing the data collection routine is as simple as changing the fields available in the electronic form.

Another advantage to pen-based systems is that, since they run standard software packages, offering all of the options in another language, say Spanish, is relatively easy. All that's required is to provide the prompts from the main program in that language.

Variations

Pen-based systems have other capabilities as well. Many people are already familiar with the ability to capture signatures electronically — this is accomplished by using a high resolution touch screen which registers the "shape" of the signature.

Some pen-based systems are configured as hand-held terminals. The major difference, of course, is that instead of a keyboard and small display, the entire face of the unit is a display.

Keyboards, if required, can be displayed for "touch" entry of variable data.

Other pen-based systems more closely resemble clipboards, offering essentially a full computer screen. This configuration is particularly useful for "electronic forms" and interface to existing programs. In the latter case, no screen redesign would be required, since the available display matches that of a computer terminal.

Some of the more exciting options available include the ability to capture "sketches" and notes electronically.

One of the frustrations of even the most sophisticated bar code data entry terminals is the inability to capture truly random information – sometimes called "ideas." Typical hand-held terminals allow the key entry of variable data but generally can not allow freeform entry. That's where pen-based systems running appropriate software offer significant advantages.

Being able to sketch an idea without having to search around for a scrap of paper can be a tremendous benefit.

At the moment, these inputs are primarily stored as bit-mapped graphics but handwriting (or printing) recognition is slowly beginning to come into its own.

Handwriting recognition is best done with limited data, such as quantities. The system typically interprets the handwritten characters and displays the input for verification. If the interpretation is not correct, it can be changed.

The RFDC Connection

Some pen-based systems can be augmented with RFDC interfaces to provide real-time access to the host. This interface offers the same benefits that people expect in RF-linked bar code terminals.

The superior graphic capabilities of some pen-based systems, however, means that a drawings could be retrieved and displayed on demand or that files can be retrieved for review.

Obviously, the more advanced applications require more processing power and software to be effective.

Limitations

Obviously, pen-based systems won't replace bar code data entry in the near term, simply because we don't want people reading strings of numbers and letters and then writing them down.

Pen-based system manufacturers recognize this and many of them provide bar code scanner input ports.

At the moment, there are a few limitations on what's practical to implement on a pen-based system. For example, trying to run a full CAD design package on a hand-held terminal so that engineering drawings can be called up is beyond the reach of most implementations.

Nonetheless, simplified drawings can be displayed...given appropriate software capabilities and sufficient transmission lag time.

Another limitation is weight. Typical pen-based systems are heavier than hand-held bar code data collection terminals (although all these are getting lighter). These systems aren't designed to be carried around for long periods of time doing extensive data collection routines – although clipboard style models can easily be used if they're placed on a flat surface.

Conclusion

Pen-based systems open up data collection to a wide range of "conditional" situations, where simple identification isn't adequate and where having a notebook full of bar code menus isn't practical.

They can also provide an almost intuitive replacement for the traditional clipboard by providing a modern interface to data processing systems with old fashioned friendliness.

Pen-based terminals aren't for everyone. But for those applications where bar code data collection terminals alone aren't sufficient, they provide the perfect "touch."