Mobile Computers Guide

PDA’s and Handheld Computers

Originally, portable barcode scanners were known as Portable Data Terminals (PDT’s). At the time of their introduction, these devices were leading edge technology in mobile data collection. Developed before the first viable laptop, PDT’s were the fathers of the modern PDA. Developed to work in an environment where portability and durability were absolute requirements, PDT’s pushed the limits of small screen displays, low voltage memory, and battery technology. PDT’s used proprietary programming tools to develop applications that performed specific and narrow data collection tasks within the enterprise.

With the introduction and popularity of PalmOS PDA’s in the late 1990’s, mobile data collection in a compact platform became widely available. Mobile data collection was able to run a range of applications which were developed by PDA enthusiasts using common programming tools. Where PDT’s could only run custom programs for specific tasks developed at high costs, the PDA user could not only run the suite of programs bundled with the PalmOS like Contacts, Calendar and Notes but could augment the capability of the PDA by including other widely available programs with specific functions like worksheet, word processing and e-book readers. The market for mobile computing was expanding and Microsoft soon entered the arena with the introduction of the PocketPC operating system.

PDT’s developed and evolved as well, mimicking PDA devices and adopting their operating systems. Because of the “business” focus of the PDT market, all manufacturers eventually adopted the PocketPC / Windows Mobile operating system for their devices. The term “Portable Data Collector” became obsolete as a descriptive term as the devices were now capable of so many more tasks. With the release of cell network and the subsequent ability of Windows Mobile to support cell network communication, this gave PDT manufacturers the ability to offer “real-time” data collection and common data source updates in any environment. From the warehouse to the mobile sales force, this new generation of PDT’s could offer solutions to any data collection need using rugged devices with integrated barcode scanners.

Today, the most common term used to describe these devices is Mobile Computer. Mobile Computers are generally available with either Windows CE, Windows Mobile and Android as an OS and they continue to be one of the most effective barcode solutions when it is not practical to bring the items scanned to the computers location point. Their use generally replaces an existing paper-based system thus avoiding all the manual re-entry of the paperwork. The Mobile Computer provides a convenient and efficient way of collecting data whilst away from the computer. When the data is collected and processed the data can be uploaded to the host system. Data can be collected in batch mode, utilise RF (Radio Frequency) or use the 3/4G Cell Networks for applications demanding real time access to the host computer virtually anywhere.

When choosing a Mobile Computer you should consider the following characteristics:

Keyboard – The keyboard is one of the most prominent features on a PDA, hence several layouts are often available on models. The keyboard selected should suit the application being used on the PDA. The keys should be large enough to be used accurately by any operator. For example, if the Mobile Computer is to be used by an operator wearing gloves, the keyboard should not be so small that incorrect keys may be pressed in error. Many PDA’s offers numeric only keyboards, ‘shifted’ alphanumeric and numeric keyboard and full alphanumeric and numeric keyboards on single keys. In some applications, it may be necessary to consider the amount of keyboard input and select the best fit.

LCD display – The display should be large enough to be easily seen and give meaningful prompts to the operator to display adequate data for validation purposes. Displays come in various sizes and most displays have a backlight function so that the terminal may be used in poor light conditions. With the majority of new devices using Microsoft as an operating System, the larger screen has become more important as the small icons on the desktop are difficult to see on these small screens.

Touch screen display – The display may also act as an input device. This pen-based interface is useful for form filling or applications that require signature capture. The operator does not rely on traditional push button controls but uses a ‘pen’ stylus to hand write characters on the screen, touch select characters from a virtual keyboard or capture the operator’s signature. Devices with touchscreen displays are available in many different formats including varying display sizes and methods of input. These units may have a scanner built in, character recognition software and touch entry, ideal if the operator does not have keyboard skills.

Barcode scanner option – When considering the purchase of a mobile computer the operation and handling should be a key decision in the selection process. The size and weight are also particularly important. Many devices are now smaller and lighter and have pistol grips specific to warehouse applications. 1D and 2D scanner options are now integral to most units. The difference is single or dual handed operation i.e. does the user need both hands to operate the barcode scanning equipment. Another consideration is the distance the operator be scanning the barcode. You do not want to order a long range scanner if most of your scanning will be done at close range – the long range scanners can be difficult to use up close to a code.

The operating system – The OS determines the method of programming. The latest devices generally use a Microsoft operating system or an Android OS, although there still are proprietary Operating Systems. Proprietary operating systems usually require a propriety programming language. The advantages of propriety operating systems are that they are designed specifically for data collection applications, require little processing power and are efficient when custom data collection applications are needed. The Microsoft Operating Systems used on mobile computers is either Windows Mobile or Windows CE and these allow a programmer to develop an application in a language that they are familiar. While once the preferred OS for these devices – Android is fast becoming the new standard.

Both Windows and Android provide the general look and feel of the PC applications and are immediately identifiable and easy to use for anybody with Windows or Android experience.

It is worth noting that care is still required when considering what you are wanting to tun on these devices – with the advent of multiple versions of both Windows OS and Android OS, software applications do not always pass seamlessly from one version to the next – so checking if your App is compatible with the version of OS is a must!

Processor – The architecture of Mobile Computers are designed to suit the barcode data collection environment. The batteries need to be higher powered, as these need to last a full shift, the processor need to fairly small and air cooled as fan cooled units would make the unit bigger and hence less portable. In general, only relatively small memory is needed as the applications are dedicated and large amounts of memory would affect the price etc.

Batch data communications – once the data has been collected, how is it transferred is another consideration. This could be a batch process through a direct connect method using USB or an RS232 serial link. Alternatively, for remote batch communications, data could be transferred over the telephone lines using a modem or the more modern Wi-Fi transmission. The risk of losing data with a batch system is minimalised by frequent data downloads. With most batch systems users generally transfer data once or twice a shift for two reasons (1) to avoid the inefficiency of frequent trips to the office to upload and download the data and (2) transfer the collected data to the host in the unlikely event of a hardware failure.

Radio frequency data communication (Wi-Fi) – Wi-Fi is used to transfer data from a Mobile Computer to a host computer in real time. Real time means the data is captured and downloaded via radio in one instantaneous and seamless process. The devices communicate with the host computer via a base station connected directly or more typically the base station is connected to the Local Area Network.

Cellular Network data communication (3G/4G ETC) – is used to transfer data collected from the field from a Mobile Computer and sent via the Mobile phone network in the same way as mobile phones are used.

Memory – The unit must be able to collect enough data to cover at least a single shift. For most applications 256MB of memory is sufficient to store a complete shift of data collection. 256MB is equivalent to over 20,000 EAN 13 digit bar codes. That’s a lot of scanning! Nowadays many mobile computers have a memory capacity of 1 Gb or more. A memory capacity of this stature will only be involved in batch data collection applications where it is deemed necessary to download a large data lookup file to the unit.

Operating environment – Where will the unit be used? Indoors, outdoors, hazardous environments or in cold stores? Scanners are available that will operate in temperature ranges from -25oC to 50oC.

Operating environment – Where will the unit be used? Indoors, outdoors, hazardous environments or in cold stores? Scanners are available that will operate in temperature ranges from -25oC to 50oC.

IP Code

The IP Code (or International Protection Rating) consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures. The standard aims to provide users more detailed information than vague marketing terms such as waterproof.
The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. Where there is no protection rating with regard to one of the criteria, the digit is replaced with the letter X.
For example, an electrical socket rated IP22 is protected against insertion of fingers and will not be damaged or become unsafe during a specified test in which it is exposed to vertically or nearly vertically dripping water. IP22 or IP2X are typical minimum requirements for the design of electrical accessories for indoor use.

First, digit in an IP Code

The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects.

The second digit in an IP Code is the level of Protection of the equipment inside the enclosure against harmful ingress of water.