01. Which Technology - Printing
GSM Printer and Label Systems Ltd. have considerable experience in installing the most appropriate type of printer for your application whether it is line matrix, laser (Mono or Colour) or thermal transfer printers. The best labelling software and the right printer will only provide the correct solution when we complete the picture by providing you with the appropriate labels.

02. It's what the scanner sees
Laser printers are great for the office, dot matrix is a must for multi-part forms. But thermal transfer is the answer for on-demand barcode labels. The thermal transfer bars look best, not only to the human eye, but to the scanner also. And that's what counts.

03. Consumables
With lasers your toner, drum and supply costs can skyrocket when you print barcodes instead of the typical text. While text requires only about 5% black, barcodes can exceed 30%. Your toner costs alone could be six times what you expect. But thermal transfer costs the same whether you print 5% or 95% black. Thermal transfer printers excel shift after shift in harsh environments with excellent throughput rivalling laser systems that cost twice as much to run.

04. Quality specialty labels, performance-matched ribbons
While only a few label materials work well with other technologies, hundreds of tested media, adhesive and ribbon combinations are available for thermal transfer systems. No matter what your need there's a solution that's just right for you.

Thermal Transfer printers: High volume, excellent quality, bar-coded labels, specialty materials such as synthetics. How it works: The print head consists of microscopic "dots", (300 of them to the inch in a 300DPI printer). The dots are heated by an electrical current causing the ink on the surface of the ribbon to melt and "transfer" to the label beneath. The dots are turned on and off under computer control to form a print image on the paper as it passes below the print head. In the case of Direct Thermal paper the heat in the dots causes a chemical change in the paper, which causes it to change colour. No ribbon is required for Direct Thermal.

Laser printers: Competitive, low-medium volumes, affordability and relatively simple integration. How it works: The drum is given a positive charge. As the drum revolves, the printer shines a laser beam across the surface to discharge certain points where the image is to be printed. The printer then coats the drum with positively charged toner. The toner clings to the negatively charged areas of the drum. With the powder pattern affixed, the drum rolls over a negatively charged sheet of paper. This charge is stronger than the negative charge on the drum so the paper pulls the toner powder away and picks up the image pattern. The paper then passes through a pair of heated rollers, which melts the loose toner powder, fusing it with the fibres in the paper.

Dot Matrix printers: Multi-part forms for invoicing, delivery notes, low consumable costs, high text only output. How it works: A head unit moves across the paper with an ink-impregnated ribbon between it and the paper. A series of retractable pins are fired in succession at the ribbon causing the ink to be deposited on the paper beneath. The pins are fired under computer control to form a print image on the paper. The physical restriction of the size of the pins together with "ink splatter" prevents high quality print for barcodes etc.

05. Bar Code verification
Bar code data capture systems can be rendered completely useless if care is not taken to ensure adequate print quality. Bar code scanners require labels of reasonable quality to operate at maximum performance. Often the scanner is blamed, when in fact the problem lies with poorly printed labels. If possible, it is prudent to "test read" newly printed bar codes with the scanner which will be used in the actual application. If this is not possible then an investment in a bar code verifier is recommended.

Bar code verifiers undertake a range of checks on print quality. They produce a report, which details the key parameters affecting the readability of the sample. Portable verifiers are available for applications where it is not possible to get the bar codes close to a computer. Some Thermal Transfer printers also have built in verifiers and some verifiers can be "bolted on" to the front of many Thermal Transfer printers. These are particularly recommended for large print runs, or runs where bar code quality must be at an optimum.

There can be confusion over the term "Verification". A simple barcode reader, such as a keyboard wedge scanner can be used to scan the code and prove that it will read and check that the content of the code is correct. A true verifier, as previously described, will perform many more tests on the code and grade its readability. The comparative costs between the two methods are considerable.

06. SCADA (Supervisory Control And Data Acquisition)
Within the "process manufacturing" sector, which includes the Food and Beverage, Chemicals, Pharmaceuticals and Bulk Raw Materials segments, any manufacturing company of any size will use SCADA software. Furthermore, within automated "heavy" manufacturing environments such as the automotive sector, SCADA software will also be found.

SCADA is not a company, nor a product. Instead, it is a generic term for a breed of software in the same way that ERP is a generic term for the powerful software that runs and co-ordinates big corporations' activities.

SCADA software within these companies is a powerful "business systems management tool", used to deliver ever higher levels of automation and (therefore) increased productivity and profitability.

SCADA software controls, configures, automates, and monitors the entire manufacturing process from the start at recipe management phase, right through to the finish in the packaging hall. In addition, sophisticated data collection throughout these activities enables detailed analysis of the entire process.

All the equipment used within the manufacturing process is connected to the SCADA system via TCPIP Ethernet - either in traditional wired form, or (increasingly) in wireless form. Indeed, when purchasing new manufacturing equipment, SCADA owners will simply not consider any equipment that is not capable of being connected to their SCADA system.

SCADA software comprises of a number of layers, which when added together make up the powerful management tool that it is. These layers include a highly graphical interface for displaying its monitoring capabilities, a highly sophisticated alarms package that includes visual and audio alarms plus e-mail, SMS text messaging and SNMP messaging, and a complex analysis tool that collects data in real-time and offers full interrogation of this data for purposes such as trending.

Whilst there are a number of leading SCADA software vendors, happily they all use a common communication protocol called OPC.

07. SCADA connectivity for Zebra printers
Until now, one of the few pieces of equipment in the manufacturing process that was not connected to the SCADA system was the barcode label printer.

Once you realise that barcode label printers are just as "mission critical" and integral to the manufacturing process as any other piece of equipment - after all, nothing can leave the factory without a label - then you begin to see why connecting the label printer to the SCADA system has real value.

Therefore, Zebra has developed a piece of software - "a driver" if you like - that will offer plug and play connection to SCADA software systems for all ZebraLink enabled Zebra printers (all ZPLII printers with x.10 or higher firmware), providing they are networked using the ZebraNet Print server II.

Once installed, this plug and play "driver" creates a 2-way relationship between the printer and the SCADA system, as illustrated in the diagram.

08. Printer Configuration for SCADA
Printer configuration and set-up can be controlled from SCADA, and label templates stored in printers' memory can be viewed and selected, and variable data coming from sources such as SCADA, Recipe Management or Manufacturing Execution Systems can be inserted onto these templates. Meanwhile, the printers can send a continual, unprompted for, stream of status data back to SCADA.

Equally, should a downtime threatening error occur to a printer, it can immediately send an alert message to SCADA, where it can be logged, visually represented and added to the alarms piece of the SCADA system for fast notification to the right personnel.

09. Labelling Standards
As the inclusion of bar coded labels becomes more widespread, standards have been introduced to regulate the packaging and shipping of materials, such as ODETTE, used in the automotive industry or standards such as those adopted by the Ministry of Defence and Rolls-Royce.

GSM Printer & Label Systems Ltd have a wealth of experience working with such standards and are thus recognised within the automotive, aerospace industries and many others, as a recommended supplier.

Rolls Royce Plc parts must be labelled according to strict guidelines set within the SQM 016 Suppliers Memorandum. These guidelines specify all information to be included on the labels, e.g. the type and size of barcode to be used, the amount of characters allowed for each piece of information, prefixes to be used on barcodes etc. Click here for more information about GSM Printer & Label Systems and Rolls Royce.

GSM Printer & Label Systems has been working closely with the logistics section of Honda on the definition of the shipping labels that Suppliers are required to print, based on the ODETTE specification. We stock the full range of label stationary that you require for shipments to Honda - card or adhesive labels in A5 and the A5/2 card for use on shallow containers. Click here for more information about Odette Master.

Our advisory team are available to discuss with you, these standards, how they affect your business and the solutions necessary to fulfil your needs.

10. Bar code readers
There is a wide range of barcode scanners available to suite every application. Price and performance can vary considerably between types:

11. Pen Scanners
low cost and low current consumption. Most often used with hand held terminals. The light source may emit visible or infra red light. The latter are used in security applications where the bar code is obscured by a black film which is invisible to the scanner. As the tip of the pen is in contact with the bar code, tip wear and code wear problems can be experienced. With poor quality codes, the pen may need to be swiped several times to obtain a "good read." For optimum use, operator training is required. Codes on loose packaged items such as crisps are difficult to read with this type of scanner.

12. CCD Scanners
These use CCD (Charge Couple Device) type photo detectors similar to those used in electronic cameras and allow a complete image across the bar code to be scanned continuously. This removes the need to physically swipe the scanner across the code. The whole bar code is illuminated by a row of LEDs and the CCD sensor will "take a picture" of the code typically 100 times per second. In general, CCD scanners must be positioned within 1 or 2 cm of the code, but unlike pen scanners, code wear is avoided.

They are most commonly used in retail applications where the type and size of code is well defined. In general, codes which are larger than the width of the line of LEDs cannot be read, so care must be taken to select the correct size of scanner. Long Range CCD scanners are available with a greater depth of field typically 10cm. However, since they are more expensive, consider low cost hand held laser scanners as a better general option. Make sure you look out for low power CCD scanners when you are connecting to portable computers. With no moving parts, these types of scanner are extremely reliable and offer rapid read rates. They are an ideal entry level investment.

13. Linear Imagers
These comparatively new devices work on the same principle as the CCD scanner but with a scanning distance typical of a Laser scanner. The added advantage over laser is that there are no moving parts so the mean time between failures is increased. Generally the form factor of a Linear imager tends to be pistol grip giving a more user friendly and intuitive feel to the operator than the standard CCD. The average cost of a linear imager is less than that of Laser for a similar performance.

14. Hand Held Laser Scanners
Laser scanning is the most flexible, but also the most expensive. Scanners are often gun shaped. Usually a laser diode is used as the light source. The beam is reflected off the bar code and back into the gun through a large lens to a photo detector. A moving mirror arrangement is used to scan the beam at a constant speed. This process is repeated typically 36 times per second. With this method, codes can be scanned from a distance and the size of the code is not critical as with CCD scanners. Both visible and infrared laser diodes are used, visible being the most popular for general applications. A typical maximum reading distances for a laser scanner are 30 - 90 cm although long range versions are available which can read in excess of 10 metres. However, the greater the distance, the larger the code must be, and the better the print contrast. For very long range scanning, special reflective media must be used. As laser scanner range increases, so does cost. In practice, scanning range is normally limited by the size (or resolution) of the bar code. Imagine an eye test. The smaller the printing, the closer you must be to read character. Irrespective of the maximum range of the scanner, it will only be able to read a small code at close range. As a general guide, a standard size EAN13 barcode can be read by any laser scanner to a maximum distance of about 30cm. Technical literature will show a "field pattern" diagram to relate the size of bar code to the operating range of the laser: Lasers are often used in portable applications where codes are not easily accessible, or in fixed positions such as DIY shop checkouts where the goods are too bulky to be positioned close to the scanner. Particularly suitable here are cordless laser scanners, using short range RF to replace the cable.

15. Fixed Position Scanners
There are many types of fixed position scanner, using pen, CCD and Laser technology. The most popular is the omnidirectional laser scanner, also called "Flatbed" or "Projection Scanner". Commonly used in large supermarkets, they use an array of mirrors to produce three dimensional patterns of scan lines. When a bar code passes over the pattern in whatever orientation, usually one scan line will cross through the full width of the code allowing a good read. These scanners are relatively expensive, but ideal for applications where a high throughput of codes is expected and where both operator's hands should be free to move coded goods. Look out for omnidirectional hand scanners, compact flatbed scanners which can be used "hands free", yet are small enough to be picked up to reach over a counter to scan bulky items. Whilst their performance is not quite as good as conventional flatbed scanners, they are less expensive and more flexible. Commercial holographic laser scanners are now in production, giving high performance omni-directional scanning over a wide area. These are particularly suitable for container tracking in freight distribution centres. Another type of fixed position scanner is the "slot reader". The technology used is similar to pen scanners, except in this case the scanner is fixed and the bar code is swiped through a slot in much the same way as a credit card would be on a till. Slot readers are common in time & attendance and access control systems. They operate in a similar way to credit card readers - a bar coded card is swiped through a slot to obtain a good read. Other fixed scanners are specifically designed for industrial conveyor systems and automated production equipment. They are metal cased and have inputs for external triggering from devices such as photo-sensors. They often have digital outputs or relays, which can be activated if the unit is triggered but no bar code is read. In a typical application with bar code labelled boxes travelling along a conveyor, the bar code scanner would cause the conveyor to stop if a box had an unreadable or missing bar code label. Modern industrial scanners can be programmed from a PC to produce different types of scan pattern to optimise scanning for a particular application.

16. Interfacing to a computer
There are several methods available to connect bar code scanners to a computer.

17. RS232
Most computing devices have an RS232 interface. A standard RS232 interface will not provide a 5v supply typically required to power a hand scanner, so an external power supply will be required. There are RS232 output versions of most scanners available.

18. Keyboard Wedge Scanners
The vast majority of PCs and computer terminals do not incorporate a dedicated bar code reader interface. Similarly most application software is written only for keyboard entry of data such as part numbers, product codes etc. A Wedge interface sends data to the host in the form of emulated keystrokes. In this way, the application software sees no difference between data which is keyed in, and data which is read in, by a bar code reader. Hand-held keyboard wedge scanners are effective and a relatively inexpensive way of improving data entry efficiency and accuracy. Data is transferred to the computer via the keyboard socket. The solution can communicate directly with the existing manually input screen.

These scanners can be attached to most terminals including an XT/AT PC keyboard socket or the keyboard of an AS4000 terminal.

19. Terminal Wedge
A Terminal Wedge interface is available for dumb terminals in addition to keyboard wedge. The scanner connects between the terminal and mainframe and therefore has two RS232 interfaces. Usually a scanner with this type of interface requires a mains adapter to provide power. RS232 data from the scanner is multiplexed onto terminal TX line to the host and therefore appears to the application software as keystrokes.

20. Data collection terminals
These are hand held computers, which are designed to be robust for use in the warehouse or manufacturing environment. They can be called Portable Data Terminals (PDT), Portable Data Collection Units (PDCU), or Hand Held Terminals (HHT). Generally they contain barcode scanners (usually laser) to speed up the data collection process. The typical applications that use these terminals are Booking-In, Booking-Out, Stock Taking and Work-In-Progress. There are two main configuration of Hand Held Terminal: Batch and RF.

21. Batch Data Collection
Conventional batch handheld systems use uploading and downloading of data at fixed points. The operator is required to periodically place the terminal in to a download cradle in order for the collected data to be transferred to the host computer. This does not provide the flexibility for real time processes. However in situations where immediate feedback is not required, such as a picking function, batch collection is a cost effective solution.

Cradles can be fitted with a modem for remote data collection, where you have a storage location within your customer site and need to monitor stock levels from head office.

Below is a typical batch data collection system diagram.

22. Wireless Data Collection
Conventional batch handheld systems, where data is up/down loaded at fixed points, do not provide the flexibility demanded by real-time processes.

The handheld terminals are in continuous contact with the central controlling host computer via a radio connection providing constant, up to the second accuracy and maximum productivity. The typical application where RF would be used is a busy warehouse where telesales staff need to know immediately a product is in stock in order to sell it on again. This technology does not rely on the operator remembering to download the hand held terminal before he goes to lunch!

A typical RF configuration has a number of radio Access Points connected back to the host computer via conventional networking technology.

The handheld terminals are free to roam through the radio-covered area, connecting with each Access Point in turn, without losing the host connection, very much as mobile phones do with the current GSM cellular technology.

Below is a typical illustration of a wireless configuration.

23. Poke-Yoke
Pronounced "PO-kah YOK-keh" is a Japanese term meaning mistake-proofing. These techniques were developed by Shigeo Shingo, creator of the Toyota production system. He realized that one important source for variation comes from the worker. This concept was developed to assist operators in tasks by using mechanical and electrical sensing devices to prevent defects from occurring.

A proper poke-yoke application should accomplish several things. It should take the immediate action of stopping operations when an error is detected such as by installing an interlocked circuit that automatically shuts down a production machine; it should alert the operator or supervisor so that the cause of the error can be properly diagnosed and corrected and it should help to improve productivity by reducing the ergonomic and cognitive demands of the task. Proper application of poke-yoke techniques can help to locate and eliminate defects and also streamline the process by guiding an operator through tasks.

Many things can go wrong in the workplace environment. Every day there are opportunities to make mistakes that will result in defective products. Defects are wasteful and if they are not discovered they disappoint the customers expectations of quality.

24. EDI Messaging
Electronic Data Interchange or EDI is "the transfer of structured trade data between the computer systems of trading partners". This includes the exchange of structured document-like messages such as purchase orders and quotations. EDI is a replacement for paper and the mechanism of exchange.

25. MRP and ERP
MRP Material Requirements Planning started as a system for planning raw material requirements in a manufacturing environment.

MRPll Manufacturing Resource Planning evolved from MRP by taking the basic MRP system and adding scheduling and capacity planning logic. Eventually MRPII evolved into:

ERP Enterprise Resource Planning, incorporating all the MRPII functionality with full financials and customer and vendor management functionality.

26. Thermostatic Mixing Valves and Legonella
In order to reduce the danger of Legionella contaminated water in hospitals, care homes, schools, hotels, leisure centres and other public buildings, hot water must be circulated at 80 degrees centigrade. This is mixed with cold water at each tap or shower to ensure that the temperature does not exceed 37 degrees centigrade.

Thermostatic mixing valves are used to ensure correct mixing. Insurance claims for scalding injuries caused by faulty valves are a common occurrence. In order to minimise claims valves must be checked regularly and the test history retained for inspection.
To find out more go to the Thermostatic Mixing Valve manufacturers association site at www.tmva.org