Advice

Bluetooth

When you use computers, telephones or PDA’s the various pieces and parts of the systems make up a community of electronic devices. These devices communicate with each other using a variety of wires, cables, radio signals and infrared light beams, and an even greater variety of connectors, plugs and protocols.

When any two devices need to talk to each other, they have to agree on a number of points before the conversation can begin. The first point of agreement is physical: Will they talk over wires, or through some form of wireless signals? If they use wires, how many are required -- one, two, eight, 25? Once the physical attributes are decided, several more questions arise:

How much data will be sent at a time? For instance, serial ports send data 1 bit at a time, while parallel ports send several bits at once.

How will they speak to each other? All of the parties in an electronic discussion need to know what the bits mean and whether the message they receive is the same message that was sent. This means developing a set of commands and responses known as a protocol.

Bluetooth takes small-area networking to the next level by removing the need for user intervention and keeping transmission power extremely low to save battery power.

Bluetooth is essentially a networking standard that works at two levels:

It provides agreement at the physical level -- Bluetooth is a radio-frequency standard.

It provides agreement at the protocol level, where products have to agree on when bits are sent, how many will be sent at a time, and how the parties in a conversation can be sure that the message received is the same as the message sent.

The big draws of Bluetooth are that it is wireless, inexpensive and automatic.

Wi-Fi

Short for wireless fidelity and is meant to be used generically when referring of any type of 802.11 network, whether 802.11b, 802.11a, dual-band, etc. The term is promulgated by the Wi-Fi Alliance.

Any products tested and approved as "Wi-Fi Certified" (a registered trademark) by the Wi-Fi Alliance are certified as interoperable with each other, even if they are from different manufacturers. A user with a "Wi-Fi Certified" product can use any brand of access point with any other brand of client hardware that also is certified. Typically, however, any Wi-Fi product using the same radio frequency (for example, 2.4GHz for 802.11b or 11g, 5GHz for 802.11a) will work with any other, even if not "Wi-Fi Certified."

RFID

Radio Frequency Identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. An RFID tag is a small object that can be attached to or incorporated into a product, animal, or person. RFID tags contain silicon chips and antennas to enable them to receive and respond to radio-frequency queries from an RFID transceiver. Passive tags require no internal power source, whereas active tags require a power source.

A typical system consists of tags with an embedded, unique identifier for the product or object being moved; "readers" designed to decode the data on the tag; and a host system or server that processes and manages the abundance of information gathered.

What is RFID? Radio frequency identification enables companies to assign unique identifiers to individual products or items. From the time a product is manufactured to when it is consumed, RFID offers real-time visibility into shipments and inventory in motion. Using radio waves, data is captured and moved wirelessly to and from the point of business activity—in real time. This unique identification is utilised to match information about the product with the information from a company's database or host system.

With RFID, items can be read or tracked with minimal human intervention. This has the potential to reduce supply chain inventory levels, operating expenses and provide unequalled supply chain visibility. These aspects—expense reduction and real-time visibility—have attracted companies to deploying RFID systems.

Scanners

Pen (Wand) Scanners

Pen Scanners can read barcodes only when they are in contact with the barcode. The maximum width of barcode that may be scanned is theoretically unlimited but practical considerations restrict it to 1m or so. Scanning is manual but may be done from left to right or right to left. Pen scanners are the most robust type available as they have no internal mirrors.

CCD Scanners

CCD Scanners can read barcodes only over small distances -- typically no more than 30mm but some types have a range up to 350mm. The maximum width of barcode that may be scanned is 80mm - 180mm depending on scanner type and reading distance. Scanning may be initiated by the trigger switch, or automatically using flash mode. CCD scanners are intermediate in robustness between the Laser and Pen scanners.

Laser Scanners

Laser Scanners can read barcodes over short to medium distances -- typically no more than half a metre but some types have a range up to several metres. The maximum width of barcode that may be scanned depends on reading distance. Scanning is initiated by the trigger switch. Laser scanners are more expensive than other types of barcode scanner and they are also the most easily damaged, but their ability to scan from a distance makes for unequalled convenience of operation.

Bar codes

A bar code represents data in a machine readable form, and therefore replaces manual key entry. A bar code is a pattern of bars and spaces holding a unique identification number. The bar code can then be decoded or read by a scanner to retrieve the information from a database. The information encoded in the bar code is shown in human readable format beneath the bar code.

Automatically capturing data through bar codes is increasingly used to speed data collection and minimise errors caused by manually keying in data.

The GS1 set of symbologies are the only symbols available for use in an open global supply-chain environment.

Versatile bar code symbologies
The GS1 System (formerly EAN.UCC System) has four bar code symbologies. Each has a different structure and purpose:

EAN/UPC
The EAN/UPC bar codes are a family of four linear bar codes encoding the 8, 12 and 13-digit GTINs. These bar codes can be read omni-directionally (in any direction) and are therefore suited for fast scanning and manual handling environments. The EAN-13 and UPC-A bar codes are the most widely used because they can be used at any point within the supply chain. The EAN/UPC bar codes are the only symbols accepted at the retail point of sale. 

                EAN-13



                UPC-A



          EAN-8



        UPC-E




ITF-14
ITF-14 is a linear bar code holding a 14- digit number. Its structure is the simplest of all GS1 symbologies, enabling it to be printed directly on to board and on lower contrast surfaces, for example brown board. 

                                           ITF-14

                                UCC/EAN-128