User's Manual

Link-It Active Tag 10 of 15

4 TECHNICAL DESCRIPTION

4.1 PRINCIPAL OF OPERATION

The principal of operation of the Link-It Tagging System s described in this section. A basic knowledge of the

system is essential before commencing with any installations or implementation. A basic system block dia-

gram is illustrated in Figure 4. Tags A ! N attached to assets, equipment and people are recognised and in-

terpreted by a network of Readers and Repeaters. In larger areas Repeaters are used in conjunction with

Readers to increase the area of operation. In smaller areas one reader will normally be sufficient to read all

tags in that area. Information regarding the relative tag positions is sent via cables from readers to a PC.

Large Area

Reader 1

Repeater 1

Reader 2 Reader 3

Repeater 2

Repeater 3

TagD

TagE

TagC

TagB

TagA

TagM

TagN

TagLTagJ

TagK

TagI

TagF

TagG

TagH

Small Area

Medium Size Area

Server

TagO

Figure 4: Basic System Block Diagram

4.1.1 TAG TO READER/REPEATER COMMUNICATION

Tag to Reader/Repeater communication is done via a RF channel. The interface is described in paragraph

3.1.1. Tags transmit their pre-programmed ID’s at a certain time-interval. These ID’s are received and inter-

preted by the Reader/Repeater. Readers/repeaters can be configured filter data received from tags. This

means that only certain tags may be interpreted by the reader/repeater.

Figure 5 illustrates a configuration of two repeaters (Repeater1 and Repeater2), one reader (Reader1) and

12 tags (TagA ! TagL). Repeater2 can be configured to receive data only from tags except for TagE, TagF,

TagG and TagH. All other tags that fall within Repeater2 receive zone will be discarded. However, this type of