User's Guide

User Guide
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User Guide, WhereTag IV GT, TFF-3110 D2280 Rev 02
© Copyright Zebra Technologies Corporation Confidential and Private
1 INTRODUCTION
1.1 System overview
The Zebra Real Time Locating System (RTLS) determines the position of tagged assets in
both indoor and outdoor facilities such as factories and freight yards. The system locates
tagged assets by a process involving redundant triangulation. Each tag autonomously emits
a 2.4 GHz direct sequence spread spectrum (DSSS) radio signal at a predetermined blink
rate. Each tag’s blink rate is randomized around its predetermined value to minimize the
number of collisions between transmissions made by different tags. The signal emitted by
the tag is received by a minimum of four Location Antennas. A typical transmission contains
a preamble which is used to synchronize the receiver, the tag’s serial number which
identifies the tag, a status word which monitors various tag functions, data stored in the tag’s
memory and finally a Cyclic Redundancy Check (CRC) used to assure that the tag’s
message is correct as received.
The principal components of the Zebra RTLS are shown in Figure 1 on page 9.