User's Manual

April ’00 Chapter 1. Introduction

1.1 General

This document provides information about the S251B Reader. It describes the reader

and how to install it.

1.2 System Description

A TIRIS system comprises a reader connected to a control device (usually a host

computer) via an RS232, or an RS422/RS485 interface, an antenna and a trans-

ponder. It is used for wireless identification of TIRIS LF transponders.

The reader sends a 134.2 kHz power pulse to a transponder, the energy of the gen-

erated magnetic field is stored in the capacitor in the transponder and when the pow-

er pulse has finished the transponder immediately sends its data back to the reader.

1.3 Product Description

The Reader is an integral part of a TIRIS system, it provides all of the RF and control

functions required to communicate with TIRIS LF transponders.

The main task of the Reader is to send a power pulse via the antenna to initialize the

transponder, to demodulate the received identification signal and then send the data

to a control device. It is also used to send programming data to Read/Write and Mul-

tipage transponders.

The Reader is housed in an IP20 Polycarbonate box as shown Figure 1.

Figure 1: S251B Reader

If connected via an RS232 or an RS422/RS485 interface the computer sends com-

mands to the reader using one of the two protocols used by the system (ASCII or TI-

RIS Bus Protocol), and the reader then communicates via its antenna with any

transponders within that antenna’s range. The antenna can be mounted up to 5 m

(depending on the antenna) away from the reader.