User Manual

41176.DOC

Page 9 of 11

The copyright in this document is vested in Basys Technology Limited. This document is issued

only for the purpose for which it is supplied. And on the express terms that it is to be treated as

commercially confidential and that it may not be reproduced in whole or in part, or used or

disclosed to others for any purpose except as authorised in writing by this company.

6.3 RAT TAG

6.3.1 Description

6.3.1.1 The

Range Adjustment

TAG

(RAT) is used to remotely turn on and off

the Reader’s short-range reception field at a required distance. This

varies the range at which the PAT tag’s shock activated transmission’s

can be received.

6.3.1.2 The R.A.T. comprises two PCB assemblies connected by a screened 6

core cable (approximately 6cms long) enclosed in an ABS enclosure with

external buttons. The main PCB is identical to the PCB in the SAT and

PAT. The second PCB within the RAT is used to mount miniature

switches beneath the external buttons. This PCB contains no other

components.

6.3.1.3 The RAT is used generally once after installation of a system.

6.3.1.4 The reader will respond with a buzzer when it receives certain

transmissions from the RAT (FIND and SEE). But the reader will always

flash an LED every time it receives a complete packet of data.

6.3.2 Transmission Characteristics

6.3.2.1 While one of the four buttons is depressed the RAT transmits a

control

signal

data packet of data at approximately 0.4s intervals at an output

field strength level described in paragraph 5.1.1.2.1 above. The

operation function of each button (FIND, SEE, + and -) is described

below.

6.3.2.1.1 The FIND button is used to set the edge of Receiver’s ON range. The user

sets the reader into a preset mode and stands to where the edge of range is

desired. The FIND button is then depressed. The received analogue signal is

compared to a variable voltage from a digital comparator which is modified

until the signal is ‘lost’. The voltage on the comparator is then incremented

once. After 5-10 seconds of the key press the reader will respond with a

buzzer sound indicating that the range has been set. The button can then be

released and the Reader mode returned to normal operation. Thus the

receiver will be ‘off’ for any low power transmissions outside of this range and

‘on’ for any inside.

6.3.2.1.2 The SEE button is used to determine the range of a reader previously set.

With the SEE button depressed the reader will respond with a buzzer when

the RAT is within the range.