(19)

(11)

EP 1 256 105 A2

(12)

(88) Date of publication A3: 18.07.2002 (43) Date of publication: 13.11.2002 Bulletin 2002/46 (21) Application number: 01904091.4 (22) Date of filing: 07.02.2001

(51) International Patent Classification (IPC)7: G08B 1/00 (86) International application number: PCT/GB0100/482 (87) International publication number: WO 0105/7819 (09.08.2001 Gazette 2001/32)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 07.02.2000 GB 0002695 05.05.2000 GB 0010857 27.09.2000 WO PCT/GB00/03717 (71) Applicants: VSD Limited Guildford,Surrey GU2 5YG (GB) Intelligent Security Limited Guildford,Surrey GU2 7YG (GB)	(72) Inventors: BLACK, Michael John,c/o Sentec Limited Cambridge CB2 1GE (GB) COLBY, Edward Grellier,c/o Sentec Limited Cambridge CB2 1GE (GB) MOORE, Ian Frederick,c/o VSD Limited Guildford,Surrey GU2 7YG (GB) (74) Representative: Harries, Simon George et al fJ Cleveland,40-43 Chancery Lane London WC2A 1JQ London WC2A 1JQ (GB)