(19)

(11)

EP 0 250 488 A1

(12)

(43) Date of publication: 07.01.1988 Bulletin 1988/01 (21) Application number: 87900030.0 (22) Date of filing: 24.12.1986

(51) International Patent Classification (IPC):  G08B 26/ 00( . ) (86) International application number: PCT/AU1986/000394 (87) International publication number: WO 1987/003988 (02.07.1987 Gazette 1987/14)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 24.12.1985 AU 19850004053 (71) Applicant: MONITRONIX LIMITED Victoria Park, W.A. 6100 (AU)	(72) Inventors: MICHAEL, Shawky, Shafeek Victoria Park, W.A. 6100 (AU) KILGOUR, Neil Tighes Hill, NSW 2297 (AU)