(19)

(11)

EP 0 328 520 A1

(12)

(43) Date of publication: 23.08.1989 Bulletin 1989/34 (21) Application number: 87905408.0 (22) Date of filing: 12.08.1987

(51) International Patent Classification (IPC):  G08C 19/ 02( . ) (86) International application number: PCT/US1987/001942 (87) International publication number: WO 1988/001417 (25.02.1988 Gazette 1988/05)

(84) Designated Contracting States: AT DE FR GB IT SE (30) Priority: 22.08.1986 US 19860899378 (71) Applicant: ROSEMOUNT INC. Eden Prairie, MN 55344 (US)	(72) Inventor: FRICK, Roger, L. Chanhassen, MN 55317 (US) (74) Representative: Wayte, Dennis Travers  BOULT, WADE & TENNANT 27 Furnival Street London, EC4A 1PQ London, EC4A 1PQ (GB)