G PHYSICS
G08 SIGNALLING
G08B SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
7/00 Signalling systems according to more than one of groups G08B3/00 - G08B6/00; Personal calling systems according to more than one of groups G08B3/00 - G08B6/00
G08B7/06 using electric transmission; , e.g. involving audible and visible signalling through the use of sound and light sources