Coded transponder for indentification system

摘要: Access control equipment for restricting unauthorised access to stored or transmitted data secure premises, suitable use with an appropriate interrogation unit, takes the form of a transponder which is encapsulated in electrically non-conductive material and comprises at least one programmable code-carrying means, logic elements algorithm sealed therein. For example, may include microprocessor non-volatile memory storing code and/or algorithm, signals be passed from by electromagnetic other non-contact coupling. The system described particularly terrestrial satellite video audio broadcasts.