COMMUNICATIONS AND CONTROL NETWORK

摘要

A communications and control system includes an operations centre connected to a public communications network, a number of customer location interface units each allocated to a respective customer location or part thereof, and at least one customer apparatus present at a respective customer location, and a security controller integrated with the customer apparatus. The system transmits from the operations centre via the interface unit to the control means a permission code and the controller enables the apparatus in response to the permission code. The apparatus transmits back via the interface unit to the operations centre state data indicating an operational state of the apparatus.