Product interoperability is essential when using home control standards, such as the Home Electronic System (HES). Models have been developed to foster interoperability among products from competing or complementary manufacturers. These models are intended to facilitate validation of the language being specified for HES in ISO/IEC TR 15067-1: Information technology - Home Electronic System (HES) application model - Application services and protocol. Models for lighting and energy management have already been developed and accepted. This Technical Report defines a typical security system and describes the communications services needed. A high-level model for a security system using HES is presented.