Abstract: An HVAC system is provided with control communication over a serial data bus. In this manner, the hard wired controls of the prior art are eliminated. A thermostat includes a central control microprocessor that communicates control signals to and from a microprocessor at an indoor unit. The indoor unit may be a furnace or a fan/heater combination. The microprocessor on the indoor unit is operable to receive signals from the central control microprocessor and control the indoor unit accordingly. Moreover, the microprocessor at the indoor unit is operable to pass control signals on to an outdoor unit such as an air conditioner or heat pump. Most preferably, this outdoor unit is provided with its own microprocessor. Further, other peripheral units may be incorporated to be controlled over the same data bus from the thermostat. Iristallation and updating of HVAC systems is greatly simplified by this control arrangement.

Abstract: A system for self-configuring complex HVAC systems has each of several units provided with a microprocessor control. The several units are each available in various optional styles, sizes, etc. The microprocessors provide information to a central control of the particular characteristic of the particular unit. Thus, when the HVAC system is initially assembled, the microprocessors associated with the individual units report these characteristics to the control. The control then determines the characteristics of each of the individual units, and accesses control strategies for the combination of individual units that are being utilized in the particular HVAC system.

Abstract: A unified policy management system for an organization including a central policy server and remotely situated policy enforcers. A central database and policy enforcer databases storing policy settings are configured as LDAP databases adhering to a hierarchical object oriented structure. Such structure allows the policy settings to be defined in an intuitive and extensible fashion. Changes in the policy settings made at the central policy server are automatically transferred to the policy enforcers for updating their respective databases. Each policy enforcer collects and transmits health and status information in a predefined log format and transmits it to the policy server for efficient monitoring by the policy server. For further efficiencies, the policy enforcement functionalities of the policy enforcers are effectively partitioned so as to be readily implemented in hardware.

Abstract: A substrate having a diamond or diamond-like carbon coating of at least one micron thickness on an underlayer of an insulating material such as AlN. Such a substrate is advantageously used as a mounting for passive electrical components such as microwave and radio-frequency (rf) resistors, capacitors, attenuators, terminators and loads.