ABSTRACT
Based upon the drivers and issues that have been outlined in this chapter, options for users include two protocol standards for networking and communication. It was also believed that an open or standard protocol, employed in the design of all new control systems, would allow end users to mix and match various manufacturers’ components in the same system. At the core of the open protocol issue are end user requests for: remote communication from a front end to more than one system and standardized networking for communication between distributed controllers. Open protocols differ from other protocols only because the source code is not proprietary, it is published and available, but is often controlled by a company. Systems that use gateways to integrate existing and new DDC equipment and perhaps add interface to a variety of other computer-based facility equipment can fit the definition of an open system.
