DDC Networks and Controls Protocols

As direct digital control (DDC) started in the ventilation, and air conditioning (HVAC) industry, manufacturers each developed their own unique, proprietary, application software to produce a DDC system for HVAC. These proprietary systems could not communicate with each other unless a “translator,” called a gateway, was developed to translate the messages from one system to another. These proprietary systems, now often called “legacy” systems, caused many challenges for users. Specifically, operators needed to interact separately with each system and to know how each one worked in order to do any maintenance. Theoretically, one could change a site with three legacy systems into a single virtual system for the operator. Each gateway acts as a translator, converting from a legacy language to, in this case, operatworterminal language. Developing each gateway is expensive and requires full details of the legacy proprietary language.