Transitioning to An Open Protocol Controls System

Department of Interior (DOI)

The Department of the Interior (DOI), through the use of an Energy Savings Performance Contract (ESPC) is committed to reducing energy consumption at the Main Interior Building (MIB).

Conquest Solutions (CQS) worked alongside Ameresco to create a thorough Statement of Work for the enhancement of the existing Direct Digital Control (DDC) system to ensure a successful integration of the existing legacy control system with a new open protocol control system. The scope of work for the comprehensive roll out of the DDC included the following: Interoperability, Centralized Infrastructure, and Systems Integration.


The new, comprehensive, open protocol DDC system will use existing and new sequences of operation to optimize the operation of the equipment by using a global approach to controlling the building. The new file and software structure will be hierarchical in nature and capable of managing multiple devices simultaneously. The new DDC upgrade will be designed so that it can support robust expansion limited only by Local Area Network (LAN) infrastructure.

Centralized Infrastructure

The new DDC platform will be capable of supporting multiple users and systems at the same time and can be accessed from anywhere on the DOI network. This thin client server application allows for control of all DDC equipment and central storage of archival data, alarm/event tables and network management configurations.

Systems Integration

The new DDC system will be capable of integrating various sub-systems such as lighting control, metering and other ancillary monitoring control systems to provide a common platform and user interface to improve the operations of the facility.

These enhancements to the DDC system in addition to implementation of energy conservation measures such as light emitting diode (LED) lighting technologies, optimization of chiller plant operations, and HVAC commissioning will reduce electrical energy consumption by at least 25%.