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The typical control system network architecture, such as an HVAC control system, consists of several network levels:

  • Management Level
  • System-Level or Building-Level Controllers
  • Field-Level Controllers

 

The top level of an HVAC control system is typically the building management system (BMS). The BMS is an operator administration workstation that can communicate with, interrogate, and control any of the controllers and devices on the network. A BMS monitors, supervises, controls, and reports on building control systems. These systems may include access control, video surveillance, fire alarm, HVAC control, programmable lighting, and electric power management. Its basic functions are:

  • Providing information on those supervised building functions including, but not limited to, current status, archived historical information, summaries, analysis, displays, and reports on control and management functions
  • Detecting, annunciating, and managing alarms and other conditions
  • Diagnostic monitoring and reporting of system functions, nodes, devices, and communication networks
  • Interfacing or integrating between individual building control systems.

 

These systems typically display the following responses to an operator's workstation:

  • Alarm summary
  • Event summary
  • Trend set displays
  • Group control and group trend displays
  • System status
  • Configuration displays
  • Communication links status
  • System parameters configuration
  • Time schedule assignment
  • Holiday assignment
  • History assignment
  • Events archive and retrieval
  • Time period summary and configuration
  • Point detail for every configured point

 

Attributions

Image and content courtesy of Whole Building Design Guide – National Institute of Building Sciences