Emerson DeltaV™ Digital Automation System Concepts
Modules that work closely together to perform a specific process control function are
typically grouped in an area. An area is a logical division of a plant. Areas typically
represent plant locations or main processing functions. The configuration engineer
determines how to logically divide the plant into areas.
Nodes are physical pieces of equipment on the control network, such as a controller
or a workstation. You control your process by downloading modules in the controller
nodes. The configuration tells the node how to act and what information to receive or
save from the process.
Device Tags represent the instruments, valves, and other field devices. A Device
Signal Tag consists of a specific signal from a device.
Alarms alert the operator that an event has occurred. (Alarms are assigned to
modules.) Typically, you want the operator to perform some action and respond to the
alarm. Alarms can be both visible and audible.
The database contains configuration information and lets you make off-line changes
without affecting the process. Online control algorithm monitoring and modification
are also available.