Today with the level of automation that is being applied in manufacturing, operators are dealing with higher and higher amounts of information. Alarming and event subsystems have been used to indicate areas of the process that require immediate attention. Areas of interest include (but are not limited to); safety limits of equipment, event detection, abnormal situations. In addition to operators, other client applications may collect and record alarm and event information for later audit or correlation with other historical data.
Alarm and event engines today produce an added stream of information that must be distributed to users and software clients that are interested in this information. Currently most alarming/event systems use their own proprietary interfaces for dissemination and collection of data. There is no capability to augment existing alarm solutions with other capabilities in a plug-n-play environment. This requires the developer to recreate the same infrastructure for their products as all other vendors have had to develop independently with no interoperability with any other systems.
In keeping with the desire to integrate data at all levels of a business (as was stated in the OPC Data background information), alarm information can be considered to be another type of data. This information is a valuable component of the information architecture outlined in the OPC Data specification.
Manufacturers and consumers want to use off the shelf, open solutions from vendors that offer superior value that solves a specific need or problem.
To identify interfaces used to pass alarm and event information between components which would be suitable to standardization. Additionally this document details the design of those interfaces in such a way as to compliment the existing OPC Data Access Interfaces.
This specification complements but is separate from the OPC Data Access and the OPC Historical Data Access specifications. It references the OPC Common specification, in that OPC Event Servers support the interfaces specified there.