To develop and standard set of interface for managing alarm and event notifications.

This system should complement the other OPC Interfaces (particularly Data Access)

Alarms and events include (but are not limited to) Process alarms, Operator manual action requests generated by the system, Informational messages such as Batch Completion, Tracking/Auditing messages such as a change in a setpoint or tuning parameter by an operator.

To allow clients to subscribe to the types of messages it needs via some form of filtering.

To keep the design in the form of a low level foundation which can be used to build interfaces to existing and future systems and to which vendors can add their own functionality while retaining a high degree of interoperability.

To create a design which (as much as possible) accommodates a wide range of applications from simple to complex without imposing too much complexity on the simple applications or too many limits on the complex applications.

To support (if possible) the implementation of multi-tier systems (for example the creation of an 'alarm concentrator' which gathers alarms from multiple simple devices such as RTUs and forwards those alarms to a more complex client such as an Operator station or a logging package).

Note that as with other OPC interfaces our intend is not to impose constraints or rules on the design of products but rather to provide an enabling technology which will allow easier interconnectivity or these products.