1. Copyright 1998 Intellution, Inc. All Rights Reserved OPC Alarms and Events Technical Overview TM OLE for Process Control and Factory Automation Al Chisholm - OPC Technical Chairman 11/98

2. Copyright 1998 Intellution, Inc. All Rights Reserved Topics A review of the Problem Design Features Assumptions about the Applications The Objects The functionality they provide

3. Copyright 1998 Intellution, Inc. All Rights Reserved Why is OPC needed? Software Driver Software Driver Software Driver Software Driver Display Application Trend Application Report Application

4. Copyright 1998 Intellution, Inc. All Rights Reserved How does OPC Solve the Problem? Software Driver Software Driver Software Driver Software Driver OPC Display Application Trend Application Report Application OPC

5. Copyright 1998 Intellution, Inc. All Rights Reserved Where does OPC Alarms Fit? Low level sensors Typically use a dedicated Hardware Interface and protocol Device Specific I/O Control Data Monitor SubSystem OPC OPC (via DCOM)can also be used between subsystems and Management Consoles OPC is generally used between Monitoring applications and I/O specific software drivers

6. Copyright 1998 Intellution, Inc. All Rights Reserved What Does OPC Provide? Alarms on sensor data - temp, pressure, flow Alarms on Control parameters - open, close, run, stop Updates on Status information – Status of the hardware connection – Status of the local software and subsystem Completion of system sequences such as batches OPC can expose any data available OPC Interfaces Sensor Alarms Comm Status System Performance OS Statistics

7. Copyright 1998 Intellution, Inc. All Rights Reserved General Features of OPC Alarms Based on COM - to leverage Microsoft ‘Plumbing’ Flexible - to support many applications Efficient - to support large applications Hi performance - well behaved on a Network Easy to understand

8. Copyright 1998 Intellution, Inc. All Rights Reserved Fundamental Assumptions (I) Each OPC Server such as Alarms and Events is a Separate Object which complements the other OPC Objects Alarms and Events is primarily Subscription based Event Types – Simple, Tracking, Condition (Alarm) Conditions – Single State, Multi State

9. Copyright 1998 Intellution, Inc. All Rights Reserved Fundamental Assumptions (II) Alarm State Information includes – Enabled, Active, Acknowledged Areas Source Names Categories Filtering

10. Copyright 1998 Intellution, Inc. All Rights Reserved The Logical Object Model OPCServer Subscription Custom Interfaces Subscription Conditions and Events...

11. Copyright 1998 Intellution, Inc. All Rights Reserved Typical Server Design OPC/COM Interfaces OPC Subscription Object Management Condition Monitoring and Optimization Device Specific Protocol Logic (if needed) Hardware Connection Management (if needed)

12. Copyright 1998 Intellution, Inc. All Rights Reserved The Server Interfaces The server is a COM object which provides: IOPCCommon IOPCEventServer IConnectionPointContainer OPCServer

13. Copyright 1998 Intellution, Inc. All Rights Reserved The Subscription Object Interfaces The Subscription is a COM object which provides: IOPCEventSubscriptionMgt IConnectionPointContainer OPCServer Subscription

14. Copyright 1998 Intellution, Inc. All Rights Reserved The Client Side Intefaces The Client provides 2 COM interfaces that the server can call IOPCShutdown IOPCEventSink Server Object Subscription Object(s) Client IOPCEventSink IOPCShutdown

15. Copyright 1998 Intellution, Inc. All Rights Reserved Client/Server Connection ClientServer Subscription OnEvent 1 2 3 CPC CP OnEvent 4

16. Copyright 1998 Intellution, Inc. All Rights Reserved Performance and Flexibility OPC Alarms and Events is complete, powerful and flexible because it is a combination of the best ideas of many of the best companies in our business. OPC Alarms and Events is Fast because it was designed from the start with networking in mind.

17. Copyright 1998 Intellution, Inc. All Rights Reserved Summary The OPC Alarms and Events Interfaces: Support exception based updates via Filtered Subscriptions Are designed to be vendor neutral Allow connections to both simple and complex devices Are optimized for use over a network www.opcfoundation.org