Copyright 1998 Intellution, Inc. All Rights Reserved OPC Alarms and Events Technical Overview TM OLE...

Copyright 1998 Intellution, Inc. All Rights Reserved

OPC Alarms and Events OPC Alarms and Events Technical OverviewTechnical Overview

TM

OLE for Process Control and Factory

AutomationAl Chisholm - OPC Technical Chairman11/98


TopicsTopics

• A review of the Problem• Design Features• Assumptions about the Applications• The Objects• The functionality they provide


Why is OPC needed?Why is OPC needed?

SoftwareDriver

SoftwareDriver

SoftwareDriver

SoftwareDriver

DisplayApplication

TrendApplication

ReportApplication


How does OPC Solve the Problem?How does OPC Solve the Problem?

SoftwareDriver

SoftwareDriver

SoftwareDriver

SoftwareDriver

OPC OPC OPC OPC

DisplayApplication

TrendApplication

ReportApplication

OPC OPC OPC


Where does OPC Alarms Fit?Where does OPC Alarms Fit?

Low level sensorsTypically use a dedicated

Hardware Interface and protocolDevice Specific I/O Control

Data MonitorSubSystem

OPC

OPC (via DCOM)can also be used between subsystemsand Management Consoles

OPC is generally usedbetween Monitoring

applications and I/O specificsoftware drivers


What Does OPC Provide?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

CommStatus

System Performance

OS Statistics


General Features of OPC AlarmsGeneral 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


Fundamental Assumptions (I)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


Fundamental Assumptions (II)Fundamental Assumptions (II)

• Alarm State Information includes– Enabled, Active, Acknowledged

• Areas• Source Names• Categories• Filtering


The Logical Object ModelThe Logical Object Model

OPCServer

Subscription

CustomInterfaces

Subscription Subscription

Conditions and Events...


Typical Server DesignTypical Server Design

OPC/COM Interfaces

OPC Subscription Object Management

Condition Monitoring and Optimization

Device Specific Protocol Logic (if needed)

Hardware Connection Management (if needed)


The Server InterfacesThe Server Interfaces

• The server is a COM object which provides:

• IOPCCommon• IOPCEventServer• IConnectionPointContainer

OPCServer


The Subscription Object InterfacesThe Subscription Object Interfaces

• The Subscription is a COM object which provides:

• IOPCEventSubscriptionMgt• IConnectionPointContainer

OPCServer

Subscription


The Client Side IntefacesThe Client Side Intefaces

• The Client provides 2 COM interfaces that the server can call

• IOPCShutdown• IOPCEventSink Server Object

Subscription Object(s)

Client

IOPCEventSink

IOPCShutdown


Client/Server ConnectionClient/Server Connection

Client Server

Subscription

OnEvent

1

2

3CPCCP

OnEvent4


Performance and FlexibilityPerformance 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.


SummarySummary

• 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

Copyright 1998 Intellution, Inc. All Rights Reserved OPC Alarms and Events Technical Overview TM OLE...

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Transcript of Copyright 1998 Intellution, Inc. All Rights Reserved OPC Alarms and Events Technical Overview TM OLE...