Network Monitoring using OPC - (OLE) for Process Control Project Advisor : Dr. Chung-E-Wang

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Network Monitoring using OPC - (OLE) for Process
Control Project Advisor Dr. Chung-E-Wang

• Prepared By Bhumi Patel

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Topics

• OPC Introduction
• OPC Advantages
• OPC Standards
• OPC DA and OPC XML DA
• OPC XML DA Service Types
• Polled Subscription Interaction
• OPC XML DA Disadvantages
• Technology
• Network Monitoring
• Future Enhancement

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What is OPC?

• OPC is a software interface standard that allows
  Windows programs to communicate with industrial
  hardware devices.
• It was originally created in 1996 to specify
  standards for the communication of real-time
  plant data between control devices from different
  manufacturers.
• OPC is heavily used within the process industries
  and discrete manufacturing.

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OPC Origin

• Traditionally, any time a package needed access
  to data from a device, a custom interface, or
  driver, had to be written.

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OPC Origin (Continued)

• There were many problems associated with custom
  driver based communications some of these most
  common ones were
• High cost
• Proprietary technology that tied users to a
  particular vendor
• Hard to configure
• Maintain - because each custom driver had its own
  way of doing things
• Hard to keep up-to-date because of the constant
  release of new devices and applications

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OPC Origin (Continued)

• The purpose of OPC is to define a common
  interface that is written once and then reused by
  any business, SCADA, HMI, or custom software
  packages.

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OPC Advantages

• OPC is an open standard, which means lower costs
  for manufacturers and more options for users.
• Hardware manufacturers need only provide a single
  OPC server for their devices to communicate with
  any OPC client.
• Software vendors simply include OPC client
  capabilities in their products and they become
  compatible with thousands of hardware devices.
• Users can choose any OPC client software they
  need, resting assured that it will communicate
  seamlessly with their OPC-enabled hardware, and
  vice-versa.

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OPC Standards

• OPC Data Access (OPC DA)
• OPC Alarms Events
• OPC Batch
• OPC Data eXchange
• OPC Historical Data Access
• OPC Security
• OPC XML-DA
• OPC Complex Data
• OPC Commands

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OPC Data Access (DA)

• OPC Data Access was the first OPC specification.
• It is a group of standards that provides
  specifications for communicating real-time data
  from data acquisition devices like PLCs.
• It was based on COM/DCOM protocol.
• Problem
• It is based on Microsoft Platform, and is not
  portable to other operating systems
• DCOM timeouts

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OPC XML DA

• It is the first web service or SOAP (Simple
  Object Access Protocol) based protocol known as
  XML-DA specification.
• It allows access to process data from operating
  systems other than Microsoft in a standardized
  way.

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OPC XML DA Service Types

• Status Mechanism for checking server status
• Read Provides ability to read item values and
  quality
• Write Writes values for one or more items
• Subscription Used to initiate a subscription
  contract with a server
• Subscription Polled Refresh Periodically
  acquire the latest item values
• Subscription Cancel Terminate subscription
• Browse Browse available items on server
• Get Properties Get server properties

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Polled Subscription Interaction
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OPC XML DA Disadvantages

• Not suitable for transferring large data
• XML is slower than COM
• OPC XML DA is a stateless service

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Network Monitoring

• The application will monitor following network
  variables using OPC XML DA
• Upload Speed
• Download Speed
• Sent Packets
• Received Packets
• Server
• Windows Communication Foundation (WCF) using
  C.NET 4.0
• Client
• ASP.NET 4.0 with C.NET 4.0

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References

• www.opcfoundation.org/
• http//en.wikipedia.org/wiki/OLE_for_process_contr
  ol
• http//www.matrikonopc.com/opc-server/opc-data-acc
  ess-versions.aspx
• Integrated IEDs With OPC Technology by Pankaj
  Bhatt and Roger P. Baldevia
• http//www.opcdatahub.com/WhatIsOPC.html

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• Questions?
• Thank you !!