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Industrial AutomationAutomation IndustrielleIndustrielle Automation
4 Application Layer Protocols
4.2 Open Process Control (OPC)
OPC 4.2 - 2Industrial Automation 2013
OPC: Open Process Control
Source: http://home.hit.no/~hansha/documents/lab/Lab%20Work/opc.htm
OPC 4.2 - 3Industrial Automation 2013
OPC: Open Process Control
Manufacturer-independent application programming interface (API) for automation
-To implement clients which can access plant data coming from remote devices (PLCs, field bus devices, real-time databases) easily
-Set of commands collected in a software library (DLL) to access OPC servers
OPC clients
-read and write process variables, read alarms and events and acknowledge alarms, and retrieve historical data from data bases according to several criteria
-Implemented on automation platforms (e.g. ABB Ax800), which may act themselves as an OPC server to publish their data, events and historical data.
OPC server
-Supplied by manufacturer of automation devices supplies
-Communicates with its devices through a proprietary protocol
-Manages several devices of the same type, several servers can run in parallel and each server can be accessed by several clients in the same network
OPC 4.2 - 4Industrial Automation 2013
OPC Overview
4.2.1 OPC OverviewUsage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm Conditions
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 5Industrial Automation 2013
4.2.1 What is OPC ?
OPC (formerly: "OLE1 for Process Control", now: "Open Process Control") is an industry standard set up by the OPC Foundation (http://www.opcfoundation.org/) specifying the software interface (objects, methods) to a server that collects data produced by field devices and programmable logic controllers.
OPC serverX
application(OPC client)
OPC server(simulator)
OPC serverY
APIcovered by the OPC standard servers
PLCs Brand X
:
Field busEthernet
Sensors/Actors
1) OLE (Object Linking and Embedding) is a Microsoft technology for connecting software components.It has since been extended by the COM / DCOM technology. It corresponds to Java Beans.
PLCs Brand Y
OPC 4.2 - 6Industrial Automation 2013
Before OPC
ABB PLCs Télémécanique PLCs Siemens PLCs
MasterBusMMS driver
XWAY driver
Profinetdriver
visualizationhistory
data base
OPC 4.2 - 7Industrial Automation 2013
With OPC
ABB AC800M Télémécanique TSX Siemens S7
ABBOPC server
SchneiderOPC server
SiemensOPC server
Operatorapplication software is written independently from the type of controller
Historian(Information Manager)
MMS XWAY ProfiNet
the drivers still exist,but the clients do notsee them anymore
OPC 4.2 - 8Industrial Automation 2013
Importance of OPC
• Greatest improvement in automation since IEC 61131.
• More than 150 vendors offer OPC servers to connect their PLCs, field bus devices, displays and visualization systems.
• Used for data exchange between applications and for accessing databases
• DLL for Automation Interface (VB,..) and Custom applications (C++,..)
• Three major components:1) OPC - DA = Data Access (widespread, mature)2) OPC - AE = Alarms and Events 3) OPC - HDA = Historical Data Access
… and some profiles* (batch,…) * A “profile” is a subset or a specialization of a standard to form a stricter standard, adapted to an application. E.g. 100 Mbit/s, full-duplex, fibre-optical Ethernet is a profile of IEEE 802.3.
OPC 4.2 - 9Industrial Automation 2013
Specification 1: OPC DA for Data Access
Process variables describe the plant's state, they are generated by the sensors or calculated in the programmable logic controllers (PLCs).
Process variables can be sent upon a change, on demand or when a given time elapsed.
The OPC DA (Data Access) specification addresses collecting Process Variables.The main clients of OPC DA are visualization and (soft-) control.
OPC 4.2 - 10Industrial Automation 2013
Specification 2: OPC AE for Alarms and Events
determine the exact time of change (time stamping)
categorize by priorities
log for further use
acknowledge alarms(events are not acknowledged)
link to clear text explanation
Events are changes in the process that need to be logged, such as "production start"Alarms are abnormal states in the process that require attention, such as "low oil pressure"
OPC AE (Alarms and Events) specifies how alarms and events are subscribed, under which conditions they are filtered and sent with their associated messages.The main clients of OPC AE are the Alarms and Event loggers.
OPC 4.2 - 11Industrial Automation 2013
Specification 3: HDA for Historical Data Access
Historical Data are process states and events such as: process variables, operator actions, recorded alarms,... that are stored as logs in a long-term storage for later analysis.
OPC HDA (Historical Data Access) specifies how historical data are retrieved from the logsin the long-term storage, filtered and aggregated (e.g. compute averages, peaks).
The main client of OPC HDA are Trend Displays and Historians.
OPC 4.2 - 12Industrial Automation 2013
Beyond Microsoft: OPC UA
In a move to get more independence from Microsoft and use web technology, a new specification called " Unified Architecture" (formerly. OPC XML) that uses web services for all kinds of transactions: query, read, write, subscribe,...
The classical OPC DA, AE and HDA are implemented with XML / SOAP / WSDLthis allows encryption and authentication of process data.
OPC UA does not only standardize the interfaces, but also the transmitted data.
OPC 4.2 - 13Industrial Automation 2013
Client and Servers
4.2.1 OPC OverviewUsage and specificationsClients and Servers: configuration and communication
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm ConditionsAutomation Interface
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 14Industrial Automation 2013
Server(s) and Client(s) in the same node
OPC server
client application(OPC client)
OPC server OPC server
client application(OPC client)
Clients and servers run as parallel processes
The OPC specification defines the interface between client and server in the formof objects and methods.
devices devices devicesdevices
node
OPC 4.2 - 15Industrial Automation 2013
OPC for internal communication: ABB’s SCADA (800xA) as example
ABB's Operator Workplace (800xA) is at the same time OPC server and OPC client. Software components (agents) within AIP expose their properties as OPC objects.Internal (within the PC) and external communication (between PCs) takes place over OPC.
800xA
ABBOPC server
SchneiderOPC server
SiemensOPC server
AssetOptimizer
EnterpriseHistorian
aspects
OPC client
OPC server
processdata base
OPCconnections
aspectsfunctions
Windows PC
OPC 4.2 - 16Industrial Automation 2013
Direct and Fieldbus access
(local)OPC server
client application(OPC client)
fieldbus
(local)OPC server
FB Manager
fieldbus
PLC
FB agent
fieldbus
PLC
FB agent
direct connection fieldbus connection
can also be a point-
to-point link
client application(OPC client)
proprietary protocol
The OPC server is runningall the time, even if noclient is present
I/O devices
OPC 4.2 - 17Industrial Automation 2013
Accessing a server in another node
TCP/IP
stubDCOM
TCP/IP
OPC server
DCOM
TCP/IP
OPCserver
DCOM
FB Manager
fieldbus
DCOM
client application(OPC client)
Limitation:does not work over firewalls.Solution:TunnellerOPC UA
OPC 4.2 - 18Industrial Automation 2013
Assessment Overview
• What is the objective of OPC ?
• On which technology does OPC rely ?
• What is an OPC Server ?
• What do the main OPC specifications describe ?
• How can an OPC Server access data on another machine? And how does it work for OPC clients?
OPC 4.2 - 19Industrial Automation 2013
OPC Data Access
4.2.1 OPC OverviewUsage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm ConditionsAutomation Interface
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 20Industrial Automation 2013
OPC DA: Item properties
The process data are represented by three dynamic properties of an item:
1.value: numerical or text
2.time-stamp: time at which this data was transmitted from the PLC to the serverUTC, not local time.
3.quality:validity of the reading (not readable, dubious data, o.k.)
optional static properties
description: a text string describing the use and of the variable (optional)
engineering unit: the unit in which the variable is expressed (optional)
Q TV D UID
OPC 4.2 - 21Industrial Automation 2013
OPC DA: Objects as viewed by the OPC server
An OPC server is structured as a directory with root, branches and leaves (items)
Controller 1
Machine 2
Controller 2
Controller_3.Prog_2
Controller_3.Prog_1
Cell 1
Level_1
Level_2
Ramp4
TAG
TAG
TAG
Branches may contain other branches and itemsThe structure may also be flat instead of hierarchicalThis structure is defined during engineering of the attached devices and sensor/actors.(Intelligent servers can configure themselves by reading the attached devices)
An item is identified by its "fully qualified ItemID", e.g. "Process_Line_1.Controller_2.Level_2"
Process Line 1Tag Name
OPC 4.2 - 22Industrial Automation 2013
OPC DA: Objects as viewed by the OPC client
A client builds its own hierarchy, using the server’s hierarchical view.
Items in the server are defined by the programmer of the PLC
A full-fledged PLC may export some 10’000 items, a client needs only a subset.
A client builds groups, populating them with items it is interested in.
Items of a group are expected to have similar real-time requirements
Groups are not hierarchical, but flat.
OPC 4.2 - 23Industrial Automation 2013
OPC DA: Mapping items to groups
Each client structures its items by groups, independently from the server.
Initially, the client browses the server structure to check if the items it is interested in exist.
A client registers its groups and items at the server. The server keeps the structure of all its clients.
Temperature
Heat_On
TAG
TAG
Server root
GroupX
Level
Empty_Valve
Fill_Valve
TAG
TAG
TAG
Area 1
Area 51
Oven_1
Tank_1
Area 2
GroupZ
Client1
Item1 Item2 Item3 Item1 Item2
server
clients
Client2
OPC 4.2 - 24Industrial Automation 2013
OPC DA: Communication Model
4.2.1 OPC CommonOverview: usage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm ConditionsAutomation Interface
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 25Industrial Automation 2013
4.2.2 OPC DA: Example of access to a variable
Network
controller program
OPCserver
Reactor_1
MW%1003 MotorSpeed
MW%1004 Temperature
… ….
symbolsload symbol table
ReadItem ("OPC:Reactor1:
Program2.MotorSpeed")
Get () 192.162.0.2, MW%1003) Return (MW%1003, 112)
Value: 112
Reactor_1.Program2
Program 2
code
Marker: MW%1003
OPC application
OPC 4.2 - 26Industrial Automation 2013
server
Subscribe
Notify
OPC DA: Read Communication Models (per group)
myGroup.SynchRead()
client
Call
Reply
myGroup.IsSubscribed
myGroup_DataChange()
myGroup.AsyncRead()
myGroup_AsyncReadComplete()
server
Call
Reply
myGroup_DataChange()
server client
client
synchronous asynchronous
on change("subscription-based")
Notify
OPC 4.2 - 27Industrial Automation 2013
OPC DA: Write Communication Models (per group)
myGroup.SynchWrite()
client
Call
Reply
myGroup.AsyncWrite()
myGroup_AsyncWriteComplete()
server
Call
Reply
server client
The OPC interface accesses only groups, not individual items.
OPC 4.2 - 28Industrial Automation 2013
OPC DA: communication paradigm
OPC DA works according to the “shared memory” paradigm.
This means that a newer value overwrites the older one, no queues or history are kept.
The server does not guarantee that different clients see the same snapshot of the plant.
The server does not guarantee that all changes to variables are registered, changes may be missed if the polling period is too long.
OPC DA Client OPC DA Client
OPC DA Server
OPC 4.2 - 29Industrial Automation 2013
OPC DA: Assessment
1. How does the OPC server know a) where to fetch an item? b) which items belong to which group?
2. What are the DA the read and write operations ?
3. Is communication done by items, by groups or by collection of groups ? Why?
4. Can a change of an OPC variable be notified as an event, or shall the client poll ?
5. What are the implications of the shared memory paradigm for the application developer?
OPC 4.2 - 30Industrial Automation 2013
OPC Alarms and Events
4.2.1 OPC OverviewUsage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm Conditions
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 31Industrial Automation 2013
Alarms and Events: Purpose
The controllers (PLC) generate events in response to changes in the plant variables.together with their precise time of occurrence, type, severity and associated message for the human operator. An OPC AE server registers these events and makes them available to several clients
Alarms are described as state machines and may require acknowledgement.
The OPC Alarms & Events Interface gives access to the AE server, allowing to:
- browse the OPC AE Server for predefined events.- enable or disable alarms and events- subscribe to alarms and events of interest- receive the event and alarm notifications with the associated attributes- acknowledge alarms
OPC 4.2 - 32Industrial Automation 2013
AE: Definitions
An event is a general change of state that is relevant to the OPC server.An event signal a change: 1) in the field device ("production started")2) in the OPC server ("alarm acknowledged")3) in the application ("operator action")
An alarm indicates a state of the process that requires attention and is relevant to the OPC server. An alarm is represented by an alarm condition, which is a state machine determining if the alarm has been enabled, triggered or acknowledged. An alarm rises several events.
An event or an alarm does not transmit process values, but boolean information indicating a change of state, its originator, the time of its occurrence and a message intended for a human operator.
Alarms and events may not get lost (contrarily to OPC DA, which does not guarantee completeness)
Alarms and event are precisely time-stamped by their source, (contrarily to process variables, which are time-stamped by the receiving OPC server).
OPC 4.2 - 33Industrial Automation 2013
AE: communication paradigm
OPC AE works according to the “message passing” paradigm, contrarily to OPC DA, that works according to the "shared memory" paradigm.
This means that an event is kept in a queue until all clients have read it (or timed out).
The AE server guarantees that different clients will see all events in the same sequence.
OPC AE Client OPC AE Client
OPC AE Server
12:34 23.114
12:34 32.334
OPC 4.2 - 34Industrial Automation 2013
AE: Displaying Alarms and Events
Alarms and events are usually displayed differently on an operator screen.
- Events are displayed in an event list that can become quite long (typically 1000 entries), entries are not cleared when the source of the event returns to normal
- Alarms are displayed in a short list (typically 50 alarms)appearance changes when the alarm is acknowledged, an alarm line is cleared when the alarm signal is cleared (but remains in the log).
Ackcheckbox
OPC 4.2 - 35Industrial Automation 2013
AE: Events
4.2.1 OPC OverviewUsage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm Conditions
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 36Industrial Automation 2013
AE: Events kinds
OPC AE defines three kinds of events:
1. simple: process control system related events (change of a boolean variable)
2. condition-related: notifies a change of an alarm condition (CLEARED, ACKNOWLEDGED), (see later)
3. tracking-related: origin outside of the process (e.g. operator intervention)
OPC 4.2 - 37Industrial Automation 2013
AE: Event- identification
An event is identified by - its source (the object that generates the event. e.g. Tank1) and - the event name (which can be the same as in another object, e.g. HiLevelCond)
Tank1 Tank2
event
HiLevelCond HiLevelCond
event
event
LoLevelCond LoLevelCond
event
event signal (boolean expression)is an external signal to be used ?(boolean)
signal name for external signal (20 characters)name of the source (30 characters)
message (60 characters)
event name
Function Block
OPC 4.2 - 38Industrial Automation 2013
AE: Events - Notification
Level Switch
OPC AE Server
timestamp
AE Client
event notification
Tank1LevelHigh_SimpleEvent(source, timestamp, message, severity, category)
EventFB
Controller
Plant
Tank1
message
queue
specified communication
COM/DCOM
unspecified communicationnetwork, fieldbus or internal bus
OPC 4.2 - 39Industrial Automation 2013
AE: Events - Time Stamp
There are three places where events can be time-stamped:
- at the device that originally produced the data (external event - low-level event)allowing Sequence-Of-Events with a high accuracy, down to microseconds
- at the controller, (internal event) using the controller's clock to time-stamp messages giving accuracy not greater than the period of the tasks, about 1 ms.
- at the OPC Server, when an event message arrives (tracking events)not more accurate than DA, about 10 ms)
The OPC server can be configured to register the time stamp at the instant of the event transition (positive or negative) and the instant of the acknowledgement.
OPC 4.2 - 40Industrial Automation 2013
AE: Alarm conditions
4.2.1 OPC CommonOverview: usage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm Conditions
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 41Industrial Automation 2013
AE: Alarms - Condition Definition
An (alarm) condition is described in a named state machine
The condition state is defined by three variables:
• Enabled: the condition is allowed to send event notifications
• Active: the alarm signal is true
• Acknowledged: the alarm has been acknowledged
Alarm signal(e.g. FIC101.PV > 100 AND FIC101.PV < 150)
Acknowledgement signal(a positive transition of a boolean variable) Condition state
Enable (positive transition)Disable (positive transition)
Condition
OPC 4.2 - 42Industrial Automation 2013
AE: Alarms - Condition states and acknowledgement
alarm signal
acknowledgement
event notification
condition state InactiveAcked
ActiveUnacked
ActiveAcked
InactiveAcked
ActiveUnacked
InactiveUnacked
InactiveAcked
EnabledInactiveAcked
EnabledActiveUnacked
EnabledActiveAcked
EnabledInactiveUnacked
Ack Ack
alarm_signal
alarm_signal
alarm_signal condition state transitions
(here: always enabled)
alarm_signal
InactiveUnacked
An event is generated each time the alarm signal changes state, or is acknowledged
OPC 4.2 - 43Industrial Automation 2013
AE: Alarms - Acknowledgement
An alarm condition becomes active when the PLC produces an alarm signal describing an abnormal state defined by the application (e.g. the level of the tank is too high).
The operator is expected to acknowledge this condition (client ack)Alternatively, a local operator may use a button or HMI that the PLC reads (field ack)
LevelHigh
controllerAckButton(field ack)
OPC AE Server
time-stamp
AE Clientevent notification
client ack (acknowledger ID)Tank1Level_ConditionEvent
Network, field bus,or internal bus
Alarm Signal
messageCondition
COM / DCOM
OPC 4.2 - 44Industrial Automation 2013
COM / DCOM
AE: Summary alarms and events
controller
OPC AE Server
AE Client
Condition
OPC AE Server
timestamp
AE Client
event notification (source, timestamp, message)
message
message
alarm notification (source, timestamp, message, condition, subcondition, severity, type)
EventFB
controller
Event Alarm
ackalarmevent
OPC 4.2 - 45Industrial Automation 2013
OPC A&E: Assessment
1. What is the difference between Alarms and Events?
2. Where are Alarms and Events time stamped?
3. How does the “message passing” paradigm influence the OPC client application developer?
OPC 4.2 - 46Industrial Automation 2013
OPC Common Overview
4.2.1 OPC OverviewUsage and specificationsClients and Servers: configuration
4.2.2 OPC Data AccessObjects, Types and properties Communication model
4.2.3 OPC Alarms and Events SpecificationEventsAlarm Conditions
4.2.4 OPC Historical Data SpecificationOverview
OPC 4.2 - 47Industrial Automation 2013
Historian Example
GE Fanuc/Intellution iHistorian (iFix...)
Data collection, archiving and retrievalReport generationComputations (e.g. VBScript)Secure access (FDA 21 CFR 11)20'000 actions/ s, Up to 100'000 data points
Features:Unlimited Point CollectionSub-Second Data Collection Rates Enhanced Data CompressionTrue Thin Client AdministrationFault Tolerant Architecture
Questions to the historian:What was the value of FIC101 last week ?What was the flow average during October ?Which were the daily averages in October ?What was the total flow in each month ?How much fuel did we use for the batch ?
Give the answers in form of tables, pie diagrams, spreadsheet, reports
OPC 4.2 - 48Industrial Automation 2013
HDA: Historical Data Access
Field device
OPC HDA Server
HDA Clients
independent processes
historydatabase
Field device
OPC DA Server proprietarydata acquisition
e.g. Event Loggere.g. Trend Analysis
calculations
collector
raw and ordered data
hidden
OPC 4.2 - 49Industrial Automation 2013
HDA: Purpose
An OPC HDA server gives access to a historical data base (logs) in which data from the process have been collected and time-stamped, possibly through an OPC DA interface.
The OPC HDA interface clients, such as trend analysis, product tracking or data mining,that require ordered access these data logs.
The OPC HDA interface allows to:
- browse the historical data base
- retrieve data through proper filtering, e.g. by date range, by identity, by property
- build aggregates over the retrieved data, such as average, minimum, maximum.
- enter new entries, correct entries or remove entries
- enter / delete annotations in the history data base
OPC 4.2 - 50Industrial Automation 2013
HDA: Raw log
12.3.02 13:40 Gpcpt2ofpbonne 4824
12.3.02 13:40 Cpt2bac 50
12.3.02 13:40 Gpcpt2bac 70
12.3.02 13:40 Gpcptbe2 45
12.3.02 13:41 Gpcpt1bac 151
12.3.02 13:41 Gpcpt1ofpbonne 4826
12.3.02 13:41 Gpcptae2 45
12.3.02 13:41 Cpt1bac 49
12.3.02 13:41 Gpdefr2 64
12.3.02 13:41 Gpvoydef 2
12.3.02 13:41 Gpr3tempscycleprd 318
12.3.02 13:42 Gpstn1e1 16
12.3.02 13:42 Gpalarme1 0
12.3.02 13:42 Gpalarme2 0
12.3.02 13:43 Gpetatmodemarche 2
12.3.02 13:43 Gptpscycle 1346
12.3.02 13:43 Gpetatmodemarche 1
12.3.02 13:43 Gpdefgene1 16
12.3.02 13:43 Gpetatmodemarche 0
12.3.02 13:43 Gptpscycle 317
12.3.02 13:43 Gpdefr2 0
12.3.02 13:43 Gpvoydef 0
12.3.02 13:43 Gpdefgene1 0
12.3.02 13:44 Gpetatmodemarche 1
12.3.02 13:44 Gpr2tempscycleprd 1992
12.3.02 13:44 Gptpscycle 435
12.3.02 13:44 Gpalarme3 1
12.3.02 13:44 Gpalarme4 1
12.3.02 13:44 Gpalarme3 0
12.3.02 13:44 Gpcpt2ofpbonne 4823
Data in the historical database are identified by their
• itemID (here, represented by their name), • value, (of the respective type)• quality (good, stale, bad), and • timestamp (UTC).
By definition, values are registered when they change.(even if data are acquired by periodic polling)
OPC 4.2 - 51Industrial Automation 2013
HDA: How to reduce raw data (even before HDA comes into play)
max
min
exceptiondeviation
time
If the time scale of the log is smaller than that of the trend display in this case, values have to be interpolated to be displayed correctly
Data sent to the OPC DA server on change, collector records data in a circular buffer log
Since storage capacity is limited, data are reduced by:
1. if a variable is received more often than the log's minimal storage interval (e.g. 1s), the log keeps the latest of all values of the interval
2. if (and only if) a received variable changed by more than the "exception deviation" (e.g. 5%, analog values only), it is entered into the log.
3. if a variable changed by less than the exception deviation, it may be forced into the log after the log's maximum storage interval (e.g. 4 s) elapsed.
= process value (event) = log entry
min time max time max time max time
OPC 4.2 - 52Industrial Automation 2013
HDA Application: Trend Display
Parameters:• time scale (with possible offset, zoom, pan)• amplitude scale (low range, high range, scale units)• style: smoothed, stepped, filled (several ways to display the same data)• extrapolate: how to display values not received (e.g. because they did not yet change)
log: how were data sampled
OPC 4.2 - 53Industrial Automation 2013
yesterdayd-2d-3d-4d-5d-6d-7 today
HDA: Hierarchical logs
A hierarchical log is built on the data contained in the parent log.To reduce the log size, several aggregations can be applied:- record only maximum, minimum, average over a period, etc...
Actual data
1 mn_7 days log 6 MB
1s_24 hours log: 50 traces @ 12 B 52 MB
long-term log1 hour_forever 5.2 MB / Year 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
october1 2 3 27 28 29 30
octobreseptember
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 2223 24
OPC 4.2 - 54Industrial Automation 2013
Toy Examples: Logging Temperature
http://home.hit.no/~hansha/documents/subjects/IA6209/project/IA6209%20Project%20Work%20-%20Weather%20System.pdf
OPC 4.2 - 55Industrial Automation 2013
Real-Life Examples and Exercise
http://www.matrikonopc.com/portal/downloads.aspx?dID=132 and https://www.matrikonopc.com/portal/downloads/case_studies/AESWindGeneration_OPC.pdf
Integration of redundant GE Mark V turbine controllers at a power plantThe controllers were going to tie into the plant’s main DCS, an ABB Advant control system. Process Portal B and MicroSCADA client applications were used to visualize process data from the turbine controllers.
Exercise: Draw schema of system and describe which OPC specifications are used and how.
Wind GenerationAES Wind Generation manages 7 different wind farms across the United States, five of which comprise more than 500 turbines, with a total generating capacity of over 700 MW. There are six different turbine models, from four different manufacturers.
Exercise: Explain which OPC concepts are useful in this context and how they can be applied to support a SCADA system
OPC 4.2 - 56Industrial Automation 2013
To probe further….
OPC Foundation: Specifications http://www.opcfoundation.org
SoftwareToolbox Examples in Visual Basic http://www.softwaretoolbox.com/Tech_Support/TechExpertiseCenter/OPC/opc.html
The Code Project OPC and .NET http://www.codeproject.com/useritems/opcdotnet.asp
Matrikon Free client and server: http://www.matrikon.com
WinTech Toolkit for an OPC server http://www.win-tech.com/html/opcstk.htm
NewAge Automation Toolkit for an OPC server http://www.newageautomation.com