1. SCADA Current State and Perspective
Welcome
Several pages of this presentation were created by Axel Daneels from CERN who can not join this workshop
Matthias Clausen, DESY
(A. Daneels, CERN)
Oct. 2000
PCaPAC' DESY

2. Overview What is SCADA (compared with DCS systems)
Where and Why are SCADA systems used
What do SCADA systems Provide?
Evolution
OPC for SCADA
Benefits
Experience from DESY
Outlook
Oct. 2000
PCaPAC' DESY

3. Traditional Control 9 - 12 Oct. 2000 PCaPAC'2000 - DESY
Let‘s first look back how controls started:
a central console
Dedicated controller with dedicated links
Oct. 2000
PCaPAC' DESY

4. Traditional Control 2nd
Dedicated Consoles
Point to point communication
No network
No remote access
No remote diagnostic
Oct. 2000
PCaPAC' DESY

5. Distributed Control Network Protocol PLC’s Field Bus
Mixed operations of UNIX and PC workstations
Fontend processors of various kind
Fieldbus integration with dedicated units.
Each fieldbus needs its own integration method and support.
(this can be a lot of work!)
Field Bus
Field Bus-Integrator
Oct. 2000
PCaPAC' DESY

6. Distributed Control 2nd
Advantages:
Distributed databases/ programs created from a single development environment (also in front end processor)
Distributed access
Distributed diagnostic
Display ‘everything everywhere’
Disadvantages:
None of the DC systems are compatible to each other
Difficult:
Integration of various field bus components
Oct. 2000
PCaPAC' DESY

7. SCADA ? SCADA ? SCADA ? Supervisory Control Data Acquisition And
ERP Systems
Expert Systems
SCADA ?
SCADA ?
SCADA ?
Supervisory
Control
Data
Acquisition
And
Archiving, Logging,
Access Control, Alarms
Graphics and Batch processing
Distributed database
(page is self describing while it is updating)
Special: Data server for fieldbus integration
Several drivers for many fieldbuses available
Data Server
Data Server
PLC’s
Field Bus
Control Programs
Oct. 2000
PCaPAC' DESY

8. What, Where and Why What is “SCADA”and where is it used
Supervisory Controls And Data Acquisition
Application area :
Industrial processes: chemical, power generation and distribution, metallurgy, …
Nuclear processes: reactors, nuclear waste, ...
Experimental physics: Tokamaks, HEP laboratories
Application size:
20 K I/O to 450 K I/O, two examples of 1 M I/O under development
Why SCADA systems were evaluated for LHC SLC ?
Reduction of resources
CERN policy of “outsourcing”
SCADA is
- not a full control system, focuses on the supervisory level.
- a purely software package that is positioned on top of hardware to which it is interfaced, in general via Programmable Logic Controllers (PLCs)
SCADA systems
- used to run on DOS, VMS and UNIX;
- in recent years all SCADA vendors have moved to NT.
- One product was found that also runs under Linux.
Oct. 2000
PCaPAC' DESY

9. What do SCADA Provide? Flexible and open architecture
Basic SCADA functionality
MMI
Alarm Handling and Trending
Access Control
Automation
Logging, Archiving, Report Generation
Interfaces to H/W and S/W
Interfaces to ERP- and Expert-Systems
Development Tools
Flexible Architecture:
- Hardware and Software
Oct. 2000
PCaPAC' DESY

10. Generic Software Architecture
SCADA Developt. Environt.
SCADA Client
Graphics
Editor
Active X
Controls
MMI
Tren-
ding
Alarm
Display
Log
Display
ASCII
File
Editor
Active X
Container
Library
Client / Server - Publish / Subscribe - TCP/ IP
ASCII
Files
SCADA Server
Recipe DB
RT & Event Manager
Export /
Import
Data
Proces
Report
Gener.
Alarm
Log
Archive
Recipe
Managt
Commercial DB RT DB
SQL
Alarm DB
Log DB
Archive DB
Ref. DB
Project
Editor
The products are
- multi-tasking: run under UNIX/VMS: more advanced on NT; 1 on Linux
- based upon a real-time database (RTDB) in 1or more servers.
- Servers: perform data acquisition and handling (e.g. polling controllers, alarm checking, calculations, logging and archiving)
Internal Communication
Server-client and server-server communication:
- publish-subscribe and event-driven,
-TCP/IP protocol,
i.e., a client application subscribes to a parameter ‘owned’ by a server: only changes are transmitted
Access to Devices
- data servers poll the controllers at a user defined polling rate.
- polling rate may be different for different parameters.
- controllers pass the requested parameters to the data servers.
- Time stamping of the process parameters is performed in the controllers
ODBC: Open Data Base Connectivity DDE: Dynamic Data Exchange
API: Application Program Interface OPC: OLE for Process Control
ODBC
Commercial
Devel.
tool
Data R/W
DDE
Driver
Toolkit
API/DLL
Private
Application
EXCEL
Driver
OPC
VME
PLC
PLC
Oct. 2000
PCaPAC' DESY

11. SCADA functions (1): MMI
- Library of "generic" symbols with TAG links
- Dynamic linking of parameters to graphics
- On-line configuration and customisation of MMI
- Links can be created between display pages
- Animation and multimedia facilities
Oct. 2000
PCaPAC' DESY

12. SCADA functions (2) * ! Experience @ DESY Alarm Handling
Based on limit and status checking *
More complicated expressions developed by creating derived parameters *
Alarms are time stamped and logically centralised *
Notifications (audible, visual, , GSM)
Multiple alarm priority levels
Grouping of alarms and handling of groups is possible
Suppression and masking of alarms either individually or as a complete group
Filtering of alarms is possible
DESY experience: how alarms can be implemented
( see slide 26)
* ! DESY
Oct. 2000
PCaPAC' DESY

13. SCADA functions (3) Trending Multiple trending charts
Charts are pre-defined or configured on-line
Charts contain multiple pens,
Zooming, scrolling, panning, ‘Hairline’
Real-time and historical trending
Write data to RDB
Oct. 2000
PCaPAC' DESY

14. SCADA functions (4) Access Control Automation
Users organised in groups with a set of allocated privileges
Large number of groups possible
Privileges limit write access to process parameters
Some allow access to graphics and functionality to be limited
Automation
Actions can be initiated automatically triggered by an event *
Recipes
Sequencing and scripting possibilities
Automation
a scripting lnguage is provided to define automatic action like:
- load a particular display,
- send an , run a user defined application or script and write to the RTDB.
- Recipes: allow particular system configuration can be saved to a file and then re-loaded at a later date.
- Sequencing : allow to execute a complex sequence of actions on one or more devices
Oct. 2000
PCaPAC' DESY

15. SCADA functions (5) * ! Experience @ DESY Logging, Archiving
Data stored in compressed and proprietary format
Logging / Archiving either for a set number of parameters or for a set period of time
Logging / Archiving can be frequency or event driven *
Logging of user actions together with a user ID
VCR facility for playback of stored data
Writing logs into RDB
Report Generation
Reports created using SQL type queries to the RTDB or logs
Automatic generation, printing and archiving of reports
Use of ‘components’ for report generation
* ! DESY
Oct. 2000
PCaPAC' DESY

16. Interfaces to H/W and S/W
Multiple communication protocols supported in a single system (in particular CERN supported Field busses)
Support for major PLCs/DCSs but not VME
S/W
API
ODBC, DDE and OLE I/F to PC Products
OPC Client and OPC Server
ActiveX Containers
Web clients
H/W
multiple communications protocols supported by 1 server:
- in general as many such protocols as it has slots for interface cards
S/W
- Application Program Interface (API): supporting C, C++, VB
- Open Data Base Connectivity (ODBC) interface to the data in the archive/logs, but in general not to the configuration database
- OPC: a lack of devices/controllers, which provide OPC server software, but this improves rapidly
Oct. 2000
PCaPAC' DESY

17. Development Tools Project editor Graphics editor
Configuration through parameter templates
Scripting language
Most processing tools based on IEC 1131
Batch configuration according to S88.1
Driver Development Tool Kit
Project Editor:
- to configure the system; stores configuration data in a Configuration or Reference database that is:
- generally of proprietary format
- logically centralised
- physically distributed
Graphics Editor:
- standard drawing facilities, lines, squares, circles, freehand etc
- library of generic symbols that can be linked to variables and animated
- links between views to navigate
Oct. 2000
PCaPAC' DESY

18. Evolution Frequent new versions
From “tag/ channel-based” to “device oriented”
Multi-team development
Web technology, Active X, Java, etc.
OPC for internal communication
Etc
Frequent new versions:
-1 major, up to 2 minor / year
To take advantage of:
- new market opportunities,
- new requirements
- evolution of technology
Tag-based or Channel-based <-> device oriented
Industrial applications grow in size and complexity (2 examples of 1 M I/O channels under development).
Therefore:
- design the SCADA systems to handle devices and subsystems as full entities that encapsulate all their specific attributes and functionality
Oct. 2000
PCaPAC' DESY

19. Why is OPC Data Access needed?
Display
Application
Trend
Application
Report
Application
Software
Driver
Software
Driver
Software
Driver
Software
Driver
This slide illustrates what we call ‘The I/O Driver Problem’.
Clearly each software driver requires a unique, device specific chunk of code for the device or network it wants to connect to.
That is not a problem we are trying to address. That is something fieldbus is trying to address, and devicenet, and profibus, and lonworks, and a bunch of others.
The problem we needed to deal with was that each of these software drivers also presented a different Software interface to the calling application.
As a result, each application also requires a unique, chunk of code for each driver, device or network it wants to connect to.
Nobody was enjoying this situation.

20. How does OPC Solve the Problem?
Display
Application
Trend
Application
Report
Application
OPC
OPC
OPC
OPC
OPC
OPC
OPC
Software
Driver
Software
Driver
Software
Driver
Software
Driver
OPC Solvs this problem be creating a ‘software bus’
Applications need only know how to get data from OPC data sources. As a result, they are simpler, smaller and easier to use.
Device Drivers (servers) need only know how to provide data in a single format (OPC Server). As a result they are easier to write (and there is more of a market for such servers).

21. Where does OPC Data Access Fit?
OPC (via DCOM)can also
be used between subsystems
and Management Consoles
Data Monitor
SubSystem
OPC is generally used
between Monitoring
applications and I/O specific
software drivers
OPC
While the MAIN problem we want to solve is the ‘I/O Driver’ problem, OPC is flexible enough to be used not only between Devices and SCADA, SoftPLC or DCS systems, but also between the SCADA SoftPLC or DCS engines and the high level applications such as HMI, Trends, Reports, etc. which use their data.
Note that in this architecture, the SCADA system, the DCS system or the SOFTLOGIC system really just represents a ‘smarter’ device.
Low level sensors
Typically use a dedicated
Hardware Interface and protocol
Device Specific
I/O Control
Oct. 2000
PCaPAC' DESY

22. Benefits of SCADA Standard frame for application
Rich functionality ( p-yrs investment)
Reliability and Robustness (very large installed base, mission critical processes)
Limited specific development
Technical support and maintenance
….. Etc
Standard framework for Applications:
particularly interesting in case of large collaborations as for the CERN LHC experiments as it ensures a common framework for:
- development of applications
- operation of the detectors: same look and feel whatever part of the experiment is controlled
Oct. 2000
PCaPAC' DESY

23. Let’s go for it ! ??? Let’s go for it !
More Aspects to take into Account:
Configuration of SCADA Systems
Data Access Mechanism’s
DESY Experience:
Namespace: flat vs. OO
System Load
Network
Processor
Project Management
Oct. 2000
PCaPAC' DESY

24. Configuration of SCADA Systems
Field Bus
Data Server
PLC’s
Different Namespaces!!
Oct. 2000
PCaPAC' DESY

25. Configuration of SCADA Systems 2nd
PLC
SCADA
Communication
Processor
Programs
Analog-Input
Value-AI-0
Value-AI-1
Analog-Output
Value-AO-0
Value-AO-1
Analog-Input
Vacuum_VALUE
Pressure_VALUE
Analog-Output
Valve_1_OUT
Heater_1_OUT
Mapping
Field Bus
Oct. 2000
PCaPAC' DESY

26. Configuration of SCADA Systems 3rd (Alarms)
Data Server
Alarm Generation
Analog-Input
Vacuum_VALUE
Pressure_VALUE
Analog-Output
Valve_1_OUT
Heater_1_OUT
(generic) Alarm scripts:
IF (Pressure_VALUE > Pressure_HIHI_ALARMVAL)
{Pressure_ALARM_HIHI=TRUE
Pressure_ALARM_STATE=CRITICAL
Pressure_ALARM_COLOR=RED }
IF (Pressure_VALUE < Pressure_LOLO_ALARMVAL)
{Pressure_ALARM_LOLO=TRUE
Pressure_ALARM_STATE=ATTETION
Pressure_ALARM_COLOR=BLUE }
Oct. 2000
PCaPAC' DESY

27. Winnings !!!
How many individual Tags did I create up to now in my example? 17 8 10 10 4
Vacuum_VALUE
Pressure_VALUE
Valve_1_OUT
Heater_1_OUT
Pressure_VALUE
Pressure_HIHI_ALARMVAL Pressure_ALARM_HIHI Pressure_ALARM_STATE Pressure_ALARM_COLOR
Pressure_LOLO_ALARMVAL Pressure_ALARM_LOLO
Pressure_ALARM_STATE
Pressure_ALARM_COLOR 4 4 2
Oct. 2000
PCaPAC' DESY

28. Data Access Mechanism's
Alarm Server
Alarm Server typically poll data from the data server
( -> impact on network bandwidth)
More advanced techniques like publish / subscribe are available in some cases
Data from field buses are mainly polled
Asynchronous protocols are difficult to handle
Data Server
Polling
Polling
Field Bus
Oct. 2000
PCaPAC' DESY

29. DESY Experience 1st Namespace System Load
Individual tags for each property blow up the namespace
Flat namespaces of thousands of tags can not be properly handled without adequate tools
Latest SCADA technology clearly shows the trend to support the definition of objects which cleans up the namespace
System Load
Additional –non standard- features like
calculating alarms for each channel
temperature conversions ( 6th grade polynomial)
... can cause a lot of overhead which needs to be taken into account for the calculation of the system load on process controllers ( here: in a SCADA-like DCS system)
Oct. 2000
PCaPAC' DESY

30. DESY Experience 2nd Project Management
Small systems can be easily handled with in-house personal
Big systems (several thousand of channels) should be coordinated by an engineering office because of:
The coordination of the Field Bus (PLC) databases and the SCADA databases
The knowledge of the various tools which come along with a SCADA system
One of the main arguments for SCADA systems is: outsourcing
Oct. 2000
PCaPAC' DESY

31. Let’s go for it ! ??? Let’s go for it ! ???
Utility DESY use EPICS as a SCADA system
H1 is going to use PVSS for their slow controls
There‘s no alternative for big projects like TESLA
Various subsystems can be controlled by SCADA systems:
Utility Controls (water, energy, air, heating...)
Cryogenic Controls (cryogenic plants, cryogenic distribution)
Vacuum Systems (insulation vacuum, beam vacuum)
Special developments i.e. for RF control should have a ‚SCADA-aware‘ design
Oct. 2000
PCaPAC' DESY

32. Is SCADA the only Future ? ...
New Technology: JetWeb
Each node is an individual Web Server
All nodes and all I/O hooked up to the Ethernet
... probably not, but a very attractive one.
Oct. 2000
PCaPAC' DESY

33. That’s all Folks
Oct. 2000
PCaPAC' DESY