11 March 2008IT&EE Palaver, Dietrich Beck Neues vom CS-Framework Motivation Grundlagen Entwicklungen der letzten Jahre Status und Ausblick

11 March 2008 IT&EE Palaver, Dietrich Beck

Neues vomNeues vom CSCS-Framework-Framework

• Motivation

• Grundlagen

• Entwicklungen der letzten Jahre

• Status und Ausblick


Definition of "Framework"Definition of "Framework"

Wikipedia: "A software framework is a reusable design for a software system. ... (It) may include support programs, code libraries, a scripting language, or other software to help develop and glue together the different components of a software project..."

freie Übersetzung: "Ein Software Framework ist ein wieder verwertbares Design für ein Software system. ... (Es) kann Hilfsprogramme, Code-Bibliotheken, ein Scripting-Werkzeug und andere Software enthalten, die es erlauben, verschiedene Komponenten für ein konkretes Softwareprojekt zu entwickeln und zusammenzufügen."


Why Frameworks for Control SystemsWhy Frameworks for Control Systems

• standardization of code– re-usability of software components– maintainability of software components– ...

• flexibility– exchange of hardware during run-time– add/remove hardware during run-time– change operational states on-the-fly– ...

• common solutions– same look and feel at different experiments– ease transfer of know-how

• ...


Definition of the Definition of the CSCS framework framework

• optional usage of sequencers (= sequences of commands)

• optional usage of state machines (= states and actions)

• optional GUIs on the device level

• optional interfaces to control systems of accelerator and DAQ

• standardization via a framework, here: ControlSystem framework

Main emphasis: device control, not process control

Back-end (SCADA, GUI, ...)

Middleware (communication, ...)

Front-end (devices, drivers, ...)

Ansatz: "Three-layer architecture"


Definition of the Definition of the CSCS frameworkframework

control system = framework + add-ons

EE/KS

and contributors

experiment

bug reports, new features requested

add-ons may become part of framework

bug fixes, new features, maintenance

CycleControl

AFGTiming+DAQ HV

GUI


Different Points of View – A Framework is...Different Points of View – A Framework is...

Developer: User:

... a tool box ... something ready to use

(sth. to solve a problem) without additional work

(= the solution!)


Cooking Recipe for the Cooking Recipe for the CSCS Framework Framework

• One development tool LabVIEW

• Standardization object oriented approach

• Distribution to many nodes DIM (www.cern.ch/dim) – Event driven communication for everything

– Scaling to large systems by distribution

– Remote access

– …

• SCADA functionality (alarming, trending, …) LabVIEW DSC module

http://www.cern.ch/dim


LabVIEW is...LabVIEW is...

• ...just another programming language.– graphical programming instead of text based programming– dataflow paradigm

• ...an enormous collection of tools and libraries.


Object Orientation (OO) with Object Orientation (OO) with CSCS

• "BaseClass" provides basic functionality (communication layer, active threads, ...)

• "DeviceClass" adds functionality according to specs of device type "DS345".

• Instantiation: one object per device

"BaseClass"

"Device Class"

inheritance

AFG1AFG2

AFG3

• of course: classes for GUIs, Sequencer, State machines, ...

• OO implemented by CS using pure LabVIEW (no LVOOP)


Example for a Simple Control SystemExample for a Simple Control SystemUser PC n

Control GUIOn-line Analysis GUI

Central PC

Sequencer

DataCollector DSC EngineDSC Interface

SR430 FPGA DS345

Front-end PC 1

Data Acquisition

DataAcq. Instr. Driver

Timing

Timing Instr. Driver

AFG

AFG Instr. Driver

High Voltage

HV Instr. Driver

IHQF015p

Hardware Software (Proc) Software (Lib) Exp. Specific General Part Buy! Event OPC

Front-end PC n

DiscArchiver


Developments During the Past YearsDevelopments During the Past Years

1. project managementa. CS as Open Source Project on SourceForge

b. CS Wiki-Page @ GSI

c. source code control using Subversion

2. DIM as communication layer

3. Domain Management System for process management

4. CS for different operating systems (Windows, Linux, Pharlap)

5. reservation mechanisms for sub-systems

6. device base classes

7. configuration database

8. stability and performance


CS-CS-Wiki @ GSIWiki @ GSI


Statistics from SourceForgeStatistics from SourceForge

• among top 1% of SourceForge projects

• > 800 downloads of CSMain

• 29 packages (of 2 maintainers)

• 42 (open 3) bugs

• 30 (open 1) feature requests

• 16 (open 2) patches

• 3 feature requests

• 8 developers


Distributing Distributing CSCS• developer: source code control via Subversion at GSI

• user: packages on SourceForge (+Unpackager)– dependency/conflict checking– package checking– installing packages– removing packages– downloading packages– ...– "three-click installation"


Communication Layer: DIMCommunication Layer: DIM• Distributed Information Management: www.cern.ch/dim

• originally developed at DELPHI@LEP/CERN around 1991

• available for a multitude of platforms and languages

• light-weight, aiming at high performance, based on TCP/IP

• today: "backbone" of control systems for LHC experiments

• concept: named services, peer-to-peer connections

DIM server A

DIM server B

DIM client 1

DIM client 2

service "i"

service "ii"

command "iii" DIM name server(negotiates connections)

http://www.cern.ch/dim


DIM-LabVIEW PerformanceDIM-LabVIEW Performance

Event rate of LabVIEW DIM interface: WinXP versus Linux, local versus remote, inter-process versus process-intern

1

10

100

1000

10000

100000

1 300 1000 3000 10000 30000 100000 300000 1000000 3000000 1E+07

Service Size [bytes]

Eve

nt

Rat

e [H

z]WinPC->WinPC (local)

WinPC->WinPC (int)

WinPC->LxPC

LxPC->WinPC

LxPC->LxPC(local)

LxPC->LxPC(int)

Throughput of LabVIEW DIM interface: WinXP versus Linux, local versus remote, inter-process versus process-intern

0.0001

0.001

0.01

0.1

1

10

100

1 300 1000 3000 10000 30000 100000 300000 1000000 3000000 1E+07

Service Size [bytes]

Th

rou

gh

pu

t [M

byt

es]

WinPC->WinPC (local)

WinPC->WinPC (int)

WinPC->LxPC

LxPC->WinPC

LxPC->LxPC(local)

LxPC->LxPC(int)


Domain Management System: Domain Management System: Process Management in a Distributed EnvironmentProcess Management in a Distributed Environment


Example: DMSViewerExample: DMSViewer


Device Base Classes: MotivationDevice Base Classes: Motivation

• Standardization of parameters for– events (command pattern, "call process")– services (publisher-subscriber pattern, status info)

• "Standard" defined by device model– arbitrary function generator– power supply– motor– ...

• Allows exchange of different hardware device types of the same device model

• Requires only one GUI for all classes of the same class model

• Defines interface/behavior for programming a device class


Class HierarchyClass Hierarchy

BaseProcess

DeviceBase

PSChannelBase

SimPowerSupply

PSChannelBaseGUI

BaseGUI


PSChannelBaseGUI Class (user view)PSChannelBaseGUI Class (user view)

• available via double-click in "GOG"

• one instance per power supply object

• one GUI class for all classes inheriting from the PSChannelBaseClass


Configuration versus ProgrammingConfiguration versus Programming• create objects during run-time

– identical binaries for different experiments possible

– application characterized by configuration

• configuration data base– presently using MS-Access

– device interfaces, bus-addresses,...

– access via TCP/IP

• settings "database"– typically as XML files

– ...

Back-end (SCADA, generic GUIs, ...)

Middleware (communication,

generic management of settings...)

Front-end (devices, drivers, ...)


Testing Stability and PerformanceTesting Stability and Performance• dedicated set-up including hardware for testing

– long term stability (months...)– interoperability of different versions– stress situations– performance– ...


Experiments using the Experiments using the CSCS framework... framework...

• require high flexibility

• have a large variety of hardware types

• have up to 10,000 (1M possible) process variables

• require fast ( 100 ns) timing control using dedicated hardware

PHELIXPHELIX

Motion CaveAMotion CaveASHIPTRAPSHIPTRAP

ISOLTRAPISOLTRAP

REXTRAPREXTRAP

LEBITLEBIT

GSI, GermanyGSI, Germany

Mainz, GermanyMainz, Germany

Greifswald, GermanyGreifswald, Germany

CERN, SwitzerlandCERN, Switzerland

MSU, USAMSU, USA

Lanzhou, ChinaLanzhou, China

data takingdata taking

developmentdevelopment

commissioningcommissioning

FOPIFOPI

RISINGRISING

others ...others ...HITRAPHITRAP LPTLPT

TrigaTRAPTrigaTRAP

ClusterTRAPClusterTRAP


Conclusion and OutlookConclusion and Outlook

• CS 3.10 released for LV8.2.1.

• about 10-15 active applications

• 1,000,000 PVs demonstrated, an even larger number should be feasible

• 5,000 objects ( hardware devices) demonstrated, an even larger number should be feasible

• stability of a distributed CS system is better than a few hundred hours of continuous operation

• about 15 (60) hardware devices supported on SourceForge (Subversion)

• FAIR: MATS and parts of HITRAP have selected CS as control system framework. NUSTAR? PANDA?


Acknowledgements...Acknowledgements...

Holger Brand, Dietrich Beck, Alexander Schwinn, Falk Ziegler, Romain Savreux, Chabouh Yazidjian, Klaus Blaum, Dennis Neidherr, Melanie Wolf, Stefan Schwarz, Josh Savory, Stefan Götte, Maximilian Kugler, Tobias Habermann, Michael Block, Frank Herfurth, Christian Rauth, Stephen Koszudowski, Manas Mukherjee, Thomas Rechel, ..., IT@GSI, ...


Event basicsEvent basics

• an entity waits for the next event, no polling!

• timeout handling is an important issue

publisher

subscriber subscriber subscriber

client client client

receiver

observer pattern: "one-to-many" command pattern: "many-to-one"

datacommand

example: radio, televisionadded in CS 3.0

example: typical human communicationsole possibility for CS < 3.0

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11 March 2008IT&EE Palaver, Dietrich Beck Neues vom CS-Framework Motivation Grundlagen Entwicklungen der letzten Jahre Status und Ausblick