3-Feb-2011CS-Workshop 2011, Dietrich Beck Overview CS-Framework Introduction (Over)view Lessons...
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Transcript of 3-Feb-2011CS-Workshop 2011, Dietrich Beck Overview CS-Framework Introduction (Over)view Lessons...
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Overview Overview CSCS-Framework-Framework
• Introduction
• (Over)view
• Lessons Learned
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Starting Point (Starting Point (2001)2001)
• Control System– Control devices (power supplies, function generators, timing, complex
experimental procedure…)– No process control– DAQ and data processing is only a minor issue– Integrate things that were not developed to work together as a system
• Ever changing set-up– The same experiment is never done twice– Reconfiguration of complete hardware (seconds!)– Integration of new hardware (next beam-time)
• Small and medium size experiments– No dedicated staff for control systems– Different experiments but similar problems to solve (configuration,
complex timing schemes, similar hardware,…)• … What about a “Framework”?
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
"Framework""Framework"
Wikipedia: “…a software framework is an abstraction in which common code providing generic functionality can be selectively overridden or specialized by user code, thus providing specific functionality…”
• Common Code – Standardization – re-usability of software components– maintainability of software components– same look and feel at different experiments– ease transfer of know-how
• User Code - Specialization– concentrates on experiment specific requirements– extension of framework, specializing code
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Different Points of View – A Framework is...Different Points of View – A Framework is...
Developer: User:
picture pocket knife
... a tool box ... something ready to use
(sth. to solve a problem) without additional work
(= the solution!)
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Definition of the Definition of the CSCS-Framework-Framework
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
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
PHELIX PHELIX (Petawatt High-Energy Laser for Heavy Ion Experiments)(Petawatt High-Energy Laser for Heavy Ion Experiments)
UNILAC
Z6
SIS
PHELIX
HHT
Injection box
Mai
n A
mp
lifi
erS
enso
rFaraday
Isolator
Switch Yard
Compressor
Target Chamber
fs Front End
Fiber ns Front End
Pre-amplifier2 x 19 mm heads1 x 45 mm head
X-ray Lab(low energy)
TW compressor
Target chamber
Z6 experimental
area
Heavy ions
Laser Bay
Double-pass 31.5 cm amplifier
70 m
(slide by S. Götte, GSI)
Up to 3 MJ electrical energy converted to 1kJ light energy or 0.5 Petewatt laser power. 2300 documented “shots” (Dec. 2010). About 10k process variables distributed on 15+ nodes in 2 buildings
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Quad-Triple Trap Mass Spectrometer ISOLTRAPQuad-Triple Trap Mass Spectrometer ISOLTRAPHigh-precision mass determination of unstable nuclei with a Penning trap mass spectrometer at ISOLDE/CERN High-precision mass determination of unstable nuclei with a Penning trap mass spectrometer at ISOLDE/CERN
www.cern.ch/isoltrap
– Nuclear-, Astro-, Fundamental PhysicsNuclear-, Astro-, Fundamental Physics
m/m m/m 10 10-8 -8 (typically!)(typically!)
– via cyclotron frequency of stored ionsvia cyclotron frequency of stored ions
– ““sub-µs ion-juggling” every secondsub-µs ion-juggling” every second
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Cooking Recipe for the Cooking Recipe for the CSCS Framework Framework
• One development tool LabVIEW
• Standardization object oriented approach, base classes
• 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
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Event Driven CommunicationEvent Driven Communication
• DIM (www.cern.ch/dim) – Peer-to-peer connection, no intrinsic bottle neck– Named service as concept (a name server aids in setting up connections)– “service”: publisher-subscriber-pattern, one-to-many– “command service”: command-pattern, many-to-one
• CS objects communicate via– DIM services: publishing/subscribing to state information– DIM commands:
• triggering actions• synchronous commands (timeout, “expire date”,…)
• everybody may talk to everybody
• Events provide the interface between– device object and it’s GUI object– device object and application layer– hierarchical state machines– …
• Design Approach - First: communication layer, Second: framework• Connectivity to other programming languages and OSs
Caller Callee
Back-end (SCADA, GUI, ...)
Middleware (communication,.)
Front-end (devices, drivers, ...)
3-layers
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
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)
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Standardization ofStandardization of Services and Cmds Services and Cmds_birthday, time/date of creation
_classID, class name
_condition, object created successfully…
_systemID, name of (sub)system
_accessID, reservation mechanism...
_evtCounter, number of cmds received
status of threads… Ping, thread alive?
GetDescriptors (Introspection!!!)
Reset (override by child classes)
…
_deviceGUI, name of GUI class Initialize, init interface
_deviceID, ID string of device Close, close interface
_deviceState, OK, ERROR, … IDQuery, query device ID
… …
_nomFrequency, frequency set-value SetFrequency, sets nominal value
_actFrequency, frequency get-value GetFrequency, gets actual value
… …
CSObjTHE base class
CAEObjsend/rec. events
BaseProcessthreads for eventsand periodic action
DeviceBasebasic deviceproperties
AFGBasearbitrary function
generator…
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
(Over)view (Over)view CSCS-Framework-Framework
• Introduction
• (Over)view
• Lessons Learned
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
SourceForge: downloads, tracker (bugs, features,…)SourceForge: downloads, tracker (bugs, features,…)
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
SCC via SubVersion @ GSISCC via SubVersion @ GSI
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Domain Management System: Domain Management System: Process Management in a Distributed EnvironmentProcess Management in a Distributed Environment
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Process MonitoringProcess Monitoring
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
PackagingPackaging
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Documentation via WikiDocumentation via Wiki
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Class Documentation via UML ToolsClass Documentation via UML Tools
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Status Status CSCS-Framework-Framework
• Introduction
• Over(view)
• Lessons Learned
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned – What Users say about Lessons Learned – What Users say about CSCS(from a talk by Stefan Götte, at the NI BIG PHYSICS Round Table, Paris, 2009)
Stress Field of the Responsible Person:• The OS (XP) and/or the intranet are always unreliable,• the programming language (LabVIEW) never really fulfills the need,• the framework (CS) is only close to the requirement,• the classes of other CS collaborators are typically not usable,• there is no way to test things since there is no test system available
while the real system is always in use, • the users never define what the program has to do, but• are not pleased with what the programmer delivers, and• they misuse the system additionally.• Anyhow: The goal is an easy system where the happy user does not
realize what happens behind the scene, which works reliable and for ever (better: till the next LabVIEW version is installed).
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
““The OS (XP) and/or the intranet are always The OS (XP) and/or the intranet are always unreliable” (assumption for design phase)unreliable” (assumption for design phase)
Design principles of major importance• A control system must be designed to crash and• (auto-)recover from failures of all kinds
– Fileserver down– Computer down/reboot
• Installation of updates• Switched-Off/On by users• …
– Network down– Power cuts– …
• The system is stressed most, when– everything goes wrong (failures, alarms, sub-system crash…) and– all kinds of asynchronous signals fire at the same time (self-induced
DoS-Attack) and– availability is most important.
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned – What Users say about Lessons Learned – What Users say about CSCS(from a talk by Stefan Götte, at the NI BIG PHYSICS Round Table, Paris, 2009)
Stress Field of the Responsible Person:• The OS (XP) and/or the intranet are always unreliable,• the programming language (LabVIEW) never really fulfills the need,• the framework (CS) is only close to the requirement,• the classes of other CS collaborators are typically not usable,• there is no way to test things since there is no test system available
while the real system is always in use, • the users never define what the program has to do, but• are not pleased with what the programmer delivers, and• they misuse the system additionally.• Anyhow: The goal is an easy system where the happy user does not
realize what happens behind the scene, which works reliable and for ever (better: till the next LabVIEW version is installed).
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned - DocumentationLessons Learned - Documentation
The fundamental problem about documentation• Two lines of text are not enough, but• Two pages of docs – (almost) nobody will read that*
• Docs out of date …
Solutions• HOW-TOs, FAQs• Auto-generated documentation
– Class documentation, CS2JavaUML– Requires well documented code (again: coding conventions!)– Release notes
• Demo-system (delayed…)
* sometimes not even the first two lines…
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned – Generic/Common ToolsLessons Learned – Generic/Common Tools
Generic tools (generic control system GUI, generic device GUIs)
• Sometimes difficult to understand ( documentation problem)
• Lot’s of work to maintain
• Don’t match the users’ needs exactly
• Either– least common denominator (missing features), or– include all requested features (too complex)
“Nobody likes them, but everybody uses them.”
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned – Missing FeaturesLessons Learned – Missing Features
Identifying missing features sometimes
• requires telepathic skills
• results in cool solutions that are finally not used (nice to have versus really useful)– CS Access System– Sequencer– ObjectNets, PetriNets– some base classes
• …
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned – CompatibilityLessons Learned – Compatibility
Backward Compatibility (“does my old code still work?”)
• Is maybe THE most important feature of a framework
• Often results in a impressive mix of different versions (core system v1, base classes v2, GUI v4, device classes v3,…)
• Makes it hard to correct wrong design decisions
• Requires clear public library routines or class methods, but…
• using conventions on what is public/private does not work
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Lessons Learned – The “Saving-Time-Myth”Lessons Learned – The “Saving-Time-Myth”
Wikipedia: “…software frameworks … reducing overall development time” (?)
Amount of time for solving a problem• decreases dramatically, if a problem may be solved with
(generic) existing software. “configuration instead of coding”• does not change – but the solution is much better• may even increase (short-term), compared to a dedicated
solution not (!) using the framework (required: training, courses, understanding and application of conventions)
• decreases (long-term): framework maintained by others, re-usability of code, replacing hardware, coding conventions enforced, maintainability, common language, know-how transfer, …
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
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
commissioningcommissioningFOPIFOPI
RISINGRISING
others ...others ...HITRAPHITRAP LPTLPT
TrigaTRAPTrigaTRAP
ClusterTRAPClusterTRAP
POLARIS, HIJPOLARIS, HIJ
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Conclusion and OutlookConclusion and Outlook
• CS 3.21 released for LV2009.
• about 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.
3-Feb-2011 CS-Workshop 2011, Dietrich Beck
Acknowledgements...Acknowledgements...
Holger Brand, Dietrich Beck, Mathias Richter, 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, Martin Feldmann, IT@GSI, ……………...