F.Carena, CERN/ALICE The ALICE Experiment Control System F. Carena / CERN-PH

F.Carena, CERN/ALICEF.Carena, CERN/ALICE

The ALICE Experiment The ALICE Experiment Control SystemControl System

F. Carena / CERN-PHF. Carena / CERN-PH

F.Carena, CERN/ALICEF.Carena, CERN/ALICE 210 October 2005, ICALEPCS 2005, Geneva10 October 2005, ICALEPCS 2005, Geneva

IntroductionIntroduction ALICE (A Large Ion Collider Experiment) is the heavy-ion ALICE (A Large Ion Collider Experiment) is the heavy-ion

experiment being prepared for the Large Hadron Collider (LHC) at experiment being prepared for the Large Hadron Collider (LHC) at CERNCERN


IntroductionIntroduction ALICE consists of many particle detectors that can be operated:ALICE consists of many particle detectors that can be operated:

All together to collect All together to collect experimental dataexperimental data As standalone, independent objectsAs standalone, independent objects

• In the present test and commissioning phaseIn the present test and commissioning phase• In the future, final setup for calibration and test purposesIn the future, final setup for calibration and test purposes

Running the experiment implies performing a set of activities on the Running the experiment implies performing a set of activities on the detectors. These activities belong to different domains:detectors. These activities belong to different domains: Detector Control System (Detector Control System (DCSDCS)) Data Acquisition (Data Acquisition (DAQDAQ)) Trigger system (Trigger system (TRGTRG)) High Level Trigger (High Level Trigger (HLTHLT))

Every domain of activities requires some form of controlEvery domain of activities requires some form of control In ALICE independent ‘online systems’ have been developed to In ALICE independent ‘online systems’ have been developed to

control the different domains control the different domains


IntroductionIntroduction The existing, independent ‘online systems’The existing, independent ‘online systems’

Operate with all the detectorsOperate with all the detectors Allow partitioning (partitioning is the capability to concurrently Allow partitioning (partitioning is the capability to concurrently

operate groups of ALICE detectors)operate groups of ALICE detectors) The Experiment Control System (ECS) must coordinate the The Experiment Control System (ECS) must coordinate the

operations controlled by the ‘online systems’ for every detector in operations controlled by the ‘online systems’ for every detector in every partitionevery partition

The ECS is a layer of software on top of the existing ‘online The ECS is a layer of software on top of the existing ‘online systems’. It gets status information from the ‘online systems’ and systems’. It gets status information from the ‘online systems’ and sends commands to them through interfaces based on Finite State sends commands to them through interfaces based on Finite State Machines (FSM)Machines (FSM)

Access control mechanisms in the interfaces manage the ECS rightsAccess control mechanisms in the interfaces manage the ECS rights ‘‘online systems’ under the ECS controlonline systems’ under the ECS control ‘‘online systems’ operated as independent systemsonline systems’ operated as independent systems


PartitionsPartitions A partition is a group of detectors identified by a name and defined A partition is a group of detectors identified by a name and defined

by:by: A list of ’assigned’ detectors. It contains the names of the A list of ’assigned’ detectors. It contains the names of the

detectors that detectors that can becan be activeactive in the partition in the partition A list of ‘excluded’ detectors. It contains the names of the A list of ‘excluded’ detectors. It contains the names of the

detectors that are assigned to the partition but detectors that are assigned to the partition but are not activeare not active (active in another partition, operated in standalone mode, or (active in another partition, operated in standalone mode, or because of explicit operator request)because of explicit operator request)

Two types of operations are possible within a partition:Two types of operations are possible within a partition: Global operations involving all the active detectorsGlobal operations involving all the active detectors Individual detector operations involving one single detectorIndividual detector operations involving one single detector

• Individual detector operations can be concurrently performed Individual detector operations can be concurrently performed within a partition (e.g. parallel calibration procedures of within a partition (e.g. parallel calibration procedures of different detectors)different detectors)

GlobalGlobal and and individual detector operationindividual detector operation are mutually are mutually exclusiveexclusive


PartitionsPartitions The handling of global operations in a partition requires the The handling of global operations in a partition requires the

coordination of coordination of the the DCSDCS for for allall the active detectors the active detectors the the DAQDAQ Run Control that steers the data acquisition for the Run Control that steers the data acquisition for the

partitionpartition the Trigger Partition Agent (the Trigger Partition Agent (TPATPA) that connects the partition to ) that connects the partition to

the Central Trigger Processor (the Central Trigger Processor (CTPCTP))

DCS_1DCS_1

TPATPA

DAQ_RCDAQ_RCDCS_2DCS_2

DCS_3DCS_3


PartitionsPartitions

The handling of an individual detector operation in a partition The handling of an individual detector operation in a partition requires the coordination of requires the coordination of the the DCSDCS for for oneone detector detector the the DAQDAQ Run Control that steers the data acquisition for the Run Control that steers the data acquisition for the

detectordetector the Local Trigger Unit (the Local Trigger Unit (LTULTU) associated to the detector) associated to the detector

DCSDCS

LTULTU

DAQ_RCDAQ_RC


Standalone detectorsStandalone detectors A standalone detectors is a detector operated A standalone detectors is a detector operated

out of all the defined partitions out of all the defined partitions totally disconnected from the Central Trigger Processor (totally disconnected from the Central Trigger Processor (CTPCTP))

The handling of a standalone detector requires the coordination of The handling of a standalone detector requires the coordination of the the DCSDCS for the detector for the detector the the DAQDAQ Run Control that steers the data acquisition for the Run Control that steers the data acquisition for the

detectordetector the Local Trigger Unit (the Local Trigger Unit (LTULTU) associated to the detector) associated to the detector

DCSDCS

LTULTU

DAQ_RCDAQ_RC


ComponentsComponents The main components of the ECS are the Partition Control Agent The main components of the ECS are the Partition Control Agent

(PCA), the Detector Control Agent (DCA), the PCA Human Interface (PCA), the Detector Control Agent (DCA), the PCA Human Interface (PCAHI), and the DCA Human Interface (DCAHI) (PCAHI), and the DCA Human Interface (DCAHI)

There is one PCA per partitions.There is one PCA per partitions. Handles global operations in the partitionHandles global operations in the partition Delegates individual detector operations to the DCAsDelegates individual detector operations to the DCAs Handles the structure of the partition (inclusion/exclusion of Handles the structure of the partition (inclusion/exclusion of

detectors)detectors) Accepts commands from one PCAHI at a timeAccepts commands from one PCAHI at a time

PCAHIPCAHIMaster Master

OperatorOperator

PCAHIPCAHI

PCAPCA


ComponentsComponents There is one DCA per detectorThere is one DCA per detector

When the detector is in standalone modeWhen the detector is in standalone mode

• Handles standalone operationsHandles standalone operations

• Accepts commands from a DCAHI at atimeAccepts commands from a DCAHI at atime When the detector is active in a partitionWhen the detector is active in a partition

• Handles individual detector operations within the partitionHandles individual detector operations within the partition

• Accepts commands from the PCA onlyAccepts commands from the PCA only

PCAHIPCAHIMaster Master

OperatorOperator

DCADCAPCAPCA

DCAHIDCAHIDCAHIDCAHIMaster Master

OperatorOperator

DCADCA

DCAHIDCAHI


DCA Human InterfaceDCA Human Interface

PCA Human InterfacePCA Human Interface


ArchitectureArchitecture Example of architecture with 3 detectors (SDD, SPD, and SSD)Example of architecture with 3 detectors (SDD, SPD, and SSD)

The SDD detector is operated in standalone modeThe SDD detector is operated in standalone mode SPD and SSD are active in a partition called ITSSPD and SSD are active in a partition called ITS


InterfacesInterfaces The components of the ECS get status information from the ‘online The components of the ECS get status information from the ‘online

systems and send commands to them through interfaces based on systems and send commands to them through interfaces based on Finite State Machines (FSM)Finite State Machines (FSM)

The FSM package used for these interfaces is SMI++The FSM package used for these interfaces is SMI++

http://www.cern.ch/smihttp://www.cern.ch/smi

The interfaces also contain access control mechanisms that allow to The interfaces also contain access control mechanisms that allow to control the rights granted to the ECS. The ‘online systems’ can be control the rights granted to the ECS. The ‘online systems’ can be under the control of the ECS or be operated as independent systems: under the control of the ECS or be operated as independent systems: in this case the ECS get status information but does not send in this case the ECS get status information but does not send commands commands


ECS/DCS interfaceECS/DCS interface


ECS/TRG interfaceECS/TRG interface


ECS/DAQ, ECS/HLT ECS/DAQ, ECS/HLT interfacesinterfaces

The interface between the ECS and the The interface between the ECS and the DAQDAQ is made of SMI objects is made of SMI objects representing Run Control processesrepresenting Run Control processes An RC process per detector. Every RC process steers the data An RC process per detector. Every RC process steers the data

acquisition for a given detector and for that detector onlyacquisition for a given detector and for that detector only An RC process per partition to steer the data acquisition for the An RC process per partition to steer the data acquisition for the

whole partition with data produced by all the active detectorswhole partition with data produced by all the active detectors

The ECS gets status information through a single SMI object The ECS gets status information through a single SMI object representing the representing the HLTHLT ‘online system’ as a whole.‘online system’ as a whole.


ITS combined testITS combined test In October 2004 the ECS has been used to control the combined test In October 2004 the ECS has been used to control the combined test

of the ALICE Inner Tracking System consisting ofof the ALICE Inner Tracking System consisting of 3 detectors3 detectors

• Silicon Drift Detector (SDD)Silicon Drift Detector (SDD)

• Silicon Pixel Detector (SPD)Silicon Pixel Detector (SPD)

• Silicon Strip Detector (SSD)Silicon Strip Detector (SSD) Trigger SystemTrigger System

• 3 LTUs3 LTUs

• Special version of the TPASpecial version of the TPA DAQ SystemDAQ System

• 4 independent data acquisitions4 independent data acquisitions Dummy DCS system for the 3 detectorsDummy DCS system for the 3 detectors


ITS test setupITS test setup

SDDSDD SPDSPD SSDSSD

LL

DD

CC

LL

DD

CC

LL

DD

CC

GG

DD

CC

CONTROLCONTROL

Fast EthernetFast Ethernet

DD

DD

LL

DD

DD

LL

DD

DD

LL

Local Local disksdisks

SDD-LTUSDD-LTU SPD-LTUSPD-LTU SSD-LTUSSD-LTU

TPATPA

DAQ runControl DAQ runControl processesprocesses

ECS processes ECS processes (PCA+DCAs)(PCA+DCAs)


ResultsResults All the possible modes of operation were successfully testedAll the possible modes of operation were successfully tested

3 detectors in standalone mode3 detectors in standalone mode Any combination of 2 detectors running together and the 3Any combination of 2 detectors running together and the 3rdrd one one

in standalone modein standalone mode 3 detectors running together3 detectors running together

Switching from a mode of operation to another wasSwitching from a mode of operation to another was Fast (a few seconds)Fast (a few seconds) Totally transparent for the DAQ and the TRG ‘online systems’Totally transparent for the DAQ and the TRG ‘online systems’


ConclusionConclusion The ECS has been intensively developed during the last 18 monthsThe ECS has been intensively developed during the last 18 months The architecture and the interfaces have been implemented and The architecture and the interfaces have been implemented and

successfully tested during the ITS combined test beamsuccessfully tested during the ITS combined test beam Some developments are still neededSome developments are still needed

Several detectors have not yet implemented a DCS based on FSM Several detectors have not yet implemented a DCS based on FSM and therefore the DCS states are not yet included in the ECSand therefore the DCS states are not yet included in the ECS

Some detectors have not yet developed their calibration Some detectors have not yet developed their calibration proceduresprocedures

Some information like the definition of the Trigger classes is not Some information like the definition of the Trigger classes is not available yet (temporary definition used for the time being)available yet (temporary definition used for the time being)

The above issues will be included as soon as available. The above issues will be included as soon as available. The ECS The ECS architecture has been proved to be solid and flexible enough to architecture has been proved to be solid and flexible enough to include all the future extensions.include all the future extensions.

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F.Carena, CERN/ALICE The ALICE Experiment Control System F. Carena / CERN-PH