André Augustinus 10 October 2005 ALICE Detector Control Status Report A. Augustinus, P. Chochula, G. De Cataldo, L. Jirdén, S. Popescu the DCS team, ALICE collaboration, CERN Geneva Switzerland

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 2 Outline  The ALICE experiment at CERN  Organization of the controls activities in ALICE  Design goals and strategy  DCS architecture  Key concepts  DCS infrastructure  Summary - Conclusion

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 3  ALICE is one of the four LHC experiments  Located at point 2 of the LHC at CERN  18 different sub-detectors, 2 magnets  Dedicated for heavy ion physics; participate in pp  1000 members, 86 institutes, 29 countries Introduction Located at point 2 of the LHC at CERN A Large Ion Collider Experiment

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 4 Introduction  Many sub-detector teams have limited expertise in controls, especially in large scale experiments  ALICE Controls Coordination (ACC) team put strong emphasis on coordination and support  Joint COntrols Project (JCOP) is a collaboration between CERN and all LHC experiments to exploit communalities in the control systems JCOP ATLAS CMS LHCb CERN (IT/CO) ALICE (ACC) SubDet

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 5 Design goals  DCS shall ensure safe and efficient operation Intuitive, user friendly, automation  Many parallel and distributed developments Modular, still coherent and homogeneous  Changing environment – hardware and operation Expandable, flexible  Operational outside datataking, safeguard equipment Available, reliable  Large world-wide user community Efficient and secure remote access  Data collected by DCS shall be available for offline analysis of physics data

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 6 Strategy and methods  Common tools, components and solutions Strong coordination within experiment (ACC) Close collaboration with other experiments (JCOP)  In ALICE there are many similar sub-systems  Identify communalities through User Requirements Collected in URD (lightweight) and Overview Drawings Through meetings and workshops

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 7 Hardware Architecture  3 layers: supervisory, control, and field layer Supervisory: operator nodes, server nodes Control: worker nodes connecting to devices Field: devices, sensors and actuators  Reduce sharing of equipment between sub-detectors  Standard hardware for computers  Limit diversity of devices in field layer Dependent on sub-detector hardware Use common hardware for similar tasks General Purpose Monitoring System  Interlocks and DSS for protection of equipment DSS is safe and reliable part of DCS

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 8 Software Architecture  A tree like structure; representing sub-detectors, sub-systems and devices Leaves (Device Units) ‘drive’ devices Nodes (Control Units) model and control sub-tree below Commands flow down, states flow up the tree  Operation is done from the root node Any sub-tree can be removed from tree and operated independently and concurrently : partitioning  Behaviour and functionality of a control unit is modelled as a Finite State Machine (FSM)

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 9 Software Architecture Commands States and alarms Each CU logically combines states and distributes commands

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 10 DCS key concepts  The FSM concept is fundamental to the DCS Intuitive and generic method to model behaviour of a system or a device An object has a well defined collection of states Moves between states by executing actions Triggered by an operator or an external event  DCS will interface to variety of Front End Electronics Front End Device (FED) concept: hides the implementation details through a common client-server interface (based on DIM)  Use common software tools: PVSSII, JCOP framework

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 11 Common solutions  Does not stop with selection of common tools and standard hardware  Define a standard behaviour for the same class of devices (e.g. HV power supplies) Provide the sub-detectors with a standard state diagram  Define standard states/actions/operational sequences (automation) that can be used when defining behaviour of sub-detector  Guidelines for development, naming, numbering, look and feel of user interfaces etc.

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 12 DCS infrastructure  DCS needs adequate infrastructure (computers, network,...)  Installation and maintenance of the network will be done by the CERN networking group (IT/CS)  All computers installed for the DCS will be procured, installed and maintained by a central team Highly standardized hardware  Operation of network and computers will follow rules and guidelines and use tools from the “Computing and Network Infrastructure for Controls” (CNIC) working group

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 13 Network  The controls network will be a separate, well protected network Without direct access from outside the experimental area With remote access only through application gateways With all equipment on secure power  A first estimate shows the need of around 350 network connections, 2/3 in the experimental cavern Not including ~50 switches connecting ~800 embedded processors on the detector  Current installations use the CERN campus network  The controls network will be operational starting the 2 nd quarter of 2006

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 14 Remote access  With the large world-wide user community remote access is an important aspect  Remote users will access PVSSII projects through a remote user interfaces via a Terminal Server  By default only observer rights, higher privileges can be granted to experts for specific, well defined tasks

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 15 Remote access  This strategy has been tested with 60 remote users simultaneously running a user interface No degradation of performance (nor project, nor TS)  Tested successfully from several places around the world

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 16 Computers  2U rack mounted PCs, in specially equipped racks Cooling doors, power control, on secure power  Baseline operating system is Windows Linux is used in specific cases  The DCS will be run as a large distributed PVSSII system Based on several performance tests on large distributed systems More detailed performance tests on several components are being performed

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 17 Computers  A first distribution of tasks across computing nodes has led to the need of nodes Including servers and system management nodes Combining low resource demanding tasks Maintaining separation between sub-detectors  A core DCS system has been installed this summer 5 machines, to be used by sub-detectors for equipment test at first installations More worker nodes and devices to be installed soon 50% installed by 1 st quarter 2006, rest 3 rd quarter 2006

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 18 Further activities at site  The DSS is being commissioned Experimental area surveillance  Interfaces to first gas systems and site infrastructure (CERN safety system, power control, environment monitoring, …) are installed and made available to users Will be extended gradually as the installation of the services (cooling, electricity, etc.) progress  Coordinated operation of the online systems (DAQ, Trigger, DCS) will start early 2006 Cosmic runs with TPC and other detectors

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 19 Summary  Many sub-detectors have implemented parts of their control system and used them in lab and beam tests They could profit from the coordination and collaboration Their very valuable feedback allowed us to optimise and improve the DCS design The chosen architecture proved to be well adapted to the sub-detector needs  The process will continue with the first installations and this together with extensive performance tests will help us to further optimise and refine the system

André Augustinus CERN – European Organization for Nuclear Research 10 October 2005ICALEPCS 2005, Geneva 20 Conclusion  Results so far make that we are confident that the ALICE Detector Control System will be fully operational at the beginning of Well in time to allow safe and efficient operation of the experiment to record first collisions at LHC