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Welcome to the Leade Twiki. LEADE is the working group for the LHC Experiment-Machine Data Exchange and the main purpose of this web is the description of the items to be exchanged. The minutes of LEADE are recorded in http://lhc-data-exchange.web.cern.ch/lhc-data-exchange/ The functional specification is available in the EDMS document 701510 by E. Tsemelis. New requirements have been added since by LHC operations, listed in http://cern.ch/lhc-commissioning/systems/data-exchange/data-exchange.htm .

Data exchanged between the LHC machine and experiments

Data exchange is via DIP (Data Interchange Protocol) as described in https://edms.cern.ch/file/457113/2/DIPDescription.doc. DIP is maintained by IT/CO http://itcofe.web.cern.ch/itcofe/Services/DIP/welcome.html. The following chapters describe the items to be exchanged, their location and estimated availability. Announcements of publication availability, new requirements, changes, etc. are announced through the lhc-exp-coms@cern.ch mailing list.

In the LHC machine environment all floating point data is typically produced as double (64-bit) and will be published as such. During the conversion some loss of precision may occur.

Machine to experiments

All publications from LHC are under dip/acc/LHC/ followed by the category of interest (Beam, RunControl, Safety, etc) and the publication items. The following tables depict the publication details. Additional information on some of the publications is available at http://ts-dep-lea-int.web.cern.ch/ts-dep-lea-int/dataexchange-DIP.htm

Available publications

Publications which are fully defined and currently published. They can still be subject to some small modifications.

Measurement DIP item name/source data description Publication contact Data contact Volume Bytes Frequency
  Beam and machine observables  
Total beam intensity dip/acc/LHC/Beam/Intensity/* (Beam1 and 2)/http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BCTDCLHC ExperimentAcquisition property - Please note that there are two redundant beam intensity publications and the one which is flagged as valid is published to DIP K. Kostro AB/BI, M.Ludwig small 1 Hz
Individual bunch intensities dip/acc/LHC/Beam/IntensityPerBunch/* (Beam1 and 2)/* (A and B) BI documentation ExperimentAcquisition property - Please note that there are two redundant bunch intensity publications and the one which is flagged as valid is published to DIP K. Kostro AB/BI, M.Ludwig ~50 KB 1 Hz
Average 2D beam size dip/acc/LHC/Beam/Size* (Beam1 and 2) http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BSRTSLHC AcqToExperiments property K. Kostro AB/BI, A.Guerrero 1 KB 1 Hz
Luminosity cdte mean dip/acc/LHC/Beam/LuminosityAverage/* http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI¤tInstrument=BRASCLHC¤tDomain=LHC Acquisition property K. Kostro AB/BI, S.Bart Pedersen 16 1 sec
Luminosity cdte b-by-b dip/acc/LHC/Beam/LuminosityPerBunch/* http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI¤tInstrument=BRASCLHC¤tDomain=LHC Acquisition property K. Kostro AB/BI, S.Bart Pedersen 28 512 10 sec
Luminosity Gas mean dip/acc/LHC/Beam/LuminosityAverage/* http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BRASGLHC Acquisition property K. Kostro AB/BI, S.Bart Pedersen 16 1 sec
Luminosity Gas b-by-b dip/acc/LHC/Beam/LuminosityPerBunch/* http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BRASGLHC Acquisition property K. Kostro AB/BI, S.Bart Pedersen 28 512 10 sec
Abort Gap Beam Current dip/acc/LHC/Beam/AbortGapIntensity/* http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BSRALHC Acquisition property K. Kostro AB/BI, S.Bart Pedersen + 3*640 doubles 1 sec
Average Beam Loss dip/acc/LHC/Beam/BLM/LSS* integrated beam losses 10us, 633ms, 1310ms from monitors 260m around IP. Data is coming from BLM concentrator, which itself gets it from BLM monitors as described in http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BLMLHC K. Kostro BLM concentrator, M.Misiowiec 400 doubles and monitor names 1 sec
Beam Loss thresholds dip/acc/LHC/Beam/BLM/LSS*_thr Beam loss thresholds for 10us, 633ms, 1310ms for BLM monitors 260m around IP. Thresholds are calculated in the BLM concentrator and are adjusted by operation K. Kostro BLM concentrator, M.Misiowiec 400 doubles and monitor names on change
HOR & VER Positions dip/acc/LHC/Beam/BPM Vertical and horizontal positions from selected BPMs. Includes BPM names and error strings. They are published as arrays i.e. the position of a BPM which name is at index i will be at index i. If more BPMs are added, they will be added at the end but if you use it in a program, make a check if the name is at the expected position. Value may be not correct if the corresponding error string is not empty. Data is from beam orbit concentrator OFSU.LHC which itself gets it from closed orbit position measurement as descibed in http://bdidev1.cern.ch/bdisoft/development/BDI-Domains/bdeyelids/bdeyelids.php?currentSelection=GI&currentDomain=LHC&currentInstrument=BPMLHC The positions are given in micro-meter ('um') w.r.t. to the BPM center, which in usually about the same as the design orbit. The BPM misalignment errors are estimated to about 0.2-0.5 mm r.m.s. Note:positions from the 2 ATLAS Roman Pots are missing yet K. Kostro R. Steinhagen 48 doubles, status strings and monitor names 1 sec
Beam energy dip/acc/LHC/Beam/Energy multiply by 120 to get MeV value K. Kostro AB/CO, I. Kozsar 1 int on change up to 10Hz
Collimator positions dip/acc/LHC/Machine/CollimatorPositions/* 8 position values from the MeasuredCornerPositions property, see: https://edms.cern.ch/file/934341/0.1/LHC-TC-ES-0002-00-10.pdf Positions and gaps in mm, positions relative to the collimator center K. Kostro AB/ATB M. Donze 8 doubles per collimator 1 sec
TCDQ Collimator positions dip/acc/LHC/Machine/TCDQPositions/* 2 position values from the MeasuredCornerPositions property, see: https://edms.cern.ch/file/934341/0.1/LHC-TC-ES-0002-00-10.pdf Positions in mm, relative to the collimator center K. Kostro AB/ATB M. Donze 2 doubles per collimator 1 sec
TED Dump position dip/acc/LHC/Machine/TEDPosition/* position from the Status property, position=2 means OUT (beam through), position=3 means IN (dump), other values: 0 (unknown), 1(installation), 4 (transport), 5 (undefined position) K. Kostro AB/ATB M. Donze 1 int on change
Injection lines intensity dip/acc/LHC/Beam/IntensityInj/* (TI2.29125, TI8.87750) The size of totalIntensityHigh is alvays one and unit is in charges with a unit-exponent of '10' so for example, the nominal LHC pilot (5E9 charges) would give "0.5". You have to check the value of cycleName as not all cycles are for LHC. The cycle names are assigned by operation and can change with time. K. Kostro AB/BI L. Jensen 1 float + 1 string every SPS cycle
Luminosity Scan dip/acc/LHC/Beam/LuminosityScan K. Kostro S.M. White numbers and strings on change

Item DIP item name/source data description Publication contact Data contact Volume Bytes Frequency
  Run Control  
Machine Mode dip/acc/LHC/RunControl/MachineMode accelerator mode string defined by LHC operation https://edms.cern.ch/cedar/plsql/doc.info?cookie=8501908&document_id=865811&version=1.0&p_tab=TAB6 K. Kostro AB/OP, M. Lamont string on change
Beam Mode dip/acc/LHC/RunControl/BeamMode beam mode string defined by LHC operation https://edms.cern.ch/cedar/plsql/doc.info?cookie=8501908&document_id=865811&version=1.0&p_tab=TAB6 K. Kostro AB/OP, M. Lamont string on change
Beam type dip/acc/LHC/RunControl/BeamType/* (Beam1 and 2) beam type encoding defined by LHC operation http://wwwpsco.cern.ch/private/timing/timing/Seq/tgmLines.html?mode=OPER&net=LHC&mch=LHC K. Kostro AB/CO, I. Kozsar 1 int on change
Safe beam flags dip/acc/LHC/RunControl/SafeBeam/* (Beam1 and 2) flags encoding defined by LHC operation http://wwwpsco.cern.ch/private/timing/timing/Seq/tgmLines.html?mode=OPER&net=LHC&mch=LHC K. Kostro AB/CO, I. Kozsar 1 int, bitmap on change
Fill number dip/acc/LHC/RunControl/FillNumber LHC fill number http://wwwpsco.cern.ch/private/timing/timing/Seq/tgmLines.html?mode=OPER&net=LHC&mch=LHC K. Kostro AB/CO, I. Kozsar 1 int on change
Circulating Bunch Configuration dip/acc/LHC/RunControl/CirculatingBunchConfig/* (Beam1 and 2) Circulating Bunch Configuration, per beam. Contains an array which encodes mapping of circulating bunches to RF buckets i.e. the first element contains the RF bucket number of the bunch 1 etc. If the value is 0 then there is no corresponding bunch. K. Kostro AB/OP M. Lamont 2808 integers on change
Injection Bunch Configuration dip/acc/LHC/RunControl/InjectionBunchConfig/* (Beam1 and 2) Injection Bunch Configuration, per beam. Contains an array which encodes mapping of injected bunches to RF buckets i.e. the first element contains the RF bucket number of the bunch 1 etc. If the value is 0 then there is no corresponding bunch. The 'ACTIVE' field will be set to true for the injected beam and to false for the other beam. K. Kostro AB/OP M. Lamont 288 integers on change

Item DIP item name/source data description Publication contact Data contact Volume Bytes Frequency
  Handshakes  
LHC handshake dip/acc/LHC/Handshake/* Injection, Adjust and Beamdump handshakes from LHC operations, see http://cern.ch/lhc-commissioning/systems/data-exchange/data-exchange.htm K. Kostro AB/OP M. Lamont string on change

Item DIP item name/source data description Publication contact Data contact Volume Bytes Frequency
  Safety  
SPS probe beam flag dip/acc/LHC/Safety/* (MaxSpsProbeBeamA and B) SPS Probe Beam Flag Threshold which gives the maximum beam intensity that can be injected into an empty LHC (probe beam). Value is in units of 1E8 charges. K. Kostro AB/OP J. Wenninger 1 integer on change

Item DIP item name/source data description Publication contact Data contact Volume Bytes Frequency
  Miscellaneous  
Post Mortem Timestamp dip/acc/LHC/Timing/PostMortem Postmortem Event. Typically postmortem request is delivered as HW signal but this software event allows to determine the timestamp of the last PM event to be included with the PM data K. Kostro AB/CO I. Kozsar small on change

Missing publications

Publications which are planned but delayed because equipment is not available yet or for other reasons
Missing publication DIP item name/source data description Publication contact Data contact Volume Bytes Frequency Estimated availability
Average bunch length dip/acc/LHC/Class/Property/Device K. Kostro AB/RF A.Butterworth 8 1 min after 2008
Total longitudinal distribution dip/acc/LHC/Beam/LongitunalDistribution K. Kostro AB/BI 285.120 1 min after 2008

Experiments to machine

Whenever the same kind of publication is expected from several experiments, they shall follow the same naming schema and field definitions so that they can be used by LHC controls in a common way. For instance the same hanshake names and values are expected from all experiments. The following table defines this.

All publications used pricipally by LHC operation shall be under /dip/EXPERIMENT/LHC/. When a single field is published, the field name shall be the DIP default (__DIP_DEFAULT__). When several items which belong together it is preferred that they are published as a single DIP publication. We will always try to prototype the publications with one experiment and others can follow then.

Item DIP item name/source data description CMW device and property Required field names and types Frequency Example to follow
Experiment handshake dip/EXPERIMENT/LHC/Handshake/* (EXPERIMENT_INJECTION, EXPERIMENT_ADJUST, EXPERIMENT_BEAMDUMP) Handshake details are described in http://lhc-commissioning.web.cern.ch/lhc-commissioning/systems/data-exchange/handshakes.htm device name: DIP.EXPERIMENT (e.g. DIP.ATLAS) properties: InjectionHandshake, AdjustHandshake, BeamdumpHandshake Field name: __DIP_DEFAULT__, field type: String on-change /dip/ALICE/LHC/Handshake/*
CMS HF Luminosity dip/CMS/HF/LumiData DIP.CMS/HF.LumiData As published on-change specific?
CMS HF Luminosity histogram dip/CMS/HF/LumiDataLH DIP.CMS/HF.LumiDataLH As published on-change specific?

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Topic revision: r50 - 2010-03-02 - KrisKostro
 
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