Lumi with DDL2

1. Lumi with DDL2

2. Content • General • System overview • Interaction record (IR) • DDL2 block • Data rate JIRA: https://alice.its.cern.ch/jira/browse/TC-3

3. DDL2 IR for lumi • dump everything what CTP sends (see estimated data rate below) on DAQ side, • transport this information to offline: • option a) as special raw file and analyse it during reconstruction • option b) use shuttle and filter it at this point , so OCDB can contain already much reduced info.

4. System Overview VME BUS DIM Counters Any Client (Ivan Lumi) VME CPU CTPLM0 board CTPL1 board DDL2 CTP server CTP ReadOut CTPL2 board DDL1 FO boards CTPINT • DDL1 • CTP readout+Interaction Record Old (IR1) • when link full -> CTP BUSY • DDL2 • Interaction Record New (IR2) • When link full -> nothing • CTP server publishes streams • No additional action • CTP ReadOut builds events • CTP event=L2a+-N IR (N=2)

5. Options • Counters • it require very little development • traffic on CTP VME backplane increases by factor 60  as every counter reading requires CTP board access which causes more electrical background and may lead to unexpected effects , e.g. more CDH errors (see system overview) • DIM traffic which is used between various processes is also increased by factor 60 ... • IR record • Best option is after today discussion Ivan service • Little development

6. IR2 data block • Variable size : min=1 word, max=1024 words • Missing data flag: if more then 510 ints in ORBIT • Max 510 interactions per orbit=>5.6 MHz • Transmission error flag: if DDL2 is full and data are lost • Interaction is written if at least one of selected inputs is 1 Interaction:

7. DDL2 block • Fixed size: 1024 32 bit words • CTP has DDL2 block counter • Example No Interactions: • DDL2 block= 1024 IR blocks with no interactions (only Orbit numbers) • DDL2 block rate: 11200/1024 =11 Hz • Example Interaction rate> 5.6 MHz • DDL2 block = IR block • DDL2 block rate = 11200 Hz

8. Data rates • Max: 4 kByte x 11200Hz = 45 MHz • Typical rate of DDL2 blocks is 1000Hz • Run 286937 example • DDL2 defined as OR of following inputs: • DDL2_IR 0VBA 0VBC 0T0C 0VGA 0UGC 0OMU 0V0M 0UBA 0UBC 0PH0 0MSL 0MSH 0MLL 0MUL 0EMC 0DMC

9. Backup

10. DDL1 Data Format CTP readout block

11. DDL1 Data Format IR1 block • Max 249 BC= 2.79 MHz

12. IR2 in readout • CTPDATA DDL1 • IR - 2       DDL2 • IR - 1       DDL2 • IR            DDL2 • IR + 1      DDL2 • IR + 2      DDL2

13. New interaction in Aliroot 1. Done class AliTriggerIR: public TObject{ private: UInt_tfOrbit; // Orbit number UInt_tfNWord; // Number of recorded interaction signals Bool_t*fInt1; //[fNWord] signals for interaction 1 Bool_t*fInt2; //[fNWord] signals for interaction 2 UShort_t*fBC; //[fNWord] bunch-crossing number Bool_tfIncomplete; // flag which says if the IR is incomplete or not Bool_tfTransErr; // flag which says if there was a transmission error (gap) or not UInt_t fNWord2; ULong64_t *fIntRun2;// [fNWord2] UShort_t*fBC2; Bool_tfIncomplete2; // flag which says if the IR is incomplete or not Bool_tfTransErr2; // flag which says if there was a transmission error (gap) or not } 2. AliCTPRawStream – after discussion with DAQ 3. AliESDHeader