DCS operation during data taking (proposal)

1. DCS operation during data taking (proposal) FV

2. Some definitions • Detector Operation Mode (DOM) is a set of rules used by DCS for detector operation in specific conditions. The rules also determine the way how the DCS moves from one DOM to another and communicate with external systems. Typical DOMs are: RUN (or DATA TAKING), TUNING, SHUTDOWN, EMERGENCY, etc. • Recipes is a set of parameters fully defining operation of a sub-system or full detector. This set include states (ON/Off), setting values, alarms thresholds, etc. The recipes are stored in an external data base (ORACLE) and can be edited with dedicated editor, uploaded to the system, modified and saved back to the data base. • Run Type defines type of physical run foreseen for current data taking period. For example it could be MUONS, COSMICS, KAONS, LOW INTENSITY, etc. For each Run Type there is corresponding recipes set. VF

3. Possible Detector Operation modes • TUNING - main mode for run preparation • RUN - the DCS should guarantee that: • all detector channels are in requested states (NA48 style) or ON (LHC style) and • all parameters influencing data quality are in good (requested) range. A deviation from these stable conditions should abort the RUN DOM and move the NA62 experiment node to corresponding TUNING state • EMERGENCY - the detector is in the safest state • SHUTDOWN ? • MAINTENANCE ? VF

4. Starting the TUNING DOM • When the system is starting in TUNING mode an operator will be asked which recipes (Run Type) should be applied • Last Used • One from the predefined list • Once the choice is done the system will • either restart with old recipes without reloading of them or • download and apply the new recipes from the data base VF

5. Short digression – two visions of Detector Units behavior: “NA48” and “LHC” styles ECS T.S. LHC DAQ DSS DCS ... ... GAS DetDcs1 DetDcsN DetDaq1 Status & Alarms Commands SubSys1 SubSys2 SubSysN Dev1 Dev2 Dev3 DevN To Devices (HW or SW) VF

6. Two visions of DU: “NA48” and “LHC” styles • “NA48” style • The state of FSM detector units is evaluated depending of hardware readiness of for the data taking. For example in case a HV channel is supposed to be OFF but is ON, the model will evaluate its state as an ERROR. The state of the HV channels can be: • READY • RAMPING • ERROR – channels is in wrong state or voltage is outside of tolerance limits • UNKNOW • “LHC” style • The state of FSM detector units is evaluated depending of hardware physical state. The model will reflect the state of HV channel based on real state of hardware and independently its requested state. The state of the HV channels can be: • READY • NOT_READY - channel is OFF • RAMPING • ERROR – there is an error reported by hardware • UNKNOWN VF

7. TUNING DOM states and actions NA48 like model LHC like model Control Units NA62 detector READY UNKNOWN ERROR RAMPING NOT READY Configure Recover Recover ABANDON Other CUs READY UNKNOWN ERROR RAMPING NOT READY RAMPING Recover Recover ABANDON ABANDON GO_TO_READY Device Units HV channel READY UNKNOWN ERROR RAMPING NOT READY RAMPING ON ON OFF OFF ON OFF OFF Expert panel Expert panel Expert panel Analogue input OK UNKNOWN ERROR Recover Expert panel Expert panel OR VF

8. TUNING DOM commands • “Recover” commands: • ERROR state: switch ON tripped channels • UNKNOWN state: reset corresponding ELMB • Device Unit operation: • Basic ON/OFF commands • Access to “Expert panel”: • Allows setting of all channel parameters, including voltage tolerance limits • At the moment of closing the panel an operator will be asked whether he/she would like to safe current settings to present recipes. VF

9. From TUNING to RUN • The RUN DOM can be initialized in TUNING DOM only by explicit operator GO_TO_RUN command • To be able to send this command he/she should login to the system with Run Control (not his/here personal) password. • The GO_TO_RUN command will: • Lock the whole FSM tree and block any operator commands • Send “Detector is ready” signal to DAQ VF

10. From TUNING to RUN TUNING DOM Operator actions RUN DOM Take control with Run Control password To DAQ: Detector is Ready GO_TO_RUN NA62 detector state NA62 detector state READY READY ERROR ERROR UNKNOWN UNKNOWN RAMPING RAMPING To DAQ: Detector is not Ready VF

11. From RUN to TUNING and back • In cases: • The NA62 detector node changed its state from READY to any other state • Operator send command “Go_TO_TUNING” DCS should send “Detector is not Ready” signal to DAQ and automatically mode to TUNING DOM • To cure the problem an operator has to take the control with his/here password and proceed with problem fixing • Once the NA62 detector is in READY state the system can be returned to RUN mode VF

12. General questions • Should the actions during data taking be locked? • Do we need automatic actions in RUN DOM? • Should we allow running with a part of detector excluded from the hierarchy? • How often the Type of Run will be changed? • What is acceptable duration of downloading and applying of recipes (changing of Run Type)? • Which Device Unit model is preferable? VF

13. “NA48” and “LHC” styles comparison • “NA48” style • Advantages: • Simple for interpretation : everything is based on one parameter – readiness to data taking • Can be implemented in any DOMs including EMERGENCY and SHUTDOWN • Allow to treat On and OFF state in the same way • Shortcoming: • Doesn’t reflect physical state of device (can be compensated by independent graphical presentation, the hardware errors will be treated by alarms) • “LHC” style • Advantages: • Reflect hardware state: ON, OFF, Hardware Error • Shortcoming: • Difficult for interpretation. Examples: • ISEG HV channel doesn’t have an Over/Under voltage state. • System is in NOT_READY state: is it because of some channels OFF or some channels RAMPING? • Doesn’t allow to have OFF channels included in the FSM tree (all OFF channels should be manually excluded from the hierarchy before the RUN) • Can not be used in EMERGENCY and SHUTDOWN VF