André Augustinus 10 September 2001 DCS Architecture Issues Food for thoughts and discussion.
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Transcript of André Augustinus 10 September 2001 DCS Architecture Issues Food for thoughts and discussion.
André Augustinus10 September 2001
DCS Architecture Issues
Food for thoughts and discussion
10 September 2001DCS Workshop 2André Augustinus
Disclaimer
What will be presented is not a proposal to be accepted or rejected.
It is merely a collection of (personal) ideas. It is meant to make you start thinking and
trigger discussions. With the outcome of these discussions we could start to design the full Detector Control System.
We are eager to hear your comments!
André Augustinus10 September 2001
André’s ideas on DCS
A rather personal view
and probably somewhat DELPHI biased
10 September 2001DCS Workshop 4André Augustinus
Introduction
From the ALICE Controls Coordination mandate:
The DCS should allow centralised operation• By a single operator
• Not necessarily a DCS expert
• From a central control room
… to have the Detector Controls System (DCS) ready for exploitation by the end of 2005, allowing to control and operate the experiment (from a central operator workplace) during all modes of operation …
10 September 2001DCS Workshop 5André Augustinus
Introduction
A central (non-expert) operator should• at all times be informed about anomalies in the
experiment• be able to give the necessary commands to run
the experiment efficiently (minimal downtime)
A detector (expert) operator should• have a detailed view of the detector/system• be able to give any expert commands
10 September 2001DCS Workshop 6André Augustinus
The DCS, global view
Hierarchical system• Central DCS• Detector CS’s and/or sub-detector CS’s
Connected to external systems• Gas, Electricity etc.• Magnet, DAQ, LHC Accelerator etc.
10 September 2001DCS Workshop 7André Augustinus
The DCS, global view
Gas, Electricity, …Magnet, DAQ, LHC
ITS, TPC, TRD,TOF, Muon, …
ITS-SPD, ITS-SDD, ITS-SSDMuon-Track, Muon-Trig
10 September 2001DCS Workshop 8André Augustinus
The DCS, global view
Central DCS collects the status of all detectors and external systems
Through the Central DCS the operator will give generic commands to all or a set of detectors
The Central DCS can perform pre-programmed operations (automated operation)
10 September 2001DCS Workshop 9André Augustinus
The DCS, global view
A Detector CS consists of a collection of sub-system controls
The sub-system controls is controlling a collection of equipment or devices that is logically grouped together• HV, LV, Cooling, …
The sub-system controls is the interface to the hardware of the detector
10 September 2001DCS Workshop 10André Augustinus
The DCS, global view
CentralDCS
TPC DetectorDCS
HV LV Cooling
HVcrate 1
HVCrate 2
LVcrate
Coolingsystem
T monitor
Tsensors
10 September 2001DCS Workshop 11André Augustinus
Central operation, an example
Operator issues command “get ready for physics”• Get ALICE ready for datataking
• Ramp up HV, switch on or off equipment, change operational parameters.
Command is issued through an operator interface (PVSS) to the Central DCS
Central DCS dispatches the command to Detector CS’s
10 September 2001DCS Workshop 12André Augustinus
Central operation, an example
Upon receipt the Detector CS will issue commands to sub-system controls
• “Ramp up” to HV, “Switch on” to LV, “load physics” to temperature monitoring
The sub-system controls will perform the necessary action on the hardware
• Send a command to CAEN to initiate a ramp
At this moment the command execution has finished
10 September 2001DCS Workshop 13André Augustinus
Central operation, an example
The operator should get feedback on the execution of the command• Should know when command is finished
• (Has reached the hardware)
• Should get feedback from the hardware• (The hardware is doing/has done something)
10 September 2001DCS Workshop 14André Augustinus
Central operation, an example
CAEN received command and starts ramping It reports this back to Detector CS: “I’m
ramping up” and the Detector CS will detect a change from “off” to “ramping up”
Based on this new information it will recalculate its own state and change from “not ready” to “HV ramping up”
This state is seen by the Central DCS and shown to the operator
10 September 2001DCS Workshop 15André Augustinus
Background
Detector CS: operations logic• Programmed commands• Generic devices• Programmed logic, maybe templates/framework
Sub-system controls: hardware details• One sub-system controls per type of device• “device driver”
10 September 2001DCS Workshop 16André Augustinus
External Systems
Information from external systems is essential• For display to operator• For archiving• To trigger actions
In principle, all information from any external system is available, via software
Crucial events should be backed up by hardwired interlocks
10 September 2001DCS Workshop 17André Augustinus
Dividing the system
Each detector should, if needed, be able to run independent from central operation• Commissioning, debugging, calibration, …
Partitioning Propagation of commands and events should
be handled properly in case of partitioning Who decides who has control
10 September 2001DCS Workshop 18André Augustinus
The DCS, global view
CentralDCS
ITSDCS
TRDDCS
TOFDCS
HMPIDDCS
• Partitioning
10 September 2001DCS Workshop 19André Augustinus
Archiving and Logging
Archiving• Store the value of a monitored parameter for later
retrieval (time stamped)• Performance• Post Mortem analysis• For use with offline data analysis
Logging• Store all events that occurred in the system
• Commands given (what, by whom)• Anomalies, errors, alarms
10 September 2001DCS Workshop 20André Augustinus
Configuration
Aim for a uniform system, that only needs to be configured to the needs of the user• Provide an ALICE DCS framework• Configurable, nothing “hard coded”• Configuration data should be stored in some
database
10 September 2001DCS Workshop 21André Augustinus
More ideas
Central DCS and Detector CS could be very conveniently implemented as Finite State Machines (will be (is) part of PVSS)
User interfaces (user defined) can be connected at any point in the system
Access control and access rights can be applied at any point in the system
10 September 2001DCS Workshop 22André Augustinus
More ideas
One could envisage automated operation:• Routine operation
• LHC declares stable beam conditions• Prepare DCS and DAQ for physics• Start datataking when DCS is ready• Pause datataking when DCS detects serious problem• Ramp down at beamdump
• Apply standard corrective actions• Ramp up a tripped channel
10 September 2001DCS Workshop 23André Augustinus
Summary
Meant to trigger reflection and discussion We will produce a discussion document
elaborating on the issues presented here Come to a definition if the Alice DCS
architecture