1. ATLAS MDT HV – LV Detector Control System (DCS)
Michail Bachtis
National Technical University of Athens
NTU Athens - INFN Roma I Project

2. NTU Athens - INFN Roma I Project
DCS - Introduction
Detector Control Systems
Systems to control (via computers) the operation of a HEP experiment
Appeared in 1980’s
Increasing Complexity of the Experiments
Control of a large amount of parameters
Check of the smooth operation of the experiment
Characteristics
Operators don’t need to be sub-detector experts
Operation procedures become very easy
Automatic Error Recovery procedures can be implemented
NTU Athens - INFN Roma I Project

3. NTU Athens - INFN Roma I Project
ATLAS
ATLAS
Inner Detector
Calorimeters
Muons
TRT
Pixel
LArg
Tile
SCT
Trigger
Precision
TGC
RPC
MDT
CSC
NTU Athens - INFN Roma I Project

4. NTU Athens - INFN Roma I Project
MDT Chambers
+3080V
High Voltage
Electronics
Drift Tube
Also
-Alignment Modules
-Temperature (NTC)
Sensors
-B – Field Sensors
Gas Inputs/
Outputs
Read Out
Electronics
Tubes
NTU Athens - INFN Roma I Project

5. NTU Athens - INFN Roma I Project
MDT Chamber DCS
MDT
GAS
Power Supply
Alignment
MDM Part HV LV
Temp
B-Field
JTAG
~2000 HV Channels
~700 LV Channels
NTU Athens - INFN Roma I Project

6. Power Supply Hardware Requirements CAEN Power Supplies EASY SYSTEM
Computer Control
Compatibility with Control
Software
Radiation Protection
Solution…
NTU Athens - INFN Roma I Project

7. CAEN EASY System Architecture
NTU Athens - INFN Roma I Project

8. NTU Athens - INFN Roma I Project
Software (I/II)
CAEN OPC Server
Connection with Hardware (I/O)
Unfortunately supported only for Windows OS
ETM PVSS II
JCOP Framework
Oracle Database
NTU Athens - INFN Roma I Project

9. NTU Athens - INFN Roma I Project
Software (II/II)
OPC Server
PVSS II
JCOP FRAMEWORK
ORACLE
Conditions
Database
Hardware
CAEN EASY SYSTEM
NTU Athens - INFN Roma I Project

10. NTU Athens - INFN Roma I Project
System Design
Hierarchical Design
Hardware Hierarchy
Logical – Geographical Hierarchy
Friendly User Interface
Visualization of the system
Various Plots of the data
Customized Widgets
NTU Athens - INFN Roma I Project

11. NTU Athens - INFN Roma I Project
Hierarchical Design
Hardware Hierarchy
Ch1
Main Crate
A1676 Board
Remote Crate
Ch2
EASY Board
Logical Hierarchy
....
MDT
Ch1
Barrel
bis1a08
Ch2
EndCap
NTU Athens - INFN Roma I Project

12. NTU Athens - INFN Roma I Project
Specifications
Visualization of the system status
Tree like representation of the system
3D representation of the system
Data Management
Real time monitoring of the values (Voltage , Current , Alarms)
Versatile plotting system
Voltage , Current Plots
Data from archive
Automation
Error Recovery
System proposes procedures to the user
Automatic Recovery capabilities ( dangerous..?)
NTU Athens - INFN Roma I Project

13. NTU Athens - INFN Roma I Project
User Interface
Tree View
3D MDT Display
Controls
Log Window
NTU Athens - INFN Roma I Project

14. 3D Display ActiveX Technology Visual C++ & 3D Game Engine from
3D State
Rotation , Zoom ,
Chamber Selection
Change of chamber
Color by state
Show / Hide
Capabilities of
Different sub-detectors
(bis , eml , bil , bee ,etc)
NTU Athens - INFN Roma I Project

15. Controls Turn On /Off Monitoring Plots DB Analysis Channel Settings
Massive Operations
On/OFF, Set values
System Status
(always exists)
Logical view, FSM,OPC,RdB
NTU Athens - INFN Roma I Project

16. NTU Athens - INFN Roma I Project
Plots
NTU Athens - INFN Roma I Project

17. NTU Athens - INFN Roma I Project
Automation
Example
An On/Off Switch
Modeling of system behavior using Finite State Machine (FSM) Algorithms
Each System is represented using a finite number of states
Each state contains actions
The actions can be transitional or non - transitional On
pressed ON On
pressed
Off
pressed
OFF
Off
pressed
NTU Athens - INFN Roma I Project

18. NTU Athens - INFN Roma I Project
FSM(I/II)
HIGH VOLTAGE FSM
LOW VOLTAGE FSM
OvC
OvC
Error Recovery
Error Recovery
Physics
(ON)
Trip
Physics
(ON)
Trip
RUp
RDwn
Other
Errors
Other
Errors
Off
Off
Error Recovery
Error Recovery
NTU Athens - INFN Roma I Project

19. NTU Athens - INFN Roma I Project
FSM(II/II)
Error Recovery Process
The user is informed and proposed a procedure
Automatic Recovery is possible
Chamber State
The state of the chamber is resolved by the HV and LV channel states using some state propagation rules
Propagation Rules
If all Off -> Chamber Off
If all Physics->Chamber Physics
If any Error->Chamber Error
If all warning or (warning and off ) or (physics and off) or (warning and physics) ->Chamber Warning
NTU Athens - INFN Roma I Project

20. Trip Recovery (Under Study)
On Chamber
HV Electronics
Problem
An example using history search
Propose:
1)Leave Channel
Off
2) Call Expert
Very often
~ms
~ s
How often does
The channel Trip?
Time between
Trip and On
TRIP
Occurs
Archive
Search ~s
Not often!
Gas problem
(ie Low Pressure)
Random Effect
Propose:
Bring Channel
Back On
NTU Athens - INFN Roma I Project

21. NTU Athens - INFN Roma I Project
Conclusions
MDT Power Supply DCS - > Complex System
2700 Channels to be read and stored to the Oracle Database
Up to 6 PCs may be used to handle the data
Final User Interface and Automatic Error Recovery under study .
NTU Athens - INFN Roma I Project