Slow Controls Upgrade for STAR Jennie Burns, Undergraduate Student, Department of Physics, Creighton University for the STAR Experiment This work was supported by the Office of Science, U.S. Department of Energy.

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Slow Controls Upgrade for STARJennie Burns,
Undergraduate Student, Department of Physics,
Creighton University for the STAR ExperimentThis
work was supported by the Office of Science, U.S.
Department of Energy.
Currently the STAR (Solenoidal Tracker At RHIC)
experiment is using specialized VME-based front
end processors for its data acquisition and
control systems. After years of design work and
construction, STAR was assembled at Brookhaven in
1998 but over the last 10 years processor speed
has increased and the use of personal computers
for the control and monitoring of these
experiments is now possible. The system is being
revised to replace old hardware with PC's which
are less expensive and more easily maintained in
order to accommodate new detector subsystems. The
original STAR control system is compared with the
upgraded system. The architecture and the
implementation of upgraded control systems for
the Ground Integrity Device (GID) and Time
Projection Chamber (TPC) Forward Time
Projection Chamber (FTPC) Gas Systems of the STAR
experiment are also presented.

• Current Status of Hardware Controls
• VME-based front end processors for detector
  control.
• Front end cards were housed in VME crates.
• EPICS R3.12.4 or R3.13.1 on Sun Ultra-10
  workstations running SunOS.
• Most workstations open an X-window with MEDM
  (Motif Editor and Display Manager) displays for
  the control and monitoring of experiment
  parameters.
• Data for the user interface is received from
  local Ethernet broadcasts.
• 30 MVME 167 and 162 processors running VxWorks
  5.2.
• VME boards are 10-yr-old dedicated specialized
  processors with low memory capability.
• Some VME boards use program code that is
  incompatible with newer versions of VxWorks.
• Startup files are downloaded over Ethernet from a
  single Sun host workstation.
• Commands can also be entered over a serial line
  and reboot can be initiated using CANbus controls
  for the VME crates.
• CDEV (Control DEVice) is used to exchange data
  between the STAR control system and other
  external systems.
• Archived controls data is web accessible.
• A limited amount of data is passed to the event
  stream and to the online database.

• Upgrade of Hardware Controls
• PC-based front end processors for new subsystems.
  
• Existing subsystems which use serial interfaces
  are being moved to the PC-based system.
• VME-based front end processors continue to be
  used for existing subsystems whose front end
  electronics is housed in VME crates.
• Linux workstations are used for new and upgraded
  subsystems.
• Sun Ultra-10 workstations are being phased out.
• Upgrading to new versions of VxWorks is required
  for compatibility with EPICS R3.14.
• VME boards system is being upgraded to Linux
  compilable VxWorks 5.5.
• RTEMS 4.6 is also being evaluated for use as an
  operating system.
• Program code is available locally on the PC
  processors. Program code for the VME processors
  is downloaded from a Linux workstation.
• Requirements for the new systems must be
  backwards compatible, existing software and
  programming should be retained as much as
  possible in appropriate settings , and there
  should be a migration towards current generation
  of hardware where possible.
• Soft IOCs will provide a model for other various
  other upgrades of the STAR experiment.

Upgraded Systems at STAR

• GID (Ground Integrity Device)
• Reads current and detects deviations from earth
  ground.
• Entire STAR experiment bases its data and
  calculations of subatomic particles from the
  energies running into and out of such devices
  like the particle tracking system within the
  experiment, which makes knowing these energies
  vital in determining the particles properties
  because the entire experiment bases its
  measurement of current signal strength from the
  signals amplitude with respect to ground.
• Measurements of energy deposited in the particle
  tracking system are used to reconstruct what
  particles passed through the detector, where they
  passed, and with what momentum they passed.
• Current Monitoring System
• For years has been monitored by journal entry
  periodically throughout the day.
• Upgraded Monitoring System
• GID is located in experiment hall and connected
  to a PC placed within the Data Acquisition (DAQ)
  Room by cable.
• PC is connected to the local network which makes
  it possible for the GID readings to be directly
  monitored and archived in the main controls room.
• PC runs EPICS (Experimental Physics and
  Industrial Control System) which is a framework
  for building alarms, archives, control panels,
  displays, etc.
• PC also uses a Linux operating system soft-IOC
  for developing EPICS device support for GID.
• Can either use a sequencer/State Notation
  Language Compiler or Stream Device for data
  sorting.
• Used Stream Device (data sorting software) which
  easily formats input data.
• Properly set up Stream Device for the particular
  processing of the GIDs stringed data using C
  programming.
• Processed data is sent into MEDM (Motif Editor
  and Display Manager) installed on same PC for
  creating the control panel (user interface).
• PC connected to local network by Ethernet.
• Data is broadcasted and then can be easily
  accessed and monitored within the main controls
  room.

• TPC FTPC Gas Systems
• STAR TPC (Time Projection Chamber) and FTPC
  (Forward Time Projection Chamber) gas systems
  regulate a mixture of gases at a certain
  temperature and pressure to the TPC and FTPC.
• Gas systems parameters are archived and
  purification of the recirculating gas mixture is
  controlled using a computer data
  acquisition/control system.
• An alarm and interlock system separate from the
  data acquisition/control system prevents the TPC
  and FTPC from operating under unsafe conditions.
• Current Monitoring and Control System
• Gas systems located at STAR experiment on RHIC
  (Relativistic Heavy Ion Collider) stream data
  into ASCII files which are sent to a processor
  located in STAR control room.
• ASCII files are run through sequencer on VME
  processor located on platform for reformatting
  and then sent back to computer in control room
  for archiving, monitoring, and controlling.
• Upgraded Monitoring and Control System
• Gas monitoring systems save data to Linux
  processor running EPICS located in STAR control
  room on which reformatting and processing takes
  place.
• SED (Stream EDitor) is used for reformatting of
  ASCII files saved by monitoring systems and
  declaring of new variables for each gas subsystem
  so that the new system for monitoring and control
  runs in parallel with existing monitoring and
  control system.
• Reformatted data is then sent into a database
  using caput command and CRON (Command Run ON)
  is used to pull out data from the database
  containing the reformatted files every 1 minute.