IMPLEMENTATION OF SOFTWARE INPUT OUTPUT CONTROLLERS FOR THE STAR

EXPERIMENT

J. M. Burns, M. Cherney*, J. Fujita*Creighton University, Department of Physics, Omaha, NE

Relativistic Heavy Ion Collider (RHIC)

• Located at Brookhaven National Laboratory (BNL) on Long Island, New York.

STAR

• Collide gold-gold nuclei in order to study nuclear matter created in a hot, dense state like that of the earliest stages of the Big Bang.

STAR Experiment• STAR (Solenoidal Tracker at RHIC)

• slow controls and collision data analysis

• consists of several detectors for tracking and studying large numbers of charged particles emerging from collisions

• location of relativistic heavy ion collisions

Original Configuration of Hardware Controls

• 10-year-old specialized front end processors for detector control with low memory capability

• front end cards housed in crates• ~30 specialized processors

running an old version of the real-time operating system

• startup files are downloaded over Ethernet from a single Sun host workstation

Upgrade of Hardware Controls

• PC-based front end processors for new subsystems with high memory capability

• system upgraded to Linux compilable new versions of the real-time operating system

• phasing out Sun workstations to those running Linux for the new and upgraded subsystems

Original Configuration of Hardware Controls

• Some specialized processors use program code that is incompatible with newer versions of real-time operating system.

• Most workstations open user interfaces for the control and monitoring of the experiment.

• Data for the user interface is received from local Ethernet broadcasts.

Upgrade of Hardware Controls

• Existing subsystems using serial interfaces are being moved to the PC-based system.

• Program code compatible with newer versions of real-time operating system is available locally on the PC processors.

• Program code for the specialized processors is downloaded from a Linux workstation.

• Continue using same user interfaces.

• Data still received from local Ethernet.

EPICS

• Experimental Physics & Industrial Control System

• a set of open source software tools

• developed collaboratively

• framework for creating alarms, archives, control panels, displays, etc.

Soft IOC

• Software Input Output Controller

• replaces specialized processor card that served as a hardware IOC

• Soft IOC’s are run on PC’s with Linux operating systems

Again, Why Upgrade?

• processor cost

• easily maintained

• higher memory capability

• faster processing speed

• multiple applications on one PC

Slow Control Projects

• Temperature and Humidity Monitors

• Ground Integrity Device

• TPC FTPC Gas Systems

• Detector Control Bits Application

Temperature and Humidity Monitors

• monitors temperature and dew point throughout the experimental area

• dew point should always be lower than the cooling water temperature

1. Hygrometer 2. PC interface3. Old Processor

Ground Integrity Detector (GID)

• experiment ground is the basis of signal size measurements of the experiment

• signal size is necessary for determining the energy deposited by the particle in the detector

• reads current

• detects deviations between experiment ground and earth ground

GID Project• originally monitored by log entry periodically throughout the day

• GID is located in experiment hall

• connected to a PC placed within the Data Acquisition (DAQ) Room by cable

• PC connected to local network

• makes it possible for GID readings to be directly monitored and archived in the main controls room

GID DAQ Room Control Room

Upgrade of GID• GID raw data output:

Original Data Formatted DataGID raw data output:GID raw data output:

TIPO PV AL1TIPO PV AL1 AL2AL2 STASTA

COMCOM +00087. ABN+00087. ABN ABNABN NORNORCOMCOM +00087. ABN+00087. ABN ABNABN NORNORCOMCOM +00086. ABN+00086. ABN ABNABN NORNORCOMCOM +00087. ABN+00087. ABN ABNABN NORNORCOMCOM +00087. ABN+00087. ABN ABNABN NORNOR

Stream Device (data sorting software) which easily Stream Device (data sorting software) which easily formats input dataformats input data

properly set up Stream Device for the particular properly set up Stream Device for the particular processing of the GIDprocessing of the GID’’s stringed data using C s stringed data using C programmingprogramming

GID raw data output:GID raw data output:

TIPO PV AL1TIPO PV AL1 AL2AL2 STASTA

COMCOM +00087. ABN+00087. ABN ABNABN NORNORCOMCOM +00087. ABN+00087. ABN ABNABN NORNORCOMCOM +00086. ABN+00086. ABN ABNABN NORNORCOMCOM +00087. ABN+00087. ABN ABNABN NORNORCOMCOM +00087. ABN+00087. ABN ABNABN NORNOR

Stream Device (data sorting software) which easily Stream Device (data sorting software) which easily formats input dataformats input data

properly set up Stream Device for the particular properly set up Stream Device for the particular processing of the GIDprocessing of the GID’’s stringed data using C s stringed data using C programmingprogramming

• use data sorting software written in C++ to format input data

Upgrade of GID

• PC connected to local network by Ethernet

• data is broadcast, then accessed and monitored in the main control room by the user interface

Why Upgrade the GID?

• make GID monitoring easily accessible

• better isolate and quickly fix problems with experiment since GID data is archived

• model for other control system upgrades for STAR

TPC & FTPC

•an alarm & interlock system separate from data acquisition/control system prevents TPC/FTPC from operating under unsafe conditions

• TPC (Time Projection Chamber) & FTPC (Forward Time Projection Chamber) gas systems regulate a mixture of gases at a certain temperature & pressure to the TPC and FTPC.

•gas systems parameters archived & purification of recirculating gas mixture is controlled by computer data acquisition/control system

Current Monitoring/Control System

• ASCII files are run through sequencer on a specialized processor located on platform for reformatting and then sent back to computer in control room for archiving, monitoring, and controlling.

• Gas systems at STAR stream data into ASCII files which are sent to a processor located in STAR control room.

Upgraded TPC/FTPC Monitoring/Control System

• SED (Stream EDitor) reformats ASCII files saved by monitoring systems & declares new variables for each gas subsystem (so new system for monitoring/control runs in parallel with existing monitoring/control system)

• gas monitoring systems save data to Linux processor running EPICS located in STAR control room on which reformatting & processing takes place

Upgraded TPC/FTPC Monitoring/Control System

• data is read, reformatted, and sent to the database every minute

FTPC Gas System formatting of ASCII file and final output of ASCII file data

TPC/FTPC Gas Monitoring

User interfaces for TPC and FTPC gas systems monitoring.

• database outputs data to an archive and user interface on a STAR control room computer

• determines which part of the experiment’s alarm system is active

• allows operator to enable and disable the subdetectors which are in use

• upgrade was relocation of systems to user PC’s running Linux

Detector Control Bits

Acknowledgments

• Brookhaven National Laboratory

• United States Department of Energy

• Ferlic Undergraduate Research Scholarship

• Creighton University High Energy Physics Group