\documentstyle{foil}

\begin{document}
\raggedright
\nofoilnumbers
\font\small=cmssbx10 at 14.4truept
\font\medium=cmssbx10 at 17.28truept
\font\large=cmssbx10 at 20.74truept
\font\hugh=cmssbx10 at 24.90truept

\begin{foil}{Euroball III}
\hugh
\subsubsection*{\bf Euroball}
An European collaboration involving Denmark, France, Germany, Italy, Sweden and
the UK.

Will initially be sited at INFN Legnaro where it is hoped to start
operation early in 1997 for a period of 15-18 months.
 
It is then scheduled to continue at Strasbourg in late 1998.

\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Euroball III}
\subsubsection*{Detectors}
  
\begin{itemize}
\item 30 Coaxial Detectors: Ge detector + 10 element BGO shield from Eurogam I
\item 26 Clover Detectors: 4 element Ge detector + 16 element BGO shield from
Eurogam II
\item 15 Cluster Detectors: 7 encapsulated Ge detectors + 18 element BGO shield 
\item ancillary detectors: will include a Silcon ball and Neutron array
\end{itemize}

\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Euroball III Electronics \#1}
 
Uses integrated electronics with full software control using the VXI 
(VMEbus eXtensions for Instrumentation) standard.

Existing electronics from Eurogam I and Eurogam II
 
\begin{itemize}
\item Ge card - total of 6 VXI cards each having 6 channels (one is a spare).
\item BGO card - total of 6 VXI cards each paired with a Ge card.
\item Clover card - total of 26 cards. Each card has 4 Ge channels (+ one spare 
Ge channel) and 1 BGO channel.
\end{itemize}

\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Euroball III Electronics \#2}
 
VXI electronics for the Cluster detectors (total of 15 sets)

\begin{itemize}
\item Ge card - 7 channels plus 1 spare channel (2 energy + 1 timing parameters
 per channel)
\item BGO card - 18 channels plus 1 spare channel (energy and timing parameters
per channel) and 1 "sum" channel (3 parameters)
\end{itemize}

\medium
A PPADC channel is under development which could be used in the future to
replace the ADCs on the Ge card. This would be a third card per detector.

The Neutron detectors are planned to have VXI cards (50 channels with 8
channels/card) and the Si ball (at least 42 channels) may use VXI.

\end{foil}

\begin{foil}{Euroball III}
\hugh
\subsubsection*{Euroball III Electronics \#3}
  
\begin{itemize}
\item Resource Manager (RM) VXI slot 0 card - one per crate
\item Master Trigger
\item ReadOut COntroller (Struck STR8080) - one per VXI crate
\item Total of 9 VXI crates (core system)
\item 3 DT32 buses (core system)
\item Hardware Histogramming Unit with 8M channels per DT32 bus
\item VME to CAMAC interface (Hytec VSD2992)
\item Event Collector (VME Module) per DT32/FERA bus


\end{itemize}

\end{foil}

\begin{foil}{Euroball III}
\footnotesize
\subsubsection*{VXI Readout}

Eurogam I and Eurogam II used "Common Dead-Time" mode VXI readout. This means 
that all the electronics remained disabled while an event was being digitized 
by the adcs and the data read from each card active in the event by the crate
ROCO. Apart from being simple this mode also ensured that there was no 
other activity in the crate during the analogue processing stages within the
VXI cards. At the time the Eurogam I VXI cards were being designed this was 
a sensible precaution.

Euroball will use a "parallel" mode in which only the VXI cards (detector
channels) active in an event will be disabled and then only until the data
is in a FIFO ready for VXI readout. All other cards will be reenabled as
soon as it is determined that they have no part in the current event.

The Eurogam I cards cannot be made to operate in this parallel mode and so
2 pairs of cards only will be installed in a VXI crate (total 3 crates) and
the crate be treated as a unit in parallel readout mode. For later phases of
Euroball the Eurogam I cards will be redesigned.

All new cards will use a General Interface and Readout (GIR) unit for the
VXI/VME interface and readout. This enables the VXI cards to be more modular
and removes the need for each card design to reproduce the VXI/VME interface.


\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Euroball III Data Acquisition}
  
\begin{itemize}
\item Event Collector (VME Module) per DT32/FERA bus
\item High Speed Switching Network - Fibre Channel
\item Event Distribution
\item Event Builder
\item The Processor Farm and on-line analysis
\item NEO++
\item Histogram Server
\item Tape Server
\item Experiment Control and Monitoring
\end{itemize}


\end{foil}


\begin{foil}{Euroball III}
\medium
\subsubsection*{Data Acquisition \#1}

The Euroball Data Acquisition system is required to be able to 
collect the data generated by event rates up to 50 - 100 kHz in order to
be suitable for a wide range of experimental situations. The corresponding
raw data rate will depend on the particular experiment but data rates up
to 20 Mbyte/sec are required to be handled by the initial system. Additionally
the system design has to be scalable so that higher data rates can be 
handled in the future simply by the addition of further hardware within the
existing structure.

Euroball will often be used coupled with ancillary detectors of 
varying complexity. In some cases these will have their own VXI electronics
and thus will couple into the core system without problem. However, others
will use CAMAC ADCs with FERA readout and possibly VME ADCs. It is therefore
important that the ReadOut system be able to handle these other type of
data source in addition to DT32 bus for data from the VXI crates.


\end{foil}


\begin{foil}{Euroball III}
\medium
\subsubsection*{Data Acquisition \#2}

The Eurogam ROCO can output data onto the DT32 bus at 330 nsecs/word 
(12 Mbytes/sec) which is less than the required data rate from Euroball.

In its core configuration Euroball will consist of 9 VXI crates which could
expand to 12 or more when PPADCs and ancillary detector electronics are added.

Thus Euroball will use multiple DT32 bus readout chains. It is expected that
3 buses each with 3 or 4 VXI crates will be adequate for all uses. Also the
Eurogam ROCO will be replaced by the Struck STR8080 which was developed for the Heidelberg Crystal Ball. The STR8080 contains a DSP (Motorola 96002) which can be programmed to generate the control tokens needed for secure operation within a multi-bus 
readout system. It can output data onto the DT32 bus at 100 - 125 nsecs/word 
(dependent on DSP program) which is 32 - 40 Mbyte/sec and thus greater than
our requirements for Euroball.


\end{foil}


\begin{foil}{Euroball III}
\medium
\subsubsection*{Event Collector}

The Event Collectors act as a bridge between the data readout bus and the 
event builder processors. They each collect event fragments for a given 
number of events (at high rates this would be typically 10K events) to
generate a "Super-Event" fragment buffer. The "Super-Event" fragment buffer
in all Event Collectors must contain only data from the same Master Trigger
events. These buffers will be generated at a rate of not more than 
10 per second which will allow all subsequent buffer handling to be 
performed at non real-time rates and thus allow the use of standard UNIX 
operating systems.

The Event Collector contains a DSP (Texas TMS 32000) which is mainly 
used for control of the data readout and counting of events to 
determine when a "Super-Event" fragment buffer is complete. It can also 
be used for some data integrity testing.

\end{foil}



\begin{foil}{Euroball III}
\medium
\subsubsection*{Event distribution - Fibre Channel Network}

One of the most critical parts of the system is the event builder and
thus the event distribution from the Event Collectors to the 
processor farm which performs the  task of combining event fragments
into complete events.

The event distribution for Euroball will be performed using a switching 
network to the Fibre Channel Standard (FCS). A 16*16 node switch will be used
with individual interface ports at 255 Mbits/sec. Switched networks such as
FCS and ATM have total throughputs measured currently at several Gbits/sec
(the data rate on the switch backplane).
This is a significant advantage over broadcast networks such as ethernet and
fddi in which the total throughput is limited by the individual port 
data rates (100 Mbits/sec in the case of fddi).

Fibre Channel is being developed by manufacturers such as IBM and HP to
connect disc farms to processor farms. Also see the SCSI-3 proposals.

\end{foil}


\begin{foil}{Euroball III}
\medium
\subsubsection*{Event Builder \#1}

Super-Event fragment buffers of the same events collected in the Readout Units
are sent in parallel via the FCS switch to the same destination processor to
be analysed. The fragments are tagged with the event number within the ROCOs.

The event builder function includes tasks such as:-
\begin{itemize}
\item Basic consistency checks on the event fragments. The raw data format 
contains redundant information for security and this can be checked for
self consistency to detect possible hardware errors during data readout.
\item Using the event number within each fragment complete events are
constructed. Further checks can be performed on the complete event to ensure 
correct functioning of the frontend electronics and readout mechanism. For
example the data received can be checked against the hardware setup to 
detect readout errors.
\end{itemize}
\end{foil}

\begin{foil}{Euroball III}
\medium
\subsubsection*{Event Builder \#2}

\begin{itemize}
\item  The fragment tokens are removed at this stage and the 
formatted complete event is now in a more compact format than the raw data.
\item Statistical information is produced so that a constant check can be
kept on the quality of the raw data and alarms produced if the error rate
exceeds reasonable levels.
\end{itemize}

All data sources (ROCOs and FERA masters) are required to generate an
event fragment even if it contains no data. This is important for the 
event construction since it is possible to detect a missing event fragment
or malfunctioning data source
which would not be the case if empty fragments were not required.

\end{foil}


\begin{foil}{Euroball III}
\medium
\subsubsection*{Processor Farm}

The Event Building and Online data analysis functions take place within the
Processor Farm. This is composed of standard commercially available workstations which are connected to the FCS switch. The data buffering 
within the Event Collectors both allows for efficient use of the
Fibre Channel and reduces the interrupt rate of individual processors within 
the farm to a few Hz. This allows the use of a standard UNIX system within the
farm processors. The use of UNIX allows for a much better software development
environment and thus more secure software than is normally possible if a 
dedicated real-time operating system is used.

Control communication between the elements of the Processor Farm and the
Event Collectors is performed using ethernet which is possible at the
low interrupt rate being used.

The processors within the farm are controlled using the 
Common Object Request Broker Architecture (CORBA).
\end{foil}



\begin{foil}{Euroball III}
\medium
\subsubsection*{Online Analysis \#1}

Online analysis is defined as all the data processing that is performed by the 
processor farm during the acquisition of the raw data. The processor farm can be
partitioned to allow two modes of operation:-

\begin{itemize}
\item Type 1. Full Online Data Processing. This has to process all the raw data
events before sending them to tape. In addition to the basic functions of
event building, data checking and event formatting it can also include
functions such as calibration, filtering and event sorting. In this case
it is necessary to consider the impact of such processing on the final
data rate. Also any errors introduced may seriously effect the correct 
output of data to tape.
\end{itemize}
If required all processors in the farm can be used for this mode of operation
in which case Type 2 will not be available.
\end{foil}

\begin{foil}{Euroball III}
\medium
\subsubsection*{Online Analysis \#2}

\begin{itemize}
\item Type 2. On request (spy) online analysis. This would always run in 
conjunction with a basic Type 1 program which would just perform the
event building, data checking and event formatting steps and output the data
to tape. The data output from stage 1 would be available to the Type 2 
program for calibration and event sorting. However in this mode of operation
the correct or otherwise operation of the software can have no effect on the 
output of data to tape and is thus a more secure mode of operation.
\end{itemize}

In this mode of operation a predetermined percentage of events is sent to
the processors or more likely all output data and the processors just 
handle as much as is possible.

\end{foil}


\begin{foil}{Euroball III}
\medium
\subsubsection*{NEO++}

Nuclear Event Orientation

A complete development tool called the Neo++ Development Center is available to
users to aid the programming of the processor farm in both Types of operation. 
The tool allows the user to  create programs (following the Neo++ rules), to
compile it, load it into the farm and execute it. A full source debugger is also
available. The appropiate interface procedures will be available to users 
who which to run their own analysis codes on the processor farm.

Neo++ is an extension of the C++ language providing the statements to 
program the processor farm. In particular it provides the grammar needed to
describe the raw data format of the expected input events, the data processing 
required, the output data streams, the building of histograms and gates and
dynamically setable variables to allow run-time interaction with the 
analysis code.
\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Histogram Server}

The Histogram Server is based on a set of workstations connected to the
FCS switch. It receives output from the processor farm and constructs 
histograms as requested by the analysis program running on the farm. Histograms
are initially cached in RAM and then from time to time dumped to disk. The
histograms can be retrieved at any time for viewing.

The same access method as used for the hardware histogrammer will be used
thus enabling the histogram viewer and analysis codes to freely mix online 
hardware and software histograms with offline histograms.

\end{foil}

\begin{foil}{Euroball III}
\medium
\subsubsection*{Tape Server}

Hardware configuration for Euroball III

\begin{itemize}

\item 6 Digital Linear Tapes (DLT) 
\item 8 Exabyte 8500 tape drives fitted with robot changers (from Eurogam)

\end{itemize}

Supports up to 4 data streams

Each data stream may be output to any number of the drives in either
duplication mode, parallel mode or any combination of these.

Currently DLT4000 available (20 Gbyte/tape and 1.4 Mbyte/sec). By Summer 1996
it is expected that 5 Mbyte/sec (raw) will be available.

The Exabyte 8500 drive can write up to 5Gbyte of data onto a 8mm video
cassette at a continuous rate of up to 0.5 Mbyte/sec.

\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Control \& Monitoring}

Experiment control and monitoring will be based on the Eurogam
system. 

The Eurogam Register Server will be used for control functions 
with an interface developed to communicate with the CORBA system.

The Tool Command Language (as used by Eurogam) will be used
to generate the Graphical User Interface.

\end{foil}


\begin{foil}{Euroball III}
\hugh
\subsubsection*{Other Items}

High Voltage Control System

\medium
Will use existing Eurogam LeCroy mainframes with new CAEN mainframes.

Software control system based on the Eurogam system.

\hugh
Autofill System

\medium
Will use the hardware controller from GaSP with a largely standalone
system based on UNIX and LabView.

\end{foil}

\begin{foil}{Euroball III}
\medium
\subsubsection*{Further Information}
 
By World Wide Web (WWW)

connect to http://nnsa.dl.ac.uk/Eurogam and  http://nnsa.dl.ac.uk/Euroball

For this talk connect to
       http://nnsa.dl.ac.uk/Eurogam/documents/edoc303/ps

For the talk on Eurogam connect to
       http://nnsa.dl.ac.uk/Eurogam/documents/edoc204/ps

For Netscape postscript viewer use ImageTool for these.

For some documents ImageTool fails and PageView may work better.

\end{foil}

\end{document}
