The CDR of Computer Service System for SSRF Project
D.K.Liu * T.J. Shen**SSRF Project TeamAbstract
Before the year 2000, the SSRF (Shanghai SynchrotronRadiation Facility) project is the largest scientific project
to be approved by Chinese Government in CHINA. It
consists of a 100MeV LINAC, 2 GeV Booster and Storage
Ring. The R&D of SSRF has been approved by theScience and Technology group of the Government. Mostof the Pre -Research and Design (R/D) will start early ofnext year(1998). The location of SSRF project will beselected soon. This paper will describe present progressand its computer service system including computer
network, accelerator control system, beam diagnosis
system, computer simulation system, user service system
for light beam line and office automation for a new labShanghai National Laboratory of Synchrotron Light
Facility .
1 Introduction
According to the physical requirement of scientists frommany research fields, a new proposal for a light source wasprompted in the 1995 Spring under the Shanghai
Government and Chinese Academy of Science . In theSeptember,1996, the International review meeting for
SSRF was held in Shanghai, China.
2 Design philosophy•••••

Reliability, in general: if the total down time is lessthan 5% of running time, then the users will smile.
However, the computer system is low level equipment
so it′s fault rate should be much less than 1% to0.1% .
Advanced technique: The computer technology isdeveloping rapidly, and the their cost decreasing day
by day. We should consider this factors in selecting
our computer architecture so that it can keep enoughcapability at the early part of the next century .
Standardize and commercial products: According to
the limited resources and manpower in the recent
China. Select of standard commercial and industrial
products as much as possible.
High ratio of performance /cost: we should selectthose with a high ratio of performance /cost becauseof the limited budget.
Cooperation with other labs on the world. There arearound 30 Labs of light sources in the world. Theirexperience and technique would be much helpful forour design and construction of the SSRF project.

3 Main performance of SSRF

Item
EnergyCircumference
Beam Current

Emittance
Bunch Length
Beam lifetime
Beam position
stability

Parameter
2.2GeV~300m
300-400ma(multi bunch)>5ma(single bunch)
3~4rad~30ps-50ps>8hrs+/- 10 µ m

4 Computer system architecture
The entire computer structure is illustrated as follows. It
will be composed of a control system, user service
system of light beam lines, beam diagnostic and data
analysis system including the 3D CAD , simulationlaboratory, and office automation see Fig1.
4.1 Selection of network architecture
The network technology has rapidly changed from early
Ethernet, Token Ring Fast switched Ethernet, to the ATM
etc. In general, the bandwidth of the network is required
to be wider. Now, we just can choose a category of themwhich is advanced, and extendible. The GIGAswitch/FDDI
and GIGAswitch/ATM of DEC company can be used as
one of solution[2]. So far, the technique of FDDI is widely
adapted in many labs as the main backbone of the network.
The GIGAswitch/FDDI crossbar switch is an intelligent,high speed switching bridge allowing multiple dynamic
FDDI links to achieve unprecedented connectivity andLAN throughput-up to 3.6Gb/s aggregate bandwidth. It
can provides up to 6.25 million connections per second;
100Mbps-full duplex; According to analysis of the market
for the forthcoming 5 years, ATM technology will beadopted as industrial standard, it will be widely used forapplications such as multimedia, graphic processes, video
signal broadcasting etc. So the second solution of ournetwork structure is that the main backbone will be on
ATM network. The high-performance ATM GIGA switch
provides guaranteed bandwidth with zero cell; 10.4Gb/s
crossbar switch, scaleable from 155Mb/s Sonet/SDH port.
However, ome factors such as its standard are not fixed, its
cost is still higher. So the first choice is FDDI withextendibility to ATM when needed.
4.2 Selection between Unix and Windows NT
The UNIX OS have occupied the OS market with its
powerful function and high stability for 25 years alreadyHowever in the past 5 years, Windows of Microsoft
company have rapidly developed from the personal PC
world to the business field with its powerful flexibility,low cost, and easy of learning, there are more resources fordeveloping software on its various platforms such as
Windows 3.x, 95 and Windows NT 4.0 (beta 5.0 version
will issue soon ). The amount of Windows’s users
Beam line &station

Intern etD ata
S erver

Firew all
Wireless

PSTN
DDN/X.25

U ser W S

Computer Centre
3D/CADWSTMTM

V ns witch900E F
D E C900M X
P orts witch900T

M a inS erverTM

U ser Server

FDDI

WEB
ServerO A ServerWS

M a gnet
VMEPC
FWControl
S erver 1

RFVME

Bea m
D iagnosis

PC

OA

TM

O pera tor

PC

Control
S erver 2

O A S erver

PC

PC

O pera tor
WS

LIN A CV M E /PC

5.3 Field bus

Booster
V M E/P C

Field bus
CA N Bus
Sm a rtlin k etc.

Accelerator Control & Beam Diagnosis

Solution I of SSRF Computer Architecture

Fig1. solution of SSRF computer architecture
reached 40 million already. The simplified table illustrates
their status see table1 as follows:
Table 1 The comparison between Windows NT & UNIX
NoItem12
34
567

copyright fee
management
featurereliability
support for DB
support for businessrate occupied market

Windows NT
3.82
3.78
3.64
3.47
3.47
3.28
38.8%

field. It can run with high stability and reliability as anindustrial standard. However, our budget is limited, so weshould find out other way to resolve this problem. The
reliability of PC-based modular industrial computers has
improved under ISO 9001 certification and passed many
testing such as EMI (Electricity Fast transient)-EN500811,2; MTBF-Mil-HDBK-217f etc.. So we can adopt somemodules based -PC (such as ADVANTECH′s ADAM
5000seris) in the low speed field. The level III is intelligent
controllers embedded into various equipment with a field
bus adaptor.

UNIX
3.49
3.11
4.27
4.33
4.30
4.13
37.7%

According to table1, our selection is that the high leverfield such as the main computer, server still adopt theUnix, most of Server should use compatible hardware forboth OS such as Alpha series server. However, the lowlevel, such as division level could use Windows NT, thereal time environment could select the RTOS such as
VxWorks, or VRTX .
5 Control system
5.1 The goal of control system
The SSRF machine is middle size accelerator with around
20,000 control points. The most requirements are similar
with other labs of synchrotron light source. The system
reliability, long time stability and high ratio ofperformance /cost should be placed as a first priority ofconsideration.
5.2 Hardware structure
The entire hardware system is divided three hierarchicallevels: level I is composed of the main control network,
console, workstation, servers. Level II is composed ofvarious subsystems such as magnet power supplies,
vacuum system, RF system, beam diagnostics and coolingsystem etc. In this level, the VME system with real time
OS could be used for data acquisition and data preprocess.
VME is popular equipment in the high energy physics

In general, most of controlled equipment is located along
the accelerator with in several hundred meters. The serial
CAMAC, Mil-1553B, bitbus, CANbus, GPIB, andcommunication standard RS232, RS422, RS485 are widelyused for the past 20 years in the control world of highenergy physics. The CANBus uses a bit-wise,
nondestructive arbitration method to resolve any conflicts
if two or more nodes try to access the network
simultaneously. This process will not result in the loss ofdata or bandwidth. This feature resolves collision conflicts
and determines a ″winner″, without loss of throughput orforcing the higher priority node to re-send its data. Higher
priority data gets the right-of -way to be transmitted. TheCAN system thus meet the requirements of real timeapplications refer to Fig2.
T o Eth er n et
C A N B u s C on tr o ller

VM ECrate

M V M E162
-2 2 3 /68 0 4 0Fig 2. structure of Field bus
5.4 Timing and synchronization
Due to the ns beam pulses transmitted from the electron
gun into the booster bucket, and storage ring. The systemjitter time should be less than 200ps. Because of this, weshould pay attention to deal with various connection oftrigger signal passing through high EMI environment.
5.5 Interlock system
The machine protection and personal safety is very
important for whole working area. PLC technology issuitable for this purpose because of its reliability andreasonable cost.
5.6 Software system
We are facing two choices for our system software, one isindustrial products, the other one is non-commercialproducts. After comparing their features including its
performance, cost, second resource, maintenance service,
and considering our realistic situation with the SSRF

project. Fortunately, EPICS have been developed
successfully for many years in many accelerator Labs.
EPICS is a set of software tools and applications jointly
developed by Argone National Laboratory and Los Alamos
National Laboratory for the purpose of controlling
accelerators and large experiments.
EPICS includes operation interface (OPI) which consistsof multi-screen UNIX workstation using a graphical userinterface (GUI) based on the X-windows Motif model.
Also the EPICS has been developed on the PC which will
be easy to work on China.
WindRiver′s VxWorks5.3 and Microtec′s VRTX/OS
both provide excellent, full featured RTOS offerings.
Both are based on similar kernel technology, with kernels
which are modular due to their library style architectures.
Both kernels provide state-of-the art features such as preemptibility and priority inheritance. They have own
advantages and disadvantages. We will select them as ourReal time OS as judged by performance, application
environment and cost.

It is easy to link with many interface such as GPIB,CAMAC, PLC VME/VXI. We have developed a prototype[3].
7 Office automation--groupware
Coordination is needed between staffs of the SSRF
project. Due to the SSRF project is a modern complex
scientific project. Many messages needed to transfer
between different divisions and designers. So theGroupware ( or Intraware ) system should be adopted. At
the present time, the Domino 4.5 Lotus Notes have been
widely used on the most of 500 biggest enterprises in theworld. So far after testing three kind of Groupware, Lotus
Note 4.5, Microsoft′s Exchanger server and Novell′sGroupWise.
The Lotus Notes still ranks first. It supports the Windows
NT/95, NetWare, OS/3 and Unix platform. Also it provides
function of the personal Web Navigator which can link
many team members distributed in the world. We aresetting a prototype of Notes now see Fig.3

Input/Output.

SMTP/MTAPOP3 Server

Real Time.
Distributed.
Database.

AlarmArchiver

Notes Client

Notes Mail

Other MTAs

Notes Mobile
InterNotesNotes

Document
Database &Apps

CC:Mail orExchangeInterNotes
ServerMail Apps

WebServerBrowser onLANInternet

Sequence

InterNotes Notes
Mail Apps

ServerBrowser

Application
Program

DiplayManagerLotus Notes/DominoInternet

Manager
ODBC

There are many application software for operation of theaccelerator, such closed orbit calculation, ramping power
supply of magnets.

OLE2.0/DD
EInternet

RDBMS.

Fig3.Groupware for Office Automation

8 Conclusion
6 Beam control and diagnosis
Various beam parameters of the accelerator are very
important for machine running. In order to monitor beamcharacteristics we will set up approximately 10 category ofbeam instrumentation shown in table 2.
No123456789Item
BPM
DC current
Stripline
ProfileWall Current1
Beam loss
Beam current
photon beamsteering
Bunch feedback

Qty
220
1312
1
1set
101set2set

The most of the signals from the beam instrumentation
have fast characteristics [1] so we will adopt fast preprocess electronics and digital signal processors (DSPtechnology). Those fast signals thus converts in normalFECs. The NI′s (National Instrument company) Labview
or Lab windows is useful for beam diagnostics and various
beam line station for their data acquisition and processing.

The SSRF is the largest scientific project in the end of
this century in China. Computer technology is developing
rapidly, we should cooperate with other Labs in the world.
We sincerely hope to get valuable suggestions from otherlabs.
Acknowledgment
The author appreciate Prof. Chen Senyu for his support,
thanks DEC company have given suggestions for network
structure. Also thanks for the data in Ref.1 provided byDr.Ma LiReference[1]Shanghai Synchrotron Radiation Facility Conceptual
Design Report(Draft)[2]Total solution for PC-based Industrial Automation
ADANTECH solution guide Vol.71[3]The Virtual Instrument Control System on thisconference* Institute of High Energy Physics
P.O.Box.918 Beijing, China 100039
liudk@bepc3.ihep.ac.cn** Shanghai Institute of Nuclear Physics
P.O. Box 800-204, Shanghai, China 201800