Operation Experiences and Development of the Control System in theSRRC
Jenny Chen, C. H. Kuo, K.T. Hsu, K. K. Lin, C. J. Wang,J. S. Chen, C. S. Chen, K. T. Pan, K. H. Hu, C. C. Kuo, R. Sah
Synchrotron Radiation Research CenterNo. 1 R&D Road VI, Hsinchu Science-Based Industrial Park, Hsinchu, Taiwan
Abstract
The control system of the SRRC is a two-level system.
Console level computers consist of workstations and PCs.
The device levels consist of VME based embeddedsystems. PC based system are also used for some device
level applications. The console level operating system isVMS. DEC UNIX and WindowsNT will come soon.
Devices level supports pSOS+, LynxOS, and WindowsNT.
Most of the software components was development inhouse. Integrated commercial software packages are alsoused. Web and Java for control related applications isunder way. Device level systems have been ported toPowerPC based VME CPU modules running LynxOS ofthe control network has been changed to switched ethernet
using fast as well as standard ethernet. Sophisticatedelectronic instruments are connected to the control system
via IEEE-488 to ethernet adapter. A project to integrate thecontrol of turn-key injector with main control system has
been initiated recently. Achieving a seamless integration
with limited resources is highly desirable. The operation
experience and development of the SRRC control system
will be summarized in this report.
1 Introduction

The system has been operated since the earlycommissioning of TLS nearly five years ago. The
satisfaction level was gradually decreasing due to out-ofdate computers and increased performance requirements.
The numerous controlled devices have increased two-foldsince the dedication. Response time is too slow, network
congestion is increasing. Mass storage spaces isinadequate and latency in control applications are thetypical symptoms of the existed control system.
3 New control system environments
The new control environment includes upgrades to thefollowing: console level computer, VME crates, network,and application software development.
3.1 Console level computer development
Many new I/O channels are needed for the new devices
being installed in the storage ring. Sophisticatedapplications are consuming more computer resources.
History archive data is increasing steadily. Existing server
computer and workstations are heavy loaded. To eliminate
the degraded the server performance, upgrade activities
are in progress since mid-1996.
Draft
Rev. V1.1
97/04/27

1.3/1.5 GeV Injector
WS/X-terminal

PC-Based machine status broadcast system
Workstation/DEC UNIX

VAX System
4000 - 500

VAXstation/VMS

Process &AlphaServer
ConsolePorgram
1000A 5/400
Computer Development

WS/X-terminal

X-Terminals
PC/Windows NT

Laboratory

Ethernet
SwitchSRRC Network
Ethernet
Switch100 BaseT

100 BaseT

10 BaseT

100 BaseT

Ethernet Switch

Router

VME #2Ethernet
Switch10 BaseT
100 BaseTVME #3
VME #1

I/O
I/O
I/O
I/O

Timing
I/OI/O
I/O
I/O

VME
crate

CPU

I/O
I/O
I/O
I/O

VME
crate

CPU

I/O
I/O
I/O
I/O

CPU

VME
crate

CPU

I/O
I/O
I/O
I/O

10 /100 BaseTDevicesLevel

PC/Windows NT
Based Video Server

10 BaseT

100 BaseTCPU

The control system of the storage ring of the SRRC
(Taiwan Light Source, TLS) is a typical medium scale
experimental physics control system in operation since its
commissioning in 1993. The system is an example of thestandard model. The system is still growing due to newdevices installed on the accelerator system. There aresome good as well as bad points of the system. Upgrade
activities initiated since late 1996 use up-to-datetechnology to accommodate more devices and increase
performance requirement. Details of upgrade activities aredescribed below.

VMEcrate

Viewers
DCCT
Tune monitor
BPM... etc.

BITBUS

Fast Digitizer(Digitize
Current
Waveform ofMagnets)

Gun
Linac
VacuumVME
crate

TimingPower Supply

RF system

Vacuum system
MVME 147/pSOS+
Based VME System

Insertion Devices

PowerPC/LynxOS Based VME System(WindowsNT Based System is possible
in near future)
Screen Monitor

SR monitor

SR monitor
TR monitor
Screen Monitor

PLCInjector
e-To Storage Ring

PC/Windows NT
Based Video Server

2 Early control environment and its operationexperiences
SRRC control system is a two-level hierarchical system[1]. The upper layer consists of one server computer andseveral console workstations. The console workstations
are the user interface. The lower layer consists of many
field level controllers (VME crates system) which perform
local data acquisition, interlock generation and carry out
devices control requests from the workstations or server.
The console level computers are VAX/VMS based and thelower layer are 68K/pSOS+ VME crates. The networking
system is a standard thick/thin wire ethernet.

Figure 1. Control Hardware Architecture
Key software components of the control system on theworkstations were ported to Digital UNIX at early of
1996. A new high performance entry-level DECserver
1000A 5/400 was installed in May 1997. The server
provides more horse power and large mass storage space.
A new 41.6 GB optical disk cartridge was installed atsame time. The optical disk system provides at least 2
years of on-line archive data retrieve capability. NewENET. At presentation layer, UIM/X graphical userinterface builder was used to develop applications.
3.5 Software and application development
The control software environment is almost same asprevious system as shown in Figure 3 [1] but with someenhancements. The major difference is this environment
working on different platforms and operating systems. The
new system supports new software components including
newly developed applications and commercial products.
Typical commercial products include PVwave,LabView, ... etc.
Rev. V1.01
97/07/12
H. K. T.

Computer Room(E144)

AlphaServer
1000A 5/400
SRRC02

VAX System 4000
- 500
SRRC09Phase I: Nov 15, 1996(Control room, core area)
Phase II. Feb 10, 1997
(I&C lab, machine shop)
Phase III. May 20, 1997
(Injector equipment area)
Phase IV. July 11, 1997
(Control room)
Phase V. ???, 1998
(Backbone => Gigabit Ethernet)

100 Base-T
Ethernet Switch

100 BaseT

100 BaseT

10 Base-T
Ethernet Switch

10 BaseT

E133 x 1
VME
crate

CPU

generation workstations will replace old machines toimprove the response time and support more sophisticatedapplication programs. The new server and workstations forcontrol system are expected to replace out-of-datecomputers (most of these machines are five years old). Thecontrol
systemalso
supports
PCsolutions.
PC/WindowsNT system has been in service since June
1997. The PC/WindowsNT consoles provides a similar
GUI environment for the machine operation with low cost.
PC/WindowsNT/Windows95 are also used in somedevices level applications. For example, video applications
for screen monitors and synchrotron radiation monitors
will be done by PC/WindowsNT/Windows95 environments. Applying the PC/WindowsNT environment toaccelerator related control is high receiving attention by
the control community. The development effort willcontinue in order to keep up-to-date with the pace oftechnology advance.

LynxOS Server

10 Base-T
Ethernet Switch

E132 x 1

3.2 VME crates system development
There are 25 VME crates system in service now. Several
new VME crates system will be installed in the coming
year in conjunction with the upgrade activities of theaccelerator system. The old VME crate system is based
upon MVME-147 CPU module running pSOS+ real-timekernel. The development environment is on the VAX/VMS
workstation. To increase productivity, save manpower,
improve system performance, and keep up-to-date,
PowerPC CPU module and real-time UNIX were choose
to use in the new VME environment. The current system
has 8 nodes in MVME-147/pSOS+ environment. The
remaining system is using the PowerPC/LynxOS
environments. New VME crate systems to be implemented
in the coming year includes U9 control, EPU control, 3rd
RF systems, Landau cavity project, BTS diagnostics,
several nodes for photon BPM (PBPM) front-end dataacquisition, and several nodes for injector control
integration.
3.3 Control network upgrade
Traffic on the control ethernet consumes about 30% ofthe network bandwidth 10 Mbits/sec. Load is expected toincrease steadily. Topology of the control network waschanged to switched ethernet on October 1996. The newcontrol network infrastructure supports standard and fastethernet connections. The backbone was changed to 100
Mbits/sec ethernet last November. The performance has
improved drastically. Reliability of the control network isalso highly improved. The new control network is
operating very well. There is no downtime of theaccelerator system due to network problems.
3.4 GPIB-ENET connected devices
For complex instruments, such as spectrum analyzers,
connection to the control system is made by using GPIBENET adapters. NI-488.2M software installed onworkstation is used to drive these instruments.
Applications on workstation can access every accelerator
device that is connected with the VME crates or GPIB-Injector
Equipment
Area

SRRC Network
RouterSR portx2(120 m)
ILC22 SR DIAG

ILC25 BITBUS, PLC
ILC26 Vacuum,
Screen Monitor,...etc.
ILC24 Linac Rf
control

100 BASE-T

Control Room
(E141/E142)
100 BaseT(80 m)

100 Base-T
Ethernet Switch

10 Base-T
Ethernet Switch

100 Base-T
Ethernet Switch

BD04

ILC03
SparcStation 10ILC04

Experimental Console #1(WindowsNT)

ILC05
ILC06

Machine Status
Broadcasting Station

10 Base-T
Ethernet Switch

7206/5202
I&C Group
Laboratory

ILC02

VXT 2000

Printer
Server

100 Base-T
Ethernet Switch

10 Base-T
Ethernet Switch

ILC01
SRRC07

100 BASE-FX

ILC08
ILC11ILC20

MVME 147+pSOS+

VME Crate System&X-terminal, WS
ILC07 BPM
ILC09 PS
ILC10 EPBM
ILC12 Corrector
ILC13 U5
ILC14 U9
ILC15 U10P
ILC16 EPU
ILC19 BTS Diagnostics
ILC21 Diagnostics
ILCxx Test Station
PowerPC+LynxOS

10 BASE-FX

SRRC10
SRRC08
SRRC04
SRRC01

Machine Shop

LEMEL LM-H9L
mini-hub

ILC18 1 m EPU

Core Area

Figure 2. Networking Topology of the Control System
4 Control related developments
In addition to control infrastructure changes, a lot ofcontrol related development [2,3,4,5,6] is under way. Hereare several examples.
4.1 Tune measurement
The tune measurement system is currently using aHP4396A spectrum/network analyzer to acquire spectrum
information from the beam signal. The spectrum analyzer
is connected to control system via a GPIB-ENET adapter.
The tune measurement program is able to issue commands
to drive the spectrum analyzer with the aid of NI488.2M
library. Parameters setting is done via the operatorinterface. The parameters include frequency scanning
range, beam excitation enable/disable, power level
controlling, ... etc. New tune measurements using digital
receiver technologies is under development.
4.2 Orbit display utilities
Orbit display is required during both routine operationand machine studies. A bar chart display of beam position
monitor (BPM) readings has been in service since storage

Control Applications
Parameter
Data Logging Page Prog.
and Archiving

System Status Real Time
Alarm
Trend Display
Display
Checking
Prog.

GraphicControlInterface

Beam Daig.
Program(MPAP)

Machine PrarmeterService Routines
Database Access
Layer

BPM& Magent Database
Data Access Routines

Data BaseLogging
ProgramDynamic
Data Pool

Static Database

ConsoleLevel

Data Access Routines

Network Access
Layer

10 HZ

Static Database
Server Process

DDB Upload
Server Process

Setting ServerProcess

Control LAN (EtherNet)

CommandProcessing Task

Setting ServerTask

DDB Upload
Server Task

DevicesLevel
Device Access
LayerChild task forspecial services

Self-config.
table

Data Collecting
Task

Dynaimicdata pool
Shared memory

system includes several VME crate systems, orbit
acquisition, corrector control, and photon beam position
monitor (PBPM) data acquisition. These crates share orbit
information via a VMEbus reflective memory network.
Orbit acquisition VME crate systems are PowerPC/LynxOS based and use a high speed CPU engine (200 Mhz
PowerPC) to support various operation modes. The orbit
sampling rate is currently 1 kHz. The corrector control
VME crate is also a PowerPC/LynxOS system. The
feedback DSP modules are located on the corrector crate.
Current efforts are to improve the performance of thefeedback loops and to study control algorithm
improvement. Local orbit feedback using electron beamposition monitors (EBPM) as well as PBPM is underintensive test. Efforts will continue on improving theEBPM performance, PBPM integration, and loop
performance of the local feedback.

SRRC Storage Ring
Control & MonitorDevices

4.6 Control system web development
Figure 3. Control System Software Structurering commissioning. As machine study activities increases
the ability to measure orbit changes as machine parameters
are varied is desired. Since there are a lot of requirementsfor orbit display, a real-time display utility was developed.
The utility provides display of absolute and difference
orbits. Color grading display will be supported in newversions. The line style can be dot line and line-dot. Data
averaging is also supported by the package. The updating
period without any average is less than 0.5 sec.
4.3 Lattice function measurement tools
Lattice function information is very important formachine optimization especially for low emittance ring.
Measuring the lattice function is the tedious work without
automation. In order to solve this problem, tools tosupport lattice function measurement have beendeveloped. The package provides beta function, dispersion
function, beta function, and chromaticity measurement.
The measured raw data as well as processed data can besave for later use.
4.4 Filling pattern measurement
The filling pattern plays a crucial role in the performanceof the accelerator system due to the effect of coupledbunch instabilities. A real-time filling pattern diagnostic
tool is being developed. The system is composed of aVMEbus 500 MHz digitizer using an external clock fromthe master oscillator. The signal picked up by the striplineelectrode is digitized by the fast ADC. Each data value is
proportional to the amount of charge accumulated in thecorresponding bunch.
The data is then sent to aworkstation to display the filling pattern and for otheruses.
4.5 Orbit feedback development
A digital global beam position feedback system has
been in operating since August 1996 [3,4]. The present

A web server has been available since late of last year
(http://www-icg.srrc.gov.tw). The light source web
provides a real-time machine status display, limited control
access on machine devices, and browsing on archiving
data. Web access to the on line log book will be available
in the near future. Applied Java technology for the control
system is also in progress.
4.7 Insertion devices control
Control for insertion devices (ID) has been redone and
now ID components connect to VME crate directly [6].
Clean and simple structures reduce control overhead aswell as reduce response time. The new ID control
infrastructure was tested with in-house ID engineeringmodel ID (1 meter APU and 2 meter U10P). The control
structure also will be used for U9 system which wascontract to STI Optronics.
A one meter EPU engineering model is being
implemented. The control effort is focused on system
integration and motion control loop performance
improvements. The phase of EPU should precisely control
position. The tracking during phase change scenario is also
important. Ensuring good tracking of different magnets
during phase change is an important issue. The four meter
EPU5.6 project has started recently. Control design andimplementation are under way. Control system integration
is expected to finish on April 1998.
5 Control integration for the injector system
The injector of the SRRC composed a 50 MeV linac anda 1.3 GeV electron booster. The injector system orginialy
is an turn-key system with a separate control system. It is
not convenient from maintenance and operation point ofview. The injector control integration plan has beenlaunch. The goals are to integrate injector control systemwith the TLS control system as a unified system. The
existing control system consists a Bitbus network and one
PLC to access devices of the injector. Both device levelsystems are connected to a PC working in iRMX III
environments. A VAXstation uses as control control

console.
The new system will replace the VAXstation and iRMX
system with the console computers of the main control
system and several VME crates as shown in Figure 1. The
integration will be done while the injector is in standby
mode after every TLS fill. This will minimize interferencewith the normal operation of the machine. The project isexpected to be finished before the end of 1998.

[2]

[3]

6 SummaryThe control system of TLS has five years of operation
experience. Improving performance gradually under
shrinking budgets and reduced manpower is a challenge.
New development will use mature commercial products.

[4]

[5]
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user interface database and intelligent local
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Jenny Chen, et al., “Virtual Instrumentation Interface
for SRRC Control System”, Proceedings of the 1995
IEEE Particle Accelerator Conference, 2256, May
1995.
C. H. Kuo, et al., “Digital Global Orbit Feedback
System Developing in SRRC”and “Local Feedback
Experiment in the Taiwan Light Source”,
Proceedings of the 1997 IEEE Particle Accelerator
Conference, Vancouver, Canada.
C. S. Chen, et al., “New Power Supply ControlInterface and Energy Ramping Design in SRRC”,Proceedings of the 1997 IEEE Particle Accelerator
Conference, Vancouver, Canada.
J. S. Chen, “Using WWW in the SRCC Control
System”, Proceedings of the 1997 IEEE Particle
Accelerator Conference, Vancouver, Canada.
K. T. Pan, et al., “Insertion Devices Control
Development at SRRC”, Proceedings of the 1997
IEEE Particle Accelerator Conference, Vancouver,Canada.