TUAP002
physics/0111202

A CONTROL SYSTEM OF THE JOINT-PROJECTACCELERATOR COMPLEX
J. Chiba, H. Fujii, K. Furukawa, N. Kamikubota, H. Nakagawa, N. Yamamoto
High Energy Accelerator Research Organization (KEK), Tsukuba, Japan 305-0801
H. Sakaki, H. Yoshikawa
Japan Atomic Energy Research Institute (JAERI), Tokai, Japan 319-1195
Abstract
The current status of the control system for a newhigh intensity proton accelerator, the JAERI-KEK Joint
Project, is presented. Phase 1 of the Joint Project has
been approved and recently started its construction at
the JAERI site at Tokai. The first beam commissioningis scheduled in 2006. In parallel with it, a 60-MeV
Linac is now being constructed at the KEK site at
Tsukuba for R&D purposes.
Recently the Project has officially decided to use theExperimental Physics and Industrial Control System(EPICS). Under the EPICS environment, we arechallenged with implementing the Ethernet/IP network
for all communication, even at the level of end-point
controllers which are currently connected via a fieldbus. In order to realize such a system, three newcontrollers (PLCs, WE7000 stations and generalpurpose Ethernet boards) are being developed. Aprototype EPICS driver for the PLCs works fine and isused to control the ion-source at the KEK Linac.

1 THE JOINT-PROJECTAs reported in the previous conference [1] the twoprojects, JHF at KEK and NSP at JAERI, were merged
and formed a new project, the JAERI-KEK Joint
Project. Phase 1 of the project consists of three
accelerator facilities (400-MeV Linac, 3-GeV Rapidcycling Synchrotron, and 50-GeV Synchrotron) andtwo experimental facilities (Material and Life Science
Facility at 3 GeV and Nuclear and Particle Physics
Facility at 50 GeV). The construction of Phase 1 will
be completed in 2006. The schedule of Phase 2 is notknown yet, in which a 600-MeV Super Conducting
Linac and Accelerator Driven Transmutation (ADS)
Experimental Facility will be constructed.
We are planning to make a central control systemwith which not only the accelerator but also the beams
and targets in the experimental facilities can bemonitored and operated in order to reduce theoperational costs including labor.
In addition to the facilities at Tokai mentioned above,
we are constructing a 60-Mev Linac at the KEK site. Itis comprised of an ion source, a low-energy beamtransport (LEBT), 3-MeV RFQ Linac, a mediumenergy beam transport (MEBT), a 50-MeV drift-tube
Linac (DTL), and a 60-MeV separated DTL (SDTL).
The DTL and SDTL will be transported and reinstalled at Tokai after successful beam tests.

2 DESIGN OF THE CONTROL SYSTEM
2.1 Introduction
Before forming the Joint Project, the use of theEPICS toolkit at the JHF accelerator had been decided
after intensive discussion among the JHF control groupmembers [1]. Although there were some complaints
against the use of EPICS, we recently decided to use itin the Joint Project. Since the Joint JAERI-KEK
construction team have been formed only a half year
ago, concrete rules needed for the control systemdesign are not determined yet except for the use ofEPICS.
In the following subsections, we describe our present
thought on the control system in 5 components; (1)device control, (2) network, (3) operator interface, (4)interface to beam simulator and (5) database.

2.2 Device control
In EPICS, all device controls are carried out throughinput/output controllers (IOCs). At present, only VMEs
under the vxWorks operating system can be used as an
EPICS IOC. Many VME modules are commerciallyavailable for processing normal digital and analogue
signals. EPICS drivers are already available for manyof those modules. Therefore, we don’t need to worry
about devices which require only those signals.
However, there are many devices which need special
treatments.
PLCs are cheap and reliable in a sense that they keep
running under any trouble in computers or networking,and therefore it is preferable to use PLCs for somecritical devices such as an ion-source. How PLCs

communicate with IOCs is one of the issues we have todetermine early. Our answers are as follows:• Use
Ethernet
TCP/IP.
AmongPLCs
commercially available, presently only FA-M3
PLC by Yokogawa support data transfers
protocols we required, we force equipmentgroups to use it if they need PLCs.
• Assign an identification number (ID) to eachPLC. It is dangerous to rely only on the IP
address. Before any communication with a PLC
and at any data (command) transfer to a PLC,
check the ID to make sure you arecommunicating with an appropriate PLC.
• No individual commands for operation. Only
data transfer from/to PLC memory is supported.
Any device operation should be done thoughcontents of memory in a restricted address range.
• No direct write to PLC memory. An IOC sends
3-word data (an ID, a memory address andcontent) to a communication area in the PLC
memory. Then, a PLC ladder program moves thecontent to an appropriate address after checking
its ID.
A prototype of the PLC EPICS driver has been written
and successfully used for the ion-source operation atthe KEK 60-Mev Linac, although all the rules
mentioned above are not fully implemented yet in theprototype driver. A detailed description on the device
driver may be found elsewhere [2].
Choice of waveform digitizers is another important
issue we have to consider for device control. As
reported in the previous conference [3], our choice was
the WE7000 measurement station by Yokogawa. Its
EPICS driver has been partially completed and tested.
For this station, the same TCP/IP Ethernet
communication method is used as that for the PLCs. A
detailed description is given again in Ref. [2].
For precise current control of power supplies, weshould avoid extending an analogue signal in a longdistance, and instead, should use digital data links.
Since Ethernet network runs all over the area, we chose
Ethernet for the digital data link, avoiding another typeof field bus so that all of the data communication isunified. By doing so, we can trace back all data throughthe network which will significantly help us for
operation diagnostics. Also it reduces the number ofstock items which may reduce the operational cost. To
achieve the unified Ethernet links, we are developing
an Ethernet interface board which will be usedprimarily in the power supplies for quadrupole magnets
at the DTL. The board is designed considering moregeneral uses and may be embedded in other devices.
However, some devices required for some equipment
may communicate with our control system only via amethod other than Ethernet. For example, most of lowprice power supplies have a GPIB or RS232c interface

for remote access. In such cases, we will use Ethernet
interface such as a GPIB LAN gateway for GPIB and aterminal server for RS232c to minimize the area
covered by field buses.

2.3 Network
Redundant gigabit Ethernet with fiber optics linked
as a "star" starting from the central control room (CCR)
to each accelerator (Linac, 3-GeV RCS and 50-GeVPS) and experimental facility is the backbone of thecontrol network. From each backbone station, star-like
100baseFX optical fiber cables extend to network
switches over the facility. Most of the network end
nodes such as IOCs are 100baseTX. Some nodes in ahigh EMI noise levels such as near klystrons or highpowered pulsed power supplies should be 100baseFX.
As described in previous subsection, we are going touse Ethernet links instead of other field buses.
Therefore the total number of IP addresses required forthe control system could easily exceed a few thousands.
Therefore it is impossible to use a global IP address
space. Instead we are going to use a Class B private IP
address space and use a router to communicate outside
the network.
We have not figured out how the network should be
divided into subnets. The EPICS channel access (CA)protocol requires the network broadcast. Therefore all
EPICS nodes should be in one subnet. Nodes fordiagnostic purpose should belong to a different subnet
because they must be free from the EPICS subnet. Suchdiagnostic nodes include a communication port of atraffic watcher (of course, it should also have a port in
the EPICS subnet to spy on network traffic) and an
IOC’s CPU console (RS232c through a terminal server).
Those two types of nodes are in general close eachother in space, and therefore it is better to implement
the virtual-LAN technique to reduce cabling andnumber of network switches.

2.4 Operator interface
We will use one of the standard EPICS OPI tools for
the EPICS operation, but it is not specified yet which
one should be used. Also there are two choices; (1) OPI
applications run directly on a PC Linux or (2) OPI
applications run on an X-client machine with an Xterminal (or a PC with X-server). The former choice isgood for network traffic but not good for maintaining
applications. The latter is just the opposite. Anothertype of operator interface is necessary which is related
to the issues described in the next subsection.

2.5 Interface to accelerator simulator
In order to operate the accelerator stably, it isimportant to simulate the beam before parameters arephysically changed. Accelerator physicists are
responsible for developing such a simulation code, but
the control group should help them to include theEPICS interface and operator interface in the code.
SAD code [4] used at the KEKB accelerator is acandidate in the Joint-Project. Since SAD code used at
KEKB already has the graphical user interface (GUI)and the EPICS interface, we don’t need to worry somuch about the interfaces if SAD is chosen as asimulation code. However, SAD must be significantly
modified or new simulation code should be
implemented for the Linac simulation. If new code ischosen, we have to provide the GUI and EPICS
interface similarly to the SAD case.

2.6 Database
For steady and reliable operations of the accelerator,
use of proper database system is indispensable. We
have just started to design various kinds of databases
necessary in our system.

3 PRESENT STATUS
At KEK, an EPICS application server (HP-UX, HP
9000 model D380/2) and several VME IOCs (ForcePowerCore 6750) have been installed primarily forsoftware development.
Development of an EPICS device driver for theWE7000 measurement station (Yokogawa) is being
carried out. So far we have developed EPICS device
support for 3 WE7000 modules; WE7111 (100MS/s
digital oscilloscope), WE7121 (10MHz functiongenerator) and WE7271 (4ch 100kS/s waveform
digitizer). It basically works fine. However, concurrent
use with MS Windows applications doesn’t work for
unknown reasons. Because the WE7000 has beendeveloped for MS Windows OS, there are fruitful
applications available under Windows system. Thoseapplications are very useful for the maintenance of theWE7000 stations and developments of EPICS
applications. We must solve this problem soon becausethe concurrent use with Windows is indispensable.

The present version of the EPICS driver for
Yokogawa’s FA-M3 PLC supports only simple
input/output operations. The rules for the PLC
mentioned in Sec. 2 are not implemented yet.
The EPICS system will also be used for theoperation of the 60-MeV Linac. At present, only theion-source control which uses a MA-F3 PLC is under
the EPICS environment.
The HP EPICS server, VME IOCs, PLCs and 3operators PC terminals form a Class C network withprivate IP address. Operators can access the KEK-LANvia routers (2 of freeBSD PCs). The HP server also has
a network port to KEK-LAN through which we accessto the system from outside of the accelerator building.
At JAERI, an HP EPICS application server andseveral VME IOCs are installed. A test stand for
klystron power supplies employs the EPICS system. An
EPICS driver for a VME pulse motor controller module
is now under development.

4 ACKNOWLEDGEMENTS
The authors would like to thank all members of theJoint-Project team. They also acknowledge members ofthe KEKB ring control group for their advices andsuggestions.

REFERENCES[1] J. Chiba, K. Furukawa, E. Kadokura, N.
Kamikubota, H. Nakagawa, K. Nigorikawa and Y.
Yamamoto, “A control system of the JHF
accelerator complex”, ICALEPICS’99, Trieste,Italy, 1999, p672.
[2] K. Furukawa, J. Chiba, N. Kamikubota, N.
Nakagawa, “Implementation of the EPICS
software support for network based controllers”, inthese proceedings.
[3] K. Furukawa, J. Chiba, N. Kamikubota, N
Nakagawa, “Network based EPICS drivers for
PLCs and measurement stations”, ICALEPICS’99,Trieste, Italy, 1999, p409
[4] http://acc_physics.kek.jp/SAD/sad.html (KEKB
SAD homepage)