CONTROLLING OF BEAM LINE WITH PCs
S. Muto, Y. Yano, N. Kaneko, Y. Kobayashi, T. Tahara, H. Fujimori and Y. Irie
KEK, Tsukuba, Japan

Abstract
The beam-line control system was renewed with
programmable logic controllers and personal computers.
The new system comprises three subsystems. One part iscontrol for the equipment using plural PLCs, which areconnected with a network. The 2nd is acquisition of beamdata from beam monitors. The last is a human interfaceof the control system using commercial-based graphicaluser interface tools that run under Windows NT. The
control of equipment and the monitoring of beam arepossible from console PCs on the control network.

1 INTRODUCTION
The Neutron and Meson Laboratory (NML) of the HighEnergy Accelerator Research Organization (KEK)
utilizes a 500-MeV proton beam from the Booster
Synchrotron of KEK-PS at 3 facilities: the Neutron
Science Laboratory (KENS), the Meson Science
Laboratory (KEK-MSL) and the Proton Medical ResearchCentre (PMRC), University of Tsukuba. A beam-line of
the NML delivers a 500-MeV proton beam to fourphysical experimental rooms and a medical treatment
room. The components of the beam line are listed inTable 1. In 1997 the beam-line control desks were moved
from the local control room (LCR) of the NML to the PS
central control room (CCR) to reduce the operation cost.
With this movement of desks, we renewed the beam-linecontrol system.
Along with an increase in the processing power of
personal computers (PC) and progress concerning
network environments, it has become possible to constructa more efficient system than previously constructed. The
beam-line control system was replaced with
programmable logic controllers (PLC) and PCs. In thispaper we report on the new control system of the NML
beam-line.

2 NEW BEAM-LINE CONTROL SYSTEM
To design the new beam-line control system, several
conditions resulted concerning renewal of the beam-linecontrol system:(1) The utility of the facility was allocated over 3800
hours per year. The renewal is, therefore, only
during beam-shutdown time for maintenance.
(2) The control desks have been moved to the CCR andthe operation is performed in the CCR. The beam-line equipment, however, still remain in the LCR.
Concerning maintenance of that equipment,
operation of the beam-line is possible not only fromthe CCR but also from the LCR.
(3) Reliability of beam safety operation, such as
interlock, must be kept the same as before therenewal.
Under these conditions, (1) makes the renewal difficult,because there is not enough time to modify interfaces ofsuch beam-line equipment as the magnet power supplies.
In addition, several improvements are planed as follows:(4) Fine beam tuning operation can be done fromexperimental rooms.
(5) Information of monitoring beam can be obtained
from the KEK network.
If condition (2) is satisfied, (4) is not difficult. (5) isrequired from facility users.
To satisfy the above conditions, the new control system
is constructed with PLCs and PCs and comprises threesubsystems:

Table 1. Components of the NML Beam-line
MagnetPulsed Magnet
Bending Magnet
Quadrupole Magnet
Steering Magnet
Power Supply
Pulsed Magnet PS
DC Magnet PS
Steering Magnet PS
VacuumTMP
Ion Pump
Beam Monitor
Intensity Monitor
Profile Monitor
Loss Monitor

4536244162443112213

NML Beam-line Control System
Meson1
Terminal
WindowsNT
Meson2
Terminal
WindowsNT

NML LCR

PS CCRKEK NetworK

MedicalTerminal
WindowsNT
NeutronTerminal
WindowsNT

Data Server File Server
FreeBSD WindowsNT

StatusTerminal
WindowsNTWindowsNT
BDCControlStatus
MonitorTerminal
Terminal
Terminal
WindowsNT
WindowsNT WindowsNTControl
Terminal
WindowsNT

CATV
Terminal
WindowsNT

Laboratory
Control Network (Ethernet/10BASE-5)
Gateway
DDE I/O Server
Windows3.1

WindowsNT
PDC

Data Taking
DOS/PCNFS
PLC Network (SYSNET/Optical Fiber)

PLC Network (SP)

CAMAC

PLC 6

PLC 5

PLC 4

PLC 3

PLC 2

PLC 1

PLC 0

Beam
MonitorBeam
MonitorDevices

VacuumDevicesSteering
Magnet

DC Magnet

PulsedMagnetSafetyControl

Desk
DevicesFigure 1. Diagram of the NML beam-line control system.

2.1 PLC subsystem(1) Control for the equipment using plural PLCs, which
are connected with a network.
(2) Acquisition of beam data from beam monitors anddata-server PC.
(3) A human interface of the control system usinggraphical user interface (GUI) tools on the WindowsNT.
Figure 1 shows a diagram of control system. The reasons
to choose such a system are:(1) The change of the interface in controlled equipment
is minimized because of the high connection abilityof the PLC.
(2) All of the necessary information can becommunicated between each PLC via optical fiberlinks.
(3) Terminal PCs in a control network are able tocontrol all equipment under each PLC through agateway PC.
(4) Some equipment need local sequence control, suchas vacuum pumps and gate valves.
(5) Beam information is obtained from server PC which
are linked to both the KEK network and the control
network

All beam-line equipment are grouped in their function
such as vacuum, beam-monitor controller, DC magnet
power supply, pulsed magnet power supply, steeringmagnet power supply, control-desk devices and safetycontrol devices. All equipment in each group areconnected to the PLC, made of OMRON, with various
interface modules of the PLC. The node number of eachPLC is listed in Table 2. Local control in the each groupis done by local PLC. Also global control between group,
such as interlock, are done by the exchange of information
through optical-fiber links, by which all PLCs areconnected, by OMRON SYSNET. The gateway PC for
the control network is also connected to the PLC opticalfiber network.
Table 2. PLC I/O Node Number
PLC #
PLC 0
PLC 1
PLC 2
PLC 3
PLC 4
PLC 5
PLC 6

Part
Desk Devices
Safety Devices
Pulsed Magnet PS
DC Magnet PS
Steering Magnet PS
Vacuum Devices
Beam Monitor

I/O Node #238262
97526324
126114

2.2 Data-acquisition subsystem
The signals from beam-intensity monitors, beam-profile
monitors and beam-loss monitors are processed by
CAMAC systems. Reading of the beam data fromCAMAC is performed using a PC. The data is then stored
to a data-server PC at every cycle. This beam data can beshown at all terminal PCs through the control network. In
the data-taking PC, only a data-acquisition program isrunning under DOS. As an operating system of the dataserver PC, the FreeBSD, an Unix-like operating system,
was adopted. To access the server PC from the datataking PC, the PC-NFS service is used.

2.3 Windows subsystem
Control of beam-line devices is done by a terminal PC,
which is connected to the control network and is running
Windows NT. For part of the human interface ofequipment control, we used "InTouch", a commercial
package, for constructing a GUI-based control panel on
Windows NT. The InTouch is connected to the PLC via agateway PC of control network and the PLC network
using DDE communication and control all PLCs from anapplication window. Figure 2 shows the display of theNML operation window.

Figure 3. Display of the fine-tuning operation windows.

3. CONCRUSTION
Renewal of the beam-line control system wascompleted during in the beam-shutdown time. Also
operation of the beam-line was successfully started onschedule. From all PCs on the control network, control ofthe beam-line equipment and monitoring of beam
information could be achieved. The control system has
been operating with no serious problems, though theresponse of the control operation from InTouch on
Windows NT is slow, for some unknown reasons. Beam
information is widely accessed form the KEK network.
Improvements of the system, such as introduction of adatabase and/or web-based system, are in progress.

ACKNOREGIMENTS
The authors would like to thank Dr. K. Omata for useof the CAMAC driver library.

Figure 2. Display of the NML operation window.

Beam information is also displayed on these terminalPCs. Programs used to display beam information weremade using rapid application development tool, Delphi.
Programs access to the data-server PC and read beam data.
Therefor, all PCs on the control network can operate thebeam-line control. Figure 3 shows an example of thedisplay of the fine-tuning operation windows on a PC inthe experimental room.