EXPERIENCE AND PROBLEM OF 3W TECHNOLOGY AT CNSCYCLOTRON FACILITY
S. Watanabe, CNS, the University of Tokyo, JapanAbstract

2.1 Hardware

The computer control system based on the clientserver system was extended to facilitate the WWW
services aiming at browsing the operation status ofaccelerator facility. Generation of the real-time WWWcontents and construction of the personal web server arekey technology of this extension. The capable WWW
services are browsing the operation status of CNS
cyclotron facility and the radiation safety control. Thispaper describes the data logging system, generation ofHTML files and the video server system relating withapplied WWW technology.

A data logging PC is a main of the extended datalogging system. This employs board bases 8 channels
12bits ADC with a peak hold circuit. The unified input
voltage is ranging from 0 to 5 volts. A photo coupling
circuit isolates an I/O bus circuit from the ground level.
A switching speed of the multiplexing circuit is chosen
at 50 micro-seconds/Ch. A cut off frequency of low
pass filter of the front-end circuit is chosen at 30Hz.
The favourable signal sources are magnetic field, rffrequency, room temperature, vacuum pressure andbeam gate valve. The board base FVC provides thecapability of rf signal conversion ranging from 1 MHzto 50MHz. The room temperature has been measured
by using analogue IC, AD590KF. A RAM based disk
resource has been used as a scratch disk in the datalogging PC to make sure the long-term operation. The
data logging system linked with the WWW server isillustrated in Fig.1.

1 INTRODUCTION
In 1984, a serial CAMAC system controlled with 16bit minicomputer was constructed at the coolersynchrotron TARN-II. In 1989, the computer system
was replaced to the distributed computer system toenlarge the control functions covering the TARN-II andtheir beam transport line [1]. The distributed computer
system comprises a host computer, two workstations
and three personal computers linked with the DEC-net
protocol. The host computer is a µVAX3400 with
operating system of VMS. This computer system has
been in operation until now. In 1992, This system wasextended to the injector cyclotron of TARN-II. The
extended system comprises a stand-alone CAMAC
system and a PC where is linked with the host computer.
The collected data utilise the beam diagnostics such as a
calculation of beam optics of the transport line. In 1996,
the distributed computer system was extended tofacilitate WWW services such as a remote observationof the accelerator facility. The key technology of thisextension is data logging system, real-time HTML filegeneration, personal web server and distribution ofmoving image data.
In the present paper, section 2.1 and 2.2 describe
extended data logging system. Section 2.3 discusses anoise immunity of the network system. Section 3.1 and3.2 describe a generation of real-time HTML files.
Finally, section 4.1 and 4.2 describe a radiation safetycontrol.

2 DTATA LOGGING SYSTEMThe Data logging system of the cyclotron facility is
described in detail.

2.2 Software
Kernels of data logging program are written in MSCV5 because of MS-DOSV5. The file transfer from thedata logging PC to the host computer has been done inevery data acquisition batch. The data logging PC havethe following chained program modules:• Data logging module to multiplex the 8 channelsof analogue signals and to save the data file intothe RAM disk. The time stamp is in-lined in theend of record of the data file.
• Data transfer module to communicate with hostcomputer (µVAX3400) and to transfer the datafile.
• Timing module to make sure the time interval ofdata acquisition and data transfer in every ten
minutes.

2.3 Electromagnetic Interference
The cyclotron facility comprises the high powercomponents such as a magnet, rf power source and ahigh voltage terminal. A boot up operation comprises
procedures to start up a magnet power supply, rf powersupply, high voltage power supply and so on. The bootup operation of the cyclotron facility may occurs anelectromagnetic interference since the noise signal fromthe electric sparking influences a ground level potential.
Due to the electromagnetic interference, any kinds ofoperation troubles would be occurred in a low level
control system such as the data logging system.
Unfortunately, this boot up operation had influenced thedata logging system of the CNS cyclotron facility manytimes.
The only one or few reasons are to be expected to
improve the trouble shooting. The effective noise
immunity from this electromagnetic interference is a useof an isolation transformer. The isolation transformer
provides a laminated shielding electrode between the
primary and secondary coils. The isolation transformer
with a power rating of 1KVA has been equipped in theAC power line of the data logging system. After theinstallation of this isolation transformer, same troubles
had decreased excepts the occasions of unexpected
shutdown of AC power line. The selection of groundpoint of that shielding electrode is a key issue todecrease such the noise.

Fig.1 Data Logging System with WWW server

3 HTML FILES
3.1 Generation of HTML files
A general WWW client accesses the WWW serverof CNS cyclotron facility to get the HTML files or text
files stored in the WWW server. The computer network
composed of the data logging system, HTML server,
file server and WWW server has supported this WWW
service. The HTML files have been generated by theµVAX3400 called HTML server. The HTML filecomprises flash data in every ten minutes and an
animated GIF files. There are two text files to show thehistory of the cyclotron operation such as the vacuum
pressures. A daily log file is a summary of flash data.
The summary of flash data is refreshed in every ten
minutes. A previous day file is generated in every one
handled flash data. So, the three kinds of data files areavailable to show the operation status of the cyclotron
facility.
The generation of those data files is a routine ofapplication program in the host computer. The

application program is written in FORTRAN. A time
sequential control to execute this application program isunder the control of command procedure of the VAXVMS operation system. First, the application program
read the low data transferred from the data logging
system.
Subsequently, the application program
calculates the physical values to show the present statusof the cyclotron facility.
The scaling and the offset
correction of the physical values are carried out in theapplication program.
The time stamp means thelogging time at the cyclotron facility. Finally, theapplication program writes the text file in according to arule of the HTML.

3.2 HTML File transfer
The HTML file or daily log file has been transferredto the WWW server. For convenient, the transfer ofHTML file is described in this section. First, thegenerated HTML file is copied to the VAXst3100 withthe DEC-net protocol. At the VAXst3100, HTML fileis transferred to the WWW server by using the TCP/IPprotocol. The FTP command is used to transfer theHTML file.
The logged file in every one handled shot istransferred after the small change of file name. The filetransfer program may use the wild card to transfer thedata file. This logged file is stored in the Pentium
machine because of large disk sizes comparing with theµVAX3400 or VAXst3100.
The file transfer has been carried out in every ten
minutes. A readout trouble at the HTML server would
be expected since no synchronisation is available
between the data logging system and the WWW server.
The readout sequence has been protected with the aid of
the VMS function of the HTML server. The same
WWW services are available at TARN-II to show themeasured vacuum pressures of the ring and beamtransport line.

4 RADIATION SAFETY CONTROLThe newest radiation safety control system is
described in detail.

4.1 Video server system
The video server system has been equipped in thepresent radiation safety control system to enable thedistribution of an image files. The video server systemprovides the digital output terminals to control a video
switch circuit. [2] The video switch circuit enables us
the selection of image sources such as an ITV camera
and a computer graphic panel signal of the sequencecontroller mentioned above.
The video server system distributes the moving image
data whenever the WWW client requests thedistribution. The WWW client receives the distributed

image files with the aid of the plugging software. The
privileged client may use the administrative commands
to control the video server, ITV camera and aregistration of the WWW client to receive the image
files.

4.2 Moving image data
The ITV camera has been equipped in the control
room of the cyclotron facility. The ITV camera
provides a remote control function such as a zoom up
function of the digital panel meters of the control desk.
An RS232C interface of the ITV camera enables us the
remote control by using the video server system.
The gate monitoring system based on the sequencecontroller comprises a distributed sensing system anddisplay system. The distributed sensing system enables
us the remote sensing of the gate switches such as astatus of the radiation shield doors. A computer graphic

panel of the gate monitoring system gives current statusof the shield doors, radiation level and interlock systems.
The example of WWW pages to browse the operation
status of CNS cyclotron facility is illustrated in Figure.2.
[3] The left page shows operation status of the CNS
cyclotron and the right page shows moving image datafrom the gate-monitoring system.

REFERENCES[1] S.Watanabe et al., “Computer Control Systemof The Cooler-Synchrotron TARN-II”, The Fifth
JAPAN-CHINA Joint Symposium, Osaka, Japan,Oct. 1993
[2] http://www.megachips.co.jp/[3] http://www.cns.s.u-tokyo.ac.jp/Fig.2. WWW pages to browse the status of CNS cyclotron facility