Akiyama, A

Katoh, T

Kudo, K

Nakamura, T T

Odagiri, J I

Yamamoto, N

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 5 ERGONOMICS IN KEKB CONTROL SYSTEM T. Katoh, A. Akiyama, K. Kudo, T.T. Nakamura, J-I. Odagiri, N. Yamamoto KEK, Tsukuba, JAPAN Abstract The ergonomic design implementation of the operators’ consoles for KEKBaccelerators will be described in comparison with the former TRISTANaccelerator control consoles. The basic construction policy of the KEKBoperators’ console is the flexibility for re-configuration in both hardware andsoftware ways. For TRISTAN, there were several sets of identical consoledesk made of iron frames in which two touch-panels, two graphic displaymonitors, and ten TV monitors are packed. Each set of console was directlycontrolled by a mini-computer in the TRISTAN control computer network.On the contrary, in the KEKB control system, all the man-machine interfacedevices are based on X-window system and application software runs on aUNIX server workstation. There are 30 to 40 X-window terminals realized byMacintosh and IBM PC/AT compatible PCs with X-server software. Low-cost Network Stations are also introduced as X-terminals with single screen.A Macintosh or PC is equipped with up to four display controllers or a multi-screen display controller and works as an X-terminal with only a set of amouse and a keyboard. We adopted TFT(Thin-Film Transistor) flat-panelLCD(Liquid Crystal Display)s, which are thin and light in weight, for the PCsto reduce glaring of the surface. And the sets of cordless keyboard/mouse arealso introduced for the purpose of making the table-top clear and givingfreedom of positioning. 1. INTRODUCTION1.1 The TRISTAN control computer system and control consoles The TRISTAN accelerator complex was composed of the linac which supplied 2.5 GeV electron andpositron beams to AR ( A ccumulation  R ing). AR accelerated both beams up to 8 GeV and sent toTRISTAN MR ( M ain  R ing). MR accepted both beams and stored them in its 3 000 m circumferencering. Then it accelerated both electrons and positrons up to 33 GeV to make two beams collide at fourexperimental halls. The TRISTAN control computer system [1] was based on the distributed mini-computer system with an optical-fibre token-ring network. There were 25 mini-computers (HIDIC-80)placed around TRISTAN accelerator. The devices controlled by the system are connected mainly viaCAMAC modules through 2.5 Mbps serial highway. The mini-computers were allocated to thehardware groups as shown in Table 1. The computing speed of the mini-computer is about 1 MIPS with16-bit word architecture. There were 6 sets of operators’ consoles in the central control room. Each setwas connected to corresponding mini-computer and had two 14-inch touch-panels, two 20-inch colourgraphic displays and ten 10-inch TV monitors. The touch-panels were used as the data input devicesand connected to a mini-computer via CAMAC modules (character display controllers and touch-panelinterface controllers). The graphic display controller can display 4096*3072 pixels with 12-bit colours. 1.2 PF-AR accelerator and its control consoles TRISTAN AR was converted to an SOR(Synchrotron Orbit Radiation) facility which stores 6.5 GeVelectron beam. It is now called as PF(Photon Factory)-AR(Advanced Ring). For this accelerator, 6 15 mini-computers were left and 3 sets of TRISTAN control consoles are left for the PF-AR. Three ofsix console computers are in use and the left are stand-by. Table 1:   Number of mini-computers used for TRISTAN MR: TRISTAN  M ain  R ing      AR: TRISTAN  A ccumulation  R ing or PF  A dvanced  R ing 1.3 The KEKB control computer system and KEKB control consoles The KEKB accelerator complex consists of an 8 GeV electron/3.5 GeV positron injector linac, a3.5 GeV positron ring, LER (Low Energy Ring), and an 8 GeV electron ring, HER (High Energy Ring).Control computer system for the KEKB accelerators consists of two systems. One is the linac controlcomputer system [2] and the other is the KEKB control computer system [3], [4]. The former wasdesigned and constructed before KEKB project started and upgraded just before the construction ofKEKB. The KEKB control computer system is based on EPICS(Experimental Physics and IndustrialControl System) [5]. A portable channel access server was introduced for communication between linacand KEKB control systems [6].In the EPICS environment, the system is centralized as far as operation is concerned, X-terminalsare used as man-machine interface devices. Application programmes using MEDM, SAD [7] andPython run on the server workstation in the system and they output information on the X-terminals.Therefore, operators’ consoles for the KEKB accelerator complex are composed basically ofX-terminals. Network Stations [8] and PCs(PC/AT compatibles and Macintoshes) are used withX-terminal emulation software because of their flexibility. More than two, up to four monitor screensare connected to one PC to get as much information as operators need [9]. 2. DESIGN CONCEPTS2.1 TRISTAN control consoles A photograph of the TRISTAN accelerator control consoles are shown in Figure 1. Variousdevices such as touch-panels, graphic display monitors and TV monitors were mounted on the rigidiron-framed racks. The consoles were designed to sutisfy JIS (Japanese Industry Standard)recommendations. And we tried to use as many ergonomic equipment as possible to decrease humanfatigues. They are; 1. Over-scanned character display monitors for touch-panels, 2. Positive images on the touch-panel displays. For this purpose, we developped a new CAMACmodule which generates 80 chars. x 32 lines with bright background frame. Groups AR Common MR Total Magnet and Power Supply 1 - 4 5Radio Frequency 1 - 2 3Vacuum 1 - 1 2Beam Monitor 1 - 1 2Beam Transport 1 - 1 2Operators’ Consoles - 6 - 6Library - 1 - 1General Purpose - 2 - 2Alarm 1 - 1 2 Total 6 9 10 25 7 But in order to prevent reflections from the CRT surface, we provided louvers at the lighting onthe ceiling of the control room. They decreased significantly the glaring from the surface of the CRTs,but at the same time, the illuminance on the surface of the desk was decreased down to ~300 lx, about1/3 of the recommended illuminance(~1 000 lx) by JIS for the office environment.  Fig. 1:  Layout of the TRISTAN control consoles 2.2 KEKB control consoles On the contrary, in the KEKB control system, the consoles are provided as flexible as possible to satisfythe requests from the customers, e.g. operators, KEKB accelerator commissioning team, and otherpersonnels. Several large simple tables are distributed in the central control room as shown in Figure 2.PC based X-terminals are placed on the large tables(4.0 m  ×  1.6 m) and the latest 15-inch and 18.1-inchTFT LCD monitors and keyboards are placed on the table. These LCDs are light in weight and thin sothat they require only a little space. As many LCD monitors as we could afford to buy are put on thetable. Wireless keyboard and mouse sets are also used partially and they make the table clean andsimple.As the nature of a new accelerator like KEKB many accelerator physicists want to operate andmake studies about the accelerator during the commissioning period. All of them want to use their ownX-terminals in the CCR. There are more than 30 general purpose X-terminals and 4 PCs dedicated tothe injector controls with Microsoft Windows NT. In order to provide a lot of information for oneperson, we introduced multi-screen display controllers for PCs and we put several video interface cardsinto Macintoshes. The maximum number of screens for one PC is now four. It also gives us otherbenefit of decreasing number of keyboards and mice and leaving space on the table. We obtained highilluminance(~1000 lx) enough for satisfying JIS recommendations. 2.3 Differences between TRISTAN and KEKB control rooms The most different point is the illuminance of the control room. Previous TRISTAN consoles are madeof iron-framed racks and various devices are mounted in them. In order to keep the operators from thereflected images of the light sources on the round surface of the monitors, the lighting in the controlroom was limited in strength and direction. It was so dark and the operator needed to have a stand lampwhen he want to write on the log book. Consequently, it resulted eye-fatigue of the operators.By using flat display monitors like LCDs, the reflection problem has completely gone and we canmake the room as high illuminance as required for the office room. The enough illuminance gives us19.80 m10.00 mTRISTAN ControlConsoles 8 benefit of easiness and comfort of reading and writing. Those who have dark eyes require moreilluminance than those who have light coloured eyes. At present, KEKB and PF-AR control consoles co-exist and the central control room is dividedinto two parts that have different illuminance due to glaring problem. Fig. 2:  Layout of the KEKB and PF-AR control consoles 3. EQUIPMENT USED FOR KEKB CONTROL CONSOLES3.1 LCD monitors Various types of TFT colour LCD monitors are used. An 18.1-inch monitor displays an SXGA(1280  ×  1024 pixels) screen and a 15-inch monitor displays an XGA (1024  ×  768 pixels) screen. Thereare also NTSC colour LCD TV monitors to display usual TV signals. Latest LCD monitors havecharacteristics of wide viewing angles of more than 120 degrees. 3.2 Large screen plasma display monitors For the common display use in the central control room, we have been using 27-inch colour TVmonitors for years. Some of them were damaged but we can not get the same monitor any more.Therefore, we replaced them by 40-inch plasma display monitors. A plasma display monitor isthin(about 15 cm thick) and light(about 30 kg) compared to a CRT display of 27 inches (about 60 cmdeep and 50 kg in weight). 3.3 PCs with multiple-screen display controllers There are many PCs(IBM PC/AT compatibles and Macintoshes) used as X-terminals. Multiple-video-display controllers can be installed into PCs and one can use two to four screens. By using multiple-screens, you can display much more information than single-screen not by overlapped but by separatedwindows. The most beneficial merit we get is that the use of multiple-screen decreases the number ofkeyboards and mice and you can get more space for log-books, etc.For IBM PC/AT compatibles, we adopted a PCI-bus graphic display controller board. It candisplay one to four SXGA(1280  ×  1024 pixels) screens at one time and you can have a Windows screenwith 2560  ×  2048 pixels with true colour. For a Macintosh, three conventional PCI graphic cards can beadded to get three more screens.KEKB Control ConsolesPF-ARKEKB RFSoftwareDevelopmentLINAC 9 3.4 Wireless keyboards and mice As we have many keyboards and mice with connecting cables, sometimes they are tangled or tiedtogether. We adopted a set of wireless keyboard and mouse for IBM PC/AT compatibles. For aMacintosh, a USB to PS/2 converter can be used to utilize the same set of keyboard and mouse. 3.5 Wrist-rest for keyboard and mouse In order to reduce mustle-fatigue and stiff shouulders, we introduced wrist-rest for keyboard andmouse. They are used mainly by the operators but by commissioning group members. 3.6 Ergonomic chair We tried to use so-called ergonomic chair for computer operations. One can adjust various parts of thechair, e.g. angles of the arm-supports, height of the arm-supports, reclining angle of the back. We foundit takes a little long time for operators to get accustomed to this type of chairs. 4. CONCLUSION For commissioning of the KEKB accelerators, the simplest and versatile console tables and up-to-dateequipment recently available are provided. By using these devices, we get freedom of designingconsoles and flexibility in modification. Console desks are in the chaos now, but it will be settled in thefuture in the proper state. Though we provide ergonomic environment, only the operators use as weexpected. The commissioning group people want to modify every thing as they like. We became awareof the importance of letting them know the merit of using ergonomic equipment. 5. ACKNOWLEDGMENT  We wish to express our thanks to the members of the KEKB accelerator department, especially to theKEKB commissioning group for their valuable advice and cooperation. References [1] S-I. Kurokawa, et al., ‘The TRISTAN Control System’, Nucl. Instr. And Meth., A247 (1986) pp.29-36.[2] N. Kamikubota, et al., ‘New control system with VME and workstations for the KEK e – /e + linac’, Nucl. Instr. and Meth., A352 (1994) pp. 131-134.[3] T. Katoh, et al., ‘Design of The KEKB Accelerator Control System’, ICALEPCS’95, Chicago,November 1995[4] T. Katoh, et al., ‘Present Status of The KEKB Accelerator Control System’, ICALEPCS’97,Beijing, November 1997, pp. 15-18[5] EPICS home page URL: http://www.aps.anl.gov/asd/controls/epics/EpicsDocumentation/WWWPages/[6] N. Yamamoto, et al., ‘Implementing Portable Channel Access Server Software in The KEKBAccelerator Control System’, Proc. APAC98, Tsukuba, Japan, March 23-27 1998, pp. 498-500.[7] SAD home page URL: http://www-acc-theory.kek.jp/ SAD/sad.html[8] Product of IBM Corp. [9] T. Katoh, et al., ‘The Operators’ Consoles for KEKB Acceleraors’, Proc. ICALEPCS’99, Trieste,Italy, October 4-8 1999, pp. 101-103

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