No.38 (2004)

Yokogawa periodically publishes the Yokogawa Technical Report, which contains articles that take a detailed look at the technologies employed in Yokogawa's products. At this site you will find links to all of the reports that have been published since 1997 as well as links to PDF files containing the full text of selected articles from each issue.



  • SAITO Yoji*1
  • TAKAHASHI Seiichiro*1
  • HASHIZUMI Kazuhiro*1
  • OCHIAI Satoru*1

*1 Industrial Automation Systems Business Division

Since releasing the first Fieldbus FOUNDATION™-registered devices in the world, Yokogawa has been endeavoring to improve their efficiency and usability in order to maximize the potential of intelligent fieldbus devices.

This paper describes some aspects of our recently released fieldbus devices:(1) addition of the software download capability, (2) reduction in current consumption of field devices and improvements of function block’s execution time, (3) addition of valve diagnostics performed with valve positioners and a PC tool program. The paper discusses the benefits that these fieldbus technologies bring tousers, and outlines the future direction of fieldbus device development.


  • KOMIYA Hiroyoshi*1
  • TAKIZAWA Hiroyuki*1
  • MATSUKAWA Hideo*1

KOZAKAI Kiyotaka*1

*1 Industrial Automation Systems Business Division

In the course of developing CENTUM CS3000 R3 Revision 3.04, we also developed a new FFCS field control station which has achieved compact size and high reliability. The processor cards, being compact yet high performance, utilize field-proven "Pair & Spare" technology deployed in large-scale control systems, resulting in the implementation of sophisticated control functions and high reliability equivalent to the existing controllers designed for large-scale control systems. The FFCS is designed to be the same overall size as the existing "uXL" control unit, which enables easy replacement of the control unit without any changes. Moreover, CPU nodes, processor modules, ESB coupler modules, and V-net coupler modules have been newly developed for the FFCS. Especially, SEN bus(Serial Exchange Nest bus), which is a high-speed serial bus designed to suit the program copy and data equalization between dual redundant processor modules, has been developed as a new technology for data communication.


  • TAKAKI Hitoshi*1
  • YAMAMORI Masato*1
  • KUROKI Shigekazu*1

*1 Environmental Systems Sales Division

Supervisory control systems for water supply and sewage services are changing dramatically in response to recent changes in the social environment and rapid progress in computer technology. In particular, the widespread availability of powerful yet inexpensive personal computers has generated demand for systems that are both low cost and versatile. However, the supervisory control systems for water supply and sewage services, which are essential "lifelines", must still be safe and reliable, as well as compatible with existing systems. This paper summarizes the functions required for the supervisory control systems based on market trends, and introduces Yokogawa’s approach to meeting these needs with the latest technologies.


  • OOE Kenji*1
  • OKADA Shingo*1

*1 OCS Center, Industrial Automation Systems BusinessDivision

The reverse osmosis (RO) membrane is in use today as a main component of water filtering equipment, because it has a fairly high performance record in removing various impurities such as salt from water. Especially in isolated islands and desert regions where there is no other choice but to utilize seawater as the only water resource, the RO membrane is an indispensable component of the RO module for water purification systems. To maintain high-performance filtration, however, the RO membrane which comprises a polymer composite membrane needs to be cleaned at optimal time intervals. For this, a diagnostic function that calculates the performance indicators of the RO membrane by using the data of key parameters including temperature, flow rate, and conductivity, and assesses trends in performance degradation, is needed.

This paper describes "eCUBE aqua", a one-box solution for RO membrane systems with functions such as RO membrane diagnosis, long-term data storage and remote monitoring, which is designed to be incorporated into STARDOM autonomous controllers.



  • SHIMOGAWARA Masahiro*1
  • TANAKA Hiroaki*1
  • KAZUMI Kunio*1
  • HARUTA Yasuhiro*1

*1 MEG Center, Aerospace Products Business Headquarters

The magnetoencephalograph (MEG) is a measurement instrument specifically designed to measure electrophysiological cerebral nerve activities, featuring high time and spatial resolution performance. In recent years, the evolution of the SQUID (Superconducting Quantum Interference Device) magnetic sensor utilizing superconductor technology has enabled the consistent measurement of extremely weak magnetic fields generated by the brain, and the clinical availability of MEG has been established by clinical studies based on the accumulation of MEG data, thereby resulting in the clinical application of MEG in general hospitals beyond laboratory tests. Our "MEGvision" 160-channel whole-head MEG system was released in 1998, and approved by the Japanese Pharmaceutical Affairs Law in 2000. Since then, a total of seven systems: three systems for general hospitals, two systems for the medical departments of universities, two systems for the engineering or humanities departments of universities, have been in use so far. Owing to the governmental approval of healthcare coverage for MEG examinations in April 2004, the further utilization of MEG is expected. This paper describes the technical features of MEG and examples of its application.