No.37 (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.



  • Vigilance Campaign Office*

* International Business Headquarters


  • NAGASHIMA Akira*1

*1 Director, Chief Technology Officer

Executive Vice President of Corporate Research and Development Headquarters

As we enter the 21st century, the term "ubiquitous" is becoming just that-ubiquitous. The emerging benefits of "ubiquitous computing" have the potential of fundamentally altering the way we live and work. To summarize the major benefits, a ubiquitous computing environment will enable us to utilize information 1) from anywhere 2) without conscious effort 3) with a sense of super-realism 4) from the user's point of view, and 5) with the utmost flexibility and adaptability. These benefits will usher in a new era for measurement and automation as well. That is why we have declared the "Yokogawa ubiquitous initiative," whereby we have accelerated our R&D activities to help promote the real-life applications of ubiquitous computing technologies. To name a few of these activities that combine the fruits of our decades long R&D investments, we are playing a leading role in such emerging areas as IPv6 networks, advanced network security solutions, highspeed broadband network modules, widely distributed autonomous field instrumentation networks, and net sensing systems.


  • ISHIKAWA Tamaki*1
  • ODOHIRA Tetsu*1
  • NIKKUNI Masaaki*1
  • KOYAMA Etsutaro*1
  • TSUMAGARI Tetsurou*1
  • ASADA Ryuuzou*1

*1 Industrial Automation Business Headquarters

We have newly developed the DPharp EJX series of pressure and differential pressure transmitters with the advanced silicon resonant sensor. The DPharp EJX series employs a multi-sensing technology that enables both differential pressure and static pressure to be measured simultaneously. This technology eliminates the need for pressure gauges, contributing to cost reductions in plant installations. Moreover, the silicon resonant sensor featuring long-term stability further enhances the transmitter quality and reliability that have already been demonstrated by the industry-proven EJA series. The minimum response time and compactness of these intelligent differential pressure transmitters have been achieved using innovative technologies. The user-friendly multifunctional LCD display and the enhanced self-diagnostics and maintainability provide users with increased operation efficiency. The DPharp EJX series offers a wide variety of models, including diaphragm-sealed gauge pressure transmitters, diaphragmsealed differential pressure transmitters, screw-mount gauge pressure transmitters and differential mass flow pressure transmitters. In addition, it ensures conformability to various standards, including flame explosionproof, intrinsically safe explosionproof, safety standards SIL and EC directives. The series also ensures compatibility with HART and FOUNDATION fieldbus communication protocols.

Thanks to the enhanced flexibility in model selection and the added transmitter functionality, the EJX series has the excellent capability to meet the need for versatile applications, further contributing to minimizing customers' total cost of ownership (TCO).


  • YOSHIKAWA Osamu*1
  • SHIKUYA Norihiro*1
  • TANAKA Toshiyuki*1
  • TANABE Seiji*1
  • ARAI Takashi*1
  • OHTA Hironobu*1

*1 Industrial Automation Business Headquarters

We have developed the new ADMAG AXF series, the world's first magnetic flowmeters with an electrode adhesion diagnostic function, as well as various application functions.

This paper describes the fundamental principles and development methods behind the new functions, and the advanced technology of the ADMAG AXF series, such as the linearity improvement of flow rate measurement and the decrease in variation between sensors by magnetic circuit simulation, the adhesion diagnostic function, and a full dot matrix LCD that can indicate what type of maintenance work should be performed when an alarm is issued.

"digitalYEWFLO Multivariable Type" VORTEX FLOWMETER WITH ...

  • WAKUI Hidekazu*1
  • WADA Masami*1
  • YOSHIOKA Takashi*1
  • ANDOH Tetsuo*1

*1 Industrial Automation Business Headquarters

Since its release in 2001, the "digitalYEWFLO" vortex flowmeters employing our original spectral signal processing (SSP) technology have achieved proven track records in the market with steady increases in shipment volume. Recently, we have developed one of the world's first two-wire "digitalYEWFLO Multivariable Type" vortex flowmeters with a built-in temperature sensor, which features more enhanced measuring functions while inheriting the high accuracy and reliability of the conventional "digitalYEWFLO" products.

With a temperature sensor incorporated into the flow rate sensor, "Multivariable Type" vortex flowmeters enable both fluid temperature measurement and flow rate measurement simultaniously, thereby achieving multisensing functions such as various correction calculations based on measured temperature data as represented by steam mass flow rate calculations,.

This paper outlines the structure, functions and features of "digitalYEWFLO Multivariable Type" vortex flowmeters using data from verification tests at actual users' plants.


  • KISHIMOTO Naoya*1
  • MASUTA Ken-etsu*1

*1 Industrial Automation Systems Business Division

Exaquantum is a PIMS (Plant Information Management System) software package that is one of the core components of MES (Manufacturing Execution System). Exaquantum is not only as a simple historian, but also a EUC (End User Computing) system for flexible utilization of plant information by the users. Moreover, the Exaquantum/Web function enables to meet market needs such as remote access and thin-client configuration.

In the overseas market, PIMS is regarded as an essential component that serves the bridging function between PCS (Process Control System) and a corporate information system, so that many new major projects have started using Exaquantum.


  • SATO Keiji*1
  • MATSUNO Takuya*1

*1 Industrial Automation Systems Business Division

Rapid progress in Information Technology has fueled the shift toward open architecture systems and networking in the manufacturing industry. However, even though IT has enabled data integration between systems, for surviving the global competition, it is essential to process such data strategically though closer collaboration between systems and to reform role-sharing between humans and systems. Therefore, we have newly developed and added VBScript Unit Procedures and user application unit procedures to "Exapilot" operation efficiency improvement package, thereby enabling users to tailor the icons of procedures to their needs. This upgrade facilitates interlinking of Exapilot with other systems, and then turning Exapilot into the core software in collaborative operation packages.

This paper introduces a predictive control system as an example of collaboration using Exa Series solution-based packages.


  • IKEGAYA Yoshihiro*1
  • TERASHIMA Nobuhiko*1
  • KHOO Lena Bee Yean*1

*1 Industrial Automation Systems Business Division

Advanced process control in the PCS (Process Control System) market is a key technology to glean the greatest profit from the existing equipment in the plant. The Advanced process control can be easily applied to in-service processes and helps stabilize and optimize operations taking process restrictions into consideration.

The Exasmoc (a multivariable model predictive control package) and Exarqe (a robust quality estimator package) released in 2000 have been in operation in many DCS (Distributed Control System) or PLC (Programmable Logic Controller) systems. Recently, Exasmoc R3 and Exarqe R3 which incorporate enhanced algorithms have been newly developed to realize operations for large-scale and critical control processes. Hence, these two packages are strongly recommended for adoption in the ultra-deep-hydrodesulfurization process which is now under consideration by world-wide oil refinery plants.

This paper introduces an example of the functions of Exasmoc R3 and Exarqe R3, which are recommended for use in high-level advanced process control.


  • OKAYASU Shinji*1
  • KATAOKA Norikatsu*1
  • MINE Shini-ichirou*1
  • KATASE Eiji*1

*1 Industrial Automation Systems Business Division

We have developed the Exaopc-RD, virtual OPC server software, for configuring a redundant OPC server that supports the OPC specification Data Access (DA), Alarm Event (A&E) and Historical Data Access (HDA) interfaces. Exaopc-RD is installed on the OPC client, and provides a redundancy function in a 2-OPC server/1-OPC client configuration. Exaopc-RD enables the use of redundant OPC server functions without the need to rewrite existing client programs. In consideration of the features of each OPC server, a master/standby switching system, in which a "Warm Standby" mode is defined for the DA server and a "Hot Standby" mode is defined for the A&E server, is used for enabling redundancy. Exaopc-RD provides the HDA server, which is placed as a backup function for the DA and A&E servers, with an additional function for automatically storing data while the client is down. As a result, in a 2-OPC server/1-OPC client configuration, Exaopc-RD can achieve a redundant OPC server for minimizing the loss of process data even if one of the two servers or the client fails due to a hardware or software problem.


  • IGUCHI Hirokazu*1
  • KAJI Tomohiro*1
  • TANAKA Kotoko*1
  • OKADA Satoshi*1

*1 Industrial Automation Systems Business Division

STARDOM's Autonomous Controllers FCN and FCJ feature functions for transmitting field data as information over a network in addition to control functions. These controllers are provided with a web server function and an e-mail transmission function as the key means for transmitting this information. However, the actual transmission of the information has required Java, HTML and other programming skills up till now, and thus becoming a problem of increasing engineering costs.

This paper introduces InfoWell, the information transmission package for STARDOM, which aims for the great reduction of these engineering costs by enabling the creation of web screens and the transmission of e-mail with less programming effort. This paper describes the concept behind the development of InfoWell, an outline of its configuration, its features and application examples.