No.35 (2003)

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.



  • SHIRAHATA Haruo*1
  • ITAGAKI Michihisa*1
  • KOUSAKA Fusao*1
  • ISHIDA Takashi*1

*1 Aerospace Products Business Div.

We have been developing and manufacturing liquid crystal display (LCD) panels of aircraft intended for Defense Agency of Japan. Recently, these LCD panels have been employed not only in military aircraft but also in commercial airplanes, thereby increasing demand for the LCD panels.

This time, we have developed LCD panels for commercial airplanes, based on the experience accumulated in LCD technology for the defense business. We have optimally designed the LCD panels to meet the optical characteristics and environmental conditions required in the cockpits of commercial airplanes, so that the panels have achieved good viewability performance at wide viewing angles both day and night.


  • HOSAKA Yuuji*1
  • YONEYAMA Toshiaki*1
  • MURATA Eiki*1
  • TAKAHASHI Hiroyuki*1

*1 Network Solutions Business Div.

We have developed the CX1000/CX2000 control and measurement stations, which implement a PID control function based on the functions of the DX100/DX200 paper-less recorders. The CX series has up to 6 embedded control loops and 20 channels of analog inputs. With the Yokogawa M&C Green Series Controllers connected through a communications interface, the CX series is able to control up to 16 additional external loops. In addition to the DX series’ main functions, such as recording and/or monitoring display and communication via Ethernet, the CX series has also employed new functions such as monitoring display for control loops, control operations, and ladder communications for PLC. This paper outlines the key features of the CX series.


  • KOBUCHI Keiichiro*1
  • MISAWA Go*1
  • TANIZUME Yasuhiro*1
  • MURATA Hironori*1

*1 Network Solutions Business Div.

We have successively developed PC software packages such as DAQ32Plus, DAQLOGGER, and DAQEXPLORER to support recorder products. These software packages are low-priced and easy to install, however there have often been cases where they could not consistently provide solutions for the various demands from respective users. Focusing on these software packages as key components, we have newly developed a set of flexible software for network-based solutions.

This software set facilitates the creation of sophisticated combinations of software components by using enhanced software-to-software communication for exchange of information, such as various measurement channel and displayrelated items, as well as measured data. Moreover, utilizing the features of the existing software packages, this software set can provide solutions by combining software components with minimum modification.


  • YOSHINO Yasuhiro*1
  • FUKUHARA Tatsuya*1
  • NAGUMO Yasushi*1
  • FUJITA Yasuyuki*1

*1 Network Solutions Business Div.

We have developed DAQSTATION DX100P/DX200P paperless recorders for pharmaceutical (DX-P) and dedicated software DAQSIGNIN complying with the requirements of 21 CFR Part 11 which is the regulation for electronic records and electronic signatures set by the Food and Drug Administration (FDA) in the USA. With the enhancement in security and audit trails, DX-P and DAQSIGNIN have earned the FDA compliance statement from a consulting firm, Stelex Inc. DX-P and DAQSIGNIN are expected to accelerate the digitalization of data for quality control and process control among the pharmaceutical and food industries. Many pharmaceutical companies have already started trial operations and some have adopted them.

This paper outlines items necessary to meet the requirements of 21 CFR Part 11, how DX-P meets these requirements and introduces DX-P’s remote control function and DAQSIGNIN software for DX-P.


  • NAKANISHI Hirofumi*1
  • NISHIGAKI Naoya*1
  • TACHIBANA Katsuya*1
  • SHINAGAWA Takanobu*1

*1 T&M Business Div.

We have developed the WT210/WT230 high accuracy and wide-bandwidth power meters, which can measure DC and AC signals from 0.5 Hz to 100 kHz with a fundamental accuracy of 0.2%. The WT210/WT230 models succeed the former WT200/WT130 models, with the WT210 being a single-phase model and the WT230 being a three-phase model. In addition to having the functions of the former power meters, the WT210/WT230 have improved basic functions and implemented higher accuracy and wider frequency and input ranges.

This paper outlines the WT210/WT230 power meters.


  • IWASE Hisashi*1
  • KAWASUMI Kazuo*1
  • TACHIBANA Katsuya*1
  • SHIODA Toshiaki*1

*1 T&M Business Div.

We have developed the WT1600, a high-precision, wide-bandwidth power meter. The WT1600 can measure DC and AC signals from 0.5 Hz to 1 MHz with a basic power accuracy of 0.1%. With the maximum of six input elements installed, a single WT1600 can measure the efficiency of a three-phase inverter. In addition to the functions of conventional power meters, it has wider ranges and various functions including waveform display. This paper gives an outline of the WT1600.


  • VERONESI Massimiliano*1

*1 Yokogawa Italia, Industrial Automation Department

It is known that the classical tuning formula for typical Proportional-Integral-Derivative (PID) controllers in general provides unsatisfactory results for industrial plants where the time delay exceeds the dominant lag time. For this reason, alternative strategies have been studied in order to cope with this problem and, in this context, the most popular scheme is the Smith Predictor. In this paper the theory behind this algorithm is explained and its implementation through YS170 controller language and CENTUM CS3000 Control Drawing Builder are presented in order to verify their effectiveness in industrial environments. This approach requires a good model of the process under control. In fact, the performance of the Smith Predictor can decrease dramatically (become unstable) due to modelling errors, especially for the dead time which, contrary to what would be expected, can vary considerably depending on the working conditions (i.e. the fluid flow). In this paper a simple adaptive law for the automatic tuning of the model time delay is suggested. When this method is applied, the performance of the Smith Predictor is easily improved due to the automatically tuned model dead time and the control algorithm is capable of meeting variable working conditions.