Yokogawa Electric Corporation

Teac Corporation

Takashi Nishijima

Atsushi Kimura

Yoji Saito

Makoto Tani

Yasuo Kasahara

Masahito Tsuchiya

The present invention provides a field device whereby the device's additional information can be transmitted wirelessly without the need for battery replacement or external wiring. The present invention also provides a field device whereby the firmware of a wireless module in the field device can be developed at minimum cost and whereby it can be made easy to link the firmware to applications, such as an asset management system, on the host system side. The field device in accordance with the present invention is installed in a plant, factory, or the like, connected to a higher-order distributed control system through a signal line, configured to input or output 4-20 mA signals, and comprised of:

Field device and method for transferring the field device's signals

An electricity/air pressure converter comprising a pair of housings, made of a soft magnetic material, in the middle of which pole pieces are disposed facing each other with an air gap therebetween and which have a cylindrically formed outer circumferential portion; a permanent magnet secured to one of the housings at one end thereof and surrounding one of the pole pieces; a movable member, made of a magnetic material and having spring properties, which is secured to the other end of the permanent magnet and which faces the pole pieces in the air gap; a coil which is wound around the other housing so that it surrounds the pole pieces and through which a current signal flows; and a nozzle which is disposed to face the movable member around the center of either of the pole pieces and which is in communication with one end of a restrictor which is supplied with a supply air pressure at the other end thereof, wherein back pressure is generated at the nozzle according to current signals being outputted as an air pressure signal. Advantageously, the configuration of the invention is compact, and is easily manufactured at low cost, and is highly reliable and stable.

Electricity/air pressure converter

A digital position signal generator suitable for gain control and other purposes. A typical embodiment includes a rotary disk notionally divided into a plurality of sectors of the same angle about the disk axis. Some of the disk sectors have radial extensions which are detectable by photocouplers. The photocouplers are fixedly disposed about the disk axis with angular spacings each greater than the angle of each disk sector. Thus, with the rotation of the disk, the photocouplers produce binary zero and one outputs in various predetermined combinations nonsequentially representing successive predetermined angular positions of the disk. A position data generator circuit such as a microcomputer is provided which has stored thereon meaningful position data sequentially representing the successive predetermined angular positions of the disk. Inputting each output combination of the detectors, the position data generator circuit puts out a corresponding one of the meaningful position data. Several other embodiments are disclosed.

Device for generating a signal representative of the position of an

A signal supplying unit includes a plurality of terminals, a plurality of signal sources, each of the plurality of signal sources outputting a signal, a detecting circuit for detecting whether or not at least the one of the plurality of terminals is coupled to a terminal of an external unit, and a selecting circuit for selecting signals to be supplied to the plurality of terminals from signals output from the plurality of signal sources in accordance with a detecting result obtained by the detecting circuit. In addition, a signal supplying unit includes a first terminal, a second terminal, a first signal source for outputting a first signal, a second signal source for outputting a second signal, a third signal source for outputting a third signal, a detecting circuit for detecting whether or not the first terminal is coupled to a terminal of an external unit and for outputting a detecting signal, and a selecting circuit for selectively supplying either the second signal output from the second signal source or the third signal output from the third signal source to the second terminal in accordance with the detecting signal output from the detecting circuit.

Growing community of inventors

Tokyo, Japan

Takashi Nishijima