Yokogawa Electric Corporation

Junichi Iwashita

Toru Shimura

Daisuke Harigane

Wandong Li

Gouki Nakayama

In order to improve the adaptability of diagnosis of an operating state of a field device, a field deviceaccording to the present disclosure has a diagnoserconfigured to diagnose an operating state of the field deviceby hierarchically implementing a plurality of diagnostic processes. The diagnosercan select whether to enable or disable a diagnostic result of at least one diagnostic process of a plurality of diagnostic processes in a diagnostic process after the one diagnostic process.

Field device, method of diagnosing field device and diagnostic apparatus

A drive circuit includes a primary power supplier which supplies a primary electric power in accordance with a state of the drive circuit, a secondary power supplier which supplies an operation electric power and an excitation electric power, an excitation current supplier which supplies an excitation current to an excitation coil, a power supply monitor which compares the voltage value of the operation electric power with a voltage threshold and outputs monitoring information, and a controller which determines whether a short circuit has occurred in the excitation coil based on the monitoring information, and stops supplying the excitation current if the short circuit has occurred. The voltage threshold is higher than a lowest voltage value with which the controller operates, and the voltage threshold is a voltage value representing that the short circuit has occurred in the excitation coil.

Drive circuit and electromagnetic flowmeter

A field device according to one aspect of the present invention includes a sensor, an analog-digital converter configured to continuously convert detected signals output from the sensor to digital signals, and a calculator configured to convert the digital signals to process values. The calculator starts acquisition of the digital signals output from the analog-digital converter at a first point in time that is delayed by a processing time required for the conversion process of the analog-digital converter from a start point of a timing signal defining a sampling section of the detected signals, and finishes the acquisition of the digital signals output from the analog-digital converter at a second point in time that is delayed by the processing time from an end point of the timing signal.

Field device

A signal processing circuit includes: a plurality of daisy chain-connected AD converters each including a data ready output terminal, a synchronizing signal input terminal, and a serial clock input terminal; a calculator connected to the data ready output terminal of any of the AD converters and for outputting a serial clock to the serial clock input terminal of each of the AD converters when a data ready signal is input; and a reset processor included in the calculator and for outputting a synchronizing signal to the synchronizing signal input terminal of each of the AD converters when an output time lag among data ready signals from each of the AD converters is detected for a predetermined number of times.

Growing community of inventors

Tokyo, Japan

Junichi Iwashita