Yokogawa Electric Corporation

Seiichiro Takahashi

Satoru Ochiai

Yoji Saito

Masaaki Nikkuni

There is provided a field device performing a communication through a communication line. The field device includes: first circuits involved with a smart communication; second circuits involved with a fieldbus communication; a token detecting circuit that detects a token in the fieldbus communication; and a control circuit. The control circuit is operable to: i) cause the second circuits to operate when the token is detected within a given time by the token detecting circuit; and ii) cause the second circuits not to operate when the token is not detected within the given time by the token detecting circuit.

Field device

Disclosed is a field device that transmits and receives data via a fieldbus in accordance with any of a plurality of communication protocols. The field device includes: a control section to give an instruction on a communication protocol to be used for transmitting or receiving data via the fieldbus; and a fieldbus controller including a transmitting and receiving section to transmit and receive data in accordance with any of the plurality of communication protocols, and a switching section to switch between the communication protocols to be used by the transmitting and receiving section based on the instruction from the control section.

Field device and fieldbus controller

A memory updating system for a field device involves a fieldbus, one or more field devices that incorporate a nonvolatile memory and are connected to the fieldbus, a host system that is directly or indirectly connected to the fieldbus and transmits an updating instruction and updating data to one of the field devices in order to update the nonvolatile memory of the field device, and a current control circuit that controls a current provided from the fieldbus. The current control circuit increases the current provided from the fieldbus to a value greater than a normal value before the field device erases data stored in the nonvolatile memory, and returns the current provided from the fieldbus to the normal value after the field device completes the erasing of the data stored in the nonvolatile memory.

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Musashino, Japan

Seiichiro Takahashi