Control signal protection device
AssigneeFisher Controls International LLC
InventorStephen G. Seberger
Life of this patent
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Abstract
A control signal protection device having a first operational mode and a second operational mode includes a first terminal pair that connects the signal protection device to a control system and a second terminal pair that connects the converter to a field device. The control system provided a control signal to the control system protection device. The control signal device further includes a power storing element for temporary accumulation of electric energy and a switching circuit for controlling operational mode of the signal protection device. Electric energy is stored in the power storing element in the first operational mode. Electric energy stored in the power storing element is supplied to a positive terminal in the second terminal pair in the second operational mode.
Claims18
A control signal protection device having a first operational mode and a second operational mode, comprising:
- a first terminal pair that connects the signal protection device to a control system, wherein the control system provides a control signal to a field device according to an industrial automation protocol;
- a second terminal pair that connects to the field device to provide the control signal;
- an element to control a rate of accumulating energy in the power storing element;
- and
- a power storing element for temporary accumulation of electric energy;
- a switching circuit for controlling the operational mode of the signal protection device, wherein
- electric energy is stored in the power storing element in the first operational mode without interfering with communicating the control signal from the control system;
- and
- electric energy stored in the power storing element is supplied to a positive terminal in the second terminal pair in the second operational mode.
A method of protecting a control signal provided to a field device in a process control system, the method comprising:
- providing a host station;
- communicatively coupling the host station to a plurality of input output (I/O) cards including a first card and a second card, wherein operation is selectively switched from the first card to the second card;
- providing a control signal from the host station via the first card or the second card to a control signal protection device;
- causing the control signal protection device to switch from a first operational mode to a second operational mode during a transition of operation from the first card to the second card, wherein the control signal protection device:
- stores electric energy in a power storing element in the first operational mode, and
- supplies electric energy stored in the power storing element to an output terminal of the control signal protection device in the second operational mode.
A control system for controlling a field device in a process control system, comprising:
- a host station;
- a plurality of input/output (I/O) cards coupled to the host station for providing a control signal to the field device, wherein the plurality of I/O cards includes a primary I/O card and a back-up I/O card;
- an I/O card controller configured to selectively switch between the primary I/O card and the backup I/O card;
- and
- a control signal protection device communicatively coupled to the I/O cards and to the field device, wherein the control signal protection device is configured to store electric energy in a power storing element in a first operational mode and supply electric energy stored in the power storing element to an output terminal of the control signal protection device in a second operational mode to sustain the control signal at an output of the signal protection device during a switchover operation between the primary card I/O card and the backup I/O card.
Dependencies are inferred from the claim text.