Field device power supply failure detection
First Claim
1. A field device for monitoring a manufacturing process and/or for actuating manufacturing process variables, the field device comprising:
- a discharge protection unit connected to a control bus and adapted to supply an operating current from the control bus to the field device such that the discharge protection unit inhibits a discharge of energy stored in the field device to the control bus; and
a controller unit adapted to control the operation of the field device and being powered with the operating current from the control bus;
wherein the discharge protection unit comprises at least two rectifying elements inserted into the current path of the operating current with identical conducting directions, and a signal associated with a selected rectifying element is supplied as an interrupt signal to the controller unit for power supply failure detection.
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Accused Products
Abstract
To detect a power supply failure on an intrinsically safe field bus of a manufacturing process control system in an efficient manner there is provided a field device with a discharge protection unit which is connected to a control bus for supply of an operating current from the control bus to the field device. The discharge protection unit inhibits a discharge of energy stored in the field device to the control bus. The field device also comprises a controller unit adapted to control the operation of the field device and being powered with the operating current from the control bus. According to the present invention the discharge protection unit comprises at least two rectifying elements inserted into the current path of the operating current with identical conducting directions and an input signal or an output signal of a selected rectifying element is supplied as interrupt signal to the controller unit for power supply failure detection.
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Citations
23 Claims
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1. A field device for monitoring a manufacturing process and/or for actuating manufacturing process variables, the field device comprising:
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a discharge protection unit connected to a control bus and adapted to supply an operating current from the control bus to the field device such that the discharge protection unit inhibits a discharge of energy stored in the field device to the control bus; and
a controller unit adapted to control the operation of the field device and being powered with the operating current from the control bus;
wherein the discharge protection unit comprises at least two rectifying elements inserted into the current path of the operating current with identical conducting directions, and a signal associated with a selected rectifying element is supplied as an interrupt signal to the controller unit for power supply failure detection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19)
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13. A method of operating a field device for monitoring a manufacturing process and/or for actuating manufacturing process variables, the method comprising:
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continuously monitoring a voltage on a control bus connecting the field device with a central controller or an operating current flowing from the control bus into the field device;
generating a power supply interrupt signal when the monitored voltage/operating current decreases beyond a predetermined first threshold (UB,min); and
saving internal states in a field device controller after supplying the power supply interrupt signal to the field device controller.
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20. A computer program product directly loadable into a memory of a field device controller, the product including software code for causing the field device to monitor a manufacturing process and/or to actuate manufacturing process variables, by causing the field device controller to:
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continuously monitor a voltage on a control bus connecting the field device with a central controller or an operating current flowing from the control bus into the field device;
generate a power supply interrupt signal when the monitored voltage/operating current decreases beyond a predetermined first threshold (UB,min); and
save internal states in a field device controller after supplying the power supply interrupt signal to the field device controller. - View Dependent Claims (21, 22, 23)
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Specification