Redundant fieldbus system
First Claim
1. An apparatus for use in a redundant fieldbus system, the apparatus comprising:
- first terminals adapted to connect to a first fieldbus cable, the first terminals coupled to a field device to provide power and communications from a fieldbus network to the field device;
second terminals adapted to connect to a second fieldbus cable, the second terminals coupled to the field device to provide power and communications from the fieldbus network to the field device; and
isolation circuitry connected between the first terminals and the field device and connected between the second terminals and the field device, the isolation circuitry adapted to provide power from either the first terminals or the second terminals to the field device, the isolation circuitry further adapted to isolate a short circuit between the first terminals from a power source connected to the field device through the second; and
wherein the apparatus provides independent current paths between the first terminals and the field device and between the second terminals and the field device, the apparatus further comprising first and second spur connection circuits.
1 Assignment
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Accused Products
Abstract
A redundant fieldbus system provides power and communications in a parallel physical configuration between the host system and attached field devices irrespective of any single point failure in the network. In case of a fault, the redundant fieldbus system automatically eliminates the faulty section of the network, switches power and communications to the healthy portion of the network and terminates the network for signal integrity. A device coupler for the system may include a fault detector coupled to an auto-termination circuit that terminates a fieldbus cable when a fault is detected. The device coupler may include fault detection and isolation coupled to each set of spur terminals used to connect field devices to the device coupler. A field device for the system may include circuitry for deselecting a faulty cable while maintaining connection to a healthy cable.
104 Citations
16 Claims
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1. An apparatus for use in a redundant fieldbus system, the apparatus comprising:
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first terminals adapted to connect to a first fieldbus cable, the first terminals coupled to a field device to provide power and communications from a fieldbus network to the field device; second terminals adapted to connect to a second fieldbus cable, the second terminals coupled to the field device to provide power and communications from the fieldbus network to the field device; and isolation circuitry connected between the first terminals and the field device and connected between the second terminals and the field device, the isolation circuitry adapted to provide power from either the first terminals or the second terminals to the field device, the isolation circuitry further adapted to isolate a short circuit between the first terminals from a power source connected to the field device through the second; and wherein the apparatus provides independent current paths between the first terminals and the field device and between the second terminals and the field device, the apparatus further comprising first and second spur connection circuits. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for use in a redundant fieldbus system, the apparatus comprising:
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first terminals adapted to connect to a first fieldbus cable, the first terminals coupled to a portion of a field device to provide power and communications from a fieldbus network to the field device; second terminals adapted to connect to a second fieldbus cable, the second terminals coupled to the portion of the field device to provide power and communications from the fieldbus network to the field device; and isolation circuitry connected between the first terminals and the portion of the field device and connected between the second terminals and the portion of the field device, the isolation circuitry adapted to provide power from both of the first terminals and the second terminals to the field device, the isolation circuitry providing independent current paths between the first terminals and the field device and between the second terminals and the field device, the isolation circuitry further adapted to detect a loss of power at the first terminals and to automatically isolate the first terminals from a power source connected to the field device through the second terminals when power is lost from the first terminals. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification