Redundantly powered and daisy chained power over ethernet
First Claim
1. A method for providing power to a distributed sensor system, the distributed sensor system comprising an Ethernet based interface unit having a plurality of ports, and a plurality of sensor strings, each sensor string comprising a plurality of sensor units coupled in series to one of the plurality of ports of the interface unit, the method comprising:
- providing power from at least one port of the interface unit to a first port of a first sensor unit of at least one of the plurality of sensor strings via a first Ethernet cable;
powering up the first sensor unit;
receiving, with the first sensor unit from the interface unit, a signal indicating that the first sensor unit should enable power forwarding at a second port of the first sensor unit;
in response to receiving the signal indicating that the first sensor unit should enable power forwarding at the second port, setting a low current limit for power provided by the second port to a first port of a second sensor unit in a first state, the low current limit set at a level sufficient to power only the second sensor in the first state;
in the first state, forwarding power at the low current limit from the second port of the first sensor unit to the first port of the second sensor unit of the at least one of the plurality of sensor strings via a second Ethernet cable;
monitoring a voltage at the second port of the first sensor unit;
determining whether the voltage at the second port of the first sensor in the first state indicates a short circuit condition;
in response to determining that the voltage at the second port of the first sensor unit in the first state indicates a short circuit condition, disabling power forwarding by the second port of the first sensor unit;
in response to determining that that the voltage at the second port of the first sensor unit in the first state does not indicate a short circuit condition, determining whether there is an open-circuit condition present at the second port of the first sensor unit;
in response to determining that there is an open-circuit condition present at the second port of the first sensor unit, disabling power forwarding by the second port of the first sensor unit;
in response to determining that there is not an open-circuit condition present at the second port of the first sensor unit, setting a high current limit for power provided by the second port to the first port of the second sensor unit in a second state, the high current limit set at a level sufficient to power a maximum number of sensor units in the at least one of the plurality of sensor strings;
in the second state, forwarding power at the high current limit from the second port of the first sensor unit to the first port of the second sensor unit via the second Ethernet cable;
monitoring the plurality of sensor strings for a fault condition; and
in response to detecting a fault condition in a first sensor string of the plurality of sensor strings, providing power from a second one of the plurality of sensor strings to the first sensor string to provide power to at least one of the plurality of sensor units within the first sensor string.
1 Assignment
0 Petitions
Accused Products
Abstract
According to one aspect, embodiments of the invention provide a method for providing power to a distributed sensor system, the method comprising providing power from at least one port of an interface unit to a first port of a first sensor unit of at least one of a plurality of sensor strings, powering up the first sensor unit, forwarding power from a second port of the first sensor unit to a first port of a second sensor unit of the at least one of the plurality of sensor strings, powering up the second sensor unit, monitoring the plurality of sensor strings for a fault condition, and in response to detecting a fault condition in a first sensor string of the plurality of sensor strings, providing power from a second one of the plurality of sensor strings to the first sensor string.
-
Citations
7 Claims
-
1. A method for providing power to a distributed sensor system, the distributed sensor system comprising an Ethernet based interface unit having a plurality of ports, and a plurality of sensor strings, each sensor string comprising a plurality of sensor units coupled in series to one of the plurality of ports of the interface unit, the method comprising:
-
providing power from at least one port of the interface unit to a first port of a first sensor unit of at least one of the plurality of sensor strings via a first Ethernet cable; powering up the first sensor unit; receiving, with the first sensor unit from the interface unit, a signal indicating that the first sensor unit should enable power forwarding at a second port of the first sensor unit; in response to receiving the signal indicating that the first sensor unit should enable power forwarding at the second port, setting a low current limit for power provided by the second port to a first port of a second sensor unit in a first state, the low current limit set at a level sufficient to power only the second sensor in the first state; in the first state, forwarding power at the low current limit from the second port of the first sensor unit to the first port of the second sensor unit of the at least one of the plurality of sensor strings via a second Ethernet cable; monitoring a voltage at the second port of the first sensor unit; determining whether the voltage at the second port of the first sensor in the first state indicates a short circuit condition; in response to determining that the voltage at the second port of the first sensor unit in the first state indicates a short circuit condition, disabling power forwarding by the second port of the first sensor unit; in response to determining that that the voltage at the second port of the first sensor unit in the first state does not indicate a short circuit condition, determining whether there is an open-circuit condition present at the second port of the first sensor unit; in response to determining that there is an open-circuit condition present at the second port of the first sensor unit, disabling power forwarding by the second port of the first sensor unit; in response to determining that there is not an open-circuit condition present at the second port of the first sensor unit, setting a high current limit for power provided by the second port to the first port of the second sensor unit in a second state, the high current limit set at a level sufficient to power a maximum number of sensor units in the at least one of the plurality of sensor strings; in the second state, forwarding power at the high current limit from the second port of the first sensor unit to the first port of the second sensor unit via the second Ethernet cable; monitoring the plurality of sensor strings for a fault condition; and in response to detecting a fault condition in a first sensor string of the plurality of sensor strings, providing power from a second one of the plurality of sensor strings to the first sensor string to provide power to at least one of the plurality of sensor units within the first sensor string. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
Specification