Network with redundancy properties, a branching unit for a user device in a network, redundancy manager for a network with redundancy properties and method for operating a network with redundancy properties

A network having redundancy properties, comprising

• a line including first and second line ends, the first and second line ends connected to a redundancy manager;
• the redundancy manager to:
• disconnect the first and second line ends from each other in an error-free state of the line;
• connect the first and second line ends in an error state of the line;
• feed a supply voltage into the first or second line end for supplying a user device connected to the network via a branching unit;
• feed a further supply voltage to the first line end if the supply voltage is fed to the second line end and is not detected at the first line end after lapse of a predetermined period of time by the redundancy manager;
• feed the further supply voltage to the second line end if the supply voltage is fed to the first line end and is not detected at the second line end after lapse of the predetermined period of time by the redundancy manager;
• and
• a plurality of branching units and a recording unit for recording the timely behavior of a voltage or a current related to the supply voltage at the first or second line end during forwarding of the supply voltage by any of the branching units and for determining the number of branching units fed by the supply voltage up to a physical error location.

A method of operating a network having redundancy properties, the network comprising a line having first and second line ends connected to a redundancy manager, the method comprising:

• disconnecting the first and second line ends from each other in an error-free state of the line;
• connecting the first and second line ends in an error state of the line;
• feed a supply voltage into the first or second line end for supplying a user device connected to the network via a branching unit;
• feed a further supply voltage to the first line end if the supply voltage is fed to the second line end and is not detected at the first line end after lapse of a predetermined period of time by the redundancy manager;
• feed the further supply voltage to the second line end if the supply voltage is fed to the first line end and is not detected at the second line end after lapse of the predetermined period of time by the redundancy manager;
• detecting an open or short circuit in a segment of the network line within a branching unit on an intermediate portion of the network line, and
• disconnecting the segment from the network line automatically by the branching unit.

A network with redundancy properties, comprising:

• a plurality of electrical signal branching units linked sequentially via a plurality of trunk lines, wherein each trunk line is a portion of a communication line for data and power communication;
• each branching unit comprising a first network connection to one of the trunk lines, a second network connection to an other of the trunk lines, and a trunk-terminating resistor that controllably terminates the communication line;
• the communication line comprising first and second ends connected to respective first and second ports of a redundancy manager;
• first and second line-terminating resistors in the redundancy manager that controllably terminate the respective first or second ends of the communication line;
• a third port on the redundancy manager connected to a data/power bus system;
• wherein the redundancy manager connects the third port to the first port, connects the second line-terminating resistor to terminate the second end of the communication line, then monitors a voltage received from the second end of the communication line for a threshold value indicating acceptable transmission of power though the communication line, and if the monitored voltage falls below a threshold value, the redundancy manager electrically connects the first and second ports together, and disconnects the second line-terminating resistor;
• wherein each branching unit monitors electrical current or voltage on said one or the other of the connected trunk lines, implements a state transition table to detect a short or open circuit in a failed said one or the other trunk line, and upon detecting the short or open circuit disconnects the failed trunk line, and connects the trunk-terminating resistor to terminate the communication line;
• and
• wherein if a given trunk line develops a short or open circuit, a branching unit connected thereto disconnects the given trunk line from the communication line, and the redundancy manager restores data/power to all of the branching units by connecting the first and second ports together, thereby communicating data and power on the communication line in two directions from the redundancy manager to reach all of the branching units.