A master slave communication system capable of reducing a manufacturing cost is provided. The mater slave communication system includes a master node and a plurality of slave nodes having the same initial address. A communication between the master node and one slave node among the plurality of slave nodes is established by using the initial address set as an address of the one slave node. The address of the one slave node is changed into another address which has been transmitted from the master node to the one slave node through the established communication and is different from the initial address.

In one embodiment, a method includes applying Forward Error Correction (FEC) to data at power sourcing equipment, transmitting the data and pulse power over a wire pair to a powered device, identifying data transmitted during power transitions between a pulse power on time and a pulse power off time in the pulse power at the powered device, and applying FEC decoding to at least a portion of the data based on said identified power transitions.

The present disclosure envisages a building management system for a building. The building management system includes a building controller, a power over Ethernet (PoE) adapter, and a PoE source. The building controller is configured to operate one or more building equipment of the building, wherein the building controller is powered via alternating current (AC) power. The power over Ethernet (PoE) adapter comprises one or more circuits configured to receive PoE from the PoE source, wherein the PoE source is configured to generate the PoE having direct current (DC) power. Further, the PoE adapter is configured to generate AC power based on the PoE received from the PoE source, and provide the AC power to the building controller.

Embodiments include a power distribution access network comprising power sourcing equipment (PSE) having a hybrid power-data port and at least one remote distribution node coupled to the PSE. The PSE delivers power at a first voltage to the distribution node and the distribution node delivers power at a second voltage to a remote device. Delivery of power to the distribution nodes may be based on information from the distribution node. Other embodiments include a power distribution access network with remote distribution nodes daisy-chained together by hybrid power-data cables so that a power line and a plurality of optical lines pass along the distribution nodes. The optical lines sequentially drop off along the chain and a remainder of the optical lines is indexed at each distribution node. Remote powered devices are coupled to the distribution nodes. Each remote powered device receives power and optical signals from the respective remote distribution node.

A low voltage drive circuit includes a transmit digital to analog circuit that converts transmit digital data into analog outbound data by: generating a DC component; generating a first oscillation at a first frequency; generating a second oscillation at the first frequency; and outputting the first oscillation or the second oscillation on a bit-by-bit basis in accordance with the transmit digital data to produce an oscillating component, wherein the DC component is combined with the oscillating component to produce the analog outbound data, and wherein the oscillating component and the DC component are combined to produce the analog outbound data. A drive sense circuit drives an analog transmit signal onto a bus, wherein the analog outbound data is represented within the analog transmit signal as variances in loading of the bus at the first frequency and wherein analog inbound data is represented within an analog receive signal as variances in loading of the bus at a second frequency.

A system of embedding access control logic into a network gear according to an embodiment includes a plurality of access control devices including corresponding lock mechanisms configured to control access through corresponding passageways, a headend access control system configured to manage access control data associated with the plurality of access control devices, and a network switch communicatively coupled to the headend access control system and comprising a smart communication manager, wherein the smart communication manager includes an application programming interface accessible by the headend access control system and translates commands received from the headend access control system into payloads readable by the plurality of access control devices.

A PoE powered device and method of operation are provided. The device includes a first port unit configured to negotiate receipt of a level of PoE power from a power sourcing equipment. The power is received on a first pair of taps on a first communication port. A detection unit is configured to detect a presence of a first optional circuit load and to detect a presence of a second optional power load. A control circuit is configured to establish connectivity between a second pair of taps on the first communication port and a second powered device port unit in response to the detection unit detecting the first optional load, and further configured to establish connectivity between the second pair of taps and a third pair of taps on a pass-through communication port in response to the detection unit failing to detect the first load and detecting the second load.

In an embodiment, an apparatus includes a source device including a first current limiter and a second current limiter in parallel with each other and a first transformer and a second transformer; a load device includes a third transformer and a fourth transformer in parallel with each other; and an Ethernet cable is electrically coupled between the source device and the load device, the Ethernet cable including first twisted pair lines and second twisted pair lines. A direct current (DC) voltage is provided to the first current limiter and the second current limiter, the first transformer is electrically coupled to an output of the first current limiter, and the second transformer is electrically coupled to an output of the second current limiter. The DC voltage is transmitted to the third transformer and the fourth transformer in parallel with each other via the first twisted pair lines and the second twisted pair lines. The first twisted pair lines and second twisted pair lines are included in an Ethernet cable electrically coupled between the source device and the load device.

This application provides a CAN bus circuit and a CAN bus communications method. The CAN bus circuit used for CAN bus communication includes: at least one CAN unit and one bus, where a first CAN unit includes an input port and an output port, the first CAN unit is any one of the at least one CAN unit, the output port is connected to the bus by using a first circuit, the input port is connected to the bus by using a second circuit, a first diode is disposed on the first circuit, and a second diode is disposed on the second circuit.

A method for protecting against cyber attacks in a communication network of a vehicle, including the steps of acquiring dominant voltage measurements; obtaining an electrical characteristic of nodes that transmit messages by acquiring consecutive groups of voltage measurements at receiving nodes and calculating a distribution thereof; calculating values of distribution statistics; calculating a cumulative voltage deviation for each value of statistic; and obtaining a voltage profile by adding the cumulative voltage deviations of each statistic, executing a malicious-node detection procedure and then executing a transmitting-node identification procedure including comparing the at least one characteristic parameter against all the corresponding characteristic parameters of all the messages, defining a range of variation of the characteristic parameter with respect to a given number of previous samples; and evaluating whether the value of the parameter falls within the range of variation of one of the messages and identifying as malicious the node that transmits the message.