POWER OVER ETHERNET LOCAL DATA PROCESSING

Abstract

The present invention relates to a data processing device (10) for a power over Ethernet system (100). The data processing device (10) comprises a data communicating unit (12) and a data processing unit (14). The data communicating unit (12) is configured for establishing a first connection (30) to a power sourcing equipment (24) and a second connection (32) to a powered device (26) and for intercepting central data transmitted from the power sourcing equipment (24) to the powered device (26). The data processing unit (14) is configured to process the intercepted central data in dependence of local data received from a local powered device (16). The local data comprises user input data, sensing data, or user input data and sensing data. The data communicating unit (12) is furthermore configured for transmitting the processed data to the powered device (26). Hence local data can influence central data for improving local control.

Claims

1. A data processing device for a power over Ethernet system comprising a data communicating unit for establishing a first connection to a power sourcing equipment and a second connection to a powered device, wherein the data communicating unit is configured for intercepting central data transmitted from the power sourcing equipment to the powered device, and a data processing unit configured to process the intercepted central data in dependence of local data received from a local powered device, wherein the data communicating unit is configured for transmitting the processed data to the powered device, and wherein the local data comprises user input data, sensing data, or user input data and sensing data a simple logic unit configured for encoding data in a characteristic of one or more data packets, decoding data encoded in a characteristic of one or more data packets, and/or processing data encoded in a characteristic of one or more data packets; wherein the characteristic comprises data packet length, data packet duration, number of data packets in a predetermined time interval, and/or sequence of data packets.

2. The data processing device according to claim 1, wherein the data processing unit is configured to determine the processed data by calculating a function depending on central data and local data.

3. The data processing device according to claim 1, wherein the data communicating unit is configured for intercepting data transmitted between the powered device and the power sourcing equipment.

4. The data processing device according to claim 1, wherein the simple logic unit comprises a switch, a logic gate, a comparator, a timer, and/or a counter.

5. The data processing device according to claim 1, wherein the simple logic unit is configured for processing the intercepted central data in dependence of the local data by reducing the length, duration and/or number of data packets of the central data.

6. The data processing device according to claim 1, wherein the data is encoded in a pulse-density modulation.

7. The data processing device according to claim 1, wherein the central data comprises control data comprising a command for controlling the powered device and wherein the processed data comprises control data comprising a command for controlling the powered device based on the central data and the local data.

8. A power over Ethernet system comprising a data processing device according to claim 1, a power sourcing equipment, and a powered device, wherein the data processing device is daisy chained between the power sourcing equipment and the powered device.

9. The system according to claim 8, wherein the powered device comprises a functional unit configured for performing a function based on the processed data.

10. The system according to claim 8, wherein the power sourcing equipment and/or the powered device comprises a simple logic unit configured for encoding data in a characteristic of one or more data packets and/or for decoding data encoded in a characteristic of one or more data packets, and wherein the system is configured for transmitting the encoded data between the power sourcing equipment and the powered device.

11. The system according to claim 8, wherein the powered device is a lighting device, a user interface device, a sensor device, a magnet device, an actuator device, a fan device, a heating device, a cooling device, or a temperature regulating device.

12. A method for processing data in a power over Ethernet system comprising the steps: intercepting central data transmitted from a power sourcing equipment to a powered device, receiving local data from a local powered device, wherein the local data comprises user input data, sensing data, or user input data and sensing data, processing the intercepted central data in dependence of the local data, and transmitting the processed data to the powered device, wherein the method further comprising one or more of the steps of: encoding data in a characteristic of one or more data packets, decoding data encoded in a characteristic of one or more data packets, processing data encoded in a characteristic of one or more data packets; wherein the characteristic comprises data packet length, data packet duration, number of data packets in a predetermined time interval, and/or sequence of data packets.

13. A computer program for processing data in a power over Ethernet system, wherein the computer program comprises program code means for causing a processor to carry out the method as defined in claim 14, when the computer program is run on the processor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In the following drawings:

[0063] FIG. 1 shows schematically and exemplarily a first embodiment of a data processing device,

[0064] FIG. 2 shows schematically and exemplarily a first embodiment of a power over Ethernet system with a second embodiment of the data processing device,

[0065] FIG. 3 shows schematically and exemplarily a third embodiment of the data processing device in a second embodiment of the power over Ethernet system,

[0066] FIG. 4 shows schematically and exemplarily a third embodiment of the power over Ethernet system with several data processing devices and PDs,

[0067] FIG. 5 shows schematically and exemplarily a fourth embodiment of the data processing device in a fourth embodiment of the power over Ethernet system,

[0068] FIG. 6A shows central data encoded in a number of data packets,

[0069] FIG. 6B shows local data encoded in a duration of a data packet,

[0070] FIG. 6C shows processed data encoded in a number of data packets,

[0071] FIG. 7A shows central data in a payload of a data packet,

[0072] FIG. 7B shows local data encoded in a duration of a data packet,

[0073] FIG. 7C shows processed data,

[0074] FIG. 8 shows schematically and exemplarily a fifth embodiment of the data processing device in a fifth embodiment of the power over Ethernet system,

[0075] FIG. 9 shows a first embodiment of a method for processing data in a power over Ethernet system,

[0076] FIG. 10 shows a second embodiment of a method for processing data in a power over Ethernet system.

DETAILED DESCRIPTION OF EMBODIMENTS

[0077] FIG. 1 shows schematically and exemplarily a first embodiment of the data processing device 10. The data processing device 10 is for a power over Ethernet system, such as one of the systems 100, 100, 100, 100, 10 presented in FIG. 2 to FIG. 5, and FIG. 8.

[0078] The data processing device 10 comprises a data communicating unit 12, a data processing unit 14, and a local PD in form of a user interface device, which in this embodiment is a potentiometer 16.

[0079] The data communicating unit 12 comprises ports 18 and 20 for connecting the data processing device 10 with a PSE and a PD via Ethernet connections in form of cables (not shown). Hence the data processing device 10 can be daisy chained between the PSE and the PD in order for allowing the data communicating unit 12 to intercept data transmitted between the PSE and the PD.

[0080] In this embodiment the data processing device 10 is configured to be connected to a PD in form of a lighting device with an LED array as a functional unit (not shown). The PSE in this embodiment transmits central data in form of control data in order to control the lighting device via the Ethernet Protocol. The control data therefore comprises a command for controlling the lighting device which in this embodiment is a command for adjusting the brightness to a predetermined value. The data transmitted from the PSE to the lighting device is intercepted by the data communicating unit 12. The data communicating unit 12 identifies the portions of data relevant for controlling the lighting device, i.e., in this embodiment the central data, and provides only this portion of data to the data processing unit 14 in order to process the central data. Alternatively the data communicating unit 12 can also provide the whole data to the data processing unit 14.

[0081] The data processing unit 14 additionally receives local data from the potentiometer 16. The potentiometer 16 is controlled by a user that uses it to provide his user input data. The local data can in this case be a value between 0 and 1. In other embodiments local data can be more complex information, e.g., a configuration setting with various parameter values or ranges of parameter values. In this embodiment the local data corresponds to user input data. In other embodiments the local data can for example also be sensing data or user input data and sensing data.

[0082] The data processing unit 14 processes the intercepted central data in dependence of the local data in order to generate processed data. In this embodiment the processed data comprises control data comprising a command for controlling the lighting device based on the central data and the local data. The data processing unit 14 in this embodiment therefore determines the processed data by calculating a function depending on the central data and the local data. In this embodiment the intercepted central data is multiplied with the local data, i.e. processed_data=central_data local_data in order to determine a brightness value. In other embodiments the processed data can also for example be generated by determining the minimum of the central data and the local data, i.e., processed_data=min(central_data,local_data) or the maximum of the central data and the local data, i.e. processed_data=max(central_data,local_data). In yet another embodiment the processed data can also be zero, i.e., the central data is factually blocked, as the processed data in this case for example corresponds to zero. In yet a further embodiment the PD receiving the processed data can be configured to perform a predetermined mode if no processed data is received, i.e., a zero voltage, for example activating or deactivating a PD in form of a lighting device. Such predetermined modes can also for example comprise fully activating or deactivating the lighting device, setting the brightness of the lighting device to a predetermined level, such as 10% or 100%, or setting CCT to a predetermined level, such as 2700 K, 4000 K, or 6000 K. In a further embodiment the data processing unit 14 can process the central data in order to influence multiple control parameters, for example brightness and CCT. Such processing can for example be based on two functions, such as processed_data_brightness=central_data_brightness local_data_brightness and processed_data_CCT=2000K+local_data_CCT*4500K. In yet another embodiment the local data can also override the central data, such that only local data controls the lighting device or the central data can be combined with the local data in order to allow features such as CCT dimming

[0083] The data communicating unit 12 then transmits the processed data to the lighting device via the port 18 or 20, to which the lighting device is connected. This allows local brightness control of the lighting device, as the central data transmitted from the PSE to the lighting device comprises a brightness value that is intercepted by the data processing device 10 and manipulated in dependence of the user input data. Therefore the lighting device can partly be controlled via the PSE and in addition it can be locally controlled by the potentiometer 16 of the data processing device 10.

[0084] In other embodiments local control can also be based on sensing data, such as temperature sensing data, brightness sensing data, decibel sensing data, or movement sensing data. In yet other embodiments local control can be based on user input data and sensing data.

[0085] In this embodiment the data communicating unit 12 is furthermore configured to intercept data transmitted from the lighting device to the PSE. Hence the data communicating unit 12 intercepts data transmitted between the lighting device and the PSE. In particular power requests transmitted from the lighting device to the PSE can be intercepted by the data communicating unit 12. The data communicating unit 12 provides the intercepted data to the data processing unit 14. The data processing unit 14 adds the power requirement of the data processing device 10 to the power request of the lighting device and the data communicating unit 12 transmits the processed power request to the PSE. The PSE then supplies the requested amount of power to the data processing device 10 and the lighting device via Ethernet connections in form of the cables (not shown).

[0086] In other embodiments of the data processing device 10 that have a negligible power consumption, the data communicating unit 12 can also be configured to forward the power request of the lighting device to the PSE or the data processing unit 14 can be configured for leaving the power request unmodified. In yet other embodiments the data communicating unit 12 can also only intercept data transmitted from the PSE to any PD.

[0087] In an autoclass power over Ethernet system the power requirement of the data processing device 10 and the lighting device will be recognized as a combined load by the PSE. In order to allow automatic classification of PDs in the power over Ethernet system by the PSE the functionality of the data processing device 10, i.e., the data intercepting and data processing may be temporarily deactivated in order to determine a maximal load.

[0088] FIG. 2 shows schematically and exemplarily a first embodiment of the power over Ethernet system 100. The system 100 comprises a BMS 22, a PSE 24, a second embodiment of the data processing device 10, and a PD in form of a lighting device 26. In other embodiments of the power over Ethernet system the PD can also be any other kind of PD, such as a user interface device, a sensor device, a magnet device, an actuator device, a fan device, a heating device, a cooling device, or a temperature regulating device. The BMS 22 can also be replaced by a central controller or server (not shown).

[0089] The BMS 22, the PSE 24, the data processing device 10, and the lighting device 26 are connected via Ethernet connections in form of cables 28, 30 and 32.

[0090] The second embodiment of the data processing device 10 is similar to the first embodiment of the data processing device 10. The second embodiment of the data processing device 10, however, comprises an additional simple logic unit 34. The simple logic unit 34 allows encoding data in a characteristic of one or more data packets. The simple logic unit 34 in this embodiment therefore has a simple C with switches, logic gates, comparators, timers and counters. The characteristic can for example be data packet length, data packet duration, number of data packets in a predetermined time interval, and/or sequence of data packets.

[0091] The encoded data can be transmitted to the lighting device 26 via port 20 of the data communicating unit 12 and cable 32. The lighting device 26 comprises a simple logic unit for decoding the data encoded in a characteristic of one or more data packets (not shown). In this embodiment the simple logic unit of the lighting device comprises a RX data detector, a comparator in form of a Schmitt trigger, a counter, and a timer. The simple logic unit receives data in form of voltage signals. A voltage signal is received and detected at the RX data detector. The Schmitt trigger compares the measured voltage to a reference voltage close to a default level of the line, which in this embodiment is 0 V. Hence the Schmitt trigger can detect data packets and forward the rising edge at the start of each data packet to the counter. The counter increases by one for each data packet it receives. The timer measures time intervals and resets the counter in predetermined time intervals. The counter transmits the number of data packets counted in a time interval to a lighting device driver. The lighting device driver operates an LED array of the lighting device according to the received data, i.e., the number supplied from the counter.

[0092] In another embodiment the simple logic unit can be integrated in a simple C that runs a program code to capture and count the data packets while resetting the counting in predetermined time intervals. The simple C is a low cost and low power consumption C. The simple C can then provide a control parameter generated from the counting of the data packets to the lighting device driver.

[0093] This allows using a simple data transfer protocol between the data processing device 10 and the lighting device 26 instead of the Ethernet protocol. As simple logic units only require a small amount of power, the power consumption of the data processing device 10 and lighting device 26 can be reduced compared to devices communicating via Ethernet protocol.

[0094] In another embodiment the data processing device comprises simple logic units as part of the data communicating unit for decoding encoded data and encoding data in a characteristic of one or more data packets. In yet another embodiment the data processing device can comprise a simple logic unit as part of the data processing unit for processing data encoded in a characteristic of one or more data packets.

[0095] The data can be encoded in a pulse-density modulation by the simple logic unit 34 using an amount of data packets per time interval. In this embodiment brightness control data is encoded. An amount of data packets received in a predetermined time interval, e.g., 10, 3, or 0 data packets received for example in a time interval of 100 ms corresponds to a brightness of 100%, 30%, and 0%. Any other reasonable values for the number of data packets, such as 20, 50, 100 for 100% brightness and time interval, such as 5 ms, 10 ms, 50 ms, or 200 ms can also be used. The data packets are received by the simple logic unit of the lighting device 26 that decodes the brightness value encoded in the number of data packets per time interval. Averaging over several time intervals can be used to increase resolution. The brightness of the lighting device can thus be controlled by the encoded data.

[0096] The data processing unit 14 processes the intercepted control data by adjusting the number of data packets per time interval of the central data based on the local data. This leads to a modification of the brightness based on the local data. Therefore instead of a central control by the BMS 22, local control via the potentiometer 16 is possible.

[0097] FIG. 3 shows schematically and exemplarily a second embodiment of the power over Ethernet system 100 with a third embodiment of the data processing device 10. The system 100 comprises BMS 22, PSE 24, data processing device 10, a first PD in form of a lighting device 26 and a second PD in form of a heating device 26. The data processing device 10 is daisy chained between the PSE 24 and the lighting device 26. The lighting device 26 is daisy chained between the data processing device 10 and the heating device 26.

[0098] The third embodiment of the data processing device 10 is similar to the first embodiment of the data processing device 10. The data processing device 10, however, does not have a local PD. Instead the data communicating unit 12 has an additional port 36 for establishing an Ethernet connection to port 38 of a local PD in form of a sensor device 16 via cable 40. Instead of the sensor device the data processing device 10 can also be connected to a user interface device (see FIG. 4).

[0099] The sensor device 16 in this embodiment has a brightness sensor for obtaining brightness values in order to determine the brightness in a room in which the sensor device 16 is arranged. Furthermore the sensor device 16 has a temperature sensor for determining the temperature in the room. In this embodiment the sensor device 16 is arranged in the same room as the lighting device 26 and the heating device 26. The sensors generate sensing data which is provided to the data processing device 10 as local data for processing intercepted central data.

[0100] The central data thus can be processed based on a brightness value and temperature value received by a sensor that is in proximity to the PDs that are to be controlled. If for example the central data would command the lighting device to adjust the brightness to an unnecessarily high brightness value, a lower brightness value in view of the brightness value derived by the brightness sensor can be determined by the data processing unit 14 in dependence of the central data and the local data. The processed data is then transmitted to the lighting device 26 that adjusts its brightness.

[0101] As the lighting device 26 is daisy chained between the data processing device 10 and the heating device 26, it can forward processed data to the heating device 26 via Ethernet connection in form of cable 42. Therefore also processed data for the heating device 26 can be transmitted from the data processing device 10 via the daisy chained lighting device 26 to the heating device 26. The processed data is also dependent on the sensing data obtained from the sensor device 16, in particular on the temperature values determined by the temperature sensor.

[0102] FIG. 4 shows schematically and exemplarily a third embodiment of the power over Ethernet system 100 with several data processing devices 10, 10 and PDs in form of lighting devices 26 and heating devices 26, as well as a local PD in form of a user interface device which in this embodiment is a potentiometer 16.

[0103] The system 100 furthermore comprises a PSE 24 with a power source 44, a simple logic unit 34, a control unit 46, and ports 48. The PSE 24 is directly connected to lighting device 26, data processing device 10 and three data processing devices 10 via Ethernet connections in form of cables 30 and indirectly to several more data processing devices 10, lighting devices 26 and heating devices 26 which are arranged in linear daisy chains. The PSE 24 is furthermore connected to BMS 22 via cable 28.

[0104] The power source 44 supplies power to the PDs, the simple logic unit 34 encodes data in a characteristic of one or more data packets and decodes data encoded in a characteristic of one or more data packets, and the control unit 46 controls the transmission of data packets. The control unit 46 can force the transmission of the data packets to each of the PDs 26 and 26 and/or the data processing devices 10 and 10.

[0105] The system 100 has various operation modes.

[0106] In a first operation mode central data is transmitted via cable 28 from BMS 22 to the PSE 24 using the Ethernet protocol. The central data is received by the control unit 46 which decodes the central data from the Ethernet protocol in order to identify the destination of the data packet and to identify the data stored in the data packet. The control unit 46 then transmits the data to the simple logic unit 34 for encoding the data in a characteristic of one or more data packets. The characteristic can comprise a number of data packets in a predetermined time interval (see FIG. 6A), a data packet length or a data packet duration (see FIG. 6B). In this embodiment the data is encoded in a pulse-density modulation using a number of data packets in a predetermined time interval. The simple logic unit 34 then transmits the encoded data back to the control unit 46 which transmits the encoded data to one or more of the PDs based on the identified destination of the data packet via one of the cables 30. Therefore each of the ports 48 is associated with a MAC address of one of the connected PDs. Cable 30 transmits power from the power source 44 and encoded central data from the simple logic unit 34 to the lighting device 26. A simple logic unit of the lighting device 26 decodes the central data encoded in the characteristic of the data packets. The central data comprises control data generated on or provided to the BMS 24. The control data comprises a command for controlling the lighting device 26. The control data can for example be a command to activate or deactivate one or more of the PDs or to adjust a control parameter, such as brightness, CCT, or temperature. Hence after the simple logic unit of the lighting device 26 decoded the control data it forwards the command to an LED of the lighting device 26 (not shown). The LED performs a function based on the command, e.g. it is activated or deactivated or its brightness is adjusted.

[0107] In this embodiment the five cables 30 connect the PSE 24 to five different PD arrangements. The single lighting device 26 is only controlled by central data while all other arrangements comprise at least one data processing device 10 or 10 which intercepts the central data and processes it based on local data in order to allow local control.

[0108] In a second operation mode data encoded in a characteristic of one or more data packets from any of the PDs can be received at the PSE 24. The data can for example be status data, configuration data, or control data. The simple logic unit 34 decodes the encoded data and the control unit 46 transmits the data to the BMS 22 via cable 28 using the Ethernet protocol.

[0109] In a third operation mode the control unit 46 measures a power consumption of the PDs. The control unit 46 can control the transmission of the data packets to each of the PDs based on the measured power consumption of each of the PDs. The control unit 46 can for example transmit encoded data only to specific PDs indicated by a predetermined power consumption, such as a power consumption below a predetermined threshold, for example below a few mW, e.g., below 10 mW, below 5 mW, below 2 mW, or below 1 mW. Considering the power consumption therefore allows the control unit 46 for example to determine whether the connected PD comprise a simple logic unit that can decode encoded data. In this case the encoded data can be sent to all of the PDs with predetermined power consumption, to a specific one of the PDs or to a specific group of PDs, comprising two or more PDs. The destination of the data can also be encoded in a characteristic of one or more data packets. As the system 100 only comprises a limited number of devices, only a limited amount of data is needed for uniquely identifying each of the devices of the system 100. Hence the destination can be easily encoded in a characteristic of one or more data packets.

[0110] In a fourth operation mode the system 100 is used for remote control and status check. For example in a situation when a user has left the room in which the system 100 is arranged and is not sure whether the lighting device 26 has been deactivated he can send a request for a status update to the BMS 22. The request can for example be send wirelessly via a mobile phone connection. The BMS 22 will then request the status update from the control unit 46 of the PSE 24 via Ethernet Protocol. The system 100 uses a simpler protocol for the communication to the lighting device 26, such that cost and power consumption is reduced, i.e. the simple data transmission protocol. Therefore the simple logic unit 34 encodes the status request in a characteristic of one or more data packets which are provided to the lighting device 26. The simple logic unit of the lighting device 26 decodes the encoded data comprising the status request and encodes the reply to the status request, e.g., the status of the lighting device 26 as being activated or deactivated. The encoded data with the reply to the status request is transmitted to the control unit 46 which forwards it to the simple logic unit 34 for decoding and then transmits the reply to the BMS 22 which finally informs the user about the status via the mobile phone connection, e.g., by sending an e-mail. The user can then decide whether he wants to transmit control data comprising a command for activating or deactivating the lighting device 26 according to the first operation mode.

[0111] In some of the PD arrangements two data processing devices 10 are arranged in a linear daisy chain. Hence the second data processing device 10 arranged subsequently to a first data processing device 10 can allow for further local control for the PDs arranged subsequently in the chain.

[0112] In one embodiment of the system the data processing unit of the data processing device can be configured to increase the control parameters of the central data (not shown).

[0113] FIG. 5 shows schematically and exemplarily a fourth embodiment of the data processing device 10 in a fourth embodiment of the power over Ethernet system 100. The data processing device 10 is daisy chained between PSE 24 and lighting device 26.

[0114] The data processing device 10 comprises a data communicating unit 12, a data processing unit 14, and a local PD in form of a rotary dimmer 16. The data communicating unit 12 comprises ports 18 and 20 for establishing Ethernet connections to the PSE 24 and the lighting device 26 via cables 30 and 32. The data processing unit 14 comprises a simple logic unit in form of a simple timer based switch 34. The simple timer based switch 34 comprises a timer 50 and a simple switch 52.

[0115] The PSE 24 transmits central data encoded in a characteristic of one or more data packets, in particular in a number of data packets per time interval via cable 30 to the lighting device 26. This central data is intercepted by port 18 of data communicating unit 12. The central data provides a start signal 54 for timer 50. Local data in form of user input via the rotary dimmer 16 is provided to the timer 50 as a stop signal 56. The timer 50 generates a pulse width modulated signal based on the central data and local data.

[0116] The switch 52 is opened and closed based on the pulse width modulated signal. A higher value provided by the rotary dimmer 16 leads to a longer relative time fraction in which the switch 52 is closed and therefore a longer time in which data packets can be transmitted from the PSE 24 to the lighting device 26 via switch 52. Hence a higher brightness value provided by the rotary dimmer 16 leads to more data packets reaching the lighting device 26 and therefore to a higher brightness.

[0117] This embodiment of the data processing device 10 requires only limited Ethernet functionality, in particular it does not require to be able to fully decode Ethernet data packets. In this case the data processing unit 14 can process the intercepted central data in dependence of the local data by reducing the number of data packets. Therefore the simple timer based switch 34 is sufficient. This allows for reduced power consumption and lower system complexity.

[0118] FIG. 6A, FIG. 6B and FIG. 6C show central data 58, local data 60, and processed data 62 encoded in a characteristic of data packets 64 in graphs with voltage V on the vertical axis and time t on the horizontal axis. This embodiment regards encoded control data for controlling the brightness of a lamp of a lighting device 26 as presented in FIG. 5.

[0119] FIG. 6A shows the central data 58 encoded in a number of data packets 64. The central data 58 comprises 7 data packets in a time interval 66.

[0120] FIG. 6B shows the local data 60 encoded in a duration 68 of a data packet 64. The local data in this embodiment is used for controlling the simple switch 52 according to the embodiment of the data processing device 10 as presented in FIG. 5. Hence the simple switch 52 is only closed during the duration 68 of the signal representing the local data. Therefore when the switch 52 is opened the 7th data packet of the central data is not transmitted via the switch 52 to the lighting device 26. The processed data 62 therefore only comprises 6 data packets in the time interval 66 (see FIG. 6C). The switching may not be perfectly synchronized such that only part of a data packet 64 is transmitted. In this case this may lead to a quantization error. The error can be reduced by averaging over several time intervals or increasing the number of data packets, such that a stable light output of the lighting device 26 can be achieved.

[0121] In other embodiments the duration of the data packet can be used as control parameter for controlling the lighting device 26. For such cases it is noted that the Ethernet standards define a minimal and maximal data packet length, which including the preamble ranges typically between 72 to 1526 byte. Considering a predetermined network speed the length translates into a predetermined duration 68 of the data packet 64.

[0122] In another embodiment the number of data packets can also be counted in the data processing unit 14 (not shown). Therefore a simple logic unit can be part of the data processing unit 14 that detects the presence of a differential voltage for a duration of the minimum packet length. Based on the differential voltage start and end of the data packet can be detected. Therefore the start of the data packet is detected via presence of voltage at a RX line using a simple voltage comparator. The start signal is fed to a digital counter, which in this embodiment is a simple and low cost C. In other embodiments simple logic ICs or CMOS decade counters can be used. The low cost C can run a program performing a method such as the ones presented in FIG. 9 and FIG. 10 in order to control the switch 52, i.e., open and close the switch 52.

[0123] FIG. 6C shows the processed data 62 encoded in a number of data packets. The processed data 62 shown in the graph is encoded in data packets with predetermined duration. The data packets 64 are counted by a counter in the lighting device 26, which is periodically reset by a timer in time intervals 66. Hence the counter counts 6 data packets per time interval 66. The time interval 66 is 100 ms in this embodiment, but can also be any other reasonable time interval, such as 10 ms, 25 ms, 50 ms, 200 ms, or longer time intervals. In this embodiment 10 data packets in 100 ms correspond to a brightness value of 100% while 0 data packets correspond to a brightness value of 0% and each data packet corresponds to a brightness adjustment of 10%, such that 6 data packets correspond to a brightness of 60%.

[0124] In another embodiment the number of received data packets 64 per time interval 66 can be averaged for several time intervals 66 in order to improve the resolution. Alternatively the resolution can be improved by increasing the number of data packets 64 per time interval 66.

[0125] In this embodiment the data packets 64 comprise only dummy data. Alternatively the data packets 64 can also comprise information. This information contained in the data packets 64 does not need to be processed by the lighting device and can for example only be processed by the control unit of the power over Ethernet system. Alternatively also the lighting device 64 can process the information stored in the data packets.

[0126] FIG. 7A, FIG. 7B and FIG. 7C show central data 58, local data 60, and processed data 62 in graphs with voltage V on the vertical axis and time t on the horizontal axis. The central data 58 is stored in the data packet 64. The local data 60 is encoded in a duration 68 of the data packet 64. Therefore the processed data comprises information encoded in the duration 68 of the data packet 64 as well as stored in the data packet 64, which allows encoding multiple control parameters, such as CCT and brightness. This embodiment regards encoded control data for controlling CCT and brightness of a LED of a lighting device 26 as presented in FIG. 5. The brightness is encoded in the local data 60 while CCT is encoded in the information stored in the data packet 64 of the central data 58. In other embodiments local data 60 can also be used to control for example both CCT and brightness.

[0127] FIG. 7A shows diagrammatically and exemplarily a simplified structure of an Ethernet data packet 64. The data packet 64 comprises an Ethernet frame that is used to store information for data transmission using the Ethernet protocol. The data packet 64 has a header 70 comprising a preamble, a start frame delimiter (SFD), a destination MAC address, a source MAC address, and an Ethertype. The data packet 64 furthermore has the data stored as payload 72, and a data fill field 74 comprising dummy data. The data packet 64 furthermore has a frame check sequence (FCS) 76.

[0128] The preamble consists of a 56-bit pattern of alternating 1 and 0 bits providing bit-level synchronization to allow devices connected via Ethernet connection to synchronize. The SFD marks a new incoming frame.

[0129] The destination MAC address is a unique address of a device that is meant to receive the data packet. The source MAC address is a unique address of a device which is the source of the data packet.

[0130] The Ethertype either defines the size of the payload 72 of the data packet 64 or it indicates that the data packet 64 is used as an Ethertype to indicate which protocol is encapsulated in the payload 72 of the data packet 64.

[0131] The payload 72 comprises the information to be transmitted from the source to the destination, e.g., data such as control data comprising a command. In this embodiment the payload 72 comprises CCT control data for controlling the CCT.

[0132] The data fill field 74 is used in order to add dummy data if the length of the data packet is below a minimal length. In this embodiment additional dummy data is filled in order to control the length and therefore duration of the data packets 64.

[0133] The FCS 76 is used in order to determine whether data transmitted in the data packet 64 is corrupted.

[0134] In contrast to the simple data transmission protocol the Ethernet protocol requires decoding the Ethernet data packet which inter alia requires decoding the MAC. This requires complex C or P. The simple data transmission protocol can be performed by simple logic units.

[0135] In this embodiment, however, a part of the information of the central data 58 is stored in the payload 72. Therefore the lighting device 26 comprises a complex C that is able to decode the MAC.

[0136] FIG. 7B shows the local data 60 encoded in a duration 68 of the data packet 64. The duration 68 of data packets 64 can vary. Therefore data can be encoded in the duration of the data packets 64. The data packet 64 in FIG. 7A has a longer duration than the data packet 64 in FIG. 7B. The duration 68 in this embodiment is associated with a brightness of lighting device 26, such that a shorter duration leads to lower brightness and longer duration leads to higher brightness. In other embodiments the duration of the data packet can also be associated with any other data, such as control data, status data, or configuration data.

[0137] FIG. 7C shows processed data 62. The processed data 62 is generated based on the central data 58 and the local data 60. In this embodiment the data processing device has a toggling logic unit (not shown), which allows some data packets 64 of the central data 58 to pass through the data processing device without being processed, i.e., the local data 60 is generated in such a way that the central data 58 is not modified. Based on the full length data packets 64 the validity of the data can be verified using the FCS 76. Furthermore processed data 62 comprises shortened data packets based on the local data 60 that allow deriving the information of the local data 60 at the lighting device 26, e.g., the user input for the brightness setting.

[0138] FIG. 8 shows schematically and exemplarily a fifth embodiment of the data processing device 10 in a fifth embodiment of the power over Ethernet system 100. The fifth and fourth embodiments of the data processing device are similar. The only difference is that the data processing device 10 does not comprise ports. Instead the data communicating unit of the data processing device 10 is an Ethernet connection in form of a cable 12 with two 8 position 8 contact (8P8C) connectors at each end of the cable 12 for establishing a connection with a port 78 of PSE 24 and port 80 of lighting device 26. Hence the data processing device 10 in this embodiment is integrated in a cable. Any other suitable cable can be used for integrating the data processing device. Hence also other connectors can be arranged at the end of the cable.

[0139] FIG. 9 shows a first embodiment of a method for processing data in a power over Ethernet system. In step 200 central data transmitted from a PSE to a PD is intercepted. In step 210 local data is received from a local PD. The local data comprises user input data, sensing data, or user input data and sensing data. In step 220 the intercepted central data is processed in dependence of the local data. The processed data is transmitted to the PD in step 230. The steps 200 and 210 can also be interchanged.

[0140] The data, i.e., central data, local data, and processed data in this embodiment is encoded in a characteristic of one or more data packets. In particular the data is encoded in a number of data packets per time interval. In other embodiments the data can for example also be encoded in data packet length, data packet duration, number of data packets in a predetermined time interval, and/or sequence of data packets. In yet other embodiments the data can be encoded based on the Ethernet protocol, xClip protocol or any other protocol.

[0141] FIG. 10 shows a second embodiment of a method for processing data in a power over Ethernet system. The data is encoded in a number of data packets in a predetermined time interval, in this case 100 ms. In step 300 central data in form of control data comprising a command for controlling a brightness of a lighting device that is transmitted from a PSE to the lighting device is intercepted by capturing and counting data packets. In step 310 local data in form of brightness control values for the lighting device encoded in a number of data packets is received from a user interface device in form of a potentiometer. In step 320 the number of data packets of the central data is compared to the number of data packets of the local data. Furthermore processed data is generated in step 330 by generating a pulse width modulated signal that controls opening and closing of a simple switch. The switch is arranged in the line between the PSE and the lighting device. The pulse width modulated signal is transmitted to the simple switch for closing or opening it based on the comparison result. Therefore the number of data packets of the central data is reduced if the central data is transmitted along the line with the controlled simple switch in an open state. In a closed state the simple switch allows transmission of the data packets. Therefore the processed data is generated in step 330 by reducing the number of data packets of the central data transmitted to the lighting device. In step 340 the processed data is transmitted to the lighting device. The steps 300 and 310 can also be interchanged.

[0142] The embodiments of the method can be contained in a computer program comprising program code means. The program code means can cause a processor to carry out the embodiment of the method when the computer program is run on the processor.

[0143] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. For example, it is possible to operate the invention in an embodiment wherein a control system, in particular a remote control system, is used to control lighting devices in an Ethernet System. This allows to use a simple pulse width modulated output to manipulate an Ethernet data stream instead of adding full Ethernet capability to the control system.

[0144] Furthermore it is possible to operate the invention in an embodiment wherein data security is an important aspect. By using the method according to any embodiment of the invention, a second control system, in particular remote control system, can influence the data in a first control system without being able to actually receive the data. This allows to shield data comprising sensitive information and/or secret information shared over the first network such as addressing schemes, grouping rules, or any other sensitive or secret information shared over the first network, from the second control system.

[0145] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0146] In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality.

[0147] A single unit, processor, or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0148] Operations like intercepting data, receiving data, transmitting data, processing data, receiving encoded data, transmitting encoded data, encoding data, decoding data, performing a function based on the data, et cetera performed by one or several units or devices can be performed by any other number of units or devices. These operations and/or the control of the data processing device, PD, PSE, BMS, or power over Ethernet system can be implemented as program code means of a computer program and/or as dedicated hardware.

[0149] A computer program may be stored/distributed on a suitable medium, such as an optical storage medium, or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet, Ethernet, or other wired or wireless telecommunication systems.

[0150] Any reference signs in the claims should not be construed as limiting the scope.

[0151] In summary the present invention relates to a data processing device for a power over Ethernet system. The data processing device comprises a data communicating unit and a data processing unit. The data communicating unit is configured for establishing a first connection to a power sourcing equipment and a second connection to a powered device and for intercepting central data transmitted from the power sourcing equipment to the powered device. The data processing unit is configured to process the intercepted central data in dependence of local data received from a local powered device. The local data comprises user input data, sensing data, or user input data and sensing data. The data communicating unit is furthermore configured for transmitting the processed data to the powered device. Hence local data can influence central data for improving local control.