Daisy-chained master-slave communication system and its operating method

Abstract

The present invention relates to a daisy-chained master-slave communication system and a method of operation thereof, the system including a master and a concatenation of N slaves linked in a chain, the master being connected to each of the N slaves by a communication line, the system being configured to use the communication lines for serial data communication from the master to the N slaves, the nth slave being connected to the (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N, the master including a communication port connected to a first slave of the N slaves by a first chain line, the system being configured to use the chain line for serial data communication from the slaves to the communication port of the master.

Description

[Technical field]

[0001] The present invention relates to a daisy-chained master-slave communication system including a master and a concatenation of N slaves linked in a chain. Furthermore, the present invention relates to a method of communicating data between the concatenation of N slaves arranged in a daisy chain and interconnected by chain links, and a master connected to each of the N slaves by a communication line. Furthermore, the present invention relates to a master device of the daisy-chained master-slave communication system. Furthermore, the present invention relates to an apparatus including the daisy-chained master-slave communication system. Furthermore, the present invention relates to a battery system comprising a plurality of battery cells. [Background technology]

[0002] In various applications, it may be necessary to monitor and / or control multiple units of a system or device. The units may be, for example, electrical components. Some exemplary applications are fuel cells, battery cells, photovoltaic cells, window actuators, mirror actuators, tire pressure monitors, distributed sensor systems, lighting systems, etc. In these applications, individual monitors and / or actuators, which may be referred to as slaves, are linked via a serial bus for data transfer to a master control unit. Each monitor and / or actuator node on the bus may be linked to a physical location (e.g., front / rear, left / right tire, location in the battery, etc.), and it may be important to know which data is coming from which location, for example for diagnostics.

[0003] In some cases, this can be accomplished by identifying each node circuit with a unique address and keeping a record of its location before installation. This can create production and logistics challenges because every node is different and each node must be mounted in the proper location or require individual commissioning of the nodes. For example, modbus nodes over RS-485 (also known as TIA-485(-A) or EIA-485) use such an approach. RS-485 is a standard that defines the electrical characteristics of drivers and receivers used in serial communication systems.

[0004] Another, more efficient, known method involves extra-wire daisy-chaining, where an extra wire is added that is used to allow the nodes to obtain location information after installation and during the initial boot process. This method is efficient, but requires extra cabling that is not used during normal operation. For example, the LIN bus uses this technique to identify physical location.

[0005] For example, if full-duplex communication is desired or required due to a relatively large amount of data received by the master, additional communication wires may be arranged, i.e., a first communication wire for enabling serial data communication between the master and the slave in a first direction (e.g., from the master to the slave) and a second communication wire for enabling serial data communication between the master and the slave in a second direction opposite to the first direction (e.g., from the slave to the master). However, such techniques implemented in the art in various applications have significant drawbacks. In some cases, an additional communication port needs to be provided for each slave. Moreover, incorporating such additional wiring may be cumbersome and not feasible, especially for systems with a large number of slaves (e.g., a battery system with a relatively large number of battery cells coupled to the slaves). Moreover, such additional wiring to the slaves may also result in a higher risk of failure.

[0006] In a half-duplex daisy-chained master-slave communication system with one communication line, for example, a first slave transmits data to the master, which must first wait until the data from the first slave is received, and then, when the communication line becomes available, the second slave can transmit data to the master. Data transfers from the slaves are done one at a time, i.e., the next slave must wait until the previously queried slave returns data first, before it can transmit data to the master. Such a configuration with one communication line may be overly restrictive and inefficient, especially when more slaves are deployed in the daisy-chained master-slave communication system.

[0007] There is a great need to provide a master-slave communication system that can provide simultaneous two-way (see full duplex) communication between a master and a slave in a cost-effective and robust manner. Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present invention to provide a method and system which avoids at least one of the above mentioned drawbacks.

[0009] Additionally or alternatively, it is an object of the present invention to improve the design of master-slave communication systems.

[0010] Additionally or alternatively, it is an object of the present invention to provide an improved method of communicating data between a master and a slave in a master-slave communication system. [Means for solving the problem]

[0011] Therefore, the present invention provides a daisy-chained master-slave communication system including a master and a concatenation of N slaves linked in a chain, wherein the master is connected to each of the N slaves by a communication line, the system is configured to use the communication line for serial data communication from the master to the N slaves, the nth slave is connected to the (n+1)th slave by a chain line, n is an integer greater than or equal to 1 and less than N, the master includes a communication port connected to a first slave of the N slaves by a first chain line, and the system is configured to use the chain line for serial data communication from the slave to the communication port of the master.

[0012] The first chain line usable as a serial communication line allows a cost-effective and robust way of realizing simultaneous bidirectional communication between the master and the slaves. The slaves are arranged in a daisy chain, and after configuration, the chain lines available for configuration (see address assignment) can be effectively used for serial data transfer between the slave and the master in addition to the communication lines providing direct data coupling between the master and the slaves. Advantageously, the system can be used for simultaneous bidirectional communication between the master and N slaves with limited additional cabling. In practical situations, the first chain line can have a limited impact on the design complexity. Thus, it can be prevented that additional communication lines providing direct coupling between the master and N slaves must be arranged to provide simultaneous bidirectional communication between the master and the N slaves.

[0013] The system according to the present disclosure provides a configuration that can provide significantly higher bandwidth. The cables can be shorter, resulting in less parasitic capacitance, which allows for higher bit rates. Furthermore, each transmitter only needs to drive one receiver, allowing even higher bit rates. The data lines do not need to switch direction, and therefore the resulting delays.

[0014] Optionally, the chain lines are used for configuration and / or address assignment of the slaves, which may relate to an initial configuration and / or address assignment or to a further (re)configuration and / or address assignment.

[0015] Optionally, each slave has at least two ports.

[0016] Optionally, each slave includes at least a first port and a second port, the second port of the n-th slave being connected to the first port of the (n+1)-th slave. Thus, the slaves are connected in a chain by a chain line connecting the second port of one slave to the first port of the subsequent slave. The last slave in the chain cannot be connected to a subsequent slave. Thus, its second port may be connected to ground. Additionally or alternatively, the second port of the last slave may be connectable to the master. In this way, the direction of configuration (see configuration mode) and / or communication (see communication mode) can be easily adapted. For communication, the chain line may be a communication line. The ports of the master connected to said chain line may be configured to enable data communication. The first slave is connected to the master via a first chain line connecting the communication port of the master to the first port of the first slave.

[0017] In some examples, each slave includes a first port (see downstream port) connectable to a downstream (adjacent / nearby) slave and a second port (see upstream port) connectable to an upstream (adjacent / nearby) slave. The first port of the first slave may be connectable to a communication port of the master via a first chain line. The second port of the last slave in the daisy-chain configuration may be connectable to ground or to the master. Additionally or alternatively, each slave has a logic unit operable to determine if an upstream device is not connected to the upstream port. In some examples, the upstream port receives an address allocation command from the upstream device, the address allocation command including a first device address. A slave directly connected to the master may be considered as the first slave and may be assigned the first address. The downstream port may send an (updated) address allocation command to the downstream device.

[0018] The design of the system can be greatly simplified by connecting the second port of the last slave in the daisy-chain configuration to the master by a chain line. In such a case, optionally, the communication lines providing data communication between the master and each slave can be omitted. By looping the chain lines, two-way communication (bidirectional) communication can be obtained. The system can easily operate in full-duplex mode with significantly less wiring.

[0019] Full duplex communication can be achieved without the need for dedicated communication lines connecting each slave to the master. This can be achieved by providing a communication line (see last chain line) between the last slave and the master. A second communication port on the master (to which the last slave is connected by the last chain line) allows a communication line in the reverse direction to be obtained.

[0020] Optionally, the upstream port is connected to an upstream device (e.g., a slave) via a single wire, and the downstream port is connected to a downstream device (e.g., a slave) via a single wire. For example, the downstream port of the first slave may also be connected to the master (the downstream device of the first slave).

[0021] Optionally, each slave has a dedicated port connected to the communication line.

[0022] Between each successive slave, a chain line may be placed connecting all slaves to form a slave chain. A first slave is connected to a communication port of the master via a first chain line. In some cases, the first slave can be modified, for example to change the direction of configuration and / or the direction of communication.

[0023] Optionally, the communication port is a serial data port, and the chain line forms a serial communication link between the N slaves and the master for transferring sensor and / or status data of one or more of the N slaves to the master.

[0024] The communication lines may be configured to allow bidirectional communication. However, the communication lines may not allow simultaneous bidirectional communication. In such a case, in a certain period of time, the master may send data (e.g., request / query messages) to N slaves, or the slaves may send data back by the same communication lines. Instead of using the communication lines in half-duplex mode (bidirectional, but not simultaneously in both directions), the system according to the invention is configured to allow additional serial communication of data by the chain lines. In this way, full-duplex communication can be realized in an advantageous manner.

[0025] Optionally, the master is configured to output, process and / or transmit information related to the received data from one or more slaves. In some cases, the data is pre-processed before outputting and / or transmitting information related to the received data from one or more slaves.

[0026] Optionally, the system is configured to enable full-duplex communication between the master and the N slaves, the system is configured to use a communication line for unidirectional communication from the master to one or more of the N slaves, and the system is configured to use a chain line for unidirectional communication from one or more of the N slaves to the master and / or vice versa.

[0027] In some cases, a large amount of data is collected by the master from N slaves and / or a large number of slaves are deployed in the system, thereby making it highly desirable to use the system in full duplex instead of performing half duplex communication.

[0028] Optionally, the system is configured to be switchable between a configuration mode in which address assignment for daisy-chain communication is performed using the chain lines (e.g., the chain lines can be used as address lines) and a communication mode in which master-slave data communication is performed. In the communication mode, simultaneous bidirectional communication (see full-duplex communication) between master and slave can be realized in an advantageous manner.

[0029] Optionally, the master is configured to selectively configure (eg, change the logic state of) the first data port of the first slave in a configuration process / mode.

[0030] Optionally, the master includes control circuitry.The system is selectively operable in a configuration mode and a communication mode.

[0031] Optionally, in the configuration mode, the master is configured to enable the output of its communication port to be switched between two logical states (e.g., "0"-"1", "low"-"high"). The communication port is connected to the first port of the first slave via a first chain line, so that the state of the first port can be easily switched during configuration. In the configuration mode, address distribution may be performed. Information regarding the (physical) location of the slaves and / or the devices associated with those slaves (e.g., sensors and actuators) can be determined during the configuration process. In the communication mode, the master's communication port can be used for serial data communication (e.g., receiving serial data from chained slaves).

[0032] In some cases, all slaves are queried to send their data (if possible) to the master. For example, in a battery system application, data related to each monitored battery cell (e.g., temperature, voltage, etc.) can be transferred from the slaves to the master. The communication process can begin with each slave sending its information downstream.

[0033] The chain lines arranged between the slaves can be used as configuration wires when the system operates in a configuration mode. However, these chain lines can also be used as communication wires when the system operates in a communication mode. Serial data from the slaves can be communicated to the master via a first chain line that provides a serial data communication connection between the first slave and the master.

[0034] A slave may be configured to receive data from an upstream neighboring slave and transmit that data to a downstream neighboring slave. This process may be repeated until all queried slaves have transmitted their data to the master.

[0035] Optionally, each of the N slaves is configured to forward the entire set of data signals received from a preceding slave in the chain to another slave in the chain until the set of data signals reaches the master via the chain lines.

[0036] In some examples, a slave is configured such that if it has no data to send to the master, it is passed on data from the next slave (i.e., upstream). For example, if a first slave has no data to send to the master, it may pass on data from the second slave, and so on. For example, if a third slave has to send data to the master, the data may be transmitted via a first port of the third slave, which is then received by a second port of the second slave, which may then pass on the data to the first slave via its first port, which is in communication with the second port of the first slave. The serial data received at the second port of the first slave may then be transmitted to the master via the first port of the first slave. In this way, data from the third slave may be received by the master. However, in the meantime, the master may communicate with the slave via the communication line and transmit data to the slave. In this way, full-duplex communication may be achieved in an advantageous manner.

[0037] Optionally, each slave includes a memory module.

[0038] Optionally, each of the N slaves is configured to transmit their data to downstream neighboring slaves in the event of a broadcast request sent to the slave by the master, and the data is buffered and transmitted to the downstream neighboring slaves as soon as the slave finishes its own data transmission.

[0039] For example, a first slave may transmit its data to the master by a first port connected to the master's communication port via a first chain line. A second slave may be configured to wait, and when the first slave finishes, the second slave may pass its data to the first slave, which can then pass the data to the master. The master may be configured to first receive data from the first slave, then from the second slave, etc. Thus, the data of successive slaves is received at the master's communication port in the correct order.

[0040] Optionally, at least one of the set of N slaves is configured to process the received data from the upstream slave before forwarding the data to the downstream slave. Optionally, each slave is configured to perform such processing. In some examples, a communication driver is used to perform the processing. Processing may involve, for example, reducing / mitigating noise, jitter, and / or distortion in the received data and / or reconstructing the data. Various signal processing and / or modulation techniques may be used.

[0041] Advantageously, in this way it is possible to prevent small distortions in the signal from building up in each slave, and therefore to prevent distortions from building up downstream using long chains of slaves.

[0042] Optionally, each of the N slaves is configured, in the event of a broadcast request sent by the master to the slave, to transmit their data to downstream neighboring slaves, and data is passed directly from one slave to another until the data sent by all slaves is received by the master.

[0043] All messages of a slave may be initiated by the master. A slave may respond to a given message identifier. Since all communication is initiated by the master, it may not be necessary to implement collision detection.

[0044] For example, all slaves may be configured to forward their data directly to downstream neighbors / adjacent slaves, allowing data from successive slaves to arrive at the master's communication port in the correct order.

[0045] Optionally, the system has a pre-configured first communication path from the master to all slaves, and a pre-configured second communication path from the chained slaves to the master.

[0046] Optionally, the master is configured to receive the data packages in the order in which the slaves are connected to each other in the daisy chain, and the master is configured to determine the positions of the slaves in the daisy chain based on said order.

[0047] The system may be configured to allow bidirectional data communication between the master and the slaves. At least the master may be configured to instruct the slaves to take some action, providing synchronization between the slaves when they measure, actuate, or communicate data. According to the system of the present disclosure, it is possible to build a full-duplex system. Upon input of the first slave (i.e., the first port) to the master, the usual configuration procedure can be performed. Once the configuration is complete, the daisy-chain wires (i.e., the chain lines) are used for communication towards the master. This can be done, for example, by reconfiguring the I / O pins of the slave to UART pins.

[0048] When slave ports (e.g., pins), i.e., the first and second ports, are configured for communication (normal operation), they are set to receive data from the upstream neighboring port and transmit data to the downstream neighboring port in the direction of the master. Thus, for example, two UART pins (RX and TX) may not be connected point-to-point.

[0049] When a master requests data from slaves by issuing a broadcast request, all slaves transmit data to downstream neighboring slaves, where the data can optionally be buffered and transmitted as soon as the downstream slaves finish their own data transmissions.

[0050] A table for an exemplary system with four slaves is shown below.

[0051] [Table 1]

[0052] In the above example table, S1-S4 are the first to fourth slaves, D1-D4 are data packages from the first to fourth slaves, and MA is the master. TX represents a sending action, and RX represents a receiving action.

[0053] The data packages (D1-D4) are received by the master in the order in which the slaves are connected to each other (physical location is determined by the order of the cabling).

[0054] Optionally, the N slaves are associated with sensors and / or actuators.

[0055] In some examples, a slave is associated with one or more sensors and / or (condition) monitoring devices that, for example, monitor temperature, electrical values, etc. Additionally or alternatively, a slave may be associated with an actuator that receives data and may take one or more actions based on the received data (e.g., interior lighting in a vehicle).

[0056] In some examples, a slave is associated with both sensors and actuators: for example, in a battery system, a slave may be associated with one or more sensors that monitor sensor data (e.g., voltage, temperature, etc.) and one or more actuators (e.g., injecting balancing currents into battery cells).

[0057] Advantageously, the first and second ports of the slave are not only used in the configuration mode, but also in the communication mode for transferring serial data from the slave to the master and / or vice versa, thereby realizing simultaneous bidirectional communication between the master and the slave in a cost-effective and robust manner.

[0058] In some examples, data from a selected / queried slave is directed to the master through one or more chain lines. For example, if a third slave is queried to provide data to the master, the third slave can send data to the second slave through a chain line connecting a first port of the third slave to a second port of the second slave, and similarly, the second slave can send data to the first slave, which can send data to the master.

[0059] Optionally, each slave is associated with a sensor located in the battery cell.

[0060] In a battery system with multiple cells, it may be necessary to monitor one or more parameters of multiple cells. This may be done in a master-slave configuration, where at least one slave is associated with each of the cells to be monitored. For example, such a battery system may include more than 100 cells to be monitored. In such an example, there may be, for example, 100 slaves, each slave coupled to one battery cell. Setting up additional wires between the slaves and the master may be a difficult task, prone to, for example, errors, failures, etc. Furthermore, such additional wiring may result in a significantly more complex design and increase costs. The system according to the present disclosure may provide a cost-effective, effective, and reliable solution for obtaining simultaneous bidirectional communication (see full duplex) between a master and N slaves.

[0061] The importance of high bandwidth combined with a small number of wires, short wires, and automatic configuration can be understood by observing large-scale battery systems. Battery systems may consist of hundreds of cells, each of which may require some form of monitoring (see sensor data). In some cases, these batteries may occupy entire buildings, so large amounts of data need to be transmitted to a master over significant distances. If the monitoring circuitry is built into the battery cells, each additional wire requires proper hermetic sealing. The system according to the present disclosure can provide significant advantages when applied to battery systems. However, it will be understood that the system may also be used in a variety of other systems.

[0062] In some examples, the system has more than 20 slaves, preferably more than 40 slaves, and even more preferably more than 80 slaves.

[0063] Optionally, the N slaves are identical devices.

[0064] By using identical slaves, the manpower required to set up the system can be significantly reduced. The production process of the system can be simplified. Advantageously, the daisy-chain connection allows address assignment to be done after installation by a configuration step. Even if the system setup is changed (e.g., more slaves are added), address assignment can be easily done by the configuration process.

[0065] Optionally, the master is connected in parallel with each of the N slaves by communication lines, the parallel connections providing direct communication between the master and the N slaves.

[0066] A communication line may be a physical communication line configured to allow communication in one direction at a time. Thus, simultaneous two-way communication over the communication line may not be possible.

[0067] Optionally, the master is serially connected with the N slaves by chain lines, the serial connection providing indirect communication between the master and at least a subset of the N slaves.

[0068] If one of the slaves does not operate correctly, possibly no further data may be sent from said defective slave (e.g. output fault) and / or no further data may be received from the upstream neighboring slave. For example, if the third slave fails, the master may receive data only from the first and second slaves, and possibly from the third slave (e.g. if its first port is not faulty). In this way, it can be easily determined where the fault occurred (i.e. malfunction at the input (first port) of the third slave or at the output (second port) of the third slave). Since the location of the malfunction can be effectively identified, a robust diagnosis can be performed.

[0069] Optionally, an additional chain line may be provided that connects the communication port of the master to the last slave. The additional chain line may be connected to a second port of the last slave. In this way, the direction of the configuration can be selected at configuration time. For example, when starting from the first slave, it is possible to start from the last slave. This can be done by appropriately setting the second port of the last slave to a predefined state (for example, "0" / "low" or "1" / "high" according to the convention used at configuration time). This provides increased flexibility at configuration time. However, advantageously, this can also provide a more robust system. For example, when one of the slaves is defective (for example, broken), the location of the failure can be determined based on the data received from the master. However, if data can only be received in one direction from slave to master through the chain line, some data may be blocked by the defective slave. By providing an additional chain line connected to the last slave, it is also possible to receive data in the opposite direction (for example, bypassing the broken / defective slave). In this way, more data can be obtained even at the time of failure of one of the slaves.

[0070] Like the first chain line, the last chain line can be used to transfer serial data from the slave to the master. The first chain line and the last chain line can be connected to a communication port. In some examples, the first chain line and the last chain line are connected to the same or different communication ports of the master. However, it is also envisioned that the first chain line and the last chain line are connected to two different communication ports of the master.

[0071] When the first chain line and the last chain line are connected to the same communication port of the master, the system may include a collision prevention means configured to prevent data collision during data communication. In some examples, two slaves can be prevented from simultaneously transmitting data using the same line. This can be done in various ways (e.g., time slots, priority system, etc.). In some examples, data collision is prevented by a protocol layer.

[0072] It will be appreciated that multiple chain lines can provide a communication path between a master and multiple chained slaves. The daisy-chain lines can be used for serial data communication between the slaves and the master (see communication modes / processes). However, these daisy-chain lines can also be used for configuration of the slaves (see configuration modes / processes).

[0073] Optionally, the (re)configuration of the slave in the configuration mode is performed in response to a command communicated by the master over at least one of the communication line or the chain line.

[0074] Optionally, the master is configured to determine the total number of slaves connected to it. This may be done in a configuration mode / process. This may be the case, for example, of a modular system where slaves can be added and / or removed.

[0075] In the configuration mode, the master may be configured to first send a command to initialize the N slaves. In some examples, the system is configured such that the first slave may detect the state of the first port when the initialization command is sent by the master.

[0076] Once the configuration is complete, the system can be switched from the configuration mode to the communication mode, where the multiple chain lines are used as secondary communication lines. In this way, full-duplex communication between the master and the slaves can be achieved in a cost-effective and reliable manner. Advantageously, the system has a robust design. The chain lines can be effectively used in both the configuration and communication modes.

[0077] Thus, the system allows simultaneous two-way communication between the master and the slaves. The communication port of the master is connected to a first port of a first slave, which is chained to a second slave via a chain line arranged between the first and second slave. For example, if the system has more than two slaves, the second port of the second slave is connected to a first port of a third slave via a chain line arranged between the second and third slave, and so on.

[0078] Optionally, the system is configured to detect and / or identify a topology change, the topology change including at least one of an additional slave being added to the system, the removal (and / or malfunction) of a slave in the system, powering on a slave, or powering off a slave in the system.

[0079] According to one aspect, the present invention provides a daisy-chained master-slave communication system including a master and a concatenation of N slaves linked in a chain, where the nth slave is connected to the (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N, the master includes a first communication port connected to a first slave of the N slaves by a first chain line, the master includes a second communication port connected to a last slave of the N slaves by a last chain line, and the system is configured to use the chain lines for serial data communication between the slaves and the master.

[0080] Advantageously, such a system configuration allows full-duplex communication without the need for communication lines connecting each slave with the master. A final chain line connecting the last slave with the second communication port of the master allows for a significantly simpler design of the system. A more cost-effective system, requiring fewer wiring and / or wired connections between the slaves and the master, can thus be obtained.

[0081] The second communication port of the master (to which the last slave is connected by the last chain line) allows for a communication line in the reverse direction. The connection of the last slave to the second communication port of the master allows for serial data communication in the reverse direction. The chain line can be used for two-way communication between the master and the slaves.

[0082] According to one aspect, the present invention provides a method for communicating data between a concatenation of N slaves arranged in a daisy chain and interconnected by chain lines and a master, where the nth slave is connected to the (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N, the master having a first communication port connected to a first slave of the N slaves by a first chain line, the master having a second communication port connected to a last slave of the N slaves by a last chain line, and the system configured to use the chain lines for serial data communication between the slaves and the master.

[0083] According to an aspect, the present invention provides a master device of a daisy-chained master-slave communication system according to the present disclosure, wherein the master device includes at least two different communication ports, one port connectable to a communication line for transmitting serial data and another port connectable to a first chain line for receiving the serial data.

[0084] The master can enable full duplex connections with limited cabling. Daisy chain connections can be arranged to establish the physical location of the slaves.

[0085] According to one aspect, the present invention provides a method for communicating data between a concatenation of N slaves arranged in a daisy chain and interconnected by chain links, and a master connected to each of the N slaves by a communication line, wherein the nth slave is connected to the (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N, the master having a communication port connected to a first slave of the N slaves by a first chain line, the communication lines being used for serial data communication from the master to the N slaves, and the chain lines being used for serial data communication from the slaves to the communication port of the master.

[0086] Advantageously, the chain lines that can be used as configuration lines during configuration mode can be made usable as communication lines for transmitting and / or receiving serial data from the slave to the master (and / or vice versa).

[0087] The first chain line is connected to the communication port so that serial information can be received from the N slaves by the chain lines connecting the slaves to form a chain network arrangement. The communication port may be configured to receive continuous bit data. The master may be configured to process and / or store the data. However, the same communication port may also be used to change the logic state of the first port of the first slave (e.g., switching between "low" / "0" and "high" / "1"), for example during a configuration mode of the system.

[0088] Optionally, the communication process is initiated following the configuration process. During configuration, the master may be configured to set the appropriate state of the first port (e.g., a "0" / "low" state in the above example) via a first chain line providing a connection between the communication port and the first port of the first slave. Successive slaves in the chain can then be configured sequentially. Once configuration is complete, the communication port of the slave can be used to receive (or transmit) serial data. Advantageously, the master can receive serial data from N slaves by means of multiple chain lines linking the master and the slaves in the chain.

[0089] According to one aspect, the present invention provides an apparatus including a system according to the present invention.

[0090] According to one aspect, the present invention provides a battery system including a daisy-chained master-slave communication system according to the present invention.

[0091] According to one aspect, the present invention provides a method for addressing the physical location of a slave in a system.

[0092] Batteries with multiple cells typically require monitoring of relatively large amounts of data. The present invention provides an advantageous daisy-chained master-slave communication system that can operate in full-duplex mode (referring to simultaneous bidirectional communication between master and slave), which can efficiently handle data traffic from slave to master.

[0093] The master may periodically monitor sensor data associated with the battery cells. If one or more predetermined monitored parameters (e.g., cell voltage, temperature) are too high or too low, action may be taken to make the battery system safe. For example, the main contacts of the battery may be shut off as a countermeasure.

[0094] For battery applications, the system may include means (e.g., galvanic isolation) configured to prevent high voltages from being applied to the communication ports.

[0095] The systems and methods according to the present invention can be used in a variety of other applications, such as, for example, fuel cells, photovoltaic cells, window actuators, mirror actuators, tire pressure monitors, distributed sensor systems, lighting systems, and the like.

[0096] According to one aspect, the present invention relates to a method for configuring a master-slave communication system.

[0097] According to one aspect, the present invention relates to a vehicle detection system using a daisy-chained master-slave communication system, where at least one slave set can be connected to sensors used by the vehicle detection system.

[0098] The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The term "or" is intended to be inclusive and mean any or all of the listed items. Use of "including," "comprising," or "having," and variations thereof herein are intended to encompass the items listed thereafter and equivalents thereof, as well as additional items. The terms "connected" and "coupled" are not limited to physical or mechanical connections or couplings, but may include electrical connections or couplings, whether direct or indirect. Additionally, the terms "slave," "master," and "controller" may include either a single component or multiple components, which may be active and / or passive, connected (e.g., as one or more integrated circuit chips) or otherwise coupled to provide the described functionality.

[0099] It will be appreciated that in some cases, the communication lines providing a direct (data) connection between the master and each slave may be optional. For example, full-duplex communication can still be obtained by placing a chain line between the last slave and the master. In such advantageous cases, the wiring of the system can be greatly simplified while still providing full-duplex communication between the master and the slaves.

[0100] It will be understood that terms such as "upstream" and "downstream" may relate to the direction of data transfer. For example, data may be sent from an upstream unit to a downstream unit. Other conventions may also be used.

[0101] It will be appreciated that various methods can be used to assign (unique) device addresses to a set of slaves in the system. In configuration mode, the system can perform auto-discovery and / or auto-enumeration of serially interconnected slaves (in a daisy-chain arrangement). An address may be assigned to each slave. Each slave in the system can be discovered and each slave can be enumerated.

[0102] It will be appreciated that the communication port of the master and the first and second ports of the slave may be configured to receive / transmit data in the form of bits. In some examples, data may be transferred only if 8 bits (corresponding to one byte) are received. Various serial data communication configurations may be used.

[0103] Additionally, when a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it will be understood that it may be directly connected, attached, or coupled to the other element, or intervening elements may be present. In contrast, when a feature or element is referred to as being "directly connected," "directly attached," or "directly coupled" to another element, there are no intervening elements present. Although described or illustrated with respect to one embodiment, the features so described or illustrated may be applicable to other embodiments.

[0104] Although the terms "first", "second", "further", "additional", and "last" are used herein to describe various components, it will be understood that these components are not limited by these terms. These terms are used only to distinguish one component from another. Thus, a first component described herein may be given a different name without departing from the teachings of the present invention. Like numbers refer to like elements throughout this disclosure.

[0105] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, as used herein, it will be understood that the terms "comprises" and / or "comprising" specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0106] It will be understood that any of the aspects, features, and options described in terms of the system apply equally to the methods and described master devices, apparatuses including the system, and battery cells. It will also be apparent that any one or more of the above aspects, features, and options may be combined.

[0107] The invention will be further elucidated on the basis of the exemplary embodiments shown in the drawings, which are provided by way of non-limiting example. It should be noted that the figures are only schematic representations of embodiments of the invention, which are provided by way of non-limiting example. [Brief description of the drawings]

[0108] [Figure 1] 1 shows a schematic diagram of one embodiment of a system. [Diagram 2] 1 shows a schematic diagram of one embodiment of a system. [Diagram 3] 1 shows a schematic diagram of one embodiment of a system. [Figure 4] 1 shows a schematic diagram of one embodiment of a system. [Diagram 5] 1 shows a schematic diagram of one embodiment of a system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0109] FIG. 1 shows a schematic diagram of an embodiment of a daisy-chained master-slave communication system 1 including a master 3 and a concatenation of N slaves 5a-5N linked in a chain 7, where the master 3 is connected to each of the N slaves 5a-5N by a communication line 9. The system 1 is configured to use the communication line 9 for serial data communication from the master 3 to the N slaves 5a-5N. The nth slave is connected to the (n+1)th slave by a chain line 11, where n is an integer greater than or equal to 1 and less than N. The master 3 includes a communication port 13 connected to a first slave 5a of the N slaves by a first chain line 11a. The system 1 is configured to use the chain lines 11a, 11 for serial data communication from the slaves 5a-n to the communication port 13 of the master. In this example, the master has a further communication port 15 connected to the communication line 9.

[0110] A number of slaves N may be communicatively chained by a number of chain lines 11. Furthermore, a first chain line 11a provides a communication connection of the first slave to the master. A second chain line 11 connects the first slave 5a to a second slave 5b (e.g., a neighboring slave of the first slave), a third chain line 11 connects the second slave 5b to a third slave 5c (not shown), and so on for all N slaves.

[0111] The master 3 may comprise one or more processing units. In some examples, the master is connected to one or more other units or components, for example a control unit.

[0112] The system 1 may be configured such that the chain lines 11a, 11b are available as configuration lines. In the configuration mode of the system, a two-way configuration may be possible; for example, from the left outer slave (i.e. the first slave) to the right outer slave (i.e. the last slave N) or vice versa from the right outer slave to the left outer slave (not shown in this exemplary diagram). In the configuration mode, the master may determine the number of slaves in the network and their arrangement / configuration (see order in the chain) by assigning them unique addresses. This may happen, for example, in a similar way to local interconnect networks (LIN networks).

[0113] For example, the logic state of the first port 21a of the first slave 5a may be "0" / "low" or "1" / "high", while the logic states of the first ports 21a of the other slaves (even the second slave) may still be "1" / "high" or "0" / "low", respectively. The first port 21a of the n-th slave is coupled to the second port 21b of the (n-1)-th slave via the chain line 11. For example, initially, the first ports 21a of the slaves following the first slave 5a in the chain (e.g. the second slave 5b, the third slave 5c, etc.) have a logic state of "1" / "high", while the first port 21a of the first slave 5a has the opposite logic state of "0" / "low". In this way, it can be identified that the first slave 5a is indeed the first slave 5a in the chain of N slaves. The first slave 5a may then be configured, for example, as "SLAVE1" (see address assignment). The first slave 5a may then change the logic state at its second port from "1" / "high" to "0" / "low". When the master 3 then sends a command (for example a broadcast query), the first port 21a of the second slave is "0" / "low" (i.e. due to the change in the second port of the first slave) and the other slaves still have the "1" / "high" state at their second ports. Similarly, the second slave 5b may be configured, for example, as "SLAVE2" (see address assignment) and the second port 21b of the second slave 5b may change from the "1" / "high" logic state to the "0" / "low" state. The slaves may be configured in this way successively. This process may be repeated for other slaves in the chain of slaves until the configuration of N slaves is completed.

[0114] The slave may, for example, transmit measured values ​​(e.g., temperature, electrical quantity, voltage, etc.) to the master 3 for processing. This may be done in a communication mode that typically follows the configuration mode described above. In some examples, the master 3 may use data from the slave for processing, analysis, control, etc. Half-duplex communication between the master and the slave is often too restrictive (especially when the number of slaves is relatively large) since the master needs to request data from the slaves one by one and provide enough time for each slave to individually transmit data to the master. The system according to the present disclosure provides full-duplex communication in an advantageous manner.

[0115] Advantageously, in some cases, the slaves are configured to transfer data on the chain lines 11 (see: usable as "configuration lines" when the system is in configuration mode). For example, a slave may transfer data to a downstream neighboring slave, which in turn may transfer it to a further downstream neighboring slave, and so on until the data reaches the master. In this way, data from the slaves can be communicated to the master significantly more efficiently. In this way, a cost-effective system is achieved. Furthermore, the location of the slaves (e.g., physical positioning in the system) may also play an important role. A slave may, for example, be tied to a particular unit or member (e.g., a particular battery cell, sensor, actuator, etc.). By performing configuration, the slaves can be assigned a location (e.g., address, positioning). When data from the slaves is received in the correct order over the chain lines, information about the positioning of the slaves can be obtained.

[0116] For example, in case of a defect, it may be necessary to have information about the location of the slaves so that the defective device can be easily located and replaced. After replacement, the system can be reconfigured (see configuration mode) and then the system can be used in communication mode.

[0117] Typically, configuration is done at system initialization. For example, in one example where the system is used in a battery system, slaves can be linked to battery cells and at configuration time it can be determined which slave is linked to which battery cell (see location). For example, the first slave can be linked to the first battery cell, the second slave to the second battery cell, etc. In communication mode, the master can then simply query the slaves. For example, master 3 needs data from the third battery cell and can query the third slave.

[0118] FIG. 2 shows a schematic diagram of an embodiment of a daisy-chained master-slave communication system 1. In this example, four slaves 5a-5d are arranged in a chain configuration. The last slave 5d may be connected or connectable to the master 3 by a chain line 11x. This chain line 11x may be usable to select the direction of configuration (in configuration mode) and / or the direction of communication (in communication mode). More specifically, in this example, the direction of configuration may be from left to right using the first chain line 11a or from right to left using the chain line 11x. Similarly, the direction of communication through the chain line may be chosen in this way. In this example, the chain line 11x is connected to a communication port 19. Alternatively, in some examples, instead of two communication ports 13, 19, one communication port is used to supply the chain lines to the first slave and the last slave.

[0119] The system 1 may be usable in a configuration mode in which multiple slaves (N) can be assigned (unique) addresses, and in a communication mode in which serial data communication may occur between a master and slaves.

[0120] The chain line 11 can be configured to provide at least one interconnection between each pair of adjacent slaves in the daisy chain configuration. The slaves may have at least two data ports, a first data port 21a and a second data port 21b configured to communicate on the chain line. The first data port 21a and the second data port 21b may be serial data ports configured to enable a serial communication link.

[0121] 3 shows a schematic diagram of an embodiment of a daisy-chained master-slave communication system 1. The slaves are arranged in a daisy-chain configuration. In this example, a first slave 5a and a last slave 5d are connected to the communication port 13 of the master by a first chain line 11a. This provides a simple way to select the direction of configuration and / or the direction of communication.

[0122] The system provides an advantageous method of data communication between multiple slaves arranged in a daisy-chain configuration, and can achieve highly efficient full-duplex communication between the master and slaves with limited additional wiring.

[0123] When the first chain line and the last chain line are connected to the same communication port of the master, the system may include a collision prevention means configured to prevent data collision during data communication. In some examples, two slaves can be prevented from simultaneously transmitting data using the same line. This can be done in various ways (e.g., time slots, priority system, etc.). In some examples, data collision is prevented by a protocol layer.

[0124] FIG. 4 shows a schematic diagram of an embodiment of a daisy-chained master-slave communication system 1. The slaves 5a-5N are interconnected together in a daisy chain. A chain line 11 may be a communication link configured to couple the multiple slaves 5a-5N together. The chain line 11 may be disposed between a first data port and a second data port of the slaves. The multiple slaves 5a-5N are coupled to sensors and / or actuators 10a-10N, respectively. It will be appreciated that various alternative circuit arrangements may be used.

[0125] In some examples, the system 1 according to the present disclosure may be configured to provide communication between multiple components within a vehicle, and may effectively provide a cost-effective, high bandwidth communication network.

[0126] In some cases, the slaves are units built into the battery cells. In such cases, a low number of wires is highly desirable. Advantageously, the daisy-chained master-slave communication system according to the present disclosure provides a robust and cost-effective way to achieve simultaneous bidirectional communication (see full-duplex mode communication) between the master and the slaves.

[0127] The master and slaves may be microcontrollers. Various types of hardware can be used for the master and slaves. For example, the master and slaves may be microcontrollers. In some examples, the master and / or slaves are ASICs.

[0128] It will be appreciated that the system provides a cost-effective communications network capable of supporting remote applications within a vehicle network. For example, the system may be used for mechatronic nodes in distributed automotive applications. However, the system may also be applicable in other arrangements or systems, for example in industrial applications.

[0129] Figure 5 shows a schematic diagram of an embodiment of a daisy-chained master-slave communication system 1. The slaves are arranged in a daisy-chain configuration. In this example, the first slave 5a and the last slave 5N are connected to the first communication port 13 and the second communication port 15, 19 of the master, respectively. The chain lines 11a, 11, 11x provide a loop connection between the master and the slaves. This provides a simple way to select the direction of configuration and / or the direction of communication.

[0130] The system 1 shown in FIG. 5 provides a daisy-chained master-slave communication system including a master and a concatenation of N slaves linked in a chain, in which the nth slave is connected to the (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N, the master 3 includes a first communication port 13 connected to a first slave 5a of the N slaves by a first chain line 11a, the master 3 includes second communication ports 15, 19 connected to a last slave of the N slaves by a last chain line 11x, and the system 1 is configured to use the chain lines 11a, 11, 11x for serial data communication between the slaves 5a to N and the master 3.

[0131] In this example, data can be communicated from the last slave 5N to the previous slave 5N-1 and so on until all data from the slaves reaches the master via the first chain line 11a of the communication port 13 of the master 3. Thus, the slaves' data can reach the master from right to left in this exemplary diagram. However, the system is also configured to transmit data from the master to the slaves via further / second communication ports (15, 19). The slaves can transmit relevant data to other slaves in the chain of slaves. The data from the master to the slaves can be relayed by the slaves using the chain lines. In this way, full duplex communication can be realized in an advantageous manner without the need for additional communication lines connecting the master to each slave.

[0132] Advantageously, the chain line 11x connecting the last slave to the master can provide two-way configuration in configuration mode and two-way communication in communication mode. Using the chain line 11x for data communication as well provides great advantages for obtaining full duplex communication in a simple and cost-effective design. In some cases, the chain lines 11, 11x can be used for serial data communication from the master to the slaves, and the chain lines 11a, 11 can be used for serial data communication from the slaves to the master, and / or vice versa.

[0133] It will be understood that the method may include computer-implemented steps. All the steps mentioned above may be computer-implemented steps. The embodiments may include a computer apparatus in which the process is performed in a computer apparatus. The invention also applies to computer programs, in particular computer programs on or in a carrier adapted for carrying out the invention. The program may be in the form of source or object code, or in any other form suitable for use in carrying out the process according to the invention. The carrier may be any entity or device capable of carrying a program. For example, the carrier may comprise a storage medium, such as a ROM, e.g. a semiconductor ROM or a hard disk. Furthermore, the carrier may be a transmissible carrier, such as an electric or optical signal, which may be conveyed via an electric or optical cable, or by radio or other means, e.g. via the internet or the cloud.

[0134] Some embodiments may be implemented, for example, using a machine or tangible computer-readable medium or article that may store instructions or sets of instructions that, when executed by a machine, cause the machine to perform methods and / or operations in accordance with the embodiments.

[0135] Various embodiments may be implemented using hardware elements, software elements, or a combination of both. Examples of hardware elements may include a processor, a microprocessor, a circuit, an application specific integrated circuit (ASIC), a programmable logic device (PLD), a digital signal processor (DSP), a field programmable gate array (FPGA), a logic gate, a register, a semiconductor device, a chip, an integrated circuit, a chipset, etc. Examples of software may include a software component, a program, an application, a computer program, an application program, a system program, a machine program, an operating system software, a mobile app, a middleware, a firmware, a software module, a routine, a subroutine, a function, a computer implemented method, a procedure, a software interface, an application program interface (API), a method, an instruction set, a computing code, a computer code, etc.

[0136] The present invention is described herein with reference to specific example embodiments of the present invention. However, it will be apparent that various modifications, variations, substitutions, and changes can be made without departing from the essence of the present invention. For clarity and concise description, features are described herein as part of the same or separate embodiments, but it is understood that alternative embodiments having all or some combinations of the features described in these separate embodiments are also envisioned and fall within the framework of the present invention as outlined by the claims. Thus, the specification, drawings, and examples should be regarded in an illustrative rather than restrictive sense. The present invention is intended to embrace all alternatives, modifications, and variations that fall within the scope of the appended claims. Moreover, many of the described elements are functional entities that can be implemented as discrete or distributed components, or in conjunction with other components, in any suitable combination and location.

[0137] In the claims, reference signs placed between parentheses shall not be construed as limiting the scope of the claims. The word "comprising" does not exclude the presence of other features or steps than those listed in the claim. Furthermore, the words "a" and "an" shall not be construed as being limited to "only one" but are instead used to mean "at least one" and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. 1. A daisy-chained master-slave communication system comprising: a master; and a concatenation of N slaves linked in a chain; the master is connected to each of the N slaves by a communication line; the system is configured to use the communication line for unidirectional serial data communication from the master to the N slaves; an nth slave is connected to an (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N; the master includes a communication port connected to a first of the N slaves by a first chain line; the system is configured to use the chain line for unidirectional serial data communication from the slave to the communication port of the master, thereby enabling full duplex data communication between the master and the N slaves.

2. 2. The daisy-chained master-slave communication system of claim 1, wherein the communication port is a serial data port, and the chain line forms a serial communication link between the N slaves and the master for transferring sensor data of one or more of the N slaves to the master.

3. 3. A daisy-chained master-slave communication system according to claim 1 or 2, wherein each of the N slaves is configured to forward an entire set of data signals received from a preceding slave in the chain to another slave in the chain until the set of data signals reaches the master via chain lines.

4. 4. A daisy-chained master-slave communication system according to claim 1, wherein each of the N slaves is configured to transmit their data to downstream neighboring slaves in case of a broadcast request sent by the master to the slave, and the data is buffered and transmitted to downstream neighboring slaves as soon as the slave finishes its data transmission.

5. 5. A daisy-chained master-slave communication system according to claim 1, wherein each of the N slaves is configured to transmit their data to downstream neighbouring slaves in case of a broadcast request sent by the master to said slave, and the data is passed directly from one slave to another until the data sent by all the slaves is received by the master.

6. 6. A daisy-chained master-slave communication system according to claim 1, wherein the master is configured to receive data packages in the order in which the slaves are connected to each other in the daisy-chain, and the master is configured to determine the positions of the slaves in the daisy-chain based on the order.

7. A daisy-chained master-slave communication system according to any one of claims 1 to 6, wherein the N slaves are associated with sensors and / or actuators.

8. 8. A daisy-chained master-slave communication system according to claim 1, wherein the master is connected in parallel with each of the N slaves by the communication lines, the parallel connection providing direct communication between the master and the N slaves.

9. 9. A daisy-chained master-slave communication system according to claim 1, wherein the master is serially connected to the N slaves by the chain lines, the serial connection providing indirect communication between the master and at least a subset of the N slaves.

10. 1. A method of communicating data between a concatenation of N slaves arranged in a daisy chain and interconnected by chain links, and a master connected to each of the N slaves by a communication line, wherein an nth slave is connected to an (n+1)th slave by a chain line, n being an integer greater than or equal to 1 and less than N, the master having a communication port connected to a first of the N slaves by a first chain line, the communication lines being used for unidirectional serial data communication from the master to the N slaves, and the chain line being used for unidirectional serial data communication from the slaves to the communication port of the master, thereby enabling full duplex data communication between the master and the N slaves.

11. A battery system including the daisy-chain-connected master-slave communication system according to any one of claims 1 to 9.

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