Transmitting and receiving devices

Abstract

Invention details;

Description

Transmitting device and receiving device

[0001] The present disclosure relates to a transmitting device and a receiving device.

[0002] In a power storage device, communication using a Controller Area Network (CAN) protocol (hereinafter referred to as "CAN communication") is used between a battery module and a management device that manages a plurality of battery modules. For example, Patent Document 1 discloses that CAN communication is performed between a battery module mounted on a mobile object such as an electric vehicle and an ECU (Electric Control Unit) that controls various devices mounted on the mobile object.

[0003] In CAN communication, each data frame, which is the unit of data transmission and reception, is assigned an ID (identifier), which is a unique identifier for identifying the transmitting node, which is the source of the data, and the transmitted data is stored in a data field, which is a data storage area in the data frame. A transmitting node such as a battery module then transmits the data frame containing the transmitted data to all nodes, including the receiving node, which is the destination. Meanwhile, a receiving node such as a management device receives the data frame transmitted from the transmitting node based on the ID assigned to the transmitted data frame and obtains the transmitted data stored in the data field.

[0004] International Publication No. 2018 / 147046

[0005] In CAN communication, typically, only one data frame can be transmitted per transmission. That is, the number of frames and data size that can be handled per transmission / reception process are fixed. Therefore, when transmitting data larger than the size of the data field, it is necessary to transmit the data by using multiple frames with different IDs and performing the transmission process several times.

[0006] However, since there is a limit to the number of IDs that can be assigned to a data frame, there is also a limit to the number of frames and the size of data that can be transmitted and received between devices. Therefore, when transmitting data frames with a number of IDs that exceeds the maximum number of IDs, there is a risk that there will be a shortage of IDs and the data will not be able to be transmitted properly.

[0007] An object of the present disclosure is to provide a transmitting device and a receiving device that can appropriately transmit and receive data while suppressing a shortage of identifiers.

[0008] A transmitting device according to the present disclosure is a transmitting device that divides transmission data into multiple frames, stores the frames, and transmits the frames, and has a frame generation unit that assigns a common identifier to the multiple frames, divides data fields in the multiple frames that are different from the identifier storage section into a first area and a second area, and stores identification information that distinguishes the multiple frames from each other in the first area and the transmission data in the second area.

[0009] In addition, a receiving device according to the present disclosure is a receiving device that receives transmission data stored in multiple frames, and has a data combining unit that refers to data fields divided into a first area and a second area in the multiple frames that have been assigned a common identifier, and combines the transmission data stored in the second area according to identification information for the transmission data stored in the first area.

[0010] According to the present disclosure, data can be appropriately transmitted and received while preventing a shortage of identifiers.

[0011] FIG. 2 is a schematic diagram showing an example of the configuration of a power storage device according to the present embodiment; FIG. 3 is a functional block diagram showing an example of the configuration of the BMU of FIG. 1; FIG. 4 is a schematic diagram for explaining a data frame of a standard format in CAN communication; FIG. 5 is a schematic diagram for explaining information stored in a data field; FIG. 6 is a schematic diagram showing an example of information included in transmission data transmitted and received between a BMU and a BMS; FIG. 7 is a schematic diagram for explaining data stored in a conventional data field; and FIG. 8 is a schematic diagram for explaining data stored in a data field of the present embodiment.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiments. In addition, in each drawing, components with the same reference numerals are the same or equivalent, and this is common throughout the entire specification.

[0013] [Configuration of Power Storage Device 1] Fig. 1 is a schematic diagram showing an example of the configuration of a power storage device 1 according to this embodiment. The power storage device 1 stores power supplied from an external power source (not shown) and supplies the stored power to a power supply target (not shown). As shown in Fig. 1, the power storage device 1 includes a plurality of battery modules 10 and a BMU (Battery Management Unit) 20. The battery modules 10 and the BMU 20 are connected to a bus 2.

[0014] (Battery Module 10 ) The battery module 10 includes a secondary battery 11 and a BMS (Battery Management System) 12 .

[0015] The secondary battery 11 is composed of one or more secondary battery cells. When composed of multiple secondary battery cells, the respective secondary battery cells are connected in series. The secondary battery 11 is, for example, a nickel-metal hydride secondary battery. Note that the type of the secondary battery 11 is not limited to this example, and it may be a secondary battery other than a nickel-metal hydride secondary battery, such as a lithium-ion secondary battery. Furthermore, multiple secondary batteries 11 may be provided, and in this case, the multiple secondary batteries 11 are, for example, connected in series.

[0016] The BMS 12 controls and monitors the secondary battery 11 in the battery module 10. For example, the BMS 12 monitors the voltage and temperature of the secondary battery 11 based on the detection results of various sensors (not shown). The BMS 12 also monitors and controls cell balancing for multiple secondary battery cells based on the detection results.

[0017] Furthermore, the BMS 12 communicates with the BMU 20 via the bus 2 to exchange instruction information and battery information related to the secondary battery 11 or the battery module 10. The battery information is information related to a secondary battery such as the secondary battery 11 or the battery module 10. The instruction information is information including commands for obtaining battery information related to the secondary battery 11 or the battery module 10 from the BMS 12.

[0018] In this embodiment, CAN is used as the protocol for communication between the BMS 12 and the BMU 20. Details of CAN communication using the CAN protocol will be described later.

[0019] The BMS 12 includes a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), etc. (none of which are shown). The CPU reads a program corresponding to the processing content from the ROM, loads it into the RAM, and works with the loaded program to centrally control the operation of the battery module 10.

[0020] (BMU 20) The BMU 20 controls and manages the multiple battery modules 10. For example, the BMU 20 issues instructions such as power-on to each battery module 10 and instructions such as fine adjustment of cell balance between the battery modules 10. The BMU 20 also communicates with the BMS 12 of each battery module 10 via the bus 2 via CAN to exchange instruction information and battery information.

[0021] Furthermore, the BMU 20 monitors the current of each battery module 10 based on the detection results of a sensor (not shown), and monitors, for example, overcharging and overdischarging of each battery module 10. Furthermore, the BMU 20 calculates the remaining capacity of the secondary battery based on the battery information.

[0022] The BMU 20 includes a CPU, a ROM, a RAM, etc. (none of which are shown). The CPU reads out a program corresponding to the processing content from the ROM, loads it into the RAM, and performs centralized control of the operation of the power storage device 1 in cooperation with the loaded program.

[0023] Fig. 2 is a functional block diagram showing an example of the configuration of the BMU 20 in Fig. 1. Fig. 2 shows a processing unit for functions related to communication between the BMU 20 and the BMS 12, among the functions provided by the BMU 20. Note that the BMS 12 of each battery module 10 also has the same communication-related functions as the BMU 20 and has the configuration shown in Fig. 2. Here, the BMU 20 will be used as an example for explanation.

[0024] As shown in FIG. 2, the BMU 20 includes a data acquisition unit 21 , a data division unit 22 , a frame generation unit 23 , a transmission / reception unit 24 , and a data combination unit 25 .

[0025] The data acquisition unit 21 acquires data including instruction information or battery information as transmission data. Here, the instruction information or battery information included in the transmission data is classified by data type, and the transmission data transmitted and received in one transmission / reception process includes instruction information or battery information for one common data type.

[0026] The "data type" is a rough classification of the instruction information and battery information. For example, the instruction information and battery information include "voltage-related information" relating to voltage and "temperature-related information" relating to temperature, and this voltage-related information and temperature-related information correspond to the data type referred to here. Details of the data types included in the instruction information and battery information will be described later.

[0027] The data dividing unit 22 divides the transmission data acquired by the data acquiring unit 21 into pieces of predetermined size to generate divided data. Specifically, the data dividing unit 22 divides the transmission data into pieces of size that can be stored in a data field, which is a data storage area of ​​a data frame, which is a unit of data transmission and reception. The divided data is data obtained by dividing transmission data consisting of a common data type into pieces of data content.

[0028] The "data content" is a more detailed classification of the data classified by data type. For example, data classified as voltage-related information includes information indicating the current and maximum cell voltages of the secondary battery cells that make up the secondary battery 11, and these current and maximum cell voltages correspond to the data content.

[0029] The frame generation unit 23 stores identification information and divided data in the data field of the data frame. The identification information is information for identifying multiple data frames from each other. Details of the identification information will be described later. The frame generation unit 23 also assigns a common identifier, an ID, to multiple data frames corresponding to the number of divided data, and generates the data frame.

[0030] The transceiver 24 performs a transmission process to transmit data frames from the BMU 20 to other devices connected to the bus 2, and also performs a reception process to receive data frames from other devices connected to the bus 2. For example, the transceiver 24 transmits a data frame that stores data including instruction information for the BMS 12. The transceiver 24 also receives a data frame that stores data including battery information from the BMS 12.

[0031] When the data combining unit 25 receives multiple data frames from the BMS 12 via the transceiver 24, it combines the data included in each data frame based on the identification information to restore the transmission data sent from the BMS 12. Note that when multiple data frames are received, it is not necessary to combine them to restore the transmission data. In that case, the BMU 20 can simply receive the divided data included in each data frame as is.

[0032] [Regarding CAN Communication] In this embodiment, a description will be given of CAN communication used when exchanging data between the BMS 12 and the BMU 20. As described above, in this embodiment, CAN communication is used when exchanging information between the BMS 12 and the BMU 20. Here, using the standard format in CAN communication as an example, a description will be given of a data frame, which is a frame used when transmitting and receiving data, among the frames used in CAN communication.

[0033] (Data Frame Structure) Fig. 3 is a schematic diagram for explaining a data frame in a standard format in CAN communication. As shown in Fig. 3, a data frame in CAN communication includes the following fields: SOF (Start Of Frame), ID, RTR (Remote Transmission Request), control field, data field, CRC (Cyclic Redundancy Check) sequence, CRC delimiter, ACK (ACKnowledgement) slot, ACK delimiter, and EOF (End Of Frame).

[0034] The "SOF" field is 1 bit long and indicates the start of a data frame. The "ID" field is 11 bits long and is used to identify the data content and sender. The ID field stores an ID, which is an identifier used to identify a data frame. There are 2048 IDs in the range of "0x0" to "0x7FF". Note that the "0x" at the beginning of the ID number indicates that the number is expressed in hexadecimal. The "RTR" field is 1 bit long and is used to identify whether the frame is a data frame or not.

[0035] The "control field" area is 6 bits long and contains a 1-bit Identifier Extension (IDE), a 1-bit reserved bit r, and a 4-bit Data Length Code (DLC). The "IDE" is used to distinguish between the standard format and an extended format with an extended ID. The "reserved bit r" is used to distinguish between CAN and "CAN with Flexible Data Rate (CAN FD)," which has an extended data field. The "DLC" indicates the length (in bytes) of the data field following the control field. The DLC setting range is "0" to "8," allowing 0 to 8 bytes of data to be stored in the data field in 1-byte increments.

[0036] The "data field" area is 0 to 8 bytes long and is an area for storing transmission data. The data field can store data of the data length set by the DLC.

[0037] The "CRC sequence" field is 15 bits long and is used by the receiving side to determine whether the data frame has been received correctly. Specifically, the transmitting and receiving sides calculate a value based on the SOF, ID, control field, and data field, and then compare the two values ​​to determine the correctness of the data frame. The "CRC delimiter" field is 1 bit long and indicates the end of the CRC sequence. The CRC sequence and CRC delimiter are collectively referred to as the "CRC field" field.

[0038] The "ACK slot" field is 1 bit long and is used to determine whether the data up to the CRC field has been received correctly. The "ACK delimiter" field is 1 bit long and indicates the end of the ACK slot. The ACK slot and ACK delimiter are collectively referred to as the "ACK field" field. The "EOF" field is 7 bits long and indicates the end of the data frame.

[0039] In CAN communication using such a standard format, generally, one data frame can be transmitted per transmission process. In this case, the maximum size of data that can be stored in the data field is 8 bytes, so in order to transmit data that exceeds 8 bytes, multiple data frames and IDs corresponding to each data frame are required.

[0040] On the other hand, in the standard format for CAN communication, the range of IDs is "0x000" to "0x7FF," so only 2048 IDs can be assigned to a data frame. Therefore, if the size of the transmission data increases and it becomes necessary to transmit the data using data frames with more than the maximum number of IDs, there will be a shortage of IDs and the data will not be able to be transmitted properly.

[0041] In this case, it is possible to change the format to an extended format that significantly increases the number of IDs that can be assigned, or to change the protocol to "CAN FD," which extends the transmittable data size per frame to 64 bytes. However, changing the format or protocol in an existing system is difficult because it requires redesigning all devices related to CAN communication.

[0042] Therefore, in this embodiment, data can be appropriately transmitted and received within the range of the maximum number of IDs without changing the format or protocol. Specifically, in this embodiment, a common ID is assigned to multiple data frames, and a number of data frames exceeding the maximum number of IDs is generated. Furthermore, identification information for the transmitted data is set in each data frame to distinguish between the multiple data frames assigned the common ID.

[0043] (Data Field) Fig. 4 is a schematic diagram for explaining information stored in the data field. As shown in Fig. 4, in this embodiment, a first area and a second area are set in the data field of the data frame.

[0044] The first field is an area for storing identification information that distinguishes multiple data frames from one another, and is an area of ​​the first two bytes of the data field, which is a maximum of eight bytes. The first field stores a sequence number and a data type as identification information.

[0045] The "sequence number" is identification information stored in the first byte of the data field. When transmission data is divided into multiple pieces of divided data, the sequence number indicates the order of data frames to which a common ID is assigned. In other words, the sequence number indicates the order of the transmission data that has been divided and stored in the second area of ​​multiple data frames. For example, if transmission data is divided into four pieces of divided data, sequence numbers "1" to "4" are assigned to the four data frames that store these pieces of divided data. These sequence numbers are then stored in the first byte of the data field in the order in which the transmission data was divided.

[0046] "Data type" is identification information stored in the second byte of the data field. The data type is a number indicating the content of the data stored in the second area. For example, if the divided data contains multiple pieces of data, a different data type number is assigned to each piece of data and stored. More specifically, for example, if the divided data contains different data contents, such as the current cell voltage value and the maximum voltage, the data indicating the current cell voltage value is assigned a data type of "0," and the data indicating the maximum voltage is assigned a data type of "1."

[0047] The second area is a data storage area for storing transmission data, and is a maximum 6-byte area remaining after excluding the first area of ​​the data field. The transmission data is stored in the second area. Here, if the size of the transmission data exceeds the size of the second area, the transmission data is divided into pieces of data and stored in the second area.

[0048] The area in which the sequence number and data type are stored is not limited to this example. For example, the data type may be stored in the first byte of the data field, and the sequence number may be stored in the second byte.

[0049] (Data Transmission and Reception) Next, the operation when transmitting and receiving data between a transmitting device and a receiving device will be described with reference to Fig. 2. Here, the BMS 12 of the battery module 10 functions as a transmitting device, and the BMU 20 functions as a receiving device. The description will be given taking as an example a case where battery information related to the battery module 10 is transmitted from the BMS 12 to the BMU 20.

[0050] When data is transmitted from the BMS 12 to the BMU 20, the data acquisition unit 21 of the BMS 12 first acquires data including battery information as transmission data. Then, the data acquisition unit 21 supplies the acquired data as transmission data to the data division unit 22.

[0051] When the data division unit 22 receives transmission data from the data acquisition unit 21, if the size of the transmission data exceeds the size of the data field in the data frame (maximum 8 bytes), the data division unit 22 divides the transmission data to generate divided data. Specifically, the data division unit 22 divides transmission data consisting of common data types by data content. The data division unit 22 also divides the data so that the size of the divided data is a maximum of 6 bytes. The data division unit 22 then supplies the divided data, along with information indicating the number of divisions and the data content, to the frame generation unit 23.

[0052] The frame generation unit 23 sets a sequence number based on the information indicating the number of divisions received from the data division unit 22. The frame generation unit 23 also sets a data type based on the information indicating the data content received from the data division unit 22. Furthermore, the frame generation unit 23 stores the set sequence number and data type in a first area of ​​the data field in the multiple data frames.

[0053] Next, the frame generation unit 23 stores the divided data received from the data division unit 22 in the second area of ​​the data field of each data frame, corresponding to the sequence number and data type. The frame generation unit 23 then assigns a common ID to the generated multiple data frames and supplies the multiple data frames to the transmission / reception unit 24.

[0054] The transmitter / receiver 24 sequentially transmits the multiple data frames assigned a common ID received from the frame generator 23 to the BMU 20 via the bus 2. At this time, the transmitter / receiver 24 transmits the multiple data frames, for example, in the order of their sequence numbers. The transmission of the multiple data frames is not limited to this, and may be performed in any order, as long as, for example, the BMU 20 can reliably receive all data frames assigned a common ID.

[0055] If a data frame with the same ID exists on the bus 2, an error may occur or the data frame may not be received by the BMU 20. Therefore, in this embodiment, the transmission interval between multiple data frames is set to an interval that allows the BMU 20 to receive the data frames reliably.

[0056] On the other hand, when the BMU 20 receives data from the BMS 12, the transmitter / receiver 25 of the BMU 20 receives multiple data frames assigned a common ID from the BMS 12 via the bus 2. In this case, the transmitter / receiver 25 determines that the received multiple data frames are of the same data type because they have a common ID assigned to them, and supplies the received multiple data frames to the data combiner 25.

[0057] The data combining unit 25 refers to the data fields in the multiple acquired data frames and combines the data stored in the second areas of the data fields in each data frame according to the identification information stored in the first areas of the data fields.

[0058] First, the data combiner 25 extracts sequence numbers and data types from the multiple received data frames. Next, the data combiner 25 combines the divided data stored in the data fields of the multiple data frames based on the extracted sequence numbers and data types to obtain the transmission data. Specifically, the data combiner 25 extracts divided data with common data content based on the extracted data type. Then, the data combiner 25 combines the extracted divided data in the order of the sequence numbers corresponding to each of the divided data. This restores the transmission data transmitted from the BMS 12.

[0059] In this way, in this embodiment, a common ID is assigned to multiple data frames, and the divided data is stored in the data field of each frame, along with a sequence number and data type. This reduces the number of IDs assigned when sending and receiving transmission data compared to conventional methods, thereby preventing ID shortages.

[0060] On the other hand, if the size of the transmission data acquired by the data acquisition unit 21 is 8 bytes or less, the transmission data can be stored in the data field of one data frame, so there is no need to divide the data. In this case, the data division unit 22 supplies the acquired data to the frame generation unit 23 without dividing it.

[0061] Furthermore, the frame generation unit 23 does not set a sequence number or a data type, but stores the transmission data in the entire area consisting of the first area and the second area of ​​the data field in the data frame.Then, the frame generation unit 23 assigns an ID to the data frame and supplies it to the transmission / reception unit 24.

[0062] However, this is not limited to this, and even if the size of the transmission data is equal to or smaller than the size of the data field in the data frame, the sequence number and data type may be set and the transmission data may be divided. Specifically, for example, the data dividing unit 22 divides the transmission data so that the size of the divided data is a maximum of 6 bytes, regardless of the size of the received transmission data, and generates divided data. Furthermore, the frame generating unit 23 sets the sequence number based on the number of divisions of the transmission data, and sets the data type based on information indicating the data content.

[0063] This allows the process of setting the sequence number and data type and dividing the transmission data to be performed regardless of the size of the transmission data, thereby simplifying the configuration of the device.

[0064] <Example> Next, a specific example will be given to describe transmission data exchanged between the BMU 20 and the BMS 12. In this example, the power storage device 1 is assumed to be connected to one BMU 20 and seven battery modules 10. Furthermore, the secondary battery 11 mounted in each battery module 10 is assumed to be configured by connecting 12 secondary battery cells in series.

[0065] First, the instruction information and battery information transmitted and received between the BMU 20 and the BMS 12 will be described. FIG. 5 is a schematic diagram showing an example of information included in transmission data transmitted and received between the BMU 20 and the BMS 12. In FIG. 5, "data type" indicates the type of information included in the transmission data. "ID" indicates, in this embodiment, the ID value assigned to the data frame storing the information indicated by each data type. "Number of IDs" indicates the number of IDs required when an ID is assigned to each data frame, as in conventional CAN communication. Note that the numbers at the bottom of the "ID" and "Number of IDs" columns indicate the total number of IDs required when transmitting information for all data types.

[0066] As shown in FIG. 5, the instruction information and battery information include, as data types, operation information, self-diagnosis information, voltage-related information, temperature-related information, cell balance information, manufacturing-related information, and error notification.

[0067] "Operation information" is information relating to operations such as powering on the battery module 10. The operation information includes an "operation instruction" as instruction information transmitted from the BMU 20 to the BMS 12, and an "operation acquisition" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving an "operation instruction" and an "operation acquisition", one ID is required for each.

[0068] "Self-diagnosis information" is information relating to self-diagnosis of the state of the battery module 10. The self-diagnosis information includes a "self-diagnosis / alarm instruction" as instruction information transmitted from the BMU 20 to the BMS 12, and a "self-diagnosis / alarm acquisition" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving the "self-diagnosis / alarm instruction" and the "self-diagnosis / alarm acquisition", one ID is required for each.

[0069] The "voltage-related information" is information relating to voltage, such as the voltage value of the secondary battery 11 or the secondary battery cells that make up the secondary battery 11. The voltage-related information includes a "voltage-related instruction" as instruction information transmitted from the BMU 20 to the BMS 12, and a "voltage-related acquisition" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving the "voltage-related instruction" and the "voltage-related acquisition," 77 IDs are required for each.

[0070] "Temperature-related information" is information relating to temperature, such as the temperature of the secondary battery 11 or the secondary battery cells that make up the secondary battery 11. The temperature-related information includes a "temperature-related instruction" as instruction information transmitted from the BMU 20 to the BMS 12, and a "temperature-related acquisition" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving the "temperature-related instruction" and the "temperature-related acquisition," 13 IDs are required for each.

[0071] The "cell balance information" is information related to cell balancing among the multiple secondary battery cells that make up the secondary battery 11. The cell balance information includes "cell balance instruction" and "cell balance setting" as instruction information transmitted from the BMU 20 to the BMS 12, and "cell balance acquisition" and "cell balance acceptance" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving the "cell balance instruction" and "cell balance acquisition", one ID is required for each. Furthermore, when transmitting and receiving the "cell balance setting" and "cell balance acceptance", three IDs are required for each.

[0072] "Manufacturing-related information" is information about the battery module 10 and the secondary battery 11, as well as information about manufacturing such as the serial number. The manufacturing-related information includes "manufacturing-related instructions" and "manufacturing-related settings" as instruction information transmitted from the BMU 20 to the BMS 12, and "manufacturing-related acquisition" and "manufacturing-related reception" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving "manufacturing-related instructions," "manufacturing-related acquisition," "manufacturing-related settings," and "manufacturing-related reception," one ID is required for each. When transmitting and receiving "manufacturing-related instructions," "manufacturing-related acquisition," "manufacturing-related settings," and "manufacturing-related reception," 57 IDs are required for each.

[0073] The "error notification" is information as battery information that is transmitted from the BMS 12 to the BMU 20 when an abnormality occurs in the battery module 10. When transmitting and receiving the "error notification", one ID is required.

[0074] Next, consider the case where instruction information or battery information is transmitted and received between one BMU 20 and one BMS 12. As shown in Fig. 5, when instruction information or battery information for all data types is transmitted and received between one BMU 20 and one battery module 10 (BMS 12), 421 IDs are normally required.

[0075] However, since the total number of IDs that can be used in standard-format CAN communication is 2048, the number of IDs that can be used by one BMS 12 is 292 (≈2048 / 7). Therefore, if a different ID is assigned to every data frame that is sent and received, there will not be enough IDs to send and receive information about all data types.

[0076] In contrast, in this embodiment, when transmitting and receiving information about each data type, a common ID is assigned to multiple data frames. Therefore, only one ID is required when transmitting and receiving information about each data type. Therefore, when transmitting and receiving information about all data types, only 17 IDs are required.

[0077] Next, the relationship between the data stored in the data field of the data frame and the ID will be described. FIG. 6 is a schematic diagram for explaining the data stored in the conventional data field. FIG. 7 is a schematic diagram for explaining the data stored in the data field of this embodiment. Here, an example will be described in which data including cell voltages #1 to #12 and maximum voltages #1 to #12 of 12 secondary battery cells is transmitted as transmission data. In the examples of FIGS. 6 and 7, "cell voltage" refers to the "current value of cell voltage."

[0078] As shown in Figure 6, in the past, all areas of the data field were used to store divided data pieces obtained by dividing the transmission data. For example, when dividing and transmitting transmission data containing cell voltages #1 to #12 of 12 battery cells and the maximum voltages #1 to #12 of each battery cell, six data frames were required. Each data frame was assigned a different ID (0x000 to 0x005). In other words, in the past, six IDs were required to transmit this transmission data.

[0079] In contrast, in this embodiment, as shown in Figure 7, the sequence number and data type are stored in the first area of ​​the data field, and the divided data is stored in the second area. For example, as in the example shown in Figure 6, when dividing and transmitting transmission data having cell voltages #1 to #12 and maximum voltages #1 to #12, eight data frames are required in this embodiment, which is more data frames than conventional data frames.

[0080] However, since the sequence number and data type are stored in the first area of ​​the data field, each data frame can be individually identified, and a common ID (0x000) can be assigned to each data frame. In other words, in this embodiment, only one ID is required to transmit this transmission data.

[0081] In this way, in this embodiment, the number of IDs required when transmitting transmission data of the same size can be reduced compared to the conventional method. Therefore, even when it is necessary to transmit data frames that exceed the number of available IDs, it is possible to transmit multiple data frames while preventing a shortage of IDs.

[0082] As described above, when BMS 12 or BMU 20 as a transmitting device according to the present embodiment divides transmission data into multiple data frames, stores the data, and transmits the data, BMS 12 or BMU 20 assigns a common ID to the multiple data frames. Also, BMS 12 or BMU 20 divides the data field in the multiple data frames into a first area and a second area, and stores the sequence number and data type, which are identification information, in the first area, and the transmission data in the second area.

[0083] In this way, the transmission data is divided into multiple pieces and stored in multiple data frames to which a common ID is assigned, and the transmission data can be transmitted appropriately. In addition, since a common ID is assigned to multiple data frames, it is possible to prevent a shortage of IDs.

[0084] Furthermore, when receiving transmission data, the BMU 20 or BMS 12 serving as a receiving device according to this embodiment refers to the data fields divided into a first area and a second area in multiple data frames assigned a common ID, and combines the transmission data stored in the second area according to the sequence number and data type, which are identification information for the transmission data stored in the first area.

[0085] In this way, the transmission data divided and stored in the second areas of multiple data frames assigned a common ID is combined based on the identification information stored in the first area, so that the transmission data can be received properly.

[0086] Although the present embodiment has been described above, the present disclosure is not limited to the above-described embodiment, and various modifications and applications are possible within the scope of the gist of the present disclosure. In the present embodiment, a case where CAN is applied as a communication protocol has been described, but the present disclosure is not limited to this, and can also be applied to a communication standard that uses a protocol in which, for example, only one frame assigned a unique ID can be sent in one transmission, and the number of IDs is finite.

[0087] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-007034, filed on January 20, 2023, are incorporated herein by reference in their entirety.

[0088] REFERENCE SIGNS LIST 1 Power storage device 2 Bus 10 Battery module 11 Secondary battery 12 BMS 20 BMU 21 Data acquisition unit 22 Data division unit 23 Frame generation unit 24 Transmitting / receiving unit 25 Data combination unit

Claims

DEPCT681. A transmitting device that stores transmitting information while dividing the output data into a number of frames and transmitting those frames. The transmitting device, which includes a frame constructor that assigns a common identifier to a number of frames, divides a datafield, distinct from the storage of the common identifier, into Area One and Area Two in each of a number of frames. It stores identification information for identifying a number of frames from one another in Area One and stores transmitting information in Area Two.

2. A transmitting device according to claim 1 in which the identification information includes a serial number indicating the order in which the transmitted data fragments are stored sequentially in Area Two in a number of frames.

3. A transmitting device according to claim 2, which also includes: a transmitting unit that transmits a number of frames in the order indicated by the serial numbers.

4. A transmitting device according to claim 1 in which the frame constructor assigns a common identifier to a number of frames that store transmitting information of a common data type. 5.A transmitting device pursuant to claim 1 in which the transmission data of a common data type includes transmission data of different data bodies and identification information including a data type number that identifies one corresponding body of the transmission data body; 6. A transmitting device pursuant to claim 1 in which the transmission data includes information relating to a secondary battery; 7. A receiving device which receives the transmission data that is divided and stored in a number of frames. The receiving device comprises: a data aggregator which refers to a data field, each field of which is divided into a first and a second area, and aggregates a number of transmission data stored in the second area according to the identification information about a number of transmission data stored in the first area in a number of frames to which a common identifier is assigned;

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