WO2024154586A1 - Transmission device and reception device - Google Patents

Abstract

Provided are a transmission device and a reception device capable of appropriately transmitting and receiving data while suppressing a lack of identifiers. The transmission device divides transmission data into a plurality of frames, stores the frames, and transmits the frames. The transmission device has a frame generation unit that assigns a shared identifier to the plurality of frames, divides a data field different from an identifier storage unit into a first region and a second region in the plurality of frames, and stores identification information for mutually identifying the plurality of frames in the first region, and stores transmission data in the second region.

Description

Transmitting device and receiving device

This disclosure relates to a transmitting device and a receiving device.

In an energy storage device, communication using the CAN (Controller Area Network) protocol (hereinafter referred to as "CAN communication") is used between the battery modules and a management device that manages multiple battery modules. For example, Patent Document 1 discloses that communication via CAN 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.

In CAN communication, an ID (IDentifier) is assigned to each data frame, which is the unit of data transmission and reception, to identify the transmitting node that is the sender, and the transmitted data is stored in the data field, which is the data storage area in the data frame. A transmitting node such as a battery module then transmits a data frame containing the transmitted data to all nodes, including the receiving node that 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.

International Publication No. 2018/147046

In CAN communication, normally only one data frame can be transmitted per transmission process. In other words, in CAN communication, the number of frames and data size that can be handled in one transmission/reception process are also fixed. Therefore, when transmitting data that is 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.

However, because 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 sent and received between devices. Therefore, when sending data frames worth of data that exceed 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 sent properly.

The objective of this disclosure is to provide a transmitting device and a receiving device that can properly transmit and receive data while minimizing identifier shortages.

A transmitting device according to the present disclosure includes:
A transmitting device that divides and stores transmission data into a plurality of frames and transmits the frames,
The frame generating unit assigns a common identifier to the plurality of frames, divides a data field in the plurality of frames that is different from a storage section for the identifier into a first area and a second area, and stores identification information that distinguishes the plurality of frames from one another in the first area and the transmission data in the second area.

In addition, the receiving device according to the present disclosure includes:
A receiving device for receiving transmission data stored in a plurality of frames, comprising:
The data combining unit has a data field divided into a first area and a second area in the multiple frames assigned a common identifier, and combines the transmission data stored in the second area in accordance with identification information for the transmission data stored in the first area.

According to this disclosure, data can be appropriately sent and received while preventing identifier shortages.

1 is a schematic diagram illustrating an example of a configuration of an electricity storage device according to an embodiment of the present invention. FIG. 2 is a functional block diagram showing an example of the configuration of the BMU of FIG. 1 . 1 is a schematic diagram for explaining a data frame of a standard format in CAN communication. FIG. FIG. 2 is a schematic diagram for explaining information stored in a data field. 1 is a schematic diagram showing an example of information included in transmission data transmitted and received between a BMU and a BMS. FIG. 1 is a schematic diagram for explaining data stored in a conventional data field. 4 is a schematic diagram for explaining data stored in a data field according to the present embodiment. FIG.

Below, 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 combinations of possible configurations among the configurations shown in the following embodiments. Furthermore, in each figure, items with the same reference numerals are the same or equivalent, and this is common throughout the entire specification.

[Configuration of Power Storage Device 1]
Fig. 1 is a schematic diagram showing an example of the configuration of an energy storage device 1 according to the present embodiment. The energy 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 energy 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.

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

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-hydrogen 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-hydrogen secondary battery, such as a lithium-ion secondary battery. Also, multiple secondary batteries 11 may be provided, in which case the multiple secondary batteries 11 are, for example, connected in series.

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 the cell balance of multiple secondary battery cells based on the detection results.

Furthermore, the BMS 12 communicates with the BMU 20 via the bus 2, exchanging instruction information and battery information related to the secondary battery 11 or the battery module 10. The battery information is information related to secondary batteries such as the secondary battery 11 or the battery module 10. Furthermore, 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.

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.

The BMS 12 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory) (all not shown). The CPU reads out a program from the ROM according to the processing content and loads it into the RAM, and works in conjunction with the loaded program to centrally control the operation of the battery module 10.

(BMU20)
The BMU 20 controls and manages the multiple battery modules 10. For example, the BMU 20 issues instructions such as power-on instructions to each battery module 10 and instructions such as fine adjustment of cell balance between the battery modules 10. The BMU 20 also performs CAN communication with the BMS 12 of each battery module 10 via the bus 2 to exchange instruction information and battery information.

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

The BMU 20 includes a CPU, ROM, 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 works with the loaded program to centrally control the operation of the power storage device 1.

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 of the BMU 20. Note that the communication-related functions of the BMS 12 of each battery module 10 are similar to those of the BMU 20, and have the configuration shown in FIG. 2. Here, the BMU 20 will be used as an example for explanation.

As shown in FIG. 2, the BMU 20 has 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.

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.

"Data type" is a rough classification of instruction information and battery information. For example, instruction information and battery information include "voltage-related information" about voltage and "temperature-related information" about 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 instruction information and battery information will be described later.

The data division unit 22 divides the transmission data acquired by the data acquisition unit 21 into pieces of a predetermined size, and generates divided data. Specifically, the data division unit 22 divides the transmission data into pieces of a size that can be stored in a data field, which is the data storage area of a data frame, which is the unit of data transmission and reception. The divided data is data obtained by dividing transmission data consisting of a common data type by data content.

"Data content" is a more detailed classification of 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 the current and maximum cell voltages correspond to the data content referred to here.

The frame generation unit 23 stores the identification information and the 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 according to the number of divided data, and generates the data frame.

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.

When the data combining unit 25 receives multiple data frames from the BMS 12 via the transmitting/receiving unit 24, it combines the data contained in each data frame based on the identification information, and restores 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 contained in each data frame as is.

[About 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, a data frame, which is a frame used when transmitting and receiving data, among frames used in CAN communication, will be described using the standard format in CAN communication as an example.

(Data frame structure)
3 is a schematic diagram for explaining a data frame of a standard format in CAN communication. As shown in Fig. 3, a data frame in CAN communication includes each area of 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).

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 for identifying 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 in hexadecimal notation. The "RTR" field is 1 bit long and is used to identify whether the frame is a data frame or not.

The "control field" area is 6 bits long and stores a 1-bit IDE (Identifier Extension), a 1-bit reserved bit r, and a 4-bit data length code (DLC). "IDE" is used to distinguish between the standard format and the extended format with an extended ID. "Reserved bit r" is used to distinguish between CAN and "CAN FD (CAN with Flexible Data rate)" with an extended data field. "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 1-byte units in the data field.

The "data field" area is 0 to 8 bytes long and is the area where the transmission data is stored. The data field can store data of the data length set by the DLC.

The "CRC sequence" area is 15 bits long and is used by the receiving side to determine whether or not the data frame has been received correctly. Specifically, the sending and receiving sides calculate a value based on the SOF, ID, control field, and data field, and the two values are compared to determine the correctness of the data frame. The "CRC delimiter" area 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" area.

The "ACK slot" area is 1 bit long and is used to determine whether the data up to the CRC field has been received correctly. The "ACK delimiter" area 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" area. The "EOF" area is 7 bits long and indicates the end of the data frame.

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 an ID corresponding to each data frame are required.

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 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.

In this case, it would be 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, as it would require redesigning all devices related to CAN communication.

In this embodiment, therefore, it is possible to appropriately transmit and receive data 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, in each data frame, identification information for the transmitted data is set in order to distinguish between the multiple data frames assigned the common ID.

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

The first area is an area that stores identification information that distinguishes multiple data frames from each other, and is the first 2 bytes of the data field, which is a maximum of 8 bytes. The first area stores a sequence number and data type as identification information.

The "sequence number" is identification information stored in the first byte of the data field. When the transmission data is divided into multiple pieces of divided data, the sequence number indicates the order of the data frames to which a common ID has been 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, when the 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.

"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 split data contains multiple pieces of data, a different data type number is assigned and stored for each piece of data. More specifically, for example, if the split data contains different data contents such as the current cell voltage value and maximum voltage, a data type of "0" is assigned to the data indicating the current cell voltage value, and a data type of "1" is assigned to the data indicating the maximum voltage.

The second area is a data storage area that stores the transmission data, and is a maximum of 6 bytes of the remaining area 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 divided data obtained by dividing the transmission data is stored in the second area.

Note that 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.

(Transmission and reception of data)
Next, the operation when transmitting and receiving data between the transmitting device and the 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, and the case where the BMS 12 transmits battery information related to the battery module 10 to the BMU 20 will be described as an example.

When transmitting data 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. The data acquisition unit 21 then supplies the acquired data to the data division unit 22 as transmission data.

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 and generates divided data. Specifically, the data division unit 22 divides the transmission data consisting of a common data type 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 together with information indicating the number of divisions and the data content to the frame generation unit 23.

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 the first area of the data field in the multiple data frames.

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 in each data frame, corresponding to the sequence number and data type. The frame generation unit 23 then assigns a common ID to the multiple data frames that have been generated, and supplies the multiple data frames to the transmission/reception unit 24.

The transceiver 24 sequentially transmits the multiple data frames assigned with a common ID received from the frame generator 23 to the BMU 20 via the bus 2. At this time, the transceiver 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, for example, as long as the BMU 20 can reliably receive all data frames assigned with a common ID.

If a data frame with the same ID exists on bus 2, an error may occur or the BMU 20 may miss receiving the data frame. Therefore, in this embodiment, the transmission interval between multiple data frames is set to a level that allows the BMU 20 to receive the data frames reliably.

On the other hand, when the BMU 20 receives data from the BMS 12, the transmission/reception unit 25 of the BMU 20 receives multiple data frames with a common ID from the BMS 12 via the bus 2. In this case, the transmission/reception unit 25 determines that the received multiple data frames are of the same data type because they have a common ID, and supplies the received multiple data frames to the data combination unit 25.

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.

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

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 makes it possible to reduce the number of IDs assigned when sending and receiving transmission data compared to conventional methods, thereby preventing ID shortages.

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, and 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.

Furthermore, the frame generating unit 23 does not set a sequence number or a data type, and stores the transmission data in all areas of the data field in the data frame, consisting of the first area and the second area. The frame generating unit 23 then assigns an ID to the data frame and supplies it to the transmitting/receiving unit 24.

Note that this is not limited to the above, 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 division 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 the divided data. Furthermore, the frame generation 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.

As a result, the process of setting the sequence number and data type, and dividing the transmission data, can be performed regardless of the size of the transmission data, making it possible to simplify the device configuration.

<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. Also, the secondary battery 11 mounted on each battery module 10 is assumed to be configured by connecting 12 secondary battery cells in series.

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 the 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 the ID value assigned to the data frame that stores the information indicated by each data type in this embodiment. "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.

As shown in Figure 5, the instruction information and battery information include the following data types: operation information, self-diagnosis information, voltage-related information, temperature-related information, cell balance information, manufacturing-related information, and error notifications.

"Operation information" is information related to operations such as powering on the battery module 10. Operation information includes "operation instructions" as instruction information sent from the BMU 20 to the BMS 12, and "operation acquisition" as battery information sent from the BMS 12 to the BMU 20. When sending and receiving "operation instructions" and "operation acquisition", one ID is required for each.

"Self-diagnosis information" is information related to self-diagnosis of the state of the battery module 10. Self-diagnosis information includes "self-diagnosis/alarm instruction" as instruction information sent from the BMU 20 to the BMS 12, and "self-diagnosis/alarm acquisition" as battery information sent from the BMS 12 to the BMU 20. When sending and receiving "self-diagnosis/alarm instruction" and "self-diagnosis/alarm acquisition", one ID is required for each.

"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 "voltage-related instructions" as instruction information transmitted from the BMU 20 to the BMS 12, and "voltage-related acquisition" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving "voltage-related instructions" and "voltage-related acquisition", 77 IDs are required for each.

"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. Temperature-related information includes "temperature-related instructions" as instruction information transmitted from the BMU 20 to the BMS 12, and "temperature-related acquisition" as battery information transmitted from the BMS 12 to the BMU 20. When transmitting and receiving "temperature-related instructions" and "temperature-related acquisition", 13 IDs are required for each.

"Cell balance information" is information related to cell balancing between 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 a "cell balance instruction" and "cell balance acquisition", one ID is required for each. Furthermore, when transmitting and receiving a "cell balance setting" and "cell balance acceptance", three IDs are required for each.

"Manufacturing related information" is information related to the battery module 10 and secondary battery 11, as well as information related to manufacturing such as serial numbers. 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.

The "error notification" is battery information sent from the BMS 12 to the BMU 20 when an abnormality occurs in the battery module 10. When sending and receiving an "error notification", one ID is required.

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 Figure 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 usually required.

However, because the total number of IDs that can be used in standard-format CAN communication is 2048, the number of IDs that one BMS12 can use 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 or receive information about all data types.

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 need to be used.

Next, the relationship between the data stored in the data field of the data frame and the ID will be described. Figure 6 is a schematic diagram for explaining the data stored in a conventional data field. Figure 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. Note that in the examples of Figures 6 and 7, "cell voltage" refers to the "current value of cell voltage."

As shown in Figure 6, conventionally, split data obtained by dividing transmission data is stored in all areas of the data field. For example, when dividing and transmitting transmission data having cell voltages #1 to #12 of 12 battery cells and maximum voltages #1 to #12 of each battery cell, conventionally, six data frames are required. A different ID (0x000 to 0x005) is assigned to each data frame. In other words, conventionally, six IDs are required to transmit this transmission data.

In contrast, as shown in FIG. 7, in this embodiment, 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 FIG. 6, when dividing and transmitting transmission data having cell voltages #1 to #12 and maximum voltages #1 to #12, in this embodiment, eight data frames are required, which is more than in the past.

However, by storing the sequence number and data type 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 send this transmission data.

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.

As described above, when BMS12 or BMU20 as a transmitting device according to this embodiment divides and stores transmission data into multiple data frames and transmits the data, it assigns a common ID to the multiple data frames. Furthermore, BMS12 or BMU20 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.

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

Furthermore, when receiving transmission data, the BMU 20 or BMS 12 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 to which a common ID has been assigned. Then, the BMU 20 or BMS 12 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.

In this way, the transmission data that is divided and stored in the second areas of multiple data frames that have been 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.

The present embodiment has been described above, but 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 invention is not limited to this, and can also be applied to a communication standard that uses a protocol in which only one frame with a unique ID can be sent in one transmission, and the IDs are finite.

The entire disclosures of the specification, drawings and abstract contained in the Japanese application No. 2023-007034, filed on January 20, 2023, are incorporated herein by reference.

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 (7)

A transmitting device that divides and stores transmission data into a plurality of frames and transmits the frames,
a frame generation unit that assigns a common identifier to the plurality of frames, divides a data field in the plurality of frames that is different from a storage unit for the identifier into a first area and a second area, and stores identification information that distinguishes the plurality of frames from one another in the first area and the transmission data in the second area. The identification information is
The transmitting device according to claim 1 , further comprising a sequence number indicating an order of the transmission data stored in the second area of the plurality of frames. The transmitting device according to claim 2 , further comprising a transmitting unit configured to transmit the plurality of frames in the order of the sequence numbers. The frame generating unit
The transmitting device according to claim 1 , wherein the common identifier is assigned to the plurality of frames in which the transmission data of a common data type is stored. The transmission data of a common data type includes the transmission data of different data contents,
The identification information is
The transmitting device according to claim 1 , further comprising a data type number indicating the data content of the transmission data. The transmission data is
The transmitting device according to claim 1 , further comprising data relating to a secondary battery. A receiving device for receiving transmission data stored in a plurality of frames, comprising:
A receiving device having a data combining unit that refers to a data field divided into a first area and a second area in the multiple frames to which a common identifier is assigned, and combines the transmission data stored in the second area in accordance with identification information for the transmission data stored in the first area.

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