JP3789769B2 - Data relay apparatus and multiplex communication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data relay device and a multiple communication system.
[0002]
[Prior art]
In recent years, the advancement of information communication has progressed especially against the background of advances in computer technology. For example, even in automobiles, the amount of information exchanged between control units that control mounted electrical components has increased rapidly. Yes. Thus, multiple communication systems are being adopted to reduce the number of wire harnesses that transmit information. In a multiplex communication system, a communication node such as a control ECU that transmits and receives data is connected to a common multiplex communication line, and data communication is performed between the communication nodes via the multiplex communication line. The data is configured to include data type information and the like together with the data body, and the received communication node can understand the contents of the data. In the case of the above-mentioned automobiles and the like having various control types, as shown in FIG. 32, in order to perform data communication efficiently, as shown in FIG. 32, multiple communication lines 921, 922, and 923 are used. And a plurality of communication systems 911, 912, and 913 including nodes 931 and 932 connected thereto, and communication between the nodes 931 and 932 to which the communication systems 911 to 913 belong to are performed via the data relay device 94. There is something like that. In the illustrated example, an engine ECU 931 that controls a power system such as an engine in accordance with the shift position of the shift lever 81 and a meter ECU 932 that controls display of the meter 82 and the like belong to different communication systems 911 and 912.
[0003]
The data relay device 94 is usually provided with a reception buffer for receiving data and a transmission buffer for storing data immediately before transmission to the multiplex communication line. Also, as a way to efficiently relay a large amount of data, a buffer that temporarily holds received data before it is transmitted to the relay destination multiplex communication line is provided for each type of data to be relayed. Is received, the type of the received data is identified and written into a buffer corresponding to the type (Japanese Patent Laid-Open No. 2000-244548). This technology prohibits overwriting between different types of data, so no matter how busy the communication is, it can prevent any type of data from being completely lost. Play. Japanese Patent Laid-Open No. 2000-244548 also discloses a device that alleviates data retention in the data relay device by resetting the priority of the data.
[0004]
[Problems to be solved by the invention]
By the way, in some data, not only the latest data but also the change itself of data input in time series has a meaning. In the example of FIG. 32, the meter ECU 932 lights and extinguishes the six indicators 821 “P”, “R”, “N”, “D”, “2”, and “L”, which indicate one of the display positions of the meter 82. However, data indicating whether each indicator 821 is turned on or off is received from an engine ECU 931 belonging to a communication system 911 different from the meter ECU 932.
[0005]
FIG. 33 shows an example of the structure of the data body of this ON / OFF data. The shift positions from “P” to “L” correspond to the 1st to 6th bits, and each bit is It is “1” if is turned on, and “0” if it is turned off. When the driver moves the shift lever from “P” to “L” at a stroke in 5 steps to start the car, the engine ECU 931 changes the bit that becomes “1” to the next bit after each step. The moved data is transmitted from the engine ECU 931, and the data enters the data relay device 94 continuously. In this case, if the data is replaced with the latest data by overwriting the buffer in the data relay device 94, there is a disadvantage that the shift position display is skipped in the indicator 821.
[0006]
If it is intended to transfer such data reliably, it is one idea to reset the priority as described above. However, if other types of data remain in the transmission buffer of the data relay device 94, eventually, The buffer data will be overwritten.
[0007]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a data relay device and a multiplex communication system that are highly resistant to data loss.
[0008]
According to the first aspect of the present invention, there is provided a data relay device that relays a plurality of types of data interposed between multiplex communication lines that transmit data including data type information together with the data body. In a data relay apparatus having a data controller that selects a multiplex communication line as a data relay destination and transfers received data,
A buffer that temporarily holds received data before transmission to the relay destination multiplex communication line is provided for each type of data to be relayed, and a plurality of buffers are assigned to one or more data types among the data types,
The data controller identifies a type of received data, and designates a buffer corresponding to the type as a write destination of the received data; and
In each multiplex communication line, the order in which the data from the same data type is transferred is the order in which the data is written in the buffer. Data transfer management means for managing the transfer of data from the buffer storing the data,
The data transfer management means is Starts up at a predetermined time interval, sequentially checks whether there is data to be transmitted in the buffer, and if there is data, transfers the data from the buffer, and checks whether there is data for a buffer of the same data type To perform only on the buffer that stores the data first Set.
[0009]
By providing a buffer for each data type, the buffer can be overwritten only by the latest data of the same type, and other types of data waiting for transmission can be prevented from being lost due to the received data.
[0010]
Furthermore, regarding the types of data to which a plurality of buffers are allocated, even if data is received in succession, these can be held simultaneously, and the resistance against data loss can be increased. In addition, data transfer from the buffer is performed at least when the selected multiplex communication lines are the same, since data is stored in the buffer from the earliest time. It is possible to surely prevent jumping over.
[0012]
By sequentially checking the presence / absence of data in the buffer, the existence of data to be transmitted is surely known from the buffer group, and the presence / absence of data for buffers of the same data type is first determined. Since the buffer storing the data first is checked, the data stored first can be transferred from the buffer prior to another buffer having the same data type.
[0013]
Claim 2 In the described invention, the claims 1 In the configuration of the invention, the data transfer management means is used for buffers having the same data type. Data was stored at the top After completing the transfer of data in the buffer corresponding to the selected multiplex communication line, the data received first among the data in other buffers of the same data type Data was stored first Set to move to buffer.
[0014]
By ensuring that the first data received among the same type of data always exists in the specified buffer, it is possible to ensure the presence of data to be transferred without checking the presence or absence of data for all buffers. Can be confirmed.
[0015]
Claim 3 In the described invention, in the configuration of the first aspect of the invention, the buffer information specifying the buffer in which the data is stored is included, and the order of the buffer information in the selected multiple communication line is the order in which the data is transferred from the buffer. And a transmission data list that is
The data transfer management means is set to update the transmission data list in accordance with the writing of data into the buffer and the transfer of data from the buffer.
[0016]
Even without checking the presence or absence of data in the buffer, the buffer storing the data to be transferred is known from the transmission data list, so that data can be relayed promptly.
[0017]
In addition, since the order in which data is transferred from the buffer is known for each multiplex communication line, data of the same data type is written to the buffer in succession, and a plurality of entries for the same data type are entered in the transmission data list. If the data is transferred from the buffer corresponding to one multiplex communication line and not transferred to another multiplex communication line, it corresponds to the one multiplex communication line. The buffer storing the data to be transferred next is known to be a buffer specified by the buffer information arranged next to the buffer information of the buffer storing the transmitted data. Thereby, it can avoid sending the same data accidentally.
[0018]
Claim 4 In the described invention, the claims 3 In the configuration of the invention, whether the data stored in the buffer should be transferred to the transmission data list given initial values for each multiplex communication line based on the buffer information for specifying the buffer and the transfer destination table It consists of management information on whether or not
The data transfer management means is set so as to switch the management information to information indicating that data transmission is unnecessary in accordance with the transfer of data from the buffer.
[0019]
Since it is possible to centrally manage the transfer progress of each multiplex communication line with the buffer storing the data to be transferred, the transfer of the data stored in the buffer corresponds to the selected multiplex communication line. It is easy to know whether or not everything has been completed, and the control burden can be reduced.
[0020]
Claim 5 In the described invention, a multiplex communication system is defined in claims 1 to. 4 Multiplexing that does not impair the reliability of data communication due to loss of relay data, by including the data relay device described above and a plurality of communication systems in which communication nodes that transmit and receive data are connected to the multiplex communication line. A communication system can be constructed.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 shows a data relay apparatus and a multiple communication system according to the first embodiment of the present invention. The multiplex communication system is composed of a plurality of communication systems 11, 12, and 13 and a data relay device 4 (3 in the illustrated example). Each of the communication systems 11 to 13 includes communication nodes 31, 32, and 33 connected to the multiplex communication lines 21, 22, and 23, and transmits / receives data between the communication nodes 31 to 33 using a predetermined protocol. ing. At least one communication node 31 to 33 belongs to each communication system 11 to 13.
[0022]
An example of the frame structure of the data is shown in FIG. This is a frame structure in the automobile BEAN (Body Electronics Area Network) protocol. In the following description, data communication will be described as following the BEAN protocol. SOF (Start Of Frame) represents the start of a frame and is assigned 1 bit. PRI (Priority) is an area representing the priority of a frame, and 4 bits are allocated. “1” has a higher priority than “0”. The data relay device 4 and the communication nodes 31 to 33 give priority to high-priority data when other data collide on the multiple communication lines 21 to 23 in the communication systems 11 to 13 and transmit other data. Is canceled. ML (Message Length) is an area indicating the length of the subsequent message part. The DID and MID constituting the message part are each 1 byte as described later, and DATA has a variable length, so the number of DATA bytes +2 It becomes.
[0023]
The beginning of the message part is a DID (Destination ID), which is an area representing the destination node ID of the frame. MID (Message ID) is an area representing a message ID, and is assigned 8 bits. The MID is assigned for each type of data, and specifies the type of data represented by the content of DATA, which will be described later, which is the main body of the data. The type of data exchanged by communication includes the engine speed and the like, and for example, an MID is assigned to each as shown in FIG. In the example shown in the figure, DATA of communication data with MID = 08h represents engine speed, DATA of communication data with MID = A5h represents vehicle speed, and DATA of communication data with MID = DDh represents a power window switch. Represents the state. DATA is assigned 1 to 11 bytes in the area of the data body.
[0024]
DATA is followed by CRC (Cyclic Redundancy Characters), EOM (End Of Message), and RSP (Response). The CRC is a communication error check area, and is assigned 8 bits. In the CRC, the communication node substitutes the content from the PRI to DATA into a predetermined mathematical formula and writes a bit operation result, and the received communication node compares the received data with the received data to check a communication error. EOM represents the end of the message with a predetermined bit string and is assigned 8 bits. The RSP is an area in which a communication node that has received data writes a response, and is assigned 2 bits. In the RSP, a result indicating whether or not the content of the frame has been correctly interpreted by the received communication node is written, and from this, it is determined whether or not the communication node that transmitted the data needs to be retransmitted. The end of the data is EOF (End Of Frame), which represents the end of the frame by a predetermined bit string, and is assigned 6 bits.
[0025]
Each of the multiple communication lines 21 to 23 is connected to the data relay device 4, and the data relay device 4 transfers the data transmitted from the communication nodes 31 to 33 to the communication nodes 31 to 33 belonging to the other communication systems 11 to 13. It comes to relay.
[0026]
The data relay device 4 is composed of a communication IC that interfaces with the multiplex communication lines 21 to 23, a control microcomputer, and the like. 413, transmission buffers 421, 422, 423, a buffer group 43, a data controller 44, a transfer destination table 45, and the like.
[0027]
Reception buffers 411 to 413 and transmission buffers 421 to 423 are provided corresponding to each of the multiple communication lines 21 to 23. The reception buffers 411 to 413 receive data transmitted from the multiplex communication lines 21 to 23, and the transmission buffers 421 to 423 are written with data to be transmitted. The reception buffers 411 to 413 and the transmission buffers 421 to 423 are configured by the communication IC. The data communication function may be incorporated as software executed on the CPU constituting the microcomputer. In this case, the reception buffers 411 to 413 and the transmission buffers 421 to 423 are allocated on the RAM constituting the microcomputer.
[0028]
The buffer group 43 includes a plurality of buffers 431, and each buffer 431 temporarily holds data received by the reception buffers 411 to 413 before being transferred to the transmission buffers 421 to 423, as will be described in detail later. . At least one buffer 431 is allocated to the MID of the data to be relayed, and each buffer 431 is dedicated to one MID. Among these, a plurality of buffers 431 are assigned to specific MIDs, and a plurality of data of the same MID received in succession can be simultaneously held. For example, if the buffer 431 has five types of data to be transferred, three buffers are assigned to one of them, and one buffer is assigned to each of the other types, seven buffers 431 are prepared. .
[0029]
In the following description, the buffer 431 is appropriately expressed as a buffer n (n = natural number) and has a one-to-one correspondence with the MID to be data relayed, and a buffer of MID to which a plurality of buffers 431 are assigned. With respect to 431, each buffer 431 is represented as a buffer n (k) (k = natural number) (hereinafter, k is referred to as a stage number). In the case of a data type to which a plurality of buffers are allocated, the buffer n is the entire buffer n (k). For example, as shown in FIG. 4, buffer 1 is for writing data with MID = 01h, buffer 2 is for writing data with MID = 5Fh, buffer 3 is for writing data with MID = 92h, and buffer 4 (1), buffer 4 (2), and buffer 4 (3) are for writing data with MID = C8h, and buffer 5 is for writing data with MID = EBh. The data area of the buffer group 43 is allocated on the RAM constituting the microcomputer.
[0030]
The data controller 44 selects the multiplex communication lines 21 to 23 as relay destinations of the received data, and transfers them to the transmission buffers 421 to 423 for the multiplex communication lines 21 to 23 as the relay destinations. Data transfer from 411 to 413 to the buffer 431 is controlled, and data transfer from the buffer 431 to the transmission buffers 421 to 423 is controlled. The data controller 44 is realized on software executed on a CPU constituting the microcomputer. The data controller 44, the reception buffers 411 to 413, and the transmission buffers 421 to 423 repeat the data transfer processing of the data controller 44, the reception operation of the reception buffers 411 to 413, and the transmission operation of the transmission buffers 421 to 423 alternately. Is set.
[0031]
The transfer destination table 45 associates the MID of the received data with the transmission buffers 421 to 423 for the relay destination multiplex communication line. When the MID and the multiplex communication lines 21 to 23 are designated, the received data of the MID is changed. Information indicating which of the multiplex communication lines 21 to 23 should be transferred to the transmission buffers 421 to 423 can be read. The contents of the transfer destination table 45 are written in advance together with the control program of the data controller 44 on the ROM constituting the microcomputer.
[0032]
FIG. 5 shows an example of the transfer destination table 45. If the read information is “1”, it should be transferred to the transmission buffer for the multiplex communication line. Indicates that data is not transferred to the transmission buffer for the communication line. In the illustrated example, data V with MID = 01h is transferred only to the transmission buffer 422 for the second multiplex communication line, data W with MID = 5Fh is transferred only to the transmission buffer 423 for the third multiplex communication line, The data X with MID = 92h is transferred only to the transmission buffer 421 for the first multiplex communication line, and the data Y with MID = C8h is transmitted for the transmission buffer 421 for the first multiplex communication line and the second multiplex communication line. The data Z transferred to the buffer 422 and MID = EBh represents that it should be transferred to the transmission buffer 422 for the second multiplex communication line and the transmission buffer 423 for the third multiplex communication line.
[0033]
Further, the data controller 44 is provided with buffer specifying means 441 that is executed at the time of data transfer processing from the reception buffers 411 to 413 to the buffer group 43, and identifies the MID of the data in the reception buffers 411 to 413, and the MID Is designated as the data transfer destination of the reception buffers 411 to 413.
[0034]
In addition, in the case of an MID composed of a single buffer 431, the MID buffer 431 is overwritten by the data in the reception buffers 411 to 413. However, for an MID to which a plurality of buffers 431 are assigned, In the buffer 431 in which data is not stored, data is written in order from the smallest number of stages. If there is no empty buffer 431, the buffer 431 of the last stage number kf of the buffer n (kf) is overwritten. It will be.
[0035]
Thus, the received data is written into the buffer 431 for each MID corresponding to the MID.
[0036]
The data controller 44 is provided with data transfer management means 442 that is executed during data transfer processing from the buffer group 43 to the transmission buffers 421 to 423 and manages the order of data transfer.
[0037]
6, 7, 8, and 9 are flowcharts illustrating data transfer processing from the buffer group 43 to the transmission buffers 421 to 423. This indicates the setting contents of the data transfer management means 442. In step S100, start buffer # = 1 and end buffer # = N. Here, N is the number of buffers 431 constituting the buffer group 43. In step S101, n = start buffer # (= 1). In step S102, it is confirmed whether or not data is written in the buffer n. If buffer # corresponds to the MID to which a plurality of buffers 431 are allocated, the determination as to whether or not data is written is made based only on buffer n (1).
[0038]
If written, the process proceeds to step S105 (FIG. 7). In step S105, it is confirmed whether or not the transfer destination flag is set for the data in the buffer n. The transfer destination flag is set for each of the multiplex communication lines 21 to 23. If “1” is set, it indicates that the data in the buffer n should be transferred to the multiplex communication lines 21 to 23.
[0039]
If the transfer destination flag is not set, steps S106 and S107 are executed to set the transfer destination flag. In step S106, the MID of the data in the buffer n is confirmed. In step S107, the data transfer destination table 45 is referred to obtain the data transfer destination of the buffer n, and a transfer destination flag is set in the data in the buffer n. That is, the transfer destination flag f1 is set to “1” if it should be transferred to the transmission buffer 421 for the first multiplex communication line, and the transfer destination flag f2 if it should be transferred to the transmission buffer 422 for the second multiplex communication line. Is set to “1”, and the transfer destination flag f3 is set to “1” if it should be transferred to the transmission buffer 423 for the third multiplex communication line.
[0040]
When the transfer destination flag is set, the process proceeds to step S108 (FIG. 8). In step S108, the transfer destination flag f1 is confirmed. If “1”, the process proceeds to step S109. In step S109, it is confirmed whether or not the transmission buffer 421 for the first multiplex communication line is empty. If the transmission buffer 421 is empty, the process proceeds to step S110 and the data in the buffer n is transferred to the transmission buffer 421. In step S111, the transfer destination flag f1 of the buffer n is set to “0”, and the process proceeds to step S112.
[0041]
In step S112, it is confirmed whether or not the transfer destination flag f2 is “1”. If “1”, the process proceeds to step S113. In step S113, it is confirmed whether or not the transmission buffer 422 for the second multiplex communication line is empty. If the transmission buffer 422 is empty, the process proceeds to step S114, and the data in the buffer n is transferred to the transmission buffer 422. In step S115, the transfer destination flag f2 of the buffer n is set to “0”, and the process proceeds to step S116.
[0042]
In step S116, it is confirmed whether or not the transfer destination flag f3 is “1”. If “1”, the process proceeds to step S117. In step S117, it is confirmed whether or not the transmission buffer 423 for the third multiplex communication line is empty. If the transmission buffer 423 is empty, the process proceeds to step S118, and the data in the buffer n is transferred to the transmission buffer 423. In step S119, the transfer destination flag f3 of the buffer n is set to “0”, and the process proceeds to step S120 (FIG. 9).
[0043]
In step S120, it is determined whether the transfer destination flag f1 = 0, f2 = 0, and f3 = 0. If the determination is affirmative, it means that the data transfer to the transmission buffers 421 to 423 to be transferred is completed, and the data in the buffer n is deleted in step S121. In the case of an MID to which a plurality of buffers 431 are assigned, the data in the buffer n (1) is deleted.
[0044]
In a succeeding step S122, it is determined whether or not the buffer n has a multi-stage configuration, that is, a MID to which a plurality of buffers 431 are assigned. The determination can be made based on a buffer # that has a multi-stage configuration stored in advance. If the determination is affirmative, the process proceeds to step S123, where the data in the buffer n (2) is copied to the buffer n (1). If the configuration is three or more stages, the data in the buffer n (3) is further transferred to the buffer n (2). In this way, the data in each buffer n (k) is moved to the buffer n (k) having one younger number k. This operation in the buffer 431 within the same MID is data processing substantially similar to the FIFO.
[0045]
FIGS. 10A and 10B show the transfer processing from the buffer 431 to the transmission buffers 421 to 423 (421 in the illustrated example), and the buffer group 43 is sequentially checked for the presence or absence of data to be transferred. If the data stored in the buffer 431 with MID = 92h and the number of stages 1 is transferred to the transmission buffer 421 (FIG. 10A), the data in the buffer 431 is deleted, and the number of stages 2 and 3 The data is carried forward in order, and the buffer having 3 stages is emptied (FIG. 10B). In this data movement, the physical address of the data does not actually change, and the information of the number of stages corresponding to the data may be repeated without changing the data storage location, and the two means are equivalent. It is.
[0046]
Then, it progresses to step S103 (FIG. 6). If step S122 is negative, it means a single buffer configuration, and step S123 is skipped and the process proceeds to step S103.
[0047]
In step S103, it is determined whether or not n is an end buffer #. If n ≠ end buffer #, n is incremented by one step in step S104, and the process returns to step S102, and step S102 is performed for buffer n of the next buffer #. , S108 to S123 are executed. In this way, the buffer 431 confirms whether or not there is data to be transferred in the order of the buffer #, and transfers the data to predetermined transmission buffers 421 to 423 when the data is held. When the data for the last buffer N is transferred, the data transfer process is completed.
[0048]
In the above data transfer processing, if at least one of steps S109, S113, and S117 is denied because the transmission buffers 421 to 423 hold data and are waiting for transmission, steps S110, S111, S114, Steps S115 and S118, S119 are skipped, and any one of the transfer destination flags f1, f2, and f3 remains “1”. Therefore, step S120 is denied, step S121 is skipped, and the data in buffer n is held as it is. That is, it waits for the transfer destination transmission buffers 421 to 423 to become empty. In this case, in the next data transfer process, step S105 to step S106, S107 are skipped and steps S108 to S119 are executed. Therefore, the data that could not be transferred is transferred.
[0049]
If the state of waiting for the destination transmission buffers 421 to 423 to become empty continues, the transfer from the buffer group 43 to the transmission buffers 421 to 423 is not performed. In the meantime, when new data with the same MID held in the buffer 431 is received, the buffer 431 is overwritten with the new data. However, a buffer 431 is provided for each MID of data to be relayed. As a result, overwriting with data of different data types can be avoided, so that the data of a certain MID can be prevented from being completely lost.
[0050]
In addition, if the data on whether the indicator at the shift position is turned on or off is received by the buffer 431 having a plurality of stages, even if the data is transmitted continuously from the engine ECU, Data is held in the buffer 431, and resistance to display skipping can be increased. In addition, since the first received data is always present in the buffer 431 having the number of stages 1, there is no data skipping, and the indicators are changed from “P” to “R” “N” “D” “2” “L”. It will change in the order of "."
[0051]
Moreover, the number of buffers 431 constituting the buffer group 43 is simple because the number of types of data to be relayed may be increased by adding a plurality of buffers for MIDs whose resistance to data loss is to be increased.
[0052]
Further, since the data controller 44 sequentially checks the presence / absence of data in the buffer 431, the existence of data to be transferred from the buffer group 43 to the transmission buffers 421 to 423 and transmitted to the multiplex communication lines 21 to 23 is surely known. It is done.
[0053]
Note that the buffer group 43 assigns the buffer 431 of the buffer # 431 to the important data type that should be relayed particularly quickly, for example, the data type with a higher priority (PRI), so that important data can be quickly transferred to the relay destination. It can transmit to the multiple communication lines 21-23.
[0054]
Each time the data controller 44 starts up, in the data transfer processing from the buffer group 43 to the transmission buffers 421 to 423, the data to be transmitted is confirmed for all the relay target MIDs. Data transfer processing is performed for the buffer 431 in the first half of the buffer # 43 of the buffer group 43, and data transfer processing is performed for the buffer 431 in the second half of the buffer # when it rises next. You may make it go around the group 43. In this case, with respect to the buffer 431 corresponding to the important data type, the important data is promptly transmitted to the relay destination multiplex communication lines 21 to 23 by performing both of the two data transfer processes. Can do.
[0055]
Note that the presence / absence of data in the buffer 431 is confirmed only in the buffer 431 having the number of stages 1 in the multi-stage buffer 431 as shown in FIG. 11A showing the method of the present embodiment. It is good. Other than this method As shown in FIG. 11B, for some or all of the multi-stage buffer 431, after confirming the buffer n (1), all the buffers n (k) of the MID may be confirmed. , (C), from buffer n (1) to a predetermined number of stages of buffer n (k) There is also a method, but by adopting the method of this embodiment of FIG. Transfer of data stored in buffer 431 at the earliest time in the same MID But It will be done preferentially.
[0056]
In this case, as shown in FIG. 12, the transmission buffers 421 to 423 (421 in the example) are configured in a plurality of stages to process data in the FIFO type, and transmitted to the multiplex communication line 21 in the order transferred from the buffer 431. The data relay may be performed more smoothly.
[0057]
(Second Embodiment)
FIG. 13 shows the configuration of a data relay device and a multiple communication system according to the second embodiment of the present invention. The data relay device 4A of the present embodiment is obtained by replacing the data relay device 4A with another data controller in the configuration of the first embodiment. In the data controller of the first embodiment, the buffer checking means fixes the start buffer # and the end buffer #, respectively, and checks the presence or absence of data from the buffer 1 to the buffer N in order, and performs data transfer processing. In the data controller 44A of the present embodiment, the data transfer management unit 442A is set to change the start buffer # and the end buffer # and shift the confirmation order each time it starts up. The difference from the first embodiment will be mainly described.
[0058]
FIG. 14 shows data transfer processing from the buffer group 43 to the transmission buffers 421 to 423 in the data controller 44A of the data relay apparatus 4A. In step S200, the start buffer # in the previous data transfer process is incremented by one. In a succeeding step S201, it is confirmed whether or not the start buffer # exceeds N. If not, the end buffer # is set as the start buffer # -1. That is, the transfer process from the buffer group 43 to the transmission buffers 421 to 423 including confirmation of the presence or absence of data in the buffer 431 is completed in the buffer of the buffer # immediately before the start buffer #.
[0059]
In the next step S204, n is set as the start buffer #, and in step S205, it is confirmed whether or not data is written in the buffer n. If it is written, the data is written by the same procedure as in FIGS. The transfer process is performed for the buffer n, and the process proceeds to step S206. If not written (step S205), the process proceeds to step S206 as it is.
[0060]
In step S206, it is confirmed whether or not n is an end buffer #. If n is not an end buffer #, steps S207 and S208 are executed, and then the procedure of the above-described step S205 is executed and the buffer 431 of the next buffer # is executed. Continue the data transfer process. Here, steps S207 and S208 are procedures for updating n to the serial number of the buffer 431 to be checked next. In step S207, n is incremented by 1. In step S208, it is confirmed whether or not n is greater than or equal to N. If it is less than N, the process returns to step S205, and the presence or absence of data is confirmed for n incremented in step S207, that is, the buffer 431 of the next buffer #. In this way, n sequentially increases and finally becomes N. In this case, the process proceeds from step S208 to step S209, n is set to 1, and the process returns to step S205. It is because the buffer 1 is checked next to the buffer N. In this way, the data transfer process is executed for all N buffers 431.
[0061]
In this data transfer process, the start buffer # and the end buffer # are sequentially shifted every time one search is performed, so that it is possible to prevent the degree of delay in data transfer between MIDs from being biased. it can. For example, in the example of FIGS. 4 and 5, the data transferred to the second multiplex communication line 22 is three data V, Y, and Z. Since the data V is held in the buffer 1, the data Y is held in the buffer 4, and the data Z is held in the buffer 5, the data controller 44 of the first embodiment in which the confirmation of the presence / absence of data is always started from the buffer 1 When the transmission buffer 422 is written with the data V transferred from, the data Y cannot be written (see step S113). Further, when any of the data V and Y is written in the transmission buffer 422, the data Z cannot be written. Therefore, the data Y is less likely to be transferred to the transmission buffer 422 than the data V and the data Z is delayed in the data relay device 4 as compared to the data V and Y. On the other hand, the data controller 44A of the present embodiment shifts the confirmation order of the presence / absence of data every time one search is made, so that data is transmitted fairly between the buffers 1 to N. The data can be transferred to the buffers 421 to 423. In addition, since the confirmation order is not fixed, the time required for data relay can be averaged between the buffers 431.
[0062]
In this data transfer process, the initial value of the start buffer # when the data relay device 4A is activated may be set to any one of 1 to N.
[0063]
(Third embodiment)
FIG. 15 shows a data relay device and a multiple communication system according to the third embodiment of the present invention. The difference from the first embodiment will be mainly described.
[0064]
The data relay device 4B is provided with a transmission data list 46. The transmission data list 46 can be schematically represented as shown in FIG. Information specifying the buffer 431 in which data to be transmitted to each of the multiplex communication lines 21 to 23 is stored includes the MID and the number of stages, and indicates whether or not the data should be transmitted for each of the multiplex communication lines 21 to 23. Includes transfer destination management flag. Similarly to the transfer destination flag of the first embodiment, “1” indicates that transfer is required, and “0” indicates that transfer is not required. The rank indicates the order of writing in the transmission data list 46.
[0065]
From the transmission data list 46, paying attention to one of the multiplex communication lines 21 to 23, if the transfer destination management flag is “1”, the data to be transferred is transferred from the reception buffers 411 to 413 to the buffer 431. If there are a plurality of transfer destination management flags of “1”, the transfer order is known. In other words, transfer is performed from the one with the highest priority. In the illustrated example, the transmission order of the first multiplex communication line 21 indicates that the first place is MID = C8h and the number of stage 2 buffer 431, and the second place is MID = 92h and the number of stage 1 buffer 431. Further, the transmission order of the third multiplex communication line 23 indicates that the first place is the buffer 431 having MID = 5Fh and two stages. The storage area of the transmission data list 46 is set on the RAM constituting the data relay device 4B.
[0066]
The data controller 44B is provided with data transfer management means 442B activated during data transfer processing from the reception buffers 411 to 413 to the buffer group 43 and data transfer processing from the buffer group 43 to the transmission buffers 421 to 423. The transmission data list 46 is updated, for example, the buffer information (MID and number of stages) of the buffer 431 for storing the received data and the transfer destination management flag are added to the transmission data list 46.
[0067]
Data transfer processing executed by the data controller 44B will be described with reference to FIGS. 17, 18, 19, 20, 21, and 22. FIG. 17 to 19 show data transfer processing from the reception buffers 411 to 413 to the buffer group 43, and FIGS. 20 to 22 show data transfer processing from the buffer group 43 to the transmission buffers 421 to 423.
[0068]
Data transfer processing to the buffer group 43 is processing for transferring data received from the first multiplex communication line 21 in steps S300 to S305 (FIG. 17), and steps S306 to S311 (FIG. 18) in the second multiplex communication line 22. The process of transferring data received from the third multiplex communication line 23 is performed in steps S312 to S317 (FIG. 19). Note that steps S300 to S302, S306 to S308, and S312 to S314 are procedures as the buffer specifying unit 441, and steps S301 to S304, steps S307 to S310, and steps S313 to S316 are procedures as the data transfer management unit 442B. .
[0069]
In step S300, it is confirmed whether the reception buffer 411 for the first multiplex communication line is empty. If not, the MID of the reception data stored in the reception buffer 411 is confirmed in step S301, and the reception data is determined in step S302. Is confirmed. In this case, if the MID is one to which a plurality of buffers are assigned, a storage destination that does not store data is selected. The selection method when there are a plurality of empty buffers 431 in which no data is stored is arbitrary. If data has been stored in all the buffers 431 assigned to the MID, the last buffer 431 in the transmission data list 46 with the same MID is selected as the storage destination of the received data. Next, the transfer destination of the received data is acquired based on the data transfer destination table 45 in step S303.
[0070]
In step S304, the buffer information acquired in steps S301 to S303 and the initial value of the transfer destination management flag are added to the end of the transmission data list 46. Here, the transfer destination management flag is set to “1” for the multiplexed communication lines 21 to 23 to be transferred. In the case where overwriting is performed, such as when the last buffer 431 of the transmission data list 46 is selected as the storage destination of received data in step S302, only the transfer destination management flag of the transmission data list 46 is set in step S303. Reset based on the acquired transfer destination.
[0071]
In the subsequent step S305, the data in the reception buffer 411 for the first multiplex communication line is transferred to the predetermined buffer 431 confirmed in steps S301 and S302 in the buffer group 43. Then, the process proceeds to a process of transferring data received from the second multiplex communication line 22 (steps S306 to S311). When the reception buffer 411 for the first multiplex communication line is empty in step S300, steps S301 to S305 are skipped, and the data received from the second multiplex communication line 22 is transferred (steps S306 to S311). Transition.
[0072]
In step S306, it is confirmed whether or not the reception buffer 412 for the second multiplex communication line is empty. If not, the MID of the reception data stored in the reception buffer 412 in step S307 is the same as in steps 301 to 305. In step S308, the number of stages of the buffer 431 that stores the received data is confirmed. In step S309, the transfer destination of the received data is acquired based on the data transfer destination table 45.
[0073]
Next, in step S310, the transmission data list 46 is updated with the buffer information and transfer destination management flag acquired in steps S307 to S309. In step S311, the data in the reception buffer 412 for the second multiplex communication line is stored in the buffer group 43. Among them, the data is transferred to the predetermined buffer 431 confirmed in steps S307 and S308. Then, the process proceeds to a process of transferring data received from the third multiplex communication line 23 (steps S312 to S318). If the reception buffer 412 for the second multiplex communication line is empty in step S306, steps S307 to S311 are skipped, and the process proceeds to transfer processing of data received from the third multiplex communication line 23 (step S312 to step S312). S317).
[0074]
In step S312, it is confirmed whether or not the reception buffer 413 for the third multiplex communication line is empty. If not, the MID of the reception data stored in the reception buffer 413 in step S313 is the same as in steps 301 to 305 above. In step S314, the number of stages of the buffer 431 that stores the received data is confirmed. In step S315, the transfer destination of the received data is acquired based on the data transfer destination table 45.
[0075]
Next, in step S316, the transmission data list 46 is updated with the buffer information and transfer destination management flag acquired in steps S313 to S315. In step S317, the data in the reception buffer 413 for the third multiplex communication line is stored in the buffer group 43. Among them, the data is transferred to the predetermined buffer 431 confirmed in steps S314 and S315, and the data transfer process is terminated. If the reception buffer 413 for the third multiplex communication line is empty in step S312, steps S313 to S317 are skipped, and the data transfer process is terminated.
[0076]
Next, data transfer processing from the buffer 431 to each of the transmission buffers 421 to 423 will be described. Steps S400 to S407 (FIG. 20) are data transfer processing from the buffer 431 to the first multiplex communication line transmission buffer 421, and steps S408 to S415 (FIG. 21) are processing to the second multiplex communication line transmission buffer 422. Data transfer processing, and steps S416 to S423 (FIG. 22) are data transfer processing to the third multiplex communication line transmission buffer 423. Steps S400 to S406, steps S408 to S414, and steps S416 to S422 are procedures as the data transfer management unit 422B.
[0077]
In step S400, it is confirmed whether or not the transmission buffer 421 for the first multiplex communication line is empty. If it is empty, the process proceeds to step S401 and all the transfer destination management flags for the first multiplex communication line in the transmission data list 46 are “ Confirm whether it is “0”. If a negative determination is made, that is, if there is data to be transferred from the buffer 431 to the transmission buffer 421 for the first multiplex communication line, the process proceeds to step S402, and the transfer control flag for the first multiplex communication line is “1”. The highest buffer information (MID and number of stages) is acquired. In the subsequent step S403, the data in the buffer 431 corresponding to the acquired buffer information in the buffer group 43 is transferred to the transmission buffer 421 for the first multiplex communication line. Then, in the transmission data list 46, the highest one of the transfer destination management flags for the first multiplex communication line taking “1” is cleared (“0”).
[0078]
In subsequent step S405, other transfer destination management flags of the data for which the transfer destination management flag has been cleared, that is, transfer destination management flags for the second and third multiplex communication lines, are checked, and all transfer destination management flags are set to “ If it is “0”, the information (buffer information and transfer destination management flag) of data that has been transmitted to the transmission buffer 421 in step S406 is deleted from the transmission data list 46, and the following low-order information is advanced. In step S407, the data that has been transmitted to the transmission buffer 421 is deleted from the buffer 431. Then, the process proceeds to step S408. If a positive determination is made in step S405, steps S406 and S407 are skipped and the process proceeds to step S408.
[0079]
As described above, data is transferred from the buffer 431 to the transmission buffer 421 as soon as the transmission buffer 421 becomes empty in the order written in the transmission data list 46, whereupon the transmission wait state to the first multiplex communication line 21 is awaited. Note that if data has already been written in the transmission buffer 421 in step S400, if affirmative determination is made in step S401, that is, if there is no data to be transferred to the first multiplex communication line 21, step S408 (FIG. 21). )
[0080]
In steps S408 to S415, the same procedure as in steps S400 to S407 is performed for the transmission buffer 422 for the second multiplex communication line, the buffer 431 that holds data to be transferred to the transmission buffer 422, and the transmission data list 46. That is, if the second multiplex communication line transmission buffer 422 is empty (step S408) and the second multiplex communication line transfer destination management flag in the transmission data list 46 is "1" (step S409), The highest-order buffer information is acquired from the two-multiplex communication line transfer destination management flag “1” (step S410), and the data in the buffer 431 corresponding to the acquired buffer information is transferred to the transmission buffer 422 (step S410). S411). Then, the highest transfer destination management flag for the second multiplex communication line in the transmission data list 46 is cleared (step S412).
[0081]
Next, in step S413, other transfer destination management flags for the transferred data, that is, transfer destination management flags for the first and third multiplex communication lines are confirmed, and all transfer destination management flags are “0”. If so, in step S414, the information on the data that has been transmitted to the transmission buffer 422 is deleted from the transmission data list 46, and the lower order information is carried forward. In step S415, the data that has been transmitted to the transmission buffer 422 is completed. Is deleted from the buffer 431. Then, the process proceeds to step S416 (FIG. 22).
[0082]
In steps S416 to S423, the same procedure as in steps S400 to S407 is performed for the transmission buffer 423 for the third multiplex communication line, the buffer 431 that holds data transferred to the third multiplex communication line, and the transmission data list 46. That is, if the third multiplex communication line transmission buffer 423 is empty (step S416) and the third multiplex communication line transfer destination management flag in the transmission data list 46 has a value of "1" (step S417), The highest-order buffer information among those having the transfer destination management flag for three multiplexed communication lines “1” is acquired (step S418), and the data in the buffer 431 corresponding to the acquired buffer information is transferred to the transmission buffer 423 (step S418). S419). Then, the highest one of the third multiplex communication line transfer destination management flags in the transmission data list 46 is cleared (step S420).
[0083]
Next, in step S421, other transfer destination management flags for the transferred data, that is, transfer destination management flags for the first and second multiplex communication lines are confirmed, and all transfer destination management flags are “0”. If so, in step S422, the information of the data that has been transmitted to the transmission buffer 423 is deleted from the transmission data list 46, and the lower order information is carried forward. In step S423, the data that has been transmitted to the transmission buffer 423 is completed. Is deleted from the buffer 431. Thereby, the data transfer from the buffer 431 to the transmission buffers 421 to 423 is completed.
[0084]
The data transfer process of the data controller 44B is set as described above, and in the transmission data list 46, information on data to be transmitted to the multiplex communication lines 21 to 23 is updated. The upper one of the transmission data list 46 is data received earlier. Therefore, in each of the multiplex communication lines 21 to 23, the transmission buffers 421 to 423 are in a transmission waiting state in the order in which the data to be relayed is received. Even without checking the presence or absence of data for all the buffers 431, the buffer storing the data to be transmitted written in the buffer 431 is known from the transmission data list 46, so that data can be relayed promptly.
[0085]
(Fourth embodiment)
FIG. 23 shows a data relay device and a multiple communication system according to the fourth embodiment of the present invention. The difference from the third embodiment will be mainly described.
[0086]
In the data relay device 4C, transmission data lists 461, 462, and 463 are provided for each of the multiple communication lines 21 to 23. The transmission data lists 461 to 463 are information in which data (MID and the number of stages) of buffers storing data to be transmitted to the multiplex communication lines 21 to 23 are written in the order of transmission, and are schematically shown in FIGS. (B), as shown in FIG. This is different from the transmission data list of the third embodiment in that the transfer destination management flag is not included. In the example of the figure, the transmission order to the first multiplex communication line 21 is the data stored in the buffer 431 with MID = C8h and the number of stages 2 in the first place, and the second place is the data in the buffer 431 with MID = 92h and the number of stages 1 Indicates data. The storage areas of the transmission data lists 461 to 463 are set on the RAM constituting the data relay device 4C.
[0087]
The data controller 44C is provided with data transfer management means 442C that is activated during data transfer processing from the reception buffers 411 to 413 to the buffer group 43.
[0088]
Data transfer processing executed by the data controller 4C will be described with reference to FIGS. 25, 26, 27, 28, 29, and 30. FIG. 25 to 27 show data transfer processing from the reception buffers 411 to 413 to the buffer group 43, and FIGS. 28 to 30 show data transfer processing from the buffer group 43 to the transmission buffers 421 to 423.
[0089]
The data transfer process to the buffer group 43 is a process of transferring data received from the first multiplex communication line 21 in steps S500 to S508 (FIG. 25), and steps S509 to S517 (FIG. 26) are the second multiplex communication line 22. The data received from the third multiplex communication line 23 is transferred from step S518 to S526 (FIG. 27). Steps S500 to S502, S509 to S511, and S518 to S520 are procedures as the buffer specifying means 441, and steps S501 to S507, steps S510 to S516, and steps S519 to S525 are procedures as the data transfer management means 442C. .
[0090]
In step S500, it is confirmed whether or not the reception buffer 411 for the first multiplex communication line is empty. If not, the MID of the reception data stored in the reception buffer 411 is confirmed in step S501, and the MID is determined in step S502. The number of stages of the buffer 431 for storing the data is confirmed. In step S503, the transfer destination of the received data is acquired based on the data transfer destination table 45.
[0091]
In a succeeding step S504, it is confirmed whether or not the acquired transfer destination has the transmission buffer 422 for the second multiplex communication line. If the determination is affirmed, the process proceeds to a step S505. In step S505, the buffer information (MID and the number of stages) confirmed in steps S501 and S502 is added to the end of the transmission data list 462 for the second multiplex communication line 22, and the process proceeds to step S506. In step S506, it is confirmed whether or not there is a transmission buffer 423 for the third multiplex communication line at the acquired transfer destination, and if affirmed, the process proceeds to step S507. In step S507, the buffer information (MID and the number of stages) confirmed in steps S501 and S502 is added to the end of the transmission data list 463 for the third multiplex communication line 23, and the process proceeds to step S508. When the same buffer information already exists in the transmission data lists 462 and 463 in steps S505 and S507, the buffer information is additionally written and the buffer information already written in the transmission data lists 462 and 463 is deleted.
[0092]
In step S508, the data in the reception buffer 411 for the first multiplex communication line is transferred to a predetermined buffer 431 specified by the buffer information in the buffer group 43. Then, the process proceeds to transfer processing of data received from the second multiplex communication line 22 (steps S509 to S517). When the reception buffer 411 for the first multiplex communication line is empty in step S500, additional processing (steps S501 to S507) and data transfer to the transmission data lists 462 and 463 for the second and third multiplex communication lines are performed. The process (step S508) is skipped, and the process proceeds to a process for transferring data received from the second multiplex communication line 22 (steps S509 to S517).
[0093]
In step S509, it is confirmed whether or not the reception buffer 412 for the second multiplex communication line is empty. If not, the MID of the reception data stored in the reception buffer 412 is confirmed in step S510, and the MID is determined in step S511. The number of stages of the buffer 431 for storing the data is confirmed. In step S512, the transfer destination of the received data is acquired based on the data transfer destination table 45.
[0094]
In a succeeding step S513, it is confirmed whether or not the acquired transfer destination has the transmission buffer 421 for the first multiplex communication line. In step S514, the buffer information (MID and the number of stages) confirmed in steps S510 and S511 is added to the end of the transmission data list 461 for the first multiplex communication line 21, and the process proceeds to step S515. In step S515, it is confirmed whether or not there is a transmission buffer 423 for the third multiplex communication line at the acquired transfer destination, and if affirmed, the process proceeds to step S516. In step S516, the buffer information (MID and the number of stages) confirmed in steps S510 and S511 is added to the end of the transmission data list 463 for the third multiplex communication line 23, and the process proceeds to step S517. When the same buffer information already exists in the transmission data lists 461 and 463 in steps S514 and S516, the buffer information is additionally written and the buffer information already written in the transmission data lists 461 and 463 is deleted.
[0095]
In step S517, the data in the reception buffer 412 for the second multiplex communication line is transferred to the buffer 431 specified by the buffer information in the buffer group 43. Then, the process proceeds to a process of transferring data received from the third multiplex communication line 23 (steps S518 to S526). When the reception buffer 412 for the second multiplex communication line is empty in step S509, additional processing (steps S510 to S516) and data transfer to the transmission data lists 461 and 463 for the first and third multiplex communication lines are performed. The process (step S517) is skipped, and the process proceeds to a process for transferring data received from the third multiplex communication line 23 (steps S518 to S526).
[0096]
In step S518, it is confirmed whether or not the reception buffer 413 for the third multiplex communication line is empty. If not, the MID of the reception data stored in the reception buffer 413 is confirmed in step S519, and the MID is determined in step S520. The number of stages of the buffer 431 for storing the data is confirmed. In step S521, the transfer destination of the received data is acquired based on the data transfer destination table 45.
[0097]
In a succeeding step S522, it is confirmed whether or not the acquired transfer destination has the transmission buffer 421 for the first multiplex communication line, and if affirmative, the process proceeds to a step S523. In step S523, the buffer information (MID and the number of stages) confirmed in steps S519 and S520 is added to the end of the transmission data list 461 for the first multiplex communication line 21, and the process proceeds to step S524. In step S524, it is confirmed whether or not there is the second multiplex communication line transmission buffer 422 in the acquired transfer destination. If the result is affirmative, the process proceeds to step S525. In step S525, the buffer information (MID and number of stages) confirmed in steps S519 and S520 is added to the end of the transmission data list 462 for the second multiplex communication line 22, and the process proceeds to step S526. When the same buffer information already exists in the transmission data lists 461 and 462 in steps S523 and S525, the buffer information is added and the buffer information already written in the transmission data lists 461 and 462 is deleted.
[0098]
In step S526, the data in the reception buffer 413 for the third multiplex communication line is transferred to the predetermined buffer 431 specified by the buffer information in the buffer group 43, and the data transfer processing from the reception buffers 411 to 413 to the buffer 431 is performed. Exit. When the reception buffer 413 for the third multiplex communication line is empty in step S518, additional processing (steps S519 to S525) and data transfer to the transmission data lists 461 and 462 for the first and second multiplex communication lines are performed. The process (step S526) is skipped, and the data transfer process is terminated.
[0099]
Next, data transfer processing from the buffer 431 to each of the transmission buffers 421 to 423 will be described. Steps S600 to S606 (FIG. 28) are data transfer processing from the buffer 431 to the first multiplex communication line transmission buffer 421, and steps S607 to S613 (FIG. 29) are processing to the second multiplex communication line transmission buffer 422. Data transfer processing, and steps S614 to S620 (FIG. 30) are data transfer processing to the third multiplex communication line transmission buffer 423. Steps S601 to S604, steps S608 to S611, and steps S615 to S618 are procedures as the data transfer management unit 442C.
[0100]
In step S600, it is confirmed whether or not the transmission buffer 421 for the first multiplex communication line is empty. If it is empty, the process proceeds to step S601 to check whether or not the transmission data list 461 for the first multiplex communication line is empty. . If the transmission data list 461 is not empty, that is, if there is data to be transferred from the buffer 431 to the transmission buffer 421, the process proceeds to step S602, and the top buffer information of the transmission data list 461 is acquired. In step S603, the data in the buffer 431 specified by the acquired buffer information in the buffer group 43 is transferred to the transmission buffer 421 for the first multiplex communication line. Next, the top buffer information of the transmission data list 461, that is, the information of the data transferred in step S603 is deleted, and the lower order information is moved up.
[0101]
In subsequent step S605, it is determined whether there is the same buffer information deleted in step S604 in the second and third multiplex communication line transmission data lists 642, 643. If the determination is negative, step S606 is performed. In step S603, the data is deleted from the buffer 431 in which the data that has been transferred is stored, and the process advances to step S605. As described above, the data is transferred from the buffer 431 to the transmission buffer 421 as soon as the transmission buffer 421 becomes empty in the order written in the transmission data list 461, and the transmission wait state to the first multiplex communication line 21 is entered. If data has already been written in the transmission buffer 421 in step S600, and the transmission data list 461 is empty in step S601 and there is no data to be transferred, steps S602 to S606 are skipped and step S607 (FIG. Proceed to 29).
[0102]
In steps S607 to S613, the same procedure as in steps S600 to S606 is performed for the transmission buffer 422 for the second multiplex communication line, the buffer 431 that holds data to be transferred to the transmission buffer 422, and the transmission data list 462. That is, if the transmission buffer 422 for the second multiplex communication line is empty (step S607) and there is a write in the transmission data list 462 for the second multiplex communication line (step S608), the top buffer information of the transmission data list 462 (Step S609), and the data is transferred from the buffer 431 specified by the buffer information to the transmission buffer 422 (step S610). Then, the buffer information of the head data in the transmission data list 462, that is, the buffer of the data that has been transferred is deleted, and the following low-order information is moved up (step S611).
[0103]
Next, if the first and third multiplex communication line transmission data lists 641 and 643 do not have the same buffer information deleted in step S611 (step S612), the buffer in which the data that has been transferred in step S610 is stored. Data is deleted from 431 (step S613), and the process proceeds to step S614 (FIG. 30).
[0104]
In steps S614 to S620, the same procedure as in steps S600 to S606 is performed for the transmission buffer 423 for the third multiplex communication line, the buffer 431 that holds data transferred to the third multiplex communication line, and the transmission data list 463. That is, if the transmission buffer 423 for the third multiplex communication line is empty (step S614) and there is a write in the transmission data list 463 for the third multiplex communication line (step S615), the top buffer information of the transmission data list 463 Is read (step S616), and the data is transferred from the buffer 431 specified by the buffer information to the transmission buffer 423 (step S617). Then, the buffer information of the head data in the transmission data list 463, that is, the buffer information of the transferred data is deleted, and the following low-order information is moved up (step S618).
[0105]
Next, if the first and second multiplex communication line transmission data lists 641 and 642 do not have the same buffer information deleted in step S618 (step S619), the buffer in which the data transferred in step S617 is stored is stored. Data is deleted from 431 (step S620), and the transfer processing from the buffer 431 to the transmission buffers 421 to 423 is terminated.
[0106]
The data transfer process of the data controller 44C is set as described above, and in each transmission data list 461 to 463, buffer information of data to be transmitted to the corresponding multiplexed communication lines 21 to 23 is updated. The order in the transmission data list 461 to 463 is the order of reception. For example, in the example of FIG. 24 described above, in the transmission data list 461 for the first multiplex communication line, C8h data in the first transmission order is transferred from the buffer group 431 to the transmission buffer 421, and buffer information ( Assuming that MID = C8h, stage number 2) is deleted, this buffer information (MID = C8h, stage number 2) does not include the transmission data lists 462 and 463 for the second and third multiplex communication lines. From this, it is known that the data in the buffer 431 specified by the buffer information (MID = C8h, number of stages 2) has been completely transferred, and is deleted from the buffer 431.
[0107]
Even if the data with the same MID = C8h is transmitted, even if the data of the first transmission order in the transmission data list 462 for the second multiplex communication line (MID = C8h, number of stages 1) is transmitted, the same buffer information is stored. Even if the buffer information (MID = C8h, number of stages 1) is deleted from the transmission data list 461 for the first multiplex communication line and the transmission data list 462 for the second multiplex communication line is deleted, the data stored in the buffer 431 remains It is not deleted but is basically held until it is transmitted to the transmission buffer 421 for the first multiplex communication line.
[0108]
As a result, as in the third embodiment, the buffer 431 storing the data to be transmitted written in the buffer 431 is known from the transmission data lists 461 to 463 without checking the presence or absence of data for all the buffers 431. Therefore, data can be relayed promptly. Moreover, since the transmission order to each of the multiplex communication lines 21 to 23 is the order of reception, it is possible to reliably transmit all received data without delay.
[0109]
In addition, since the transmission data lists 461 to 463 are arranged in the order in which the buffer information is transferred for each of the multiple communication lines 21 to 23, the buffer information of the same MID corresponding to each of the multiple communication lines 21 to 23 is provided. Are arranged, even if the transfer to a certain transmission buffer 421 to 423 is completed, the data is not deleted, but the next data to be transferred to the same transmission buffer 421 to 423 is not mistaken.
[0110]
In addition, for some MIDs, such as C8h in the illustrated example, by assigning a plurality of buffers 431, a plurality of data of the same MID received by the data relay device 4C in succession are all set as data to be transmitted. Since entry can be made in the transmission data lists 461 to 463, resistance against data loss can be increased.
[0111]
In each of the above embodiments, data is overwritten when data is received and the buffer is not empty. However, the data controller temporarily holds the transfer to the buffer while holding the data in the reception buffer. You may set as follows. Overwriting can be avoided if the buffer is free in the meantime. In this case, as shown in FIG. 31, a plurality of reception buffers 411 are provided for each multiplex communication line 21 to process data in the FIFO type, avoiding overwriting in the buffer 431 and ensuring the data reception operation from the multiplex communication line 21. Can be achieved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first data relay device and a multiple communication system according to the present invention.
FIG. 2 is a diagram showing a frame structure of communication data of the first data relay device and the multiple communication system of the present invention.
FIG. 3 is a diagram showing a correspondence relationship between types of communication data and their MIDs in the first data relay device and the multiple communication system of the present invention.
FIG. 4 is a schematic diagram of a buffer of the first data relay device of the present invention.
FIG. 5 is a diagram showing a correspondence relationship between data in the transfer destination table of the first data relay apparatus of the present invention and the transfer destination;
FIG. 6 is a first flowchart showing control executed in the data controller of the first data relay apparatus of the present invention.
FIG. 7 is a second flowchart showing the control executed in the data controller of the first data relay apparatus of the present invention.
FIG. 8 is a third flowchart showing the control executed in the data controller of the first data relay apparatus of the present invention.
FIG. 9 is a fourth flowchart showing the control executed in the data controller of the first data relay apparatus of the present invention.
FIGS. 10A and 10B are diagrams showing the operation of the first data relay device of the present invention, respectively.
FIGS. 11A and 11B are diagrams showing settings of the data controller, and FIGS. 11B and 11C are diagrams showing settings of modified examples, respectively.
FIG. 12 is a block diagram showing a modification of the data relay device and multiplex communication system of the present invention.
FIG. 13 is a configuration diagram of a second data relay device and a multiple communication system according to the present invention.
FIG. 14 is a flowchart showing the control executed in the data controller of the second data relay apparatus of the present invention.
FIG. 15 is a configuration diagram of a third data relay device and a multiple communication system according to the present invention.
FIG. 16 is a diagram showing a configuration of a transmission data list of the third data relay apparatus of the present invention.
FIG. 17 is a first flowchart showing control executed in the data controller of the third data relay device of the present invention;
FIG. 18 is a second flowchart showing the control executed in the data controller of the third data relay apparatus of the present invention.
FIG. 19 is a third flowchart showing the control executed in the data controller of the third data relay apparatus of the present invention.
FIG. 20 is a fourth flowchart showing the control executed in the data controller of the third data relay apparatus of the present invention.
FIG. 21 is a fifth flowchart showing the control executed in the data controller of the third data relay apparatus of the present invention.
FIG. 22 is a sixth flowchart showing the control executed in the data controller of the third data relay apparatus of the present invention.
FIG. 23 is a block diagram of a fourth data relay apparatus and multiple communication system according to the present invention.
FIGS. 24A, 24B, and 24C are diagrams showing the configuration of a transmission data list of the fourth data relay apparatus of the present invention, respectively.
FIG. 25 is a first flowchart showing the control executed in the data controller of the fourth data relay apparatus of the present invention.
FIG. 26 is a second flowchart showing the control executed in the data controller of the fourth data relay apparatus of the present invention.
FIG. 27 is a third flowchart showing the control executed in the data controller of the fourth data relay apparatus of the present invention.
FIG. 28 is a fourth flowchart showing the control executed in the data controller of the fourth data relay apparatus of the present invention.
FIG. 29 is a fifth flowchart showing the control executed in the data controller of the fourth data relay apparatus of the present invention.
FIG. 30 is a sixth flowchart showing the control executed in the data controller of the fourth data relay apparatus of the present invention.
FIG. 31 is a block diagram showing another modification of the data relay device and multiplex communication system of the present invention.
FIG. 32 is a configuration diagram of a typical example of a conventional data relay device and multiple communication system.
FIG. 33 is a schematic diagram of a main body of communication data.
[Explanation of symbols]
11, 12, 13 Communication system
21, 22, 23 Multiple communication lines
31, 32, 33 Communication node
4,4A, 4B, 4C Data relay device
411, 412 and 413 receive buffer
421, 422, 423 transmission buffer
43 Buffers
431 buffers
44, 44A, 44B, 44C Data controller
441 Buffer designation means
442, 442A, 442B, 442C Data transfer management means
45 Destination table
46,461,462,463 transmission data list

Claims (5)

A data relay device for relaying a plurality of types of data, which is interposed between multiplex communication lines for transmitting data including data type information together with the data body, and a multiplex communication line to which received data is relayed In a data relay apparatus having a data controller that selects and transfers received data,
A buffer that temporarily holds received data before transmission to the relay destination multiplex communication line is provided for each type of data to be relayed, and a plurality of buffers are assigned to one or more data types among the data types,
The data controller identifies a type of received data, and designates a buffer corresponding to the type as a write destination of the received data; and
Data transfer that manages the transfer of data from the buffer in which the data is stored so that the order in which the data from the same type of data is transferred in each multiplex communication line is the order in which the data is written to the buffer Management means,
The data transfer management means rises at a predetermined time interval, sequentially checks whether or not there is data to be transmitted in the buffer, and transfers data from the buffer if there is data. A data relay device characterized in that the presence or absence of data is set to be checked only for the buffer storing the data first . 2. The data relay apparatus according to claim 1, wherein the data transfer managing means corresponds to the selected multiplex communication line for transferring the data in the buffer in which the data is stored first for a buffer of the same data type. The data relay device is set so that the data received first among the data in the other buffers having the same data type is moved to the buffer in which the data is stored first . 2. The data relay device according to claim 1, comprising buffer information for identifying a buffer in which data is stored, wherein the order of the buffer information in the same selected multiplex communication line is the order in which the data is transferred from the buffer. Provide a list,
A data relay apparatus in which the data transfer management means is set to update the transmission data list in response to writing of data into a buffer and transfer of data from the buffer . 4. The data relay device according to claim 3, wherein the transmission data list is stored in the buffer by providing an initial value for each multiplex communication line based on buffer information for specifying a buffer and the transfer destination table. And management information on whether or not to transfer,
A data relay apparatus in which the data transfer management means is set to switch the management information to information indicating that data transmission is unnecessary in accordance with the transfer of data from the buffer . 5. A multiplex communication system comprising: the data relay device according to claim 1; and a plurality of communication systems in which communication nodes for transmitting and receiving data are connected to the multiplex communication line.

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