JP2007116364A - Data transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the abnormality of a signal line connecting a data transmitter and a hub device. <P>SOLUTION: When a data signal 9 is received to the hub device 1 from an information terminal 4 through the data transmitter 5a, the signal line 3, and a connecting port 2; the data transmission system adds a data-signal relay means for outputting the data signal to the signal line from the connecting port corresponding to the information terminal 4 specified by a destination address, and a data-signal return means for returning and outputting the received data signal to the signal line corresponding to the information terminal specified by a transmission-origin address. The time elapsed until the data signals 9 are received from the hub device 1 after the data signal from its own information terminal is transmitted to the hub device is measured in the data transmitters 5a incorporated into each information terminal. When the measured elapsed time exceeds a threshold value, a time monitor means 12 outputting the abnormality of the signal line is added. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a network system in which a plurality of information terminals are connected to a hub device through signal lines, and data transmission using the Ethernet standard (IEEE 802.3) is performed between the information terminals via the hub device. The present invention relates to a data transmission system including a hub device incorporated in the network system and a data transmission device incorporated in each information terminal connected to the hub device via an Ethernet standard signal line.

  In a network system that performs data transmission using the Ethernet standard (IEEE802.3) between information terminals via a hub device, data signals are transmitted to and received from other information terminals via the hub device. For example, a card-type data transmission apparatus is incorporated. The hub device is provided with a plurality of connection ports, and each connection port is connected to another hub device or a data transmission device of each information terminal. For the signal line connecting each connection port and the data transmission apparatus, 10Base-T is used when the transmission speed is 10 Mbps, and 100Base-TX or 100Base-FX is used when the transmission speed is 100 Mbps. As these signal lines, full-duplex signal lines capable of simultaneously performing transmission and reception between the data transmission apparatus and the data transmission apparatus are employed.

  In such a data transmission system, in order for the data signal output from each information terminal via the data transmission device to be correctly transmitted to the designated information terminal via the hub device, the hub device and each information terminal must It is assumed that no abnormality such as disconnection has occurred in the signal line connecting the built-in data transmission apparatus.

Therefore, the hub device and each data transmission device detect a failure of the signal line by monitoring a received signal from the connection destination and detecting a link up / link down state (LinkUp / LinkDown) ( For example, see Patent Document 1).
Japanese Patent Laid-Open No. 11-187030

  However, the above-described method for detecting an abnormality in the signal line still has the following problems that should be solved.

  That is, as described above, the Ethernet standard signal line connecting each connection port of the hub device and the data transmission device on the information terminal side is a downstream signal path for transmitting a data signal from the hub device to the data transmission device. And an upstream signal path for transmitting a data signal from the data transmission device to the hub device.

  Therefore, the data transmission device incorporated in each information terminal can confirm only the normality / abnormality of the downstream signal path through which the data signal from the hub device is transmitted, and the normality / abnormality of the upstream signal path cannot be confirmed. As a result, it is not possible to confirm whether or not the data signal output from the own information terminal to the upstream signal path has reached the target information terminal correctly.

  Conversely, on the hub device side, normality / abnormality of the upstream signal path to which the data signal from the data transmission device of each information terminal is input can be monitored, but the data signal is transmitted to the data transmission device of each information terminal. Normality / abnormality of the signal path cannot be confirmed.

  In addition, there is a problem that it is not possible to confirm whether or not correct data to be originally transmitted is transmitted on the data transmission system due to an abnormality in a transmission / reception circuit in the data transmission apparatus or an abnormality in a transmission / reception circuit in the hub apparatus.

  The present invention has been made in order to solve the above-described problems, and of course, there is a downstream signal path on the data transmission apparatus side through which a data signal is received by the own side among signal lines connecting the data transmission apparatus and the hub apparatus. The present invention provides a data transmission system that detects and outputs signal line abnormalities including the soundness of an upstream signal path through which a data signal is transmitted by itself and the soundness of transmission / reception circuits in a data transmission device and a hub device. For the purpose.

The present invention includes a plurality of data transmission devices incorporated in information terminals, a plurality of connection ports to which the data transmission devices are connected via Ethernet signal lines, and a destination address between the information terminals. In a data transmission system comprising a hub device that relays a data signal including a source address and data,
When a hub device receives a data signal from each information terminal via a data transmission device, a signal line, and a connection port, the data signal is output from the connection port corresponding to the information terminal specified by the destination address to the signal line. And a data signal return means for returning the received data signal to the signal line corresponding to the information terminal designated by the transmission source address.

  Further, the data transmission device incorporated in each information terminal measures the elapsed time from when the data signal from its own information terminal is transmitted to the hub device until the data signal is received from the hub device. A time monitoring means for outputting a signal line abnormality when the elapsed time counted exceeds a limit value is added.

  In the data transmission system configured as described above, the data signal of the transmission frame including the destination address, the transmission source address, and the data transmitted from the data transmission apparatus incorporated in each information terminal is transmitted on the signal line connected to itself. The signal is input to the hub device via the upstream signal path, and transmitted from the hub device to the information terminal specified by the destination address. Further, this data signal is returned to the downstream signal path of the same signal line and input to the data transmission device of the transmission source. Therefore, since this data signal passes through the upstream signal path and downstream signal path of the signal line to which the data transmission apparatus is connected, if the time from transmission to reception exceeds the limit value, the signal line is abnormal. It can be regarded as occurring.

  In another invention, the data signal loopback means of the hub device sends the received data signal to the signal line corresponding to the information terminal designated by the source address as a new data signal for the minimum transmission frame length of Ethernet. Output wrapping.

  In this way, the transmission source address is designated as a new data signal for the minimum transmission frame length of Ethernet in the received data signal without transmitting all the received data signals back to the data transmission device of the transmission source. By transmitting the data back to the data transmission device, the burden on the signal line can be reduced.

  In another invention, each data transmission device includes a transmission data length counting means for counting a data length of a data signal transmitted to the hub device, and a received data length counter for counting a data length of a data signal received from the hub device. And a data length monitoring means for outputting a signal line abnormality when the data length counted by the reception data length counting means does not match the data length counted by the transmission data length counting means.

  In the data transmission system configured as described above, it is confirmed that not only the elapsed time but also the data length of the returned data signal matches the data length of the transmitted data signal. The presence or absence of signal line abnormality can be inspected.

  In another invention, for each data transmission device, the received data length counting means for counting the data length of the data signal received from the hub device, and the data length counted by the received data length counting means are Ethernet Data length monitoring means for outputting a signal line abnormality if the data length does not match the minimum transmission frame data length.

  As described above, when the data transmission device receives the data signal having the data length of the minimum Ethernet transmission frame that has been returned, the data transmission device can count the data length of the received data signal in a short time, and the signal line is abnormal. Presence / absence determination can be performed efficiently.

  In another invention, a destination address rewriting means for rewriting the destination address in the data signal received from each information terminal to the source address included in the received data is added to the hub device, and the data signal loopback is performed. The means returns the data signal in which the destination address is rewritten to the source address to the signal line corresponding to the information terminal specified by the source address.

  Then, for each data transmission apparatus, transmission data storage means for temporarily storing data of the data signal transmitted to the hub apparatus, and the destination address and the transmission source address of the data signal received from the hub apparatus match the own address. A data reading means for reading the data of the data signal and a data content verification means for outputting a signal line abnormality if the data read by the data reading means does not match the data stored in the transmission data storage means. is doing.

  In the data transmission system configured as described above, the same own address (source address) is attached to the destination address and the source address of the data signal sent back from the hub device to the data transmission device. Since this data signal is a data signal addressed to itself, the actual data contained in this data signal is read and compared with the data of the previously transmitted data signal. If they do not match, a signal line abnormality is output. . Therefore, the signal line abnormality determination can be performed more strictly and efficiently.

  In another invention, the hub device has destination address rewriting means for rewriting the destination address in the data signal received from each information terminal to the source address included in the received data, and the data signal return means Of the data signal in which the destination address is rewritten to the source address, the Ethernet minimum transmission frame length is returned as a new data signal to the signal line corresponding to the information terminal specified by the source address.

  Then, for each data transmission device, the transmission data storage means for temporarily storing the data included in the portion corresponding to the minimum transmission frame length of Ethernet among the data of the data signal transmitted to the hub device, received from the hub device When the destination address and the source address of the data signal corresponding to the minimum transmission frame length of the Ethernet coincide with its own address, the data reading means for reading the data of the data signal, and the data read by the data reading means are the transmission Data content verification means for outputting a signal line abnormality if the data does not match the data stored in the data storage means is added.

  In the data transmission system configured as described above, each data transmission device reads data signal data corresponding to the minimum transmission frame length of Ethernet, and compares and verifies the transmitted data signal data with respect to the transmission data of the read data. Therefore, the signal line abnormality determination can be performed more efficiently.

  Furthermore, in another invention, the hub device in the data transmission system of the above invention includes a loopback execution control means for stopping the loopback output of the received data in the data signal loopback means in response to an external instruction. Each data transmission device also has time monitoring execution control means for stopping time monitoring in the time monitoring means in response to an external instruction.

  Furthermore, in another invention, each data transmission apparatus in the data transmission system of the above invention has data content verification execution control means for stopping the data content verification in the data content verification means in response to an external instruction.

  In each data transmission system configured in this way, the person in charge of the test, for example, when the inspection function for the signal line described above is added to only one of the hub device and each data transmission device. It is possible to stop the execution of both inspection functions.

  When the test is not performed, it is possible to improve the data transmission efficiency between normal information terminals by stopping the execution of both inspection functions.

  In the present invention, on the data transmission device side, of the signal lines connecting the data transmission device and the hub device, the self-side transmits the data signal as well as the downstream signal path on which the self-side receives the data signal. It is possible to detect and output signal line abnormalities including the soundness of the road and the soundness of the transmission / reception circuits in the data transmission device and the hub device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a schematic configuration of a network system in which a data transmission system according to each embodiment of the present invention is incorporated. For example, four connection ports 2 are provided in the hub device 1. Each connection port 2 is connected to a data transmission device 5 or another hub device 1 incorporated in the information terminal 4 via a full-duplex Ethernet signal line 3. The hub device 1 transmits a data signal input from each information terminal 4 via the signal line 3 to the information terminal 4 designated by the destination address of the data signal.

  The data transmission system according to the present invention includes a data transmission device 5 incorporated in each information terminal 4 in the network system described above, and a hub device 1 connected to each data transmission device 5 via a signal line 3. Yes.

(First embodiment)
FIG. 2 is a schematic diagram showing a schematic configuration of the data transmission system according to the first embodiment of the present invention. In the hub device 1, a LAN switch controller 6, an address table 7, a buffer memory 8, and a plurality of connection ports 2a, 2b,..., 2n are provided.

  Each of the connection ports 2a, 2b,..., 2n has a data transmission device 5a, 5b incorporated in each information terminal 4 via a 100Base-TX signal line 3 comprising an upstream signal path 3a and a downstream signal path 3b. ... 5n are connected. Each information terminal 4 is given an address (MAC address).

In the address table 7 in the hub device 1, as shown in FIG. 5, the addresses AD ₁ , AD ₂ , AD ₂ , AD ₂ , AD ₂ AD ₃ ,... And the numbers of connection ports 2 a, 2 b,..., 2 n to which the corresponding information terminal 4 (data transmission devices 5 a to 5 n) is connected or connected via another hub device 1 are registered. Yes.

  FIG. 4 is a frame configuration diagram of a data signal 9 transmitted and received between the data transmission devices 5a to 5n and the hub device 1. A 7-byte PA (preamble) is located at the beginning, followed by a 1-byte SFD (frame start limiter), followed by a 6-byte DA (destination address), a 6-byte SA (source address), A 2-byte TYP (used protocol type) follows, followed by data to be transmitted and a PAD, and finally a 4-byte FCS (frame check sequence). PAD (Padding) is a spare bit added when data does not reach the minimum frame length of Ethernet.

  FIG. 3 is a block diagram showing an outline of the data transmission device 5 a incorporated in the information terminal 4. Since the other data transmission devices 5b to 5n have almost the same configuration as the data transmission device 5a, the description thereof is omitted.

  The data transmission device 5a includes a transmission unit 10a that transmits a data signal 9 to the upstream signal path 3a of the signal line 3, a reception unit 10b that receives the data signal 9 from the downstream signal path 3b of the signal line 3, and a PHY (physical) The circuit 11, the loopback reception monitoring circuit 12 incorporating the time monitoring counter 13, the MAC circuit 14, the Ethernet driver processing unit 15, the IP processing unit 16, the ARP processing unit 17, the TCP / UDP processing unit 18, and the application processing unit 19 It is configured. The application processing unit 19 is formed in the information terminal 4.

  The LAN switch controller 6 of the hub device 1 in the data transmission system having such a configuration performs a relay process on the data signal 9 input from each of the data transmission devices 5a to 5n according to the flowchart of FIG.

  First, it is monitored whether or not the data signal 9 is received from the data transmission devices 5a to 5n for each of the connection ports 2a to 2n (S61), and when the data signal 9 is received, the data signal 9 is stored in the buffer memory 8 (S62). Thereafter, the address table 7 is searched to determine whether or not the transmission source address SA of the received data signal 9 has been registered in the connection ports 2a to 2n that have received data (S63). If not registered, the combination of the source address SA of the data signal 9 received this time and the connection ports 2a to 2n receiving the data signal 9 is registered in the address table 7 (S64).

  Next, the address table 7 is searched with the destination address DA in the received data signal 9, the connection ports 2a to 2n to which the data signal 9 is to be transferred are specified (S65), and the specified connection ports 2a to 2n are specified. The received data signal 9 is sent to the downstream signal path 3b of the signal line 3 (S66). Thereafter, the received data signal 9 is sent to the downstream signal path 3b of the signal line 3 of the connection ports 2a to 2n received this time (S67).

  In the data transmission device 5a, the application processing unit 19 in the information terminal 4 creates data to be transmitted by being incorporated in the data signal 9 of FIG. 4, and for this data, the TCP / UDP processing unit 18 and The IP processing unit 16 adds a 6-byte DA (destination address), a 6-byte SA (source address), and a 2-byte TYP (used protocol type) in FIG. Then, a data transmission request is issued to the Ethernet driver processing unit 15. The Ethernet driver processing unit 15 makes a transmission request to the MAC circuit 14. The MAC circuit 14 creates the data signal 9 of FIG. 4 by adding PA and SFD before [DA, SA, TYP, data] and adding FCF after that. Then, the MAC circuit 14 outputs the created data signal 9 to the PHY circuit 11, and the data signal 9 is transmitted onto the upstream signal path 3a of the signal line 3 through the transmission unit 10a.

  Here, the loopback diagnosis circuit 12 executes the monitoring control shown in FIG. That is, normally, the data signal 9 output from the MAC circuit 14 to the PHY circuit 11 is monitored with the elapsed time of the time monitoring counter 13 for return diagnosis set to 0 (S71). In this state, when it is detected that the output of the data signal 9 from the MAC circuit 14 to the PHY circuit 11 is started (S72), the time monitoring counter 13 is activated. Thereafter, the process proceeds to a monitoring process for determining whether any data is received from the PHY circuit 11 to the MAC circuit 14.

  When the data signal 9 received from the hub apparatus 1 via the downstream signal path 3b and transferred from the PHY circuit 11 to the MAC circuit 14 is detected (S73), the upstream signal path 3a The transmission path including the signal line 3 including the downstream signal path 3b is determined to be normal (S76), returns to S71, and waits for the next data signal 9 to be transmitted to the hub device 1.

  In S73, when the data signal 9 is not received, the time monitoring counter 13 is updated (S74), and the returned data signal 9 is not received even after the preset limit time has elapsed (S75). The transmission line including the signal line 3 composed of the upstream signal path 3a and the downstream signal path 3b is determined to be abnormal, and the transmission line abnormality is displayed and output to the information terminal 4 in which the data transmission device 5a is incorporated (S77).

  In the data transmission system of the first embodiment configured as described above, the data transmission device 5a incorporated in each information terminal 4 includes the data signal 9 having the frame configuration shown in FIG. 4 including the destination address, the transmission source address, and the data. Is input to the hub device 1 via the upstream signal path 3a of the signal line 3 connected to itself, and transmitted from the hub device 1 to the information terminal 4 specified by the destination address DA of the data signal 9. .

  Further, the data signal 9 input to the hub device 1 is turned back to the downstream signal path 3b of the same signal line 3 from which the data signal 9 has been transmitted, and is input to the transmission source data transmission device 5a. Therefore, since the data signal 9 passes through the upstream signal path 3a and the downstream signal path 3b of the signal line 3 to which the data transmission apparatus 5a is connected, the elapsed time from transmission to reception exceeds the limit value. It can be considered that an abnormality has occurred in the signal line.

  Thus, on the data transmission device 5a side, the data signal 9 is transmitted as well as the down signal path 3b for receiving the data signal 9 among the signal lines 3 connecting the data transmission device 5a and the hub device 1. It is possible to grasp the soundness of the upstream signal path 3a and the soundness of the transmission / reception circuits in the data transmission device 5a and the hub device 1.

  The present invention is not limited to the first embodiment described above. The LAN switch controller 6 of the hub device 1 omits the data portion of the data signal 9 having the frame configuration shown in FIG. 4 received from the data transmission device 5a via the upstream signal path 3a only to 40 bytes of data from the head. The remaining 64 bytes [PA (7) + SFD (1) + DA (6) + SA (6) + TYP (2) + data (40) + FCS (4)] data signal 9 is newly added for the minimum transmission frame length of Ethernet. It is also possible to return the data signal 9 to the downstream signal path 3b of the signal line 3 corresponding to the information terminal 4 designated by the transmission source address SA.

  In this way, the entire data signal 9 received is not transmitted back to the transmission source data transmission device 5a, and the new data signal 9 is transferred from the received data signal 9 for the minimum transmission frame length of 64 bytes of Ethernet. As described above, the transmission (traffic) burden on the signal line 3 can be reduced by returning the data to the data transmission device 5a designated by the transmission source address SA.

(Second Embodiment)
FIG. 8 is a block diagram showing a schematic configuration of the data transmission device 20 incorporated in each information terminal 4 in the data transmission system of the second embodiment of the present invention. The same parts as those of the data transmission apparatus 5a in the data transmission system of the first embodiment shown in FIG. 3 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted. Further, the hub device in the data transmission system of the second embodiment has substantially the same configuration as the hub device 1 of the first embodiment shown in FIG.

  In the data transmission device 20 of the second embodiment, in addition to the time monitoring counter 13 described above, a transmission is received in the loopback reception monitoring circuit 12a connected to the transmission path between the MAC circuit 14 and the PHY circuit 11. A data length counter 21, a transmission data length memory 22, and a reception data length counter 23 are provided.

  Next, the operation of the data transmission apparatus 20 configured as described above will be described. Similar to the data transmission device 5a of the first embodiment shown in FIG. 3, the application processing unit 19 in the information terminal 4 creates data to be transmitted by being incorporated in the data signal 9 of FIG. The TCP / UDP processing unit 18 and the IP processing unit 16 add DA (destination address), SA (source address), and TYP (used protocol type) in FIG. Then, a data transmission request is issued to the Ethernet driver processing unit 15. The Ethernet driver processing unit 15 makes a transmission request to the MAC circuit 14. The MAC circuit 14 creates the data signal 9 of FIG. 4 by adding PA and SFD before [DA, SA, TYP, data] and adding FCF after that. Then, the MAC circuit 14 outputs the created data signal 9 to the PHY circuit 11, and the data signal 9 is transmitted onto the upstream signal path 3a of the signal line 3 through the transmission unit 10a.

  Here, the loopback diagnosis circuit 12a executes the monitoring control shown in FIG. That is, normally, the data signal 9 output from the MAC circuit 14 to the PHY circuit 11 is monitored with the elapsed time of the time monitoring counter 13 for return diagnosis set to 0 (S91). In this state, when it is detected that the output of the data signal 9 from the MAC circuit 14 to the PHY circuit 11 is started (S92), the time monitoring counter 13 is activated. The transmission data length counter 21 is activated and counts the data length (number of bytes or number of bits) of the data signal 9 output and writes it in the transmission data length memory 22 (S93). Thereafter, the process proceeds to a monitoring process for determining whether or not any data has been received from the PHY circuit 11 to the MAC circuit 14.

  When the data signal 9 received from the hub device 1 via the downstream signal path 3b and transferred from the PHY circuit 11 to the MAC circuit 14 is detected (S94), the received data length counter 23 is detected. Is activated, and the data length (number of bytes or number of bits) of the received data signal 9 is counted (S95). When the data length of the received data signal 9 counted this time is compared with the data length of the transmitted data signal 9 stored in the transmission data number memory 22, if both match (S96), the upstream signal path 3a (S97), the process returns to S91 and waits for the next data signal 9 to be transmitted to the hub device 1.

  If the data length of the received data signal 9 counted this time does not match the data length of the transmitted data signal 9 stored in the transmission data number memory 22 (S96), the upstream signal path 3a and the downstream signal path 3b It is determined that the transmission line including the signal line 3 composed of is abnormal and the transmission line abnormality is displayed and output on the information terminal 4 in which the data transmission device 20 is incorporated (S98).

  In S94, if the data signal 9 is not received, the time monitoring counter 13 is updated (SS99), and the returned data signal 9 is not received even after the preset limit time has elapsed (S100). The transmission line including the signal line 3 composed of the upstream signal path 3a and the downstream signal path 3b is determined to be abnormal, and the transmission line abnormality is displayed and output to the information terminal 4 in which the data transmission device 20 is incorporated (S98).

  In the data transmission system of the second embodiment configured as described above, each data transmission apparatus 20 counts the data length of the data signal 9 transmitted to the hub apparatus 1 by the transmission data number counter 21 and transmits the transmission data length memory. 22 is temporarily stored. When the data length of the data signal 9 transmitted from the hub apparatus 1 is counted by the reception data length counter 23 and the two do not match, a signal line abnormality is output.

  Therefore, in this embodiment, not only the elapsed time from the transmission of the data signal 9 to the reception of the data signal 9 returned by the hub device 1, but also the data length of the returned data signal is the data of the transmitted data signal. Since it is confirmed that the length matches, the presence or absence of abnormality of the signal line 3 composed of the upstream signal path 3a and the downstream signal path 3b can be inspected more strictly.

  The present invention is not limited to the second embodiment described above. The hub apparatus 1 incorporated in the second embodiment has the frame configuration of FIG. 4 received from the data transmission apparatus 20 via the upstream signal path 3a as shown in the other examples in the first embodiment described above. It is also possible to return the data signal 9 to the downstream signal path 3b of the signal line 3 corresponding to the information terminal 4 designated by the transmission source address SA as a new data signal 9 corresponding to the minimum transmission frame length of Ethernet. is there.

  In this case, since the data length of the data signal 9 received from the hub device 1 in the data transmission numerical value 20 is fixed to 64 bytes, which is the minimum transmission frame length of Ethernet, the data of the data signal 9 to be transmitted to the hub device 1 The length is not counted, only the data length of the received data signal 9 is counted by the received data length counter 23. If the counted data length does not match the 64 bytes which is the minimum transmission frame length of Ethernet, the signal line An error is output.

  In such a configuration, the transmission (traffic) load on the signal line 3 can be reduced, and the processing load on the data transmission apparatus 20 can be reduced.

(Third embodiment)
FIG. 10 is a block diagram showing a schematic configuration of the hub device 24 in the data transmission system according to the third embodiment of the present invention. The same parts as those of the hub device 1 of the first embodiment shown in FIG. 2 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted. An address rewriting unit 25 is provided in the LAN switch controller 6a in the hub device 24 of the third embodiment.

  FIG. 12 is a block diagram showing a schematic configuration of the data transmission device 26 in the data transmission system of the third embodiment. The same parts as those of the data transmission device 5a of the first embodiment shown in FIG. 3 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted. A reception data diagnostic processing unit 27 is provided in the data transmission device 26 of the third embodiment.

  The LAN switch controller 6a of the hub device 24 in the data transmission system having such a configuration relays the data signal 9 having the frame configuration shown in FIG. 11A input from each data transmission device 26 according to the flowchart of FIG. To implement.

  First, it is monitored whether or not the data signal 9 is received from the data transmission device 26 for each of the connection ports 2a to 2n (S131). When the data signal 9 is received, the data signal 9 is temporarily stored in the buffer memory 8. Store (S132). Thereafter, the address table 7 is searched to determine whether or not the transmission source address SA of the received data signal 9 has been registered in the connection ports 2a to 2n that have received data (S133). If not registered, the combination of the source address SA of the data signal 9 received this time and the connection ports 2a to 2n receiving the data signal 9 is registered in the address table 7 (S134).

  Next, the address table 7 is searched with the destination address DA in the received data signal 9 of FIG. 11A to identify the connection ports 2a to 2n to which the data signal 9 is to be transferred (S135). The received data signal 9 is transmitted to the downstream signal path 3b of the signal line 3 of the connection ports 2a to 2n (S136).

Thereafter, the address rewriting unit 25 is activated, reads the source address SA (AD ₂ ) in the received data signal 9 shown in FIG. 11A, writes it in the destination address DA, and the frame shown in FIG. 11B. A data signal 9a having a configuration is generated. Therefore, the address AD ₂ of the data transmission device 26 that is the transmission source of the data signal 9 is written in the destination address DA and the transmission source address SA of the data signal 9a (S137). Then, the destination address DA is rewritten, and the data signal 9a is sent to the downstream signal path 3b of the signal line 3 of the connection ports 2a to 2n received this time (S138).

  Further, in the data transmission device 26 shown in FIG. 12, data to be transmitted by the application processing unit 19 in the information terminal 4 is created, and this data is processed by the TCP / UDP processing unit 18 and the IP processing unit 16. 4, DA (destination address), SA (source address), and TYP (used protocol type) are added. Then, a data transmission request is issued to the Ethernet driver processing unit 15.

  FIG. 14 is a flowchart showing the operation of the Ethernet driver processing unit 15. When [DA, SA, TYP, data] is input from the TCP / UDP processing unit 18, IP processing unit 16, and ARP processing unit 17 (S141), this information [DA, SA, TYP, data] is transferred to the MAC. The data is sent to the circuit 14 (S142). Further, this information [DA, SA, TYP, data] is sent to the received data diagnosis processing unit 27 (S143).

  The MAC circuit 14 outputs a data signal 9 obtained by adding PA, SFD, and FCS to [DA, SA, TYP, data] to the PHY circuit 11, and the data signal 9 is transmitted to the signal line 3 via the transmitter 10a. It is transmitted on the upstream signal path 3a.

Then, among the various data signals received by the data transmission device 26, the destination address DA is the own address AD ₂ of the data signal [DA, SA, TYP, Data passes through the MAC circuit 14, the Ethernet driver Input to the processing unit 15.

In S144 in FIG. 14, [DA, SA, TYP, data on the data signal from the MAC circuit 14 when is input, if the source address SA of the data signal is other than own address AD ₂ (S145), the Since the data signal is a regular data signal transmitted from the other information terminal 4 to itself, [DA, SA, TYP, data] of this data signal is sent to the IP processing unit 16 or the ARP processing unit 17. (S146).

On the other hand, when the transmission source address SA of the input data signal matches its own address AD ₂ , it is the data signal 9 a returned from the hub device 24, so this data signal 9 a is sent to the received data diagnostic processing unit 27. (S147).

  The reception data diagnosis processing unit 27 performs diagnosis processing of the signal line 3 using the received data signal 9a according to the flowchart shown in FIG.

  When the data signal 9 having the frame configuration shown in FIG. 11A is input from the Ethernet driver processing unit 15 (S151), the data in the transmitted data signal 9 is read and stored in the memory (S152). Then, when the data signal 9b having the frame configuration shown in FIG. 11B received from the hub device 24 is input within the predetermined allowable time (S157) (S153), the received data signal 9a The data is read, and the read data is compared with the data stored in the memory (S154). If they match (S155), the transmission including the signal line 3 composed of the upstream signal path 3a and the downstream signal path 3b is performed. It is determined that the path is normal (S156), the process returns to S151, and waits for the next data signal 9 to be transmitted to the hub device 1 and input to the received data diagnosis processing unit 27.

  If they do not match (S155), it is determined that the transmission line including the signal line 3 composed of the upstream signal path 3a and the downstream signal path 3b is abnormal, and the information terminal 4 in which the data transmission device 26 is incorporated has an abnormal transmission path. Is displayed and output (S158).

  Even if the data signal 9b having the frame configuration shown in FIG. 11B is not input within a predetermined allowable time after the data signal 9 is input (S157), the upstream signal path 3a and the downstream signal path The transmission line including the signal line 3 including the signal line 3b is determined to be abnormal, and the transmission terminal abnormality is displayed and output to the information terminal 4 in which the data transmission device 26 is incorporated (S158).

  Further, the loopback reception monitoring circuit 12 of the data transmission device 26 transmits the data signal 9 and then receives the data signal 9a in the same manner as the loopback reception monitoring circuit 12 of the data transmission device 5a of the first embodiment of FIG. If the elapsed time up to exceeds the limit value, the transmission path including the signal line 3 composed of the upstream signal path 3a and the downstream signal path 3b is determined to be abnormal.

In the data transmission system of the third embodiment configured as described above, the same own address AD is used as the destination address DA and the source address SA of the data signal 9a transmitted from the hub device 24 to the data transmission device 26. because ₂ is attached, taking the data transmission device 26, since the data signal 9a is a data signal addressed thereto, reads the actual data contained in the data signal 9a, the data of the data signal 9 which is transmitted earlier If a match is not found, a signal line abnormality is output. Therefore, the presence / absence determination of the signal line 3 including the upstream signal path 3a and the downstream signal path 3b can be more strictly and efficiently performed.

  Note that the present invention is not limited to the third embodiment described above. The hub device 24 incorporated in the third embodiment rewrites the destination address of the received data signal 9 in FIG. 11A to the transmission source address to the data signal 9a in FIG. As shown in the other examples in the first embodiment, the signal line 3 corresponding to the information terminal 4 specified by the source address SA as a new data signal 9a corresponding to the minimum transmission frame length of Ethernet among the data signals 9a. It is also possible to output the signal back to the downstream signal path 3b.

  In this case, the received data diagnosis processing unit 27 of the data transmission numerical value 26 receives the data in the new data signal 9 for the minimum transmission frame length of the Ethernet of the data signal 9 to be transmitted and the new data for the minimum transmission frame length of the received Ethernet. Compared with the data in the data signal 9a, the transmission (traffic) load on the signal line 3 can be reduced, and the load on the received data diagnosis processing unit 27 of the data transmission device 26 can be reduced.

(Fourth embodiment)
FIG. 16 is a block diagram showing a schematic configuration of the hub device 28 in the data transmission system according to the fourth embodiment of the present invention. The same parts as those of the hub device 1 of the first embodiment shown in FIG. 2 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted. The hub device 28 of the fourth embodiment is provided with a loopback condition setting circuit 29 for stopping the loopback transmission function of the data signal 9 of the LAN switch controller 6 according to an external instruction.

  FIG. 17 is a block diagram showing a schematic configuration of the data transmission device 30 in the data transmission system of the fourth embodiment. The same parts as those of the data transmission device 5a of the first embodiment shown in FIG. 3 are denoted by the same reference numerals, and detailed description of the overlapping parts is omitted. In the data transmission device 30 of the fourth embodiment, a monitoring condition setting circuit 31 is provided that stops the time monitoring function in the loopback reception monitoring circuit 12 according to an external instruction.

  The LAN switch controller 6 of the hub device 28 in the data transmission system of the fourth embodiment configured as described above performs the relay process of the data signal 9 input from each data transmission device 30 according to the flowchart of FIG.

  First, it is monitored whether or not the data signal 9 is received from the data transmission device 30 for each of the connection ports 2a to 2n (S181). When the data signal 9 is received, the data signal 9 is temporarily stored in the buffer memory 8. Store (S182). Thereafter, the address table 7 is searched to determine whether or not the transmission source address SA of the received data signal 9 has been registered in the connection ports 2a to 2n that have received data (S183). If not registered, the combination of the transmission source address SA of the data signal 9 received this time and the connection ports 2a to 2n receiving the data signal 9 is registered in the address table 7 (S184).

  Next, the address table 7 is searched with the destination address DA in the received data signal 9 of FIG. 11A to identify the connection ports 2a to 2n to which the data signal 9 is to be transferred (S185). The received data signal 9 is sent to the downstream signal path 3b of the signal line 3 of the connection ports 2a to 2n (S186).

  Thereafter, when execution of the loopback transmission function is designated in the loopback condition setting circuit 29 (S187), the data signal 9 is sent to the downstream signal path 3b of the signal line 3 of the connection port 2a-2n that has received (S188). . Then, the process returns to S181 and waits for the next data signal 9 to be input.

  If stop of the loopback transmission function is designated in the loopback condition setting circuit 29 (S187), the process returns to S181 without doing anything and waits for the next data signal 9 to be input.

  When the data transmission device 30 is set to execute the time monitoring function in the loopback reception monitoring circuit 12 in the monitoring condition setting circuit 31, the same time as the data transmission device 5a of the first embodiment shown in FIG. Execute monitoring processing. Further, when the monitoring condition setting circuit 31 is set to stop the time monitoring function in the loopback reception monitoring circuit 12, the same time monitoring processing as that of the data transmission device 5a of the first embodiment shown in FIG. 7 is not executed.

  In the data transmission system of the fourth embodiment configured as described above, the administrator of the network system in which the data transmission system is incorporated has a “return transmission function” in the hub device 28 and a “time” in each data transmission device 30. Whether or not to execute the “monitoring function” can be arbitrarily selected and set. Therefore, when each data transmission device connected to the hub device 28 is not originally provided with the loopback reception monitoring circuit 12, it is not necessary to execute the “loopback transmission function” in the hub device 28. By stopping the “return transmission function”, the transmission load on the signal line 3 can be reduced, and the processing load on the hub device 28 can be reduced.

  On the other hand, if the hub device connected to the data transmission device 30 does not originally have the “return transmission function”, the “time monitoring function” in each data transmission device 30 is stopped, The processing burden can be reduced.

  Furthermore, when the test is not performed, it is possible to improve the data transmission efficiency between normal information terminals by stopping the execution of both inspection functions.

  The present invention is not limited to the data transmission system of the fourth embodiment described above. For example, the administrator may be able to select and set whether to execute or stop the “data content verification function” in the received data diagnosis processing unit 27 shown in FIG. 12 of the third embodiment.

Schematic diagram showing a network system to which the data transmission system of the present invention is applied. 1 is a block diagram showing a schematic configuration of a data transmission system according to a first embodiment of the present invention. The block diagram which shows schematic structure of the data transmission apparatus in the data transmission system concerning the same 1st Embodiment Data signal frame structure used in the data transmission system according to the first embodiment The figure which shows the memory content of the address table provided in the hub apparatus of the data transmission system concerning the same 1st Embodiment The flowchart which shows operation | movement of the hub apparatus of the data transmission system concerning the 1st Embodiment. The flowchart which shows operation | movement of the data transmission apparatus of the data transmission system concerning the 1st Embodiment. The block diagram which shows schematic structure of the data transmission apparatus in the data transmission system concerning 2nd Embodiment of this invention. The flowchart which shows operation | movement of the data transmission apparatus in the data transmission system concerning the said 2nd Embodiment. The block diagram which shows schematic structure of the hub apparatus in the data transmission system concerning 3rd Embodiment of this invention. Data signal frame configuration used in the data transmission system according to the third embodiment The block diagram which shows schematic structure of the data transmission apparatus in the data transmission system concerning the 3rd Embodiment The flowchart which shows operation | movement of the hub apparatus in the data transmission system concerning the 3rd Embodiment. The flowchart which shows operation | movement of the Ethernet processing part of the data transmission apparatus in the data transmission system concerning the 3rd Embodiment. The flowchart which shows operation | movement of the received data diagnostic process part of the data transmission apparatus in the data transmission system concerning the 3rd Embodiment. The block diagram which shows schematic structure of the hub apparatus in the data transmission system concerning 4th Embodiment of this invention. The block diagram which shows schematic structure of the data transmission apparatus in the data transmission system concerning the 4th Embodiment The flowchart which shows operation | movement of the hub apparatus in the data transmission system concerning the 4th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 24,28 ... Hub apparatus, 2, 2a, 2b, 2n ... Connection port, 3 ... Signal line, 3a ... Up signal path, 3b ... Down signal path, 4 ... Information terminal, 5a, 5b, 5n, 20, DESCRIPTION OF SYMBOLS 26, 30 ... Data transmission apparatus, 6, 6a ... LAN switch controller, 7 ... Address table, 9, 9a ... Data signal, 11 ... THY circuit, 12 ... Return reception monitoring circuit, 13 ... Time monitoring counter, 4 ... MAC circuit 15 ... Ethernet driver processing unit, 16 ... IP processing unit, 17 ... ARP processing unit, 18 ... TCP / UDP processing unit, 19 ... Application processing unit, 21 ... Transmission data length counter, 23 ... Reception data length counter, 25 ... Address rewriting unit, 27... Received data diagnostic processing unit, 29 .. folding condition setting circuit, 31... Monitoring condition setting circuit

Claims (9)

A plurality of data transmission devices each incorporated in an information terminal, and each data transmission device has a plurality of connection ports connected via an Ethernet (registered trademark) signal line, and a destination between the information terminals In a data transmission system consisting of a hub device that relays a data signal including an address, a source address and data,
The hub device is
When a data signal is received from each information terminal via the data transmission device, signal line, and connection port, the data signal relay outputs the data signal from the connection port corresponding to the information terminal specified by the destination address to the signal line Means,
A data signal return means for returning the received data signal to a signal line corresponding to an information terminal designated by a source address;
The data transmission device incorporated in each information terminal measures the elapsed time from the transmission of the data signal from its own information terminal to the hub device until the reception of the data signal from the hub device. A data transmission system comprising time monitoring means for outputting a signal line abnormality when a measured elapsed time exceeds a limit value.   The data signal loopback means of the hub device loops back and outputs to the signal line corresponding to the information terminal specified by the transmission source address, as a new data signal, of the minimum transmission frame length of Ethernet among the received data signals. The data transmission system according to claim 1. Each of the data transmission devices is
Transmission data length counting means for counting the data length of the data signal transmitted to the hub device;
Received data length counting means for counting the data length of the data signal received from the hub device;
The data length monitoring means for outputting a signal line abnormality when the data length counted by the reception data length counting means does not match the data length counted by the transmission data length counting means. The data transmission system according to 1. Each of the data transmission devices is
Received data length counting means for counting the data length of the data signal received from the hub device;
3. The data according to claim 2, further comprising data length monitoring means for outputting a signal line abnormality when the data length counted by the received data length counting means does not coincide with the data length of the Ethernet minimum transmission frame. Transmission system. The hub device has a destination address rewriting means for rewriting a destination address in a data signal received from each information terminal to a source address included in the received data,
The data signal return means returns a data signal in which the destination address is rewritten to a source address to a signal line corresponding to an information terminal designated by the source address,
Each of the data transmission devices is
Transmission data storage means for temporarily storing data of the data signal transmitted to the hub device;
A data reading means for reading data of the data signal when the destination address and the transmission source address of the data signal received from the hub device match the own address;
2. A data transmission system according to claim 1, further comprising data content verification means for outputting a signal line abnormality if the data read by the data reading means does not match the data stored in the transmission data storage means. . The hub device has a destination address rewriting means for rewriting a destination address in a data signal received from each information terminal to a source address included in the received data,
The data signal loop-back means, to the signal line corresponding to the information terminal specified by the transmission source address using the Ethernet minimum transmission frame length as a new data signal among the data signals in which the destination address is rewritten to the transmission source address Wrap output,
Each of the data transmission devices is
Transmission data storage means for temporarily storing data included in a portion corresponding to the minimum transmission frame length of Ethernet among data of data signals transmitted to the hub device;
Data reading means for reading data of the data signal when the destination address and the source address of the data signal for the minimum transmission frame length of Ethernet received from the hub device match the own address;
2. A data transmission system according to claim 1, further comprising data content verification means for outputting a signal line abnormality if the data read by the data reading means does not match the data stored in the transmission data storage means. .   The data transmission system according to any one of claims 1 to 6, wherein the hub device includes a loopback execution control unit that stops a loopback output of received data in the data signal loopback unit in response to an external instruction. .   8. The data transmission system according to claim 1, wherein each of the data transmission devices includes time monitoring execution control means for stopping time monitoring in the time monitoring means in accordance with an external instruction. 9.   7. The data transmission system according to claim 5, wherein each of the data transmission devices includes data content verification execution control means for stopping data content verification in the data content verification means in response to an external instruction.

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