JP2000032020A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the mixed connection of a bus type network and a loop type network without using any gateway nor router by transmitting the signals which are outputted from a certain node to all nodes and disappearing the output side of its own node via each loop by means of the most downstream node that is directly connected to a common transmission path or the node that transmits the signals. SOLUTION: A token analyzer of each of loop masters 110 and 120 compares a loop address 0 of a token master node 100 stored in an initialization sequence with the address of its own loop and then switches a switch to the B side after deciding a packet that is sent from another loop if no coincidence is confirmed between both addresses. Then each token analyzer of slave nodes 111, 112 and 121 switches the switch to the A side to transmit a packet in a token mode. The token packet sent from an optical star coupler 15 is canceled by the token analyzer of the node 100 on a loop 0 of the loop address 0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system capable of realizing mixed connection of a bus network and a loop network.

[0002]

2. Description of the Related Art In recent years, digitization of video and audio data has progressed, and computer data such as control commands and MP data have been developed.
In the era when networks that transmit mixed digital AV data, such as EG, are used in homes and automobiles, various and flexible methods such as ease of node expansion, reliability ranking by device group or data, etc. There is a demand for a network connection form. Conventionally, when interconnecting networks of different topologies, such as a bus network and a loop network, for example, a document (Naohiko Kamae, July 6, 1992, "Local Area Network", Shokodo, 8
It is common to use gateways or routers at the network layer, as shown on page 8). FIG. 10 shows an example of the device in this case. 10, 101 is a bus network, 101a is a node connected to the bus network 101, 102
Is a gateway or router; 103 is a loop network; 103a is a node connected to the loop network 103;
And the loop network 103 are interconnected via a gateway or router 102.

[0003]

In general, a loop type network has fewer optical fibers and optical modules for connecting nodes and is advantageous in terms of cost and is excellent in expandability of nodes. There is a problem in reliability because the entire network becomes inoperable due to a node failure alone, and it is difficult to diagnose a failed part and there is also a problem in maintainability. On the other hand, although the bus type network is disadvantageous in terms of cost due to the increase in the number of optical fibers and optical modules, even if some optical fibers are cut or a node failure occurs, the failed node only becomes inoperable, affecting the entire network. Since it is not given, the reliability is high, and the diagnosis of a failed part is easy, so that the maintainability is excellent. Therefore, if you use a mixed connection that combines both networks based on the application and the importance of the equipment, the loop type network and the bus type network complement the disadvantages of both, and are excellent in cost, reliability, expandability, and maintainability. Network construction. However, devices such as gateways and routers have been used for mixed connection of networks, but these devices need to perform packet conversion at high speed, so computer systems and complicated devices are required, such as ordinary homes and automobiles. It was not suitable for use in terms of cost or scale.

[0004] The present invention has been made to solve the above problems, and has as its object to provide a network system capable of realizing a mixed connection of a bus type network and a loop type network without using a gateway or a router. .

[0005]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 of the present application provides at least one loop composed of a plurality of nodes connected in a loop, and a single loop. One or more loops composed of a node or a plurality of nodes connected in a loop shape have one or more input units and one or more output units, and a signal input from one of the input units is processed. A network system configured to be directly connected to a common transmission path output from all the output units without being branched, wherein a signal output from any of the nodes is transmitted to all nodes, and In the loop, the output side of the own node among the nodes disappears at any one of the most downstream node which is a node directly connected to the common transmission path or the node which has output the signal. Is shall.

According to a second aspect of the present invention, there is provided at least one loop composed of a plurality of nodes connected in a loop and a single node or a plurality of nodes connected in a loop. One or more loops configured have one or more input units and one or more output units, and a signal input from one of the input units is branched without being processed and output from all of the output units. A network system configured to be directly connected to a common transmission path, wherein the node that sent a signal eliminates the signal returned to its own node, and outputs the output of its own node among the nodes of each loop. The most downstream node whose side is a node directly connected to the common transmission path, if the node that sent the signal belongs to the same loop as its own node, passes the signal, The node that sent the No. may belong to different loop as the node is intended to eliminate the signal.

[0007] The invention according to claim 3 of the present application provides at least one loop composed of a plurality of nodes connected in a loop and a single node or a plurality of nodes connected in a loop. One or more loops configured have one or more input units and one or more output units, and a signal input from one of the input units is branched without being processed and output from all of the output units. Each node constituting the loop is directly connected to a common transmission path, has a node ID for recognizing its own node, and one node belonging to any of the plurality of loops becomes a token master node. Nodes other than the node that is the token master node are slave nodes, and among the nodes, the node whose output side is directly connected to the common transmission path is the lowest node. In the network system serving as a node, the token master node includes a transmission node ID which is a node ID of a node permitted to transmit a data packet, and a node ID of a node which should receive the transmitted data packet. A token transmitting device that transmits a token packet including a receiving node ID, a token analyzing device that analyzes the token packet, node setting information indicating whether or not its own node is the most downstream node, and a node of the token master node A storage device for temporarily storing information of an ID and a received packet, a data transmission device for transmitting a data packet, and a switch for discarding or passing the received token packet, wherein the slave node comprises: A token analyzer that analyzes token packets; A storage device for temporarily storing node setting information as to whether or not the own node is the most downstream node, a node ID of the token master node, and information of a received packet, a data transmission device for transmitting a data packet, A switch for discarding or passing the received token packet, wherein the token analyzing device of each node discards the received token packet if the own node is a token master node during the transmission of the token packet. The node is controlled by the switch so that the own node is the most downstream node as determined from the node setting information, and the own node is determined as the token master based on the node ID of the token master node and the node ID of the own node. If it belongs to a different loop from the node, the received token packet By controlling the switch to discard the packet, otherwise controlling the switch to pass the received token packet, the token packet is transmitted to all nodes and the token packet is transmitted to the network. Also, when the data packet is transmitted, the switch is controlled to discard the received data packet if the own node is the transmitting node, judging from the information of the received token packet,
If the own node is the most downstream node as determined from the node setting information, and if the own node belongs to a different loop from the transmitting node as determined from the information of the received token packet and the node ID of the own node, the reception is performed. By controlling the switch to discard the data packet, and by controlling the switch otherwise to pass the received data packet, the data packet is transmitted to all nodes, and the data packet is It can be deleted from the network.

According to a fourth aspect of the present invention, in the network system according to the third aspect, the node I
D includes a loop address which is the same value between nodes belonging to the same loop and different from each other between nodes belonging to different loops, and the most downstream node uses the loop address to determine whether a packet transmission node belongs to its own loop. It is to determine whether or not.

According to a fifth aspect of the present invention, in the network system according to any one of the first to fourth aspects, the common transmission path is an optical star coupler.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. (Embodiment 1) FIG. 1 is a diagram showing a configuration example of a network system according to Embodiment 1 of the present invention. In FIG. 1, 100, 110, 111, 112, 120, 1
21 is a node connected to the network, and 15 is an optical star coupler. Node 100 is a token master node, and nodes 110, 111, 112, 120, 12
1 is a slave node. Further, the node 100 is a loop master of a loop 0 composed of the nodes 100, the node 110 is a loop master of a loop 1 composed of the nodes 110, 111, 112, and the node 1
20 is a loop 2 composed of nodes 120 and 121
Loop Master. In FIG. 1, the direction of the arrow indicates the direction in which data flows. As shown in FIG. 1, in the network according to the first embodiment, a loop in which a plurality of nodes are connected in one direction (loop 1 and loop 2) or a loop including a single node (loop 0) The node connected to the optical star coupler 15 and having a loop whose output side is directly connected to the optical star coupler 15 among the nodes constituting each loop is the loop master.

FIG. 2 is a diagram showing a configuration of a packet transmitted on a network in the network system according to the first embodiment. In FIG. 2, 21 is a token packet, 22 is a DS packet, and 23 is a data packet. As shown in FIG. 2, the token packet 21 includes a transmitting node ID (a node ID of a node to which the token master node permits data transmission) and a receiving node ID.
(Node ID of the node to which the token master node permits data reception). Here, the node ID includes a loop address to which the node belongs and a node address on the loop. The loop address is a number unique to each loop, and the node address is a node number unique to each node on the loop. To specify a specific node on the network, the loop address to which the node belongs and the node address of the node on the loop may be specified. Node ID in the present embodiment
Is (loop address.node address). For example, the node ID of a node having a loop address of 1 and a node address of 2 is expressed as (1.2).

As shown in FIG. 2, the DS packet 22
Includes Destination Status field. The node that transmits the DS packet 22 is the node specified by the receiving node in the receiving node ID field of the token packet 21. The DS packet 22 includes information indicating whether the receiving node is in a state capable of receiving data. . The data packet 23 includes a field of data to be actually transmitted, as shown in FIG. The node that transmits the data packet 23 is specified by the transmission node in the transmission node ID field of the token packet 21.

FIG. 3 is a diagram showing a state of a packet transmitted on the network. In FIG. 3, 31 is a token packet, 32 is a DS packet, and 3
3 is a data packet. In the network system according to the present embodiment, as shown in FIG. 3, a token packet, a DS packet, and a data packet are transmitted on the network in this order, and thereafter, this is repeated at regular intervals.

FIG. 4 is a diagram showing a detailed configuration of the network system according to the first embodiment of the present invention. In FIG. 4, 100, 110, 111, 112, 120, 1
21 is a node connected to the network, and 15 is an optical star coupler. Node 100 is a token master node, and nodes 110, 111, 112, 120, 12
1 is a slave node. The node 100 belongs to loop 0, the nodes 110, 111, 112 belong to loop 1, and the nodes 120, 121 belong to loop 2. Nodes 100, 110, and 120 are loop masters. Also,
The node ID of the node 100 is (0.0), the node 110
Is the node ID of (1.0) and the node ID of the node 111
Is (1.1), and the node ID of the node 112 is (1.
2) The node ID of the node 120 is (2.0), and the node ID of the node 121 is (2.1). Thus, each node has a unique node ID.

As shown in FIG. 4, the slave node 11
1, 112, 121 and the loop masters 110, 120, which are not token master nodes, are connected to the token analyzer for analyzing tokens and packets, the nonvolatile memory for storing initial settings, and the token analyzer and nonvolatile memory. The storage device includes a storage device, a data transmission device that transmits data, and a switch that disconnects or connects a loop. The switch connects the loop when switched to the A side, and disconnects the loop when switched to the B side. As shown in FIG. 4, the token master node 100 includes a token transmitting device that transmits a token, in addition to the components of the slave node. The switch connects the loop when switched to the A side, and disconnects the loop when switched to the B side. In the above configuration, the non-volatile memory may be any memory that can store the initial settings and set the initial settings in the storage device. For example, the nonvolatile memory may be realized by a dip switch or the like.

Next, the operation of the network system according to the first embodiment configured as described above will be described. The operation will be described by taking as an example a case where the token master node 100 transmits a token packet with the transmitting node ID (2.1) and the receiving node ID (1.1). In the network system according to the first embodiment of the present invention, a node that has transmitted a packet (all packets including a token packet) switches so as to discard a packet returned to its own node. The loop master switches the switch to discard the packet transmitted by the node belonging to the other loop, passes the packet transmitted by the node belonging to the own loop, and transmits and discards the packet.

First, an outline of the operation sequence will be described. The operation sequence includes an initialization sequence and a normal operation sequence. The initialization sequence is started when power is turned on or reset, and performs an initialization process. In the initialization sequence, by reading information preset in a nonvolatile memory or a dip switch into a storage device, the token master node is set to operate as a token master node, and the loop master is set to operate as a loop master. Knows the loop address (“0” in this example) of the loop to which the token master node belongs,
All nodes including the token master node know their own node IDs (loop address and node address).

FIG. 9 is a diagram showing an example of information set in advance on the nonvolatile memory. In this example, it is assumed that the address of each flag, address, and ID on the nonvolatile memory is known in advance. Assuming that information is set on the non-volatile memory as shown in FIG. 9, for example, the information stored at the address of the token master node flag on the non-volatile memory is read out. And if it is "1", it can be set as a token master. Loop master flag, loop address of token master node and own node I
The same applies to D.

The normal operation sequence is an operation sequence in which a node actually transmits and receives a packet.
There are three modes: a token mode for transmitting token packets, a DS mode for transmitting DS packets, and a data mode for transmitting data packets. Hereinafter, the operation in each mode of the normal operation sequence will be described in detail.

First, the token mode will be described with reference to FIG. FIG. 4 is a diagram showing the state of the switch of each node when the token packet is transmitted and the flow of the token packet. In the figure, the thick line indicates the flow of the token packet. The token master node 100 assembles a token packet with a token transmitting device, processes the token packet into a form to be transmitted on a network with a data transmitting device, and transmits a token packet by switching a switch to a B side with a token analyzing device. Here, it is assumed that the transmitting node ID specified by the token packet is (2.1) and the receiving node ID is (1.1).

The token analyzers of the loop masters 110 and 120 compare the loop address “0” of the token master node 100 stored in the initialization sequence with the address of its own loop (110 is “1”, 120 is “2”). Then, since the comparison result is different, it is determined that the packet is from another loop, and the switch is switched to the B side. The token analyzers of the slave nodes 111, 112, and 121
In the token mode, the switch is switched to the A side to allow the packet to pass.

The token packet transmitted from the token master node 100 is transmitted to the nodes 100, 112 and 121 via the optical star coupler 15. In loop 0 of loop address 0, the optical star coupler 15
Is discarded by the token analyzer of the token master node 100. In the loop 1 of the loop address 1, the slave node 112,
The token packet is transmitted in the order of the slave node 111 and the loop master 110, and the token analyzer of the loop master 110 discards the token packet. Similarly, in the loop 2 of the loop address 2, the token packet is transmitted in the order of the slave node 121 and the loop master 120, and the token packet is discarded by the token analyzer of the loop master 120. The token analyzers of all nodes including the token master node store the transmission node ID and the reception node ID in the received token packet in the storage device.

As described above, the token packet is transmitted from the token master node 100 to all nodes, received, and discarded by the loop master and the token master node. The above is the operation in the token mode.

Next, the DS mode will be described with reference to FIG. FIG. 5 is a diagram showing the state of the switch of each node when the DS packet is transmitted and the flow of the DS packet. In the drawing, the thick line indicates the flow of the DS packet.
The token analyzers of all nodes including the token master node and the loop master compare the receiving node ID stored in the storage device with the own node ID by the operation in the token mode described above, and when they match (here, only the node 111 Match), if the own node can receive data, assemble a DS packet indicating “data can be received”, and if the own node cannot receive data, a DS indicating “data cannot be received” The packet is assembled, processed into a form to be transmitted on the network by the data transmission device, and the switch is switched to the B side to transmit the DS packet.

The token analyzing device of the loop master 110 determines that the own node does not output the DS packet because the receiving node ID stored in the storage device does not match the own node ID. The loop address “1” of the node ID is compared with the address “1” of the own loop. Since they match, it is determined that a DS packet is transmitted from a node in the own loop, and the switch is switched to the A side.

The token analyzers of the loop masters 100 and 120 determine that the own node does not output a DS packet because the receiving node ID stored in the storage device does not match the own node ID. The loop address "1" of the received node ID and the address of the own loop ("0" for the node 100 and "2" for the node 120) are compared, and it is determined that a DS packet is transmitted from a node in another loop because they are different. Switch to the B side. The token analyzers of the slave nodes 112 and 121 switch the switch to the A side so that the packet can pass because the receiving node ID stored in the storage device does not match the own node ID.

The DS packet transmitted from the node 111 passes through the node 110 and is transmitted to the nodes 100, 112, and 121 via the optical star coupler 15. In the loop 0, the DS packet transmitted from the optical star coupler 15 is discarded by the token master node 100. In the loop 1, the DS packet is transmitted in the order of the slave node 112 and the slave node 111, and the DS packet is transmitted.
The DS packet is discarded by the node 111 that has transmitted the packet. In loop 2, the slave nodes 121,
The DS packet is transmitted in the order of the loop master 120, and the DS packet is discarded by the loop master 120.

The token analyzers of all nodes including the token master node transmit the transmission node ID stored in the storage device by the operation in the token mode and the own node I
D and if they match (here, node 121
Only matches), receives the transmitted DS packet, and stores the contents in the storage device.

As described above, the DS packet is transmitted to the node 111 designated as the receiving node by the token packet.
To all nodes, received by the node 121 designated as the transmitting node in the token packet, and discarded by the loop masters 100 and 120 and the node 111 that transmitted the DS packet. The above is the operation in the DS mode.

Finally, the data mode will be described with reference to FIG. FIG. 6 is a diagram showing the state of the switch of each node when the data packet is transmitted and the flow of the data packet. In the drawing, the thick line indicates the flow of the data packet. The token analyzers of all nodes including the token master node and the loop master compare the transmission node ID stored in the storage device by the operation in the above-described token mode with the own node ID, and when they match (here, only the node 121 is used). In the DS mode, if the content of the DS packet stored in the storage device indicates “data can be received”, the data packet is assembled and processed into a form to be transmitted on the network by the data transmission device,
The token analyzer switches the switch to the B side to transmit a data packet. The token analyzers of all the nodes including the token master node and the loop master can store the contents of the DS packet stored in the storage device in the DS mode even when the comparison result between the transmission node ID stored in the storage device and the own node ID matches. If "data cannot be received" is indicated, data packet transmission is postponed.

Since the transmission node ID stored in the storage device and the own node ID do not match, the token analysis device of the loop master 120 determines that the own node does not output the data packet, and then transmits the data stored in the storage device. The loop address “2” of the node ID is compared with the address “2” of the own loop. Since they match, it is determined that a data packet is transmitted from a node in the own loop, and the switch is switched to the A side.

The token analyzers of the loop masters 100 and 110 determine that the own node does not output a data packet because the transmission node ID stored in the storage device does not match the own node ID. Then, the loop address “2” of the transmission node ID is compared with the address of the own loop (100 is “0”, 110 is “1”), and it is determined that the data packet is transmitted from a node in another loop because they are different. Switch the switch to B side. The token analyzers of the slave nodes 112 and 111 switch the switch to the A side so that the packet can be passed because the transmission node ID stored in the storage device and the own node ID do not match.

The data packet transmitted from the node 121 passes through the node 120 and is transmitted to the nodes 100, 112, and 121 via the optical star coupler 15. In the loop 0, the data packet transmitted from the optical star coupler 15 is discarded by the token analyzer of the token master node 100. In loop 1,
The data packet is transmitted in the order of the slave node 112, the slave node 111, and the loop master 110, and the data packet is discarded by the token analyzer of the loop master 110. In the loop 2, the data packet transmitted from the optical star coupler 15 is discarded by the slave node 121 that has transmitted the data packet. The token analyzers of all nodes including the token master node compare the receiving node ID stored in the storage device with the own node ID, and receive the transmitted data packet if they match.

As described above, the data packet is transmitted to the node 1 designated as the transmitting node by the token packet.
21 to all nodes, received by the node 111 designated as the receiving node in the token packet,
The data is discarded by the loop masters 100 and 110 and the node 121 that has transmitted the data packet. The above is the operation in the data mode. When a certain period of time has passed since the token master node transmitted the token packet last time, the mode returns to the token mode again, and in the same manner, the operations of the token mode, the DS mode, and the data mode are repeated to realize data transmission.

As described above, the node that has transmitted a packet (token packet, DS packet, data packet) switches so as to discard the packet returned to its own node, and the loop master belongs to another loop. By switching the switch to discard the packet transmitted from the node, transmission and discarding of the packet are performed.

As described above, in the network system according to the first embodiment, a simple physical or electrical switch for directly interconnecting nodes at the data link (media access control: MAC) layer is provided, and nodes other than the transmitting node are provided. The packet is transmitted or erased by determining whether to transmit the received packet as it is to the upper node or to discard it at the own node based on the loop address of the loop to which the transmitting node belongs, and by switching the switch. Therefore, it is possible to construct a loop and bus mixed type network system in which a single node or a group of nodes connected in a loop is connected to a plurality of optical star couplers.

In the network system according to the first embodiment, means for switching between transmitting the packet received by each node as it is to the upper node or discarding the packet at its own node is provided by short-circuiting the input terminal and output terminal of the node. Alternatively, the switching means is realized by a physical switch that disconnects, but the switching means has any configuration as long as it can switch between transmitting the received packet as it is to the upper node or discarding it at its own node. It may be.

Further, the configuration of the network system of the present invention is not limited to the configuration shown in the first embodiment, but includes the number of loops, the number of nodes in the loop, and the nodes directly connected to the optical star coupler. Can be arbitrarily set within the range of the bit width of the node ID and various physical restrictions. In the first embodiment,
Although the token master node is shown as being directly connected to the optical star coupler, the token master node can be located anywhere in the loop.

In the network system according to the first embodiment, the token packet, the DS packet, and the data packet are transmitted in this order, but if the receiving node cannot receive the data, the data is temporarily discarded on the transmission path. Then, the network system in which retransmission is permitted by requesting the transmission of the data from the transmission source again, or after the receiving node overwrites the data, requests the lost data group to the transmission source to permit retransmission. In the network system, the phase of DS packet transmission may not be required.

In the network system according to the first embodiment, there is only one node (node 100) on the network system that has a token transmitting device and can be a token master node.
A plurality of nodes that can be token master nodes with a token transmitting device may exist on the network system. Even in such a case, the node set to operate as the token master node based on information set in advance in the nonvolatile memory or the DIP switch or the like must be the only node on the network.

In the initialization sequence, instead of reading the initial settings previously set in a dip switch or a non-volatile memory into a storage device, as shown in FIG. 7, it is composed of an optical star coupler and a signal output device. The bus device 75 includes a signal output device 75a and a signal line 74 that outputs a signal to a node 72 connected to the optical star coupler. The nodes 71 and 72 on the loop network connected to the bus device using the optical star coupler are connected to the bus device 75. Signal line 74
Detecting devices 71a and 72a for detecting signals from
The signal output device 75a transmits a signal indicating that it is directly connected to the optical star coupler, and only the signal detection device 72a of the node 72 directly connected to the optical star coupler detects the signal. By setting the storage device of the node 72 to operate as a loop master, the node 7 directly connected to the optical star coupler is set.
2 may be configured to be automatically recognized as a loop master.

In the initialization sequence, a setting device 82 is connected to a node 81, as shown in FIG. 8, instead of reading initial settings previously set in a dip switch or a non-volatile memory into a storage device. A configuration in which the setting device 82 sets the data in the storage device 81a may be adopted.
The setting device 82 at this time may be constituted by a computer or the like, and the connection between the node 81 and the setting device 82 may be performed by serial communication.

Further, according to the present invention, a method of providing a unique loop address to a loop to which a node belongs and transmitting or discarding data by a loop master is only a network system using a token as described in the above embodiment. Instead of CSMA (Carrier Sense Multiple)
Access) and TDMA (Time-Division MultipleAc
cess) method or a network system using an arbitration method using a bus arbiter. When the present invention is applied to a network system using a CSMA system, a TDMA system, or an arbitration system using a bus arbiter, a unique loop address to which a node belongs is provided, a transmission source loop address is added to transmission data, and the information is added. The loop master analyzes and transmits or discards the data, and the transmission source node discards the data returned to the own node. As in the above embodiment, the bus and loop mixed connection using the optical star coupler is performed. Can be easily realized.

[0044]

As described above, according to the present invention (claim 1), at least one loop composed of a plurality of nodes connected in a loop and a single node or a connection in a loop are provided. One or more loops composed of a plurality of nodes having one or more input units and one or more output units, and a signal input from one of the input units is branched without being processed. A network system configured to be directly connected to a common transmission path output from the output unit, wherein a signal output from any of the nodes is transmitted to all nodes, and in each loop, Of these, the output side of the own node can be eliminated by either the most downstream node that is a node directly connected to the common transmission path or the node that outputs the signal. Data and without using complex control system, there is an effect that can realize a single node or loop-connected loops & Bath Mixed network system of nodes and multiple connections to one physical common medium.

According to the present invention (claim 2), at least one loop composed of a plurality of nodes connected in a loop and a single node or a plurality of nodes connected in a loop One or more loops having one or more input units and one or more output units, and a signal input from one of the input units is branched without being processed and output from all of the output units. A network system configured to be directly connected to a common transmission path, wherein the node that has transmitted a signal eliminates the signal that has returned to its own node, and of each of the loops, The most downstream node, whose output side is a node directly connected to the common transmission path, passes the signal if the node that sent the signal belongs to the same loop as the own node, and passes the signal. When the node that has sent the packet belongs to a different loop from its own node, the signal is deleted, so that a single node or a group of nodes connected in a loop is connected to one physical node without using a computer or a complicated control device. There is an effect that a loop and bus mixed type network system connected to a plurality of common media can be realized.

According to the present invention (claim 3), at least one loop composed of a plurality of nodes connected in a loop and a single node or a plurality of nodes connected in a loop One or more loops having one or more input units and one or more output units, and a signal input from one of the input units is branched without being processed and output from all of the output units. Connected directly to a common transmission path, each node constituting the loop has a node ID for recognizing its own node, and one node belonging to any of the plurality of loops becomes a token master node, Nodes other than the token master node are slave nodes, and the node whose output side is directly connected to the common transmission path is the most downstream node among the nodes. The token master node comprises a transmitting node ID that is a node ID of a node permitted to transmit a data packet and a node ID of a node that should receive the transmitted data packet. A token transmitting device that transmits a token packet including a certain receiving node ID, a token analyzing device that analyzes the token packet, node setting information indicating whether or not its own node is the most downstream node, and a token master node. A storage device for temporarily storing information of a node ID and a received packet, a data transmission device for transmitting a data packet, and a switch for discarding or passing the received token packet, wherein the slave node comprises: A token analyzer for analyzing the token packet, A storage device for temporarily storing node setting information as to whether or not the node is the lowermost node, a node ID of the token master node, and information of a received packet; a data transmission device for transmitting a data packet; And a switch for discarding or passing the token packet. The token analyzer of each node, when transmitting the token packet, discards the received token packet if the own node is a token master node. The switch is controlled in such a manner that the own node is the lowermost node as determined from the node setting information, and the own node is determined as the token master node based on the node ID of the token master node and the node ID of the own node. If it belongs to a different loop from the received token packet The token is transmitted to all nodes by controlling the switch so that the received token packet is passed, and the token packet is transmitted from the network. When the data packet is transmitted, the switch is controlled to discard the received data packet when the own node is the transmitting node, based on the information of the received token packet. If the own node is the lowermost node as judged from the information, and if the own node belongs to a different loop from the transmitting node as judged from the information of the received token packet and the node ID of the own node, the received data packet Control the switch to discard
In other cases, the switch is controlled so that the received data packet is passed, so that the data packet is transmitted to all nodes and the data packet is deleted from the network. There is an effect that a mixed loop and bus type network system in which a single node or a group of nodes connected in a loop is connected to a physical common medium by one optical star coupler without using a simple control device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a network system according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a packet transmitted on a network in the network system according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a sequence in which a packet is transmitted on a network in the network system according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a state of a switch of each node and a flow of the token packet when the token packet is transmitted in the network system according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a state of a switch of each node and a flow of the DS packet when a DS packet is transmitted in the network system according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a state of a switch of each node and a flow of the data packet when the data packet is transmitted in the network system according to the first embodiment of the present invention.

FIG. 7 is a diagram showing a configuration for automatically recognizing a loop master by a signal line from an optical star coupler.

FIG. 8 is a diagram showing a configuration for performing initial setting by a setting device.

FIG. 9 is a diagram showing an example of information preset on a nonvolatile memory according to the first embodiment of the present invention.

FIG. 10 is a diagram showing an example of network connection by a conventional gateway.

[Explanation of symbols]

100 Token Master Node 110 Loop Master of Loop 1 111 Slave Node of Loop 1 112 Slave Node of Loop 1 120 Loop Master of Loop 2 121 Slave Node of Loop 2 15 Optical Star Coupler 21 Token Packet 22 DS Packet 23 Data Packet 31 Token Packet 32 DS packet 33 Data packet 71 Node 71a Signal detection device of node 71 72 Node 72a Signal detection device of node 72 74 Signal line 75 Bus device composed of signal output device and optical star coupler 75a Signal output device of 75 81 Node 81a Storage device of node 81 82 Setting device 91 Example of information preset on nonvolatile memory 101 Bus-type network 101a Node 10 connected to bus-type network 2 Gateway or router 103 Loop network 103a Node connected to loop network

Claims (5)

[Claims] At least one loop composed of a plurality of nodes connected in a loop and one or more loops composed of a single node or a plurality of nodes connected in a loop are provided. It has one or more input units and one or more output units, and is configured such that a signal input from one input unit is branched without processing and directly connected to a common transmission path output from all the output units. A signal output from any of the nodes is transmitted to all nodes, and in each loop, a node in which the output side of the own node is directly connected to the common transmission path among the nodes. Or a node that has output the signal. 2. At least one loop composed of a plurality of nodes connected in a loop and one or more loops composed of a single node or a plurality of nodes connected in a loop, It has one or more input units and one or more output units, and is configured such that a signal input from one input unit is branched without processing and directly connected to a common transmission path output from all the output units. Wherein the node sending the signal cancels the signal returned to the own node, and the output side of the own node among the nodes of each loop is directly connected to the common transmission path. If the node that sent the signal belongs to the same loop as the own node, the most downstream node that is the current node passes the signal, and the node that sent the signal is the own node. Network system if they belong to different loops, characterized in that extinguishing the signal. 3. At least one loop composed of a plurality of nodes connected in a loop and one or more loops composed of a single node or a plurality of nodes connected in a loop, A signal having one or more input units and one or more output units, and a signal input from one of the input units is branched without being processed and directly connected to a common transmission path output from all of the output units; Each node constituting the loop has a node ID for recognizing its own node, and one node belonging to any of the plurality of loops becomes a token master node, and a node other than the token master node becomes Become a slave node,
A network system in which a node of which the output side of the own node is directly connected to the common transmission path is the most downstream node, wherein the token master node is a node that is permitted to transmit a data packet. A token transmitting device that transmits a token packet including a transmitting node ID that is a node ID and a receiving node ID that is a node ID of a node to receive a transmitted data packet; a token analyzing device that analyzes the token packet; A storage device for temporarily storing node setting information as to whether or not the own node is the most downstream node, a node ID of the token master node, and information of a received packet, a data transmission device for transmitting a data packet, Switch for discarding or passing the received token packet The slave node comprises: a token analyzer that analyzes the token packet; node setting information indicating whether the own node is the lowermost node; a node ID of the token master node; A storage device for temporarily storing information, a data transmission device for transmitting a data packet, and a switch for discarding or passing the received token packet, wherein the token analysis device of each node includes the token At the time of packet transmission, if the own node is a token master node, the switch is controlled so that the received token packet is discarded, and the own node is the most downstream node, judging from the node setting information, and Node I of the token master node
The switch is controlled to discard the received token packet if the own node belongs to a different loop from the token master node, judging from D and the node ID of the own node, otherwise the received token packet By controlling the switch to pass the token packet, the token packet is transmitted to all the nodes and the token packet is erased from the network, and when transmitting the data packet, it is determined from the information of the received token packet. If the own node is the transmitting node, the switch is controlled so that the received data packet is discarded. Based on the node setting information, the own node is the most downstream node, and the received token packet is determined. Information and the node ID of the own node. If the node belongs to a different loop from the transmitting node, the switch is controlled to discard the received data packet; otherwise, the switch is controlled to pass the received data packet. , A data packet is transmitted to all nodes, and the data packet is deleted from the network. 4. The network system according to claim 3, wherein the node ID includes a loop address having the same value between nodes belonging to the same loop and different values between nodes belonging to different loops. Is a network system for determining whether or not a packet transmission node belongs to its own loop based on the loop address. 5. The network system according to claim 1, wherein the common transmission path is an optical star coupler.