JP2001057566A - Signal transmission system and method initializing signal transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal transmission system where system configuration information can automatically be set to each node in a system where a plurality of single nodes or a node group in loop connection are connected to a physical common medium employing a star coupler or in a system a plurality of nodes configure one loop. SOLUTION: Each node being a component of the system has an initializing processing section, the initializing processing section of each node transmits, receives, rewrites a packet at the initializing processing of the system to decide a start node that starts system initializing, to confirm a node placed in an uppermost stream of a loop, the uppermost stream node detects number of nodes in its own loop, a lowermost stream node of its two loop and an ID of each node are decided by using number of the detected nodes and a loop master is designated to set the system configuration. In the case that absence of the uppermost stream node is detected in the initializing processing, it is recognized that the system adopts a single loop configuration to set the system configuration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a signal transmission system for transmitting digital signals and a method for initializing the signal transmission system.

[0002]

2. Description of the Related Art In recent years, digitalization of video and audio data has been advanced, and an era has come in which networks for transmitting computer data such as control commands and digital AV data in a mixed manner are used for general homes and automobiles. . Various configurations are conceivable for configuring a network, and it is necessary to consider an optimal configuration in terms of cost, reliability, and the like.

As an example of a network configuration, there is a ring network in which nodes are connected in order to form a ring. FIG. 16 shows the configuration in this case. In FIG. 16, reference numerals 1600, 1601, 1602, and 1603 denote nodes connected to a network. The node 1600 is a token master node in the present configuration.
Reference numerals 601, 1602 and 1603 are slave nodes.
In FIG. 16, the direction of the arrow indicates the direction in which data flows.

FIG. 17 is a diagram showing a configuration of a packet transmitted on a network in this configuration. In FIG. 17, 1701 is a token packet, and 1702 is a data packet. As shown in FIG. 17, the token packet 1701 has a transmission source ID (ID of a node that permits data transmission) and a reception destination ID (ID of a node that receives data).
including. Here, the transmission source ID and the reception destination ID are composed of a loop address and a node address. However, in the ring network described here, the loop address is not used and is a fixed value. To specify a specific node on the network, the node address may be specified. The description method of the transmission source ID and the reception destination ID in this conventional example is (loop address, node address). It is assumed that the loop address is 0 in the ring network. The data packet 1702 includes a field of data actually transmitted as shown in FIG. The node transmitting the data packet 1702 is the node specified as the transmission source in the transmission source ID field of the token packet 1701.

FIG. 18 is a diagram showing a state of a packet transmitted on a network. In FIG. 18, 1801
Is a token packet, and 1802 is a data packet. In the network according to this configuration, as shown in FIG. 18, a token packet and a data packet are transmitted on the network in this order, and thereafter, this is repeated at regular intervals.

FIG. 19 is a diagram showing a detailed configuration of a ring network. In FIG. 19, 1600 and 160
1, 1602 and 1603 are nodes connected to the network. Node 1600 is a token master node, and nodes 1601, 1602, and 1603 are slave nodes. The node ID of the node 1600 is (0,
0), the node ID of the node 1601 is (0, 1), the node ID of the node 1602 is (0, 2), and the node 1603
Is (0, 3). Thus, each node has a unique node ID.

[0007] As shown in FIG.
Reference numerals 01, 1602, and 1603 denote token analyzers for analyzing tokens and packets, nonvolatile memory for storing initial settings, storage devices connected to the token analyzer and the nonvolatile memory, and data for transmitting data. It includes a transmitting device, a switch for cutting or connecting a ring, an O / E for converting a received optical signal into an electric signal, and an E / O for converting an electric signal into an optical signal and transmitting the same.
The switch connects the ring when switched to the A side, and disconnects the ring when switched to the B side.

As shown in FIG. 19, the token master node 1600 includes a token transmitting device for transmitting a token in addition to the components of the slave node. The switch connects the ring when switched to the A side, and disconnects the ring when switched to the B side. In the above configuration, the non-volatile memory stores initial settings and sets the initial settings in a storage device, and may use a dip switch or the like.

Next, the operation of the ring network configured as described above will be described. If the sender ID is (0,
The operation will be described by taking as an example the case where the token master node 1600 transmits the token packet with the destination ID (0, 1) in 3). In this configuration, the node that has transmitted the packet (all packets including the token packet) switches so as to discard the packet that has returned to its own node.

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 initialization processing. In the initialization sequence, the token master node is set to operate as a token master node by reading information preset in a non-volatile memory or a dip switch into a storage device, and all nodes including the token master node are automatically configured. Know the node ID (loop address and node address).

FIG. 20 is a diagram showing an example of information set in advance in 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 nonvolatile memory as shown in FIG. 20, for example, the information stored in the address of the token master node flag on the nonvolatile memory is read out, and if it is "0", it means that it is not the token master. If it is "1", it can be set as a token master. The same applies to the own node ID.

The normal operation sequence is an operation sequence in which a node actually transmits and receives a packet, and includes a token mode for transmitting and receiving a token packet and a data mode for transmitting a data packet.

The token mode will be described with reference to FIG. FIG. 19 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 1600 assembles a token packet with a token transmitting device, processes the token packet into a format transmitted over a network with a data transmitting device,
The token analyzer switches the switch to the B side and transmits a token packet. Here, the source ID specified by this token packet is (0, 3) and the destination I
D is (0,1).

The token packet transmitted from the token master node 1600 includes nodes 1603, 1602,
1601. The token analysis devices of all nodes including the token master node store the transmission source ID and the reception destination ID in the received token packet in the storage device. As described above, the token packet is transmitted from the token master node 1600 to all nodes, received, and discarded by the token master node. The above is the operation in the token mode.

Next, the data mode will be described with reference to FIG. FIG. 21 is a diagram showing the state of the switch of each node and the flow of the data packet when the data packet is transmitted. In the figure, the thick line indicates the flow of the data packet. The token analyzers of all the nodes including the token master node compare the source ID stored in the storage device with the own ID by the operation in the token mode described above, and if they match (here, only the node 1603 matches), The packet is assembled, processed by the data transmitting device into a form to be transmitted on the network, and the token analyzer switches the switch to the B side to transmit the data packet.

The data packet transmitted from the node 1603 is transmitted in the order of the nodes 1602, 1601, and 1600, and is discarded by the node 1603 that has transmitted the data packet. The token analyzers of all nodes including the token master node use the receiver ID stored in the storage device and the own ID.
Are compared, and if they match, the transmitted data packet is received. As described above, the data packet is transmitted from the node 1603 designated as the transmitting node to all the nodes by the token packet, and received by the node 1601 designated as the receiving node in the token 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 operation in the token mode and the data mode is repeated to realize data transmission.

Although the above-described ring type network has fewer optical fibers and optical modules for connecting the nodes and is advantageous in terms of cost and excellent in expandability of the node, the network is only affected by a partial disconnection of the optical fiber or failure of the node. Since the whole becomes inoperable, there is a problem in reliability.

As another example of the network configuration, there is a hybrid network in which a plurality of loops are connected using an optical star coupler to form a system. FIG. 22 shows a configuration of an example of such a hybrid network.
In FIG. 22, 2200, 2210, 2211, 221
Reference numerals 2, 2220 and 2221 denote nodes connected to the network, and 101 denotes an optical star coupler. Node 2200
Are token master nodes, nodes 2210 and 22
Reference numerals 11, 212, 2220 and 2221 are slave nodes. The node 2200 is a loop master of the loop 0 composed of the node 2200, and the node 2210
Is the loop master of loop 1 composed of nodes 2210, 2211 and 2212, and node 2220 is
It is a loop master of loop 2 composed of nodes 2220 and 2221. In FIG. 22, the direction of the arrow indicates the direction in which data flows. As shown in FIG. 22, in the network according to this configuration, 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) is an optical star coupler. 10
1, the node whose output side is directly connected to the optical star coupler 101 among the nodes constituting each loop becomes the loop master.

The structure of a packet transmitted on the network is the same as that of the ring network described with reference to FIG. Here, the transmission source ID and the reception destination ID include a loop address to which the node belongs and a node address of the node 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. Unlike a ring network, a loop address field is used to specify a specific node. For example, the ID of a node having a loop address of 1 and a node address of 2 is (1, 2). The state of the packet transmitted on the network is the same as the case of the ring network described with reference to FIG. 18, and the detailed description is omitted here.

FIG. 23 is a diagram showing a detailed configuration of the hybrid network. In FIG. 23, 220
0, 2210, 2211, 2212, 2220, 222
1 is a node connected to the network, and 101 is a star coupler. Node 2200 is a token master node, and nodes 2210, 2211, 2212, and 222
0,2221 is a slave node. Node 2200
Belongs to loop 0, and nodes 2210, 2211, 221
2 belongs to loop 1 and loops 2220 and 2221 belong to loop 2. Nodes 2200, 2210, 2220 are loop masters. The ID of the node 2200 is (0, 0), the ID of the node 2210 is (1, 0), the ID of the node 2211 is (1, 1), and the ID of the node 2212.
Is (1, 2), the ID of the node 2220 is (2, 0), and the ID of the node 2221 is (2, 1).

As shown in FIG.
11, 212, 2221 and the loop masters 2210, 2220 which are not token master nodes include a token analyzer for analyzing tokens and packets, a nonvolatile memory for storing initial settings, and a memory connected to the token analyzer and the nonvolatile memory. A data transmission device for transmitting data, a switch for cutting or connecting a loop, and an O for converting a received optical signal into an electric signal.
/ E and an E / O for converting an electric signal into an optical signal and transmitting the optical signal. 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. 23, the token master node 2200 includes a token transmitting device for transmitting 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 stores initial settings and sets the initial settings in a storage device, and may use a dip switch or the like.

Next, the operation of the hybrid network configured as described above will be described. The operation will be described by taking as an example a case where the token master node 2200 transmits a token packet having a transmission source ID of (2, 1) and a reception destination ID of (1, 1). In this configuration, the node that has transmitted the packet (all packets including the token packet) switches so as to discard the packet that has returned to its own node. The loop master switches the switch, discards 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.

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 initialization processing. 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 embodiment) of the loop to which the token master node belongs, and all nodes including the token master node have their own node IDs.
(Loop address and node address).

FIG. 24 is a diagram showing an example of information set in advance in 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 in the nonvolatile memory as shown in FIG. 24, for example, the information stored in the address of the token master node flag on the nonvolatile memory is read out, and if it is “0”, it is determined that the token is not the token master. 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, and includes a token mode for transmitting and receiving a token packet and a data mode for transmitting a data packet.

The token mode will be described with reference to FIG. FIG. 23 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 FIG. 23, the thick line indicates the flow of the token packet.

The token master node 2200 assembles a token packet with the token transmitting device, processes the token packet into a form transmitted on the network with the data transmitting device, and switches the switch to the B side and transmits the token packet with the token analyzing device. Here, the transmission source ID specified by the token packet is (2, 1) and the reception destination ID is (1, 1).

The token analyzers of the loop masters 2210 and 2220 store the loop address “0” of the token master node 2200 stored in the initialization sequence and the loop address of the own loop of the own loop (2210 is “1”,
Reference numeral 2220 compares "2"). 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 packet transmitted from the token master node 2200 is transmitted to the nodes 2200, 2212, 2221 via the optical star coupler 101. In the loop 0 of the loop address 0, the token packet transmitted from the optical star coupler 101 is discarded by the token analyzer of the token master node 2200. In the loop 1 of the loop address 1, the token packet is transmitted in the order of the slave node 2212, the slave node 2211 and the loop master 2210, and is discarded by the token analyzer of the loop master 2210. In loop 2 of loop address 2, slave node 2
221, the token packet is transmitted in the order of the loop master 2220, and is discarded by the token analyzer of the loop master 2220.

The token analyzers of all nodes including the token master node store the source ID and the destination ID in the received token packet in the storage device. As described above, the token packet is transmitted to the token master node 22.
00 to all nodes, received and discarded at loop master and token master nodes. The above is the operation in the token mode.

Next, the data mode will be described with reference to FIG. FIG. 25 is a diagram showing the state of the switch of each node and the flow of the data packet when the data packet is transmitted. In FIG. 25, the thick line indicates the flow of the data packet.

The token analyzers of all the nodes including the token master node and the loop master transmit the source I stored in the storage device by the above-described operation in the token mode.
If D and own ID are compared and matched (here, only node 2221 matches), a data packet is assembled,
The data is processed by the data transmitting device to be transmitted on the network, and the token analyzing device switches the switch to the B side and transmits the data packet.

The token analyzer of the loop master 2220 determines that the own node does not output a data packet because the transmission source ID stored in the storage device and the own ID do not match.
Next, the loop address “2” of the transmission source ID stored in the storage device is compared with the address “2” of the own loop, and since they match, it is determined that a data packet is transmitted from a node in the own loop, Change the switch to.

The token analyzers of the loop masters 2200 and 2210 use the source ID stored in the storage device and the
Since D does not match, the node determines that it does not output a data packet. Next, the loop address “2” of the transmission source ID stored in the storage device and the address of its own loop (2200 is “0”, 2210 is “ 1 "), and since they are different, it is determined that a data packet is transmitted from a node in another loop, and the switch is switched to the B side.

The data packet transmitted from the node 2221 passes through the node 2220 and is
01 to the nodes 2200, 2212, 2221. In the loop 0, the optical star coupler 1
01 is discarded by the token analyzer of the token master node 2200. In the loop 1, the data packet is transmitted in the order of the slave node 2212, the slave node 2211 and the loop master 2210, and is discarded by the token analyzer of the loop master 2210. In the loop 2, the optical star coupler 1
01 is discarded by the slave node 2221 that transmitted the data packet.

The token analyzers of all nodes including the token master node use the destination ID stored in the storage device and the
D is compared, and if they match, the transmitted data packet is received. As described above, the data packet is transmitted from the node 2221 designated as the transmitting node to all the nodes by the token packet, received by the node 2211 designated as the receiving node in the token packet, and transmitted to the loop masters 2200, 2210 and the data packet. Is discarded by the node 2221 that has transmitted the. 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 in the token mode and the data mode are repeated to realize data transmission. By using this configuration, for example, when the optical fiber is disconnected or the node fails, the operation becomes inoperable only in the loop including the failed part. Other parts can continue to operate, thus improving the reliability of the system.

[0039]

However, in the above configuration, configuration information such as a node ID necessary for the operation of the system must be set in advance by a nonvolatile memory or a dip switch. These pieces of configuration information differ depending on the position and function of each node in the system. Therefore, there is a problem that it is necessary to replace a nonvolatile memory or set a DIP switch when the system is introduced or every time the system configuration is changed. There is also a problem that the setting needs to be changed depending on whether the network configuration is a ring type or a hybrid type.

The present invention has been made in order to solve the above-mentioned problems, and a system in which a single node or a group of nodes connected in a loop is connected to a plurality of physical common media by one star coupler or a plurality of nodes is connected to one An object of the present invention is to provide a signal transmission system and a signal transmission system initialization method that can set configuration information in each node in advance in a system forming a loop.

[0041]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention (claim 1) provides at least one loop composed of a plurality of loop-connected nodes, and a single node or a loop-connected node. One or more loops composed of a plurality of nodes have one or more input units and one or more output units, and a signal input from one input unit is branched and output from all output units. A signal transmission system configured to be directly connected to one common transmission path, wherein each of the nodes has an initialization processing unit that performs system initialization processing, and performs initialization of a system among the nodes. The initialization processing unit of the start node, which is a start node, sends out a start packet instructing the start of initialization at the time of system initialization, and connects directly to the common transmission path among the nodes to transmit the common transmission path. The most upstream node, which is a node that receives more data, detects that the initialization processing unit of the node receives the start packet a plurality of times or detects a collision of the start packet so that the own node can directly communicate with the common transmission path. Recognizing the connection, it is configured to operate as the most upstream node thereafter.

According to the present invention (claim 2), at least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are provided. A loop 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 and directly connected to one common transmission path output from all output units. Wherein each of the nodes has an initialization processing unit for performing system initialization processing, and is a node directly connected to the common transmission path and receiving data from the common transmission path. The initialization processing unit of the upstream node sends a node number confirmation packet including the counter area, and the initialization processing units of other nodes connected to the same loop as the most upstream node transmit the node number confirmation packet. When a packet is received, a predetermined value is added to the value of the counter area and the packet is transmitted.The initialization processing unit of the most upstream node refers to the counter value in the returned node number confirmation packet. , The number of nodes in the own loop is detected.

The present invention (claim 3) provides at least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes. A loop 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 and directly connected to one common transmission path output from all output units. Wherein each of the nodes has an initialization processing unit for performing system initialization processing, and is a node directly connected to the common transmission path and receiving data from the common transmission path. The initialization processing unit of the upstream node sends a lowermost node designation packet including the counter area and having a value obtained by subtracting 1 from the number of nodes in the own loop with the value of the counter area, and is the same as the most upstream node. When the initialization processing unit of another node connected to the loop receives the packet for specifying the most downstream node, the initialization processing unit reduces the value of the counter area by 1 and transmits the packet, and is connected to the same loop as the most upstream node. Among the other nodes, a node whose result obtained by subtracting 1 from the value of the counter area of the most downstream node designation packet by the initialization processing unit is 0 is directly connected to the common transmission path and thereafter to the common transmission path. It is configured to operate as the most downstream node that is a node that transmits data.

Further, according to the present invention (claim 4), in the signal transmission system according to claim 3, the initialization processing unit of the most upstream node includes a value obtained by subtracting 1 from the number of nodes in the own loop. The initialization processing unit of another node connected to the same loop as the most upstream node sets a value obtained by subtracting 1 from the value of the counter area of the received most downstream node designation packet. It is configured to be set as a node identification number.

Further, the present invention (claim 5) is a signal transmission system having at least one loop composed of a plurality of nodes connected in a loop, wherein each of the nodes performs a system initialization process. An initialization processing unit having an initialization processing unit, wherein the initialization processing unit of a start node that is a node that starts system initialization among the nodes transmits a position designation packet during system initialization and receives the position designation packet. The initialization processing unit of the other node receives the position designation packet, and the other node receives at least one loop composed of a plurality of loop-connected nodes and a single node or a plurality of loop-connected nodes. One or more loops having one or more input sections and one or more output sections, a signal input from one input section is branched, and all output sections Is directly connected to a common transmission path of one output of the signal transmission system configured Ri,
When the node is directly connected to the common transmission path and receives data from the common transmission path, when the position designation packet is received, a unique number possessed by itself is written and transmitted, and the initial value of the start node is initialized. Conversion unit,
If the specific number of the other node is not written in the position specifying packet returned after looping around the loop, the subsequent initialization processing is performed on the assumption that the signal transmission system is a system constituted by one loop. It is configured.

The present invention (claim 6) is a signal transmission system having at least one loop composed of a plurality of nodes connected in a loop, wherein each of the nodes performs a system initialization process. It has an initialization processing unit, the initialization processing unit of a start node which is a node that starts system initialization among the nodes, at the time of system initialization, has a number area and a fixed area, and the number area Each time, a start packet in which a different number is written is transmitted at least once, and the initialization processing unit of each of the nodes determines when the start packet in which the same value is written in the number area is received at least twice. A start packet in which a predetermined default value is written and transmitted in an area, the initialization processing unit of the start node transmits the start packet a fixed number of times, and a start packet in which the predetermined value is written in the determined area If not received, in which the signal transmission system is configured to perform the initialization processing after as being a system constituted by one loop.

Further, according to the present invention (claim 7), in the signal transmission system according to any one of claims 1 to 6, each node includes an initial setting transmission path for performing initial setting and a normal transmission. A transmission line for normal transmission to be performed, and a switch for switching the transmission line connected to the transmission line for initial setting to a normal transmission line after initialization processing at power-on and reset.

The present invention (claim 8) provides at least one loop constituted by a plurality of nodes connected in a loop and one or more loops constituted by a single node or a plurality of nodes connected in a loop. A loop 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 and directly connected to one common transmission path output from all output units. A signal transmission system initialization method for performing initialization of a signal transmission system, wherein a start node, which is a node for starting system initialization among the nodes, transmits a start packet instructing start of initialization at the time of system initialization. Transmitting a start packet to be transmitted, and a most upstream node which is a node directly connected to the common transmission path and receiving data from the common transmission path among the nodes. Or receiving a plurality of times the start packet, themselves by detecting a collision of the start packet is one that has a most upstream node recognition step recognizes that the most upstream node.

The present invention (claim 9) provides at least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes. A loop 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 and directly connected to one common transmission path output from all output units. A signal transmission system initialization method for performing initialization of a signal transmission system according to claim 1, wherein one of the most upstream nodes that are nodes directly connected to the common transmission path and receiving data from the common transmission path includes a counter. A node number confirmation packet transmitting step of transmitting a node number confirmation packet including an area, and another node connected to the same loop as the most upstream node includes the node number confirmation packet. A packet reception processing step of adding a predetermined value to the value of the counter area when receiving the packet, and transmitting the packet, and the most upstream node refers to the counter value in the returned node number confirmation packet. And a node number detecting step of detecting the number of nodes in the own loop.

The present invention (claim 10) provides at least one loop constituted by a plurality of nodes connected in a loop and one or more loops constituted by a single node or a plurality of nodes connected in a loop. A loop 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 and directly connected to one common transmission path output from all output units. A signal transmission system initialization method for performing initialization of a signal transmission system to be performed, wherein the most upstream node which is a node directly connected to the common transmission path and receiving data from the common transmission path includes a counter area, A lowest-downstream-node-designated-packet sending step of sending the lowest-downstream-node-designated packet with the value of the counter area being one less than the number of nodes in the loop;
A packet reception processing step in which another node connected to the same loop as the most upstream node, when receiving the most downstream node designation packet, reduces the value of the counter area by 1 and sends it out; Among the other nodes connected to the loop, a node whose result obtained by subtracting 1 from the counter value in the lowermost node designation packet is 0,
A lowermost node recognizing step of recognizing that the self is the lowermost node since the result obtained by subtracting 1 from the counter value in the lowermost node designation packet is 0.

The present invention (Claim 11) provides Claim 1
0, in the signal transmission system initialization method, the most upstream node sets a value obtained by subtracting 1 from the number of nodes in the own loop as a node identification number of the own node, and is connected to the same loop as the most upstream node. Another node has a node identification number determining step of setting a value obtained by subtracting 1 from the value of the counter area of the received most downstream node designation packet as the node identification number of the own node.

Also, the present invention (claim 12) is a signal transmission system initialization method for initializing a signal transmission system having at least one loop composed of a plurality of loop-connected nodes, A start node, which is a node that starts system initialization, among the nodes, a position designation packet sending step for sending a position designation packet at the time of system initialization, and another node receiving the position designation packet, At least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are provided with one or more input units and one or more loops. It has an output unit and the signal input from one input unit is branched and directly connected to one common transmission path output from all output units. When a node of the signal transmission system to be directly connected to the common transmission path and receives data from the common transmission path, the unique number possessed by itself is received when the position designation packet is received and transmitted. The receiving node processing step, and if the unique number of another node is not written in the position specifying packet returned by the start node making a round of the loop, the signal transmission system is constituted by one loop And a system configuration recognizing step of recognizing the system.

The present invention (claim 13) is a signal transmission system initialization method for initializing a signal transmission system having at least one loop constituted by a plurality of loop-connected nodes, A start node, which is a node that starts system initialization among nodes, has a number area and a definite area at the time of system initialization, and transmits a start packet in which a different number is written in the number area each time. Step, wherein each of the nodes stores the start packet in which the same value is written in the number area for 2 seconds.
A receiving packet processing step of writing and transmitting a predetermined value to a determined area when receiving the data more than once, and the start node performs the start packet transmitting step a fixed number of times;
And a system configuration recognizing step of recognizing that the signal transmission system is a system configured by one loop when a start packet in which the predetermined value is written in the determined area is not received. is there.

Further, the present invention (claim 14) provides claim 1
An automobile is provided with the signal transmission system according to any one of claims 7 to 10.

[0055]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A description will be given of a signal transmission system initialization method according to the first embodiment of the present invention. FIG. 1 is a diagram showing a detailed configuration of the signal transmission system according to the first embodiment of the present invention. In FIG. 1, 100,
110, 111, 112, 120 and 121 are nodes connected to the network, and 101 is a star coupler.
Node 100 is a token master node and node 1
Reference numerals 10, 111, 112, 120 and 121 are slave nodes. Node 100 belongs to loop 0 and node 11
0, 111, 112 belong to loop 1 and loop 120,
121 belongs to loop 2.

As shown in FIG. 1, the slave node 11
0, 111, 112, 120, and 121 hold a token analysis device that analyzes tokens and packets, an initialization control unit that controls system initialization, and a unique number that is a unique number in each node. A nonvolatile memory connected to the initialization control unit, a storage device connected to the token analysis device and the initialization control unit, a data transmission device for transmitting data, a switch for cutting or connecting a loop, and initialization control Sub-switch 1 and sub-switch 2 for selecting whether to connect to a unit or to perform a normal operation, an O / E for converting a received optical signal into an electric signal, and an E / E for converting an electric signal into an optical signal and transmitting the same. O is provided. The switch connects the loop when switched to the A side, and disconnects the loop when switched to the B side.

The contents of the volatile memory provided in each node of the signal transmission system according to the first embodiment do not need to be changed depending on the system configuration as in the case of the conventional embodiment. FIG. 15 is a diagram illustrating an example of information set in advance in the nonvolatile memory. In this example,
It is assumed that the address of each numerical value on the nonvolatile memory is known. Assuming that information is set on the non-volatile memory as shown in FIG. 15, at the time of initialization, for example, the information stored at the address of the unique number on the non-volatile memory is read and used in the initialization processing. RND_TIME is a value that determines the standby time of the system, and a random value is written in each node. However, it is not always necessary to set different values for each node as in the case of the unique number.

As shown in FIG. 1, the token master node 1
00 includes a token transmitting device for transmitting 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 present embodiment, when the system is started up, the sub-switch 1 and the sub-switch 2 are connected to the B side, that is, the initialization control unit, and perform processing such as ID setting, loop master notification, and master determination. After the initialization process is completed, the sub-switch 1 and the sub-switch 2 are switched to the A side, and perform the data transmission described in the conventional configuration.

Hereinafter, the initialization processing will be described. FIG.
5 is a flowchart illustrating a system initialization method according to the first embodiment. In this description, an outline of the processing will be described with reference to FIG. 2, and then the detailed processing will be described. In step 201, a starting node in the system is first determined. Here, the only node in the system is selected as the start node. The start node sends out a start packet in step 202. The most upstream node on the loop to which it belongs (hereinafter referred to as the “upstream node”) recognizes its position by receiving this start packet twice or by receiving other data (collision packet) after receiving the start packet. I do. Next, in step 203, the start node obtains the unique number of the most upstream node. At this time, if the most upstream node does not exist, the start node recognizes that the system has a ring configuration (step 20).
4). In this case, in step 211, the start node specifies the ID number of each node, and completes the initialization (step 212).

If the most upstream node exists, in step 205, the start node notifies the most upstream node on the loop to which the own node belongs to start the loop configuration. The node that has been notified (hereinafter referred to as an active node) first checks the number of nodes belonging to the loop in step 206. Next, in step 207, the ID number is notified to each node belonging to the loop, and the loop downstream is notified to the most downstream node. Step 2
At 08, the active node instructs another uppermost node to form a loop next. At this time, if there is no unconfigured loop (step 209), a token master node is determined in step 213. If the loop ID of the token master node is not 0, step 21
In step 4, the loop ID is changed to 0 and the initialization is completed (step 215).

At step 210, each upstream node negotiates to determine the next active node. The active node returns to step 206 and performs loop configuration. This operation is repeated to determine the ID of each node, notify the loop master, and determine the master.

Steps 213 and 214 are performed so that the master node is at the position of the loop master and the loop ID is 0. In this embodiment, a case will be described in which this processing is also included. However, if there is no restriction, these steps can be omitted.

In the initialization processing, each node performs communication using a packet. A packet used in the present embodiment will be described with reference to FIGS. FIG. 26 is a diagram showing a packet format according to the present embodiment.
00 is a PID indicating the type of packet, and 2601 is a Payload indicating the contents of the packet. Each node determines the type of the packet by referring to the PID 2600 of the received packet, and performs a process corresponding to the type in Payload 2
Reference is made to the contents of 601 (if necessary) and processing is performed.
FIG. 27 is a diagram showing types of packets and their contents according to the present embodiment. The description of each packet shown in the figure will be made as appropriate in the following description of each step.

Hereinafter, each step of FIG. 2 will be described in detail. FIG. 3 is a flowchart showing a start node determination method. Step 20 in FIG.
1 and determines a start node for performing initial setting at the time of startup. Each node starts a timer when starting up the system (step 301). The node that becomes the start node in the system is limited to a node that can be a token master node (hereinafter, referred to as a candidate node) (step 302). After the candidate node waits for a time determined by RND_TIME × T (steps 303, 304,
And 305), and sends out a unique number packet in which the unique number is written (step 307).

In the present embodiment, T is a time longer than the time required for a packet transmitted by a certain node to be transmitted to all nodes of the system. If a unique number packet or other data (collision data) from another node is received during the standby (step 306), the candidate node loses the right to become the start node (step 323), and becomes a non-candidate node. Perform processing (step 32
4). The unique number packet transmitted in step 307 is transmitted from the loop to which it belongs to all nodes via the star coupler. At this time, nodes other than the candidate nodes (hereinafter, referred to as non-candidate nodes) perform the processing shown in FIG.

Step 401 is initialization in the present processing. The non-candidate node starts from system startup (step 3
01) Until some data is received (step 40)
3, 404, 411), and a timer is started periodically at intervals of time T (steps 405, 406). If any data is received, the process waits for the next timeout (step 407), and proceeds to step 408.

When the non-candidate node receives the unique number packet or other data (collision data) (step 404), if it is a unique number packet (step 412), the stored (initial value 0) stored in the node is used. And rnd_no in the packet (step 4
13) If rnd_no is large, store is set to rn
Rewrite to d_no and send the unique number packet to the next node (step 414). Only when the first received packet is a packet other than the unique number packet (steps 415 and 417), the unique number packet with rnd_no = 0 is sent to the next node (step 4).
16). This is performed in order to reduce the number of nodes attempting transmission when the unique number packet disappears due to a collision and a plurality of nodes transmit the unique number packet again. Step 4
At 08, the system waits for the arrival of a start packet transmitted by another node. If the start packet has not arrived (step 40)
9) The operation after step 403 is repeated again.

After transmitting the unique number packet, the candidate node waits until time 2 × T has elapsed (step 309). This is to wait for the arrival of the unique number packet when another candidate node transmits the unique number packet at the same timing. If a unique number packet is received during standby (step 308)
The stored (initial value 0) stored in the node is compared with rnd_no in the packet (step 310).
If nd_no is large, rewritten stored to rnd_no (step 311) and send the unique number packet to the next node (step 313). Where rnd_
If no is equal to the unique number of the node, it is not transmitted to the next stage (step 312).

After a lapse of time 2 × T, the candidate node
ed is compared with the unique number of the node (step 314),
If they are equal, a start packet is transmitted (step 31).
5). If not, start the timer (step 31).
8) Wait for the arrival of the start packet (step 319).
When the start packet is received, the process proceeds to the most upstream node recognition step (step 322). If the start packet does not arrive within the time T (step 320), the node determines that the unique number packet has disappeared due to the packet collision, changes RND_TIME, starts the timer again (step 321), and returns to step 303. Return to processing. R
As a method of changing ND_TIME, there is a method using a random number, a method of adding a value of a unique number, or the like.

According to this process, when another node sends a unique packet at the same time, the one with the larger unique number gets the right to send the start packet. Further, even if a collision occurs in the star coupler and the unique number packet is lost, the candidate node can send out the unique number packet again, and the initialization does not stop.

When two different unique packets issued by two candidate nodes are input to the optical star coupler at exactly the same timing, the collision data is in the form of a logical sum of two packets due to the nature of the optical signal. In this case, the collision packet has the same format as the unique number packet. In this case, the unique number portion is larger than any of the original numbers of the two original packets. Therefore, in this case, both nodes that have transmitted the unique number packet return to step 303 again because the start packet does not arrive during the standby time, and are in a state of waiting for the transmission of the unique number packet. By using a format having a large unique number to obtain the right to transmit the start packet, malfunction of the system can be avoided. The candidate node that has sent the start packet waits for the arrival of the start packet sent by itself (step 316), becomes the start node (step 317), and moves to the most upstream node recognition step (step 322).

FIG. 5 is a flowchart showing the most upstream node recognition method. This corresponds to step 202 in FIG. 2, and the most upstream node recognizes its own position. Each node receives the start packet at least once. When each node receives the start packet, it sends the start packet to the next node only once (step 501). After the transmission, the arrival of the start packet or other data (collision packet) is waited until the time T elapses (step 503) (step 50).
2). If received, the node recognizes that it is the most upstream node (step 505), and ends this step after elapse of time T. If not received, the node is recognized as a node other than the most upstream node (step 504), and this step is ended. 3, 4 and 5, it is possible to determine one start node in the system and make the most upstream node recognize its position.

FIG. 6 is a flowchart showing a method for detecting the most upstream node. Steps 203 and 204 in FIG.
And the start node recognizes the most upstream node on the own loop. If the node is the start node (step 60
1) Start the timer (step 602), and rnd_no
= 0, node_cnt = 0, and transmits a position designation packet (step 603). The position designation packet goes around the own loop and returns to the start node (step 604).
If the start node is not the most upstream node (step 605),
If rnd_no in the packet is 0 (step 606), the system recognizes that the packet has a ring configuration, and
2 is performed (step 6).
07). Otherwise, a timeout is waited (step 608), and this step ends (step 614).

Among the nodes other than the start node, the node that is not the most upstream node (step 610) receives the position designation packet (step 609), and
The de_cnt is incremented by 1 and transmitted to the next node (step 611). The most upstream node sets rnd_no = unique number (step 612), sends a packet to the next node (step 613), and ends this step.

FIG. 7 is a flowchart showing a method of notifying the active most upstream node. Step 20 in FIG.
5 and notifies that the most upstream node of the same loop as the start node is active. If the node is the start node (step 701), r written in the position designation packet returned in step 504 in the previous processing
The most upstream notification packet in which nd_no is written is transmitted (step 702). After the transmission, the received packet is transmitted to the next node (step 703).

Of the nodes other than the start node, the node that is not the most upstream node (step 704) transmits the received packet to the next node as it is (step 705). When the most upstream node receives the most upstream notification packet (step 706), it refers to the rnd_no field (step 7).
07) If it matches the unique number held by the node, it becomes an active node (step 708).

FIG. 8 is a flowchart showing a method for detecting the number of loop nodes. This corresponds to step 206 in FIG. 2, and the active node detects the number of nodes in its own loop. If the node is the active node (step 80
1) A node number confirmation packet with node_cnt = 0 is transmitted (step 802). The node number confirmation packet goes around the loop and returns to the active node (step 803). If the node is a node other than the active node and is not the most upstream node (step 806), the node_cnt in the node number confirmation packet is incremented by 1 and transmitted to the next node (step 807). Otherwise, the node number confirmation packet is not sent to the next stage. The active node can obtain the number of nodes in its own loop by adding 1 to node_cnt of the returned packet (step 804) (step 805).

FIG. 9 is a flowchart showing an ID / loop master determination method. This corresponds to step 207 in FIG. 2, and each node on a loop having an active node determines its own ID and loop master. If the node is the active node (step 901), the value of node_cnt in the node number confirmation packet returned in step 803 in the previous process is set as its own node ID (step 902), and the node is set in the ID_cnt field.
e_cnt value to loop_no, own loop ID
An ID notification packet containing (initial value 0) is transmitted (step 903). The ID notification packet goes around the loop,
Return to the active node (step 904).

If the node is a node other than the active node and is not the most upstream node (step 905), the ID
The ID_cnt in the notification packet is decremented by 1 and transmitted to the next node (step 906). Otherwise, the node number confirmation packet is not sent to the next stage.

Each node in the loop including the active node can determine the ID by setting the value obtained by subtracting 1 from the ID_cnt of the received packet to the node ID and setting loop_no to the loop ID. Further, the node located at the lowermost position in the loop recognizes that it is the lowermost node by receiving the ID notification packet of ID_cnt = 0, and prepares to operate as a loop master.

FIG. 10 is a flowchart showing a method for starting the next loop configuration. This corresponds to steps 208 and 209 in FIG. 2, and the active node announces the end of the loop configuration. Also, the presence or absence of an unconfigured loop is detected. If the node is the active node (step 10
01), start a timer (step 1002), and
The loop ID + 1 is written in the p_no field (step 1003), and a loop configuration packet is transmitted (step 1004). The loop configuration packet goes around the loop and returns to the active node (step 1005).

After receiving the loop configuration packet, the active node waits for reception of the next packet (step 1).
006). Wait for timeout (Step 1
008) If an ACK packet is received or a packet collision is detected, the operation as an active node ends (step 1007). If the time-out has occurred, it is recognized that the entire loop configuration has been completed, and the process proceeds to the master determination step described in FIG. 13 (step 1009).

If the node is a node other than the active node and is not the most upstream node (step 1010), it receives the loop configuration packet and sends it out to the next node (step 1011). The configuration of the loop to which the most upstream node belongs is not completed (step 101
2) If the most upstream node other than the active node receives the loop configuration packet (step 1013), the loop ID of the own node is set to loop_no in the packet (step 1014), and an ACK packet is transmitted (step 1015).

FIG. 11 is a flowchart showing an active node determination method. This corresponds to step 210 in FIG. 2, and next, an active node forming a loop is determined. In this step, the most upstream node having no loop is determined to determine the next active node to be looped. The determination method is almost the same as the start node determination method described with reference to FIGS. 3 and 4, and a detailed description thereof will be omitted. In this step, the next active node is determined, and again in step 2 in FIG.
Steps 06 and below are repeated.

Each node starts a timer when starting up the system (step 1101). The node other than the most upstream node (step 1102) performs a relay process of simply transmitting the received packet to the next stage in this step (step 1104). The most upstream node to which the configuration of the loop to which the node belongs has already ended (step 1103) becomes an inactive node (step 1107), and waits for reception of a start packet from another node (step 1108) to end this processing (step 1131). ).

The most upstream node having no loop is RND_T.
After waiting for a time determined by IME × T (steps 1105, 1109 and 1110), a unique number packet in which the unique number is written is transmitted (step 111).
1). If a unique number packet or other data (collision data) is received from another node while waiting (step 1106), the node becomes inactive (step 1107). The unique number packet transmitted in step 1111 is transmitted from the loop to which it belongs to each of the most upstream nodes via the star coupler.

The node that has transmitted the unique number packet waits until the time T has elapsed (step 1115). If a unique number packet is received during standby (step 1112), stored (initial value 0) stored in the node is compared with rnd_no in the packet (step 1113).
If nd_no is large, stored is rewritten to rnd_no (step 1114).

After the elapse of time T, the node that sent the unique number packet compares stored with the unique number of the node (step 1116), and sends a start packet if they are equal (step 1117). When the start packet is received (step 1118), the node becomes an active node (step 1119), and this step ends. If not, the timer is started (step 1120), and the arrival of the start packet is waited (step 1121). Upon receiving the start packet, the node becomes an inactive node (step 112).
4). If the start packet does not arrive within the time T (step 1122), the node determines that the unique number packet has disappeared due to the packet collision, changes RND_TIME, starts the timer again (step 1123), and returns to step 1105. Return to processing.

FIG. 12 is a flowchart showing a ring node ID determination method. This corresponds to step 211 in FIG. 2, and the ID of each node is determined and the initialization is completed. Each node recognizes the end of the initialization by receiving the ring ID notification packet used in this step. The start node that has recognized that there is no upstream node in the upstream-most node detection step 102 (step 103) recognizes that the system configuration is a ring.

In this step (step 1201), the start node refers to the node_cnt field in the position designation packet received in step 304 of FIG. 3, sets ID_cnt = node_cnt (step 1202), and transmits a ring ID notification packet (step 1202). 1203). When the ring ID notification packet returns (step 1204), the node completes the initialization processing (step 1205).

When the node other than the start node receives the ring ID notification packet, it decreases the value of the ID_cnt field by 1, sets its own node ID to ID_cnt (step 1207), and sends the ring ID notification packet to the next stage (step 1208). ). The node completes the initialization processing by the transmission (step 1209). Each node that has completed the initialization in this step moves the sub switches 1 and 2 in FIG. 15 to the A side, and shifts to the normal operation shown in the conventional mode.

FIG. 13 is a flowchart showing a master determination method. This corresponds to step 213 in FIG. 2, and determines a token master node. After the execution of step 106, when the configuration of all loops is completed in step 103, the process proceeds to master determination step 110. In this step, if the node is an active node, a timer is started (step 1302), and a MASTER_REQ packet is transmitted with loop_no = 0 (step 1303) (step 1304). Wait for time T (step 1
306) If a MASTER_NOTIFY signal is received (step 1305), this step ends (step 1309). If no MASTER_NOTIFY signal is received, loop_no is increased by 1 (step 13).
08), restart the timer (step 1307), and return to step 1305. This operation is repeated.

Among the nodes other than the active node, the nodes that are not master candidates and are not the loop master (steps 1310 and 1313)
The ER_REQ and MASTER_NOTIFY signals are sent to the next node as they are (step 1314). The loop master node that is not a master candidate ends this step (step 1315).

When the master candidate and loop master node receives a MASTER_REQ packet whose loop_no field matches its loop ID (step 1311), it sends out a MASTER_NOTIFY packet (step 1312) and ends this step (step 1312). Step 1317). MASTER_NOTI
If the FY signal is received (step 1312), the present step ends (step 1318).

FIG. 14 is a flowchart showing a master changing method. This corresponds to step 214 in FIG. 2, and when a node other than loop ID = 0 becomes a master in the master determination step shown in FIG. 13, a change is made so that the loop ID of the master becomes 0. Each node recognizes the end of the initialization by receiving the master change packet used in this step. Also, even when the node with loop ID = 0 becomes the master, the completion of the initialization is notified to each node by performing this processing.

In the master determination step, MASTER_NO
The node that has transmitted TIFY (step 1401) starts a timer (step 1402). Node Loop I
If D is 0 (step 1403), new_ID =
A master change packet with 0 is transmitted (step 140).
4) Wait for time T to elapse (step 140)
7) The initialization operation is completed (Step 1408). If the loop ID of the node is other than 0, a master change packet with new_ID as the loop ID is transmitted (step 14).
05), and sets its own loop ID to 0 (step 140).
6) Wait for time T to elapse (step 140)
7) The initialization process is completed (Step 1408).

When a node other than the node that sent MASTER_NOTIFY receives the master change packet (step 1409), the node whose loop ID is 0 (step 1410) writes n with the loop ID written in the packet.
ew_ID (step 1411), loop ID is ne
If equal to w_ID (step 1412), the loop ID is set to 0 (step 1413). Node ID is 0
The other node (step 1414) sends a master change packet to the next node (step 1415). After the above processing is completed, the initialization processing is completed (step 1).
416). Each node that has completed the initialization in this step moves the sub switches 1 and 2 in FIG. 15 to the A side, and shifts to the normal operation shown in the conventional mode.

As described above, in the signal transmission system initialization method according to the first embodiment, first, the only start node in the system is determined, and the start packet transmitted by the start node is received a plurality of times, or collision is detected. By recognizing the most upstream node, assigning an ID to the node belonging to the loop to which the most upstream node belongs, specifying the loop master node, and finally determining the token master node in the system, The system can be initialized without previously specifying the token master node, the loop master node, the ID of each node, and the like using a memory or a dip switch.

The configuration of the signal transmission system according to the present invention is not limited to the configuration shown in the first embodiment, but is directly connected to the number of loops, the number of nodes in the loop, and the optical star coupler. The number of nodes can be arbitrarily set within the range of the bit width of the node ID and various physical restrictions. In the first embodiment, the token master node is directly connected to the optical star coupler. However, the token master node can be arranged at an arbitrary position in the loop. In the first embodiment, the loop ID of the loop to which the token master node belongs is 0, but the present invention is not limited to this.

The processing procedure described in the first embodiment is an example, and the start node determination, the most upstream node recognition, the ID allocation by the most upstream node, The method of specifying the loop master node is not limited to the processing procedure described in the first embodiment.

Further, in the first embodiment, the case where the system has one node having the function of the master node is shown. However, the initialization can be similarly realized when there are a plurality of nodes. In this case, the node that has the function of the master node but has not become the master node performs the subsequent operations as a slave node. Further, the packet format, the field, the number of bits, and the like used in the first embodiment are for explanation, and are not limited thereto. In the first embodiment, the method of transmitting the unique number packet in which the unique number is written when determining the start node is used. However, other methods, such as specifying the start node in advance before initialization, are used. A method may be used.

In the first embodiment, the unique number and the R
Although ND_TIME has been written in the non-volatile memory of each node, it may be determined using a random number at the time of startup at each board. In that case, the non-volatile memory becomes unnecessary. The unique number needs to be different for each node, but can be realized by taking a sufficiently large random number value. Also, write only the unique number in the nonvolatile memory, and
Needless to say, the same can be realized by a format in which _TIME is determined each time using a random number.

In the first embodiment, each node
The node ID is referred to as it is by referring to the node_cnt field of the D notification packet, but other methods, for example, the active node sequentially notifies its downstream node of the ID number, and each node returns a packet for confirmation to the active node, By repeating this, the node ID of the loop may be determined. This method is particularly effective when there is a node in which a node ID is manually set in a loop and the numbers need to be discontinuous.

In the first embodiment, the packet collision is detected when there is a possibility that a plurality of nodes simultaneously transmit packets in the steps of determining the start node and recognizing the most upstream node and collide in the star coupler. Although the method of performing the processing is used, it can be realized even when the collision cannot be detected. For example, in the most upstream node recognizing step of the first embodiment, the node that has received the start packet transmitted by the start node twice, or has detected the collision after receiving once, has become the most upstream node.
The following method can also be used. That is, after the start node is determined, the start node sequentially sends out a packet in which a different serial number is written every time, and each node changes the time for temporarily holding this packet by a random number. If the number of transmissions is sufficiently large, the most upstream node may receive a packet having the same serial number a plurality of times, and the most upstream node can be recognized without collision detection. When this method is used, an upper limit value is set for the number of transmissions, and if the most upstream node is not recognized even if packets are transmitted more than the upper limit number of times,
It can be recognized that the system configuration is a ring. A decision area is provided in the packet to determine whether the most upstream node has been recognized, and if the most upstream node recognizes its own position, the default value indicating the decision is written to the decision area and transmitted to the start node. can do. Similarly, a method using no collision is applicable to other steps using collision detection.

Note that the signal transmission system according to the present invention
Needless to say, it can be used in various environments, such as in a car as an in-vehicle LAN system.

[0106]

As described above, according to the present invention, at least one loop constituted by a plurality of loop-connected nodes and one or more loops constituted by a single node or a plurality of loop-connected nodes are provided. In a signal transmission system in which a loop is directly connected to one common transmission path, a start node that starts system initialization sends a start packet and receives the start packet multiple times or collides with the start packet. The most upstream node is determined by the detection, the most upstream node detects the number of nodes in its own loop, and the most downstream node of the own loop and the ID of each node are determined using the detected number of nodes. Master and node IDs (loop address and node address) can be set automatically. There is an effect that can be changed formed easily. Further, by detecting the case where the most upstream node does not exist, it is possible to automatically recognize whether the configuration is a ring or a hybrid, and there is an effect that the operation of setting in advance can be omitted.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a system initialization method according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a start node determining method according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a method of processing a non-candidate node according to the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating a method of recognizing the most upstream node according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating a most upstream node detecting method according to the first embodiment of the present invention.

FIG. 7 is a flowchart illustrating a method for notifying an active most upstream node according to the first embodiment of the present invention.

FIG. 8 is a flowchart illustrating a loop node number detection method according to the first embodiment of the present invention.

FIG. 9 is a flowchart illustrating an ID / loop master determination method according to the first embodiment of the present invention.

FIG. 10 is a flowchart showing a next loop configuration starting method according to the first embodiment of the present invention.

FIG. 11 is a flowchart illustrating an active node determination method according to the first embodiment of the present invention.

FIG. 12 shows a ring node I according to the first embodiment of the present invention.
It is a flowchart which shows D determination method.

FIG. 13 is a flowchart illustrating a master determination method according to the first embodiment of the present invention.

FIG. 14 is a flowchart showing a master changing method according to the first embodiment of the present invention.

FIG. 15 is a diagram showing an example of information preset on a nonvolatile memory according to the first embodiment of the present invention.

FIG. 16 is a diagram showing a configuration of a ring network according to a conventional configuration.

FIG. 17 is a diagram showing a configuration of a packet transmitted on a network in a network system having a conventional configuration.

FIG. 18 is a diagram showing a sequence in which a packet is transmitted on a network in a network system having a conventional configuration.

FIG. 19 is a diagram showing a state of a switch of a node and a flow of a token packet when a token packet is transmitted in a ring network system having a conventional configuration.

FIG. 20 is a diagram showing an example of information set in advance on a nonvolatile memory having a conventional configuration.

FIG. 21 is a diagram showing a state of a switch of a node and a flow of a data packet when a data packet is transmitted in a ring network system having a conventional configuration.

FIG. 22 is a diagram showing a configuration of a hybrid network according to a conventional configuration.

FIG. 23 is a diagram showing a state of a switch of a node and a flow of a token packet when a token packet is transmitted in a hybrid network system having a conventional configuration.

FIG. 24 is a diagram showing an example of information set in advance on a nonvolatile memory having a conventional configuration.

FIG. 25 is a diagram showing a state of a switch of a node and a flow of a data packet when a data packet is transmitted in a hybrid network system having a conventional configuration.

FIG. 26 is a diagram illustrating a form of a packet according to the first embodiment of the present invention.

FIG. 27 is a diagram showing types of packets and their contents according to the first embodiment of the present invention.

[Explanation of symbols]

 100 Token master node 101 Optical star coupler 110 Slave node 111 Slave node 112 Slave node 120 Slave node 121 Slave node

Continued on the front page F term (reference) 5K030 GA11 HA08 HB08 HC14 HD09 MD04 MD08 5K031 AA07 AA14 CA05 DA02 DA06 EA12 EC01 EC02 EC03 EC05

Claims (14)

[Claims] At least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are connected to one or more input nodes. A signal transmission system comprising a unit and one or more output units, wherein a signal input from one input unit is branched and directly connected to one common transmission path output from all output units, Each of the nodes has an initialization processing unit that performs system initialization processing, and the initialization processing unit of a start node, which is a node that starts system initialization among the nodes, performs initialization at the time of system initialization. The most upstream node, which is a node that sends out a start packet instructing the start of data conversion and is a node that directly connects to the common transmission path and receives data from the common transmission path among the nodes, The initialization processing unit of the node recognizes that the own node is directly connected to the common transmission path by detecting the reception of the start packet a plurality of times or detecting the collision of the start packet, and thereafter, A signal transmission system that operates as an upstream node. 2. The method according to claim 1, wherein at least one loop including a plurality of loop-connected nodes and one or more loops including a single node or a plurality of loop-connected nodes are connected to one or more input units. And a signal transmission system configured to have one or more output units, and to be directly connected to one common transmission path output from all input units by splitting a signal input from one input unit, Each of the nodes has an initialization processing unit that performs system initialization processing, and the initialization processing unit of the most upstream node, which is a node directly connected to the common transmission path and receiving data from the common transmission path, The initialization processing unit of another node connected to the same loop as the most upstream node receives the node number confirmation packet. When receiving the data, the predetermined value is added to the value of the counter area and transmitted. The initialization processing unit of the most upstream node refers to the counter value in the returned node number confirmation packet. And detecting the number of nodes in the own loop. At least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are connected to one or more input units. And a signal transmission system configured to have one or more output units, and to be directly connected to one common transmission path output from all input units by splitting a signal input from one input unit, Each of the nodes has an initialization processing unit that performs system initialization processing, and an initialization processing unit of the most upstream node, which is a node directly connected to the common transmission path and receiving data from the common transmission path, A lowermost node designation packet which includes a counter area and has a value obtained by subtracting 1 from the number of nodes in the own loop with the value of the counter area being transmitted, is connected to the same loop as the uppermost node. The initialization processing unit of the other node, when receiving the most downstream node designation packet, reduces the value of the counter area by 1 and sends the packet, and the other one connected to the same loop as the most upstream node Of the nodes of which the result obtained by subtracting 1 from the value of the counter area of the most downstream node designation packet in the initialization processing unit is 0, thereafter, are directly connected to the common transmission path and the data is transmitted to the common transmission path. A signal transmission system that operates as the most downstream node that is a node that transmits the signal. 4. The signal transmission system according to claim 3, wherein the initialization processing unit of the most upstream node sets a value obtained by subtracting 1 from the number of nodes in the own loop as a node identification number of the own node. The initialization processing unit of another node connected to the same loop as the most upstream node sets a value obtained by subtracting 1 from the value of the counter area of the received most downstream node designation packet as the node identification number of the own node. A signal transmission system. 5. A signal transmission system having at least one loop composed of a plurality of nodes connected in a loop, wherein each of the nodes has an initialization processing unit that performs system initialization processing. The initialization processing unit of the start node, which is a node that starts system initialization, among the nodes, transmits a position designation packet at the time of system initialization, and initializes another node that has received the position designation packet. The processing unit
Another node that has received the position designation packet has at least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes. , Which 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 and directly connected to one common transmission path output from all output units. When the node of the signal transmission system is a node directly connected to the common transmission path and receiving data from the common transmission path, when the position designation packet is received, a unique number possessed by itself is written and transmitted. The initialization processing unit of the start node, if the unique number of another node is not written in the position specification packet that has returned around the loop, The signal transmission system according to claim 1, wherein the signal transmission system is a system configured by one loop, and performs a subsequent initialization process. 6. A signal transmission system having at least one loop composed of a plurality of nodes connected in a loop, wherein each of the nodes has an initialization processing unit that performs system initialization processing, The initialization processing unit of the start node, which is a node that starts system initialization among the nodes, has a number area and a fixed area at the time of system initialization, and a start packet in which a different number is written in the number area each time. The initialization processing unit of each of the nodes, when receiving the start packet in which the same value is written in the number area twice or more, sets a predetermined value in the determined area. The initialization processing unit of the start node transmits the start packet a fixed number of times, and the start packet in which the predetermined value is written in the determined area. If not received, the signal transmission system to which the signal transmission system and performs the initialization processing after as being a system constituted by one loop, characterized in that. 7. The signal transmission system according to claim 1, wherein each of the nodes includes an initialization transmission line for performing an initial setting, a normal transmission line for performing a normal transmission, and a power-on. A signal transmission system comprising: a switch for switching a transmission path connected to the initialization transmission path to a normal transmission transmission path after completion of the initialization process at the time of resetting. 8. At least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are connected to one or more input units. And an initial setting of a signal transmission system having one or more output sections and directly connected to one common transmission path output from all input sections and a signal input from one input section is branched. A method for performing a signal transmission system initialization method, comprising: a start packet sending step of sending a start packet instructing a start of initialization at the time of system initialization, wherein a start node that is a node that starts system initialization among the nodes; The most upstream node which is a node directly connected to the common transmission path and receiving data from the common transmission path among the nodes transmits the start packet a plurality of times Or signal, itself has a most upstream node recognition step recognizes that the most upstream node, signal transmission system initialization wherein the by detecting a collision of the start packet. 9. At least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are connected to one or more input units. And an initial setting of a signal transmission system having one or more output sections and directly connected to one common transmission path output from all input sections and a signal input from one input section is branched. A method of initializing a signal transmission system, wherein one of the most upstream nodes, which is a node directly connected to the common transmission path and receiving data from the common transmission path, transmits a node number confirmation packet including a counter area. Sending a node number confirmation packet to the node, and when the other nodes connected to the same loop as the most upstream node receive the node number confirmation packet, A packet reception processing step of adding a predetermined value to the value of the data area and transmitting the packet, and the most upstream node refers to the counter value in the returned node number confirmation packet, and determines the number of nodes in its own loop. A signal transmission system initialization method, comprising the steps of: 10. At least one loop composed of a plurality of loop-connected nodes and one or more loops composed of a single node or a plurality of loop-connected nodes are connected to one or more input units. And an initial setting of a signal transmission system having one or more output sections and directly connected to one common transmission path output from all input sections and a signal input from one input section is branched. A signal transmission system initialization method, wherein the most upstream node, which is a node directly connected to the common transmission path and receiving data from the common transmission path, includes a counter area, and stores the value of the counter area in its own loop. A step of transmitting a lowermost-node designation packet having a value obtained by subtracting 1 from the number of nodes; a step of transmitting a lowermost-node designation packet; A node receiving, when receiving the lowermost node designation packet, a packet receiving processing step of reducing the value of the counter area by 1 and transmitting the packet, and the lowermost one of the other nodes connected to the same loop as the uppermost node. A node whose result of subtracting 1 from the counter value in the node designation packet is 0 recognizes that it is the most downstream node because the result of subtracting 1 from the counter value in the packet of the most downstream node designation is 0. A signal transmission system initialization method, comprising: 11. The signal transmission system initialization method according to claim 10, wherein the most upstream node sets a value obtained by subtracting 1 from the number of nodes in its own loop as a node identification number of the own node, and And the other nodes connected to the same loop have a node identification number determining step of setting a value obtained by subtracting 1 from the value of the counter area of the received most downstream node designation packet as the node identification number of the own node. Characteristic signal transmission system initialization method. 12. A signal transmission system initialization method for performing initialization of a signal transmission system having at least one loop including a plurality of nodes connected in a loop, wherein initialization of a system among the nodes is started. A starting node, which is a node to perform, transmitting a position specification packet at the time of system initialization, and the other node receiving the position specification packet comprises a plurality of nodes in which the own node is connected in a loop. At least one loop and one or more loops composed of a single node or a plurality of nodes connected in a loop have one or more inputs and one or more outputs and one input A signal transmission system configured by directly connecting an input signal to one common transmission path that is branched and output from all output units A receiving packet processing step of directly connecting to the common transmission path and receiving data from the common transmission path, writing and transmitting a unique number possessed by itself when receiving the position designation packet, A system in which the start node recognizes that the signal transmission system is a system constituted by one loop, when the unique number of another node is not written in the position designation packet that has returned around the loop. A signal transmission system initialization method, comprising: a configuration recognition step. 13. A signal transmission system initialization method for initializing a signal transmission system having at least one loop composed of a plurality of nodes connected in a loop, wherein the system initialization of the nodes is started. A start node that is a node to perform, at the time of system initialization, has a number area and a definite area, and transmits a start packet in which a different number is written in the number area each time; A receiving packet processing step of, when receiving the start packet in which the same value is written in the number area twice or more, writing a predetermined value in the determined area and transmitting the same, and wherein the start node transmits the start packet. If the start packet in which the predetermined value is written in the determined area is not received, the signal transmission system A system configuration recognizing step of recognizing that the system is a system configured by one loop. 14. An automobile comprising the signal transmission system according to claim 1. Description: