JPH07288538A - Lan and data collection method in lan - Google Patents

Abstract

PURPOSE:To use the system even outdoor by devising the system for a quick reply, simplifying a transmission protocol and detecting easily an intermittent fault. CONSTITUTION:One master node 11 and plural slave nodes 12A, 12B, 12C are connected in a ring by transmission lines 13, 14 of routes 1, 2, the master node 11 interrupts the connection of the ring transmission lines 13, 14, and no bypass circuits are provided to the master node 11 and the loopback circuit but a bypass circuit is provided to the slave nodes 12A-12C. In the LAN configured as above, the master node 11 injects a signal addressed to all the slave nodes 12A-12C periodically and adds an injected invitation signal. A succeeding node relays an upperstream node signal to a downstream, the received injection invitation signal is reset to inject the signal addressed to the master node 11 and the other slave nodes 12A-12C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN and a data collection method in the LAN.

[0002]

2. Description of the Related Art A local area network (hereinafter referred to as LA
One of these is called a token ring system. This token ring method is an improved method for improving the efficiency of acquisition of the transmission right, and is a method that adopts a token that matches the ring connection form in particular. Here, the token method is a general term for a method of rotating a specific bit pattern called a token (authentication) on the ring. This method passes the token if the node does not have outgoing information, and if the node has outgoing information. In this case, a token is fetched, a message (frame for the token) is inserted in the preceding stage of the token, and then the circuit is circulated.

FIG. 8 shows a conventional example of the above LAN.
In the figure, 81A to 81D are nodes, and 82 and 83 are each node 8
It is a transmission path of route 1 and route 2 connecting 1A to 81D. In the LAN configured as shown in FIG.
When a failure occurs in the transmission paths 82 and 83 at the positions shown by X in FIG. 9, nodes 81A and 81B are configured to form a loopback circuit as shown in FIG.

FIG. 10 shows a concrete example of the LAN shown in FIG. 8, and in FIG.
D is provided with transmission control units 85A to 85D. The transmission control units 85A to 85C are provided with monitored control units 86A to 86C, and the transmission control unit 85D is provided with a monitoring control unit 87.

FIG. 11 is a diagram for explaining the concrete structure of each of the nodes 81A to 81D. Reference numerals 91 and 92 are route 1 and route 2.
Since the switching units 91 and 92 have the same configuration, the switching unit 91 will be described below. Reference numerals 91a and 91b are optical path change-over switches, and these optical path change-over switches 91a and 91b are for switching between an inactive state [bypass mode BP (this mode is a slave mode only)] and an active state (normal mode, loopback mode, etc.). is there. Reference numeral 91c is a photoelectric converter, and 91d is an electro-optical converter. The output of the photoelectric converter 91c is supplied to the receiving unit 91e, and then the delay unit 91f switches between the relay side and the injection side through a changeover switch 91g to set the normal mode and the loop. It is supplied to the electro-optical converter 91d via the changeover switches 91h and 91i for switching the back mode. 91j is a receiver 91
In the token detector connected to e, the output of the token detector 91j is supplied to the transmitter 91k and the AND circuit 91m. The output of the transmitter 91k is given to the AND circuit 91m. The outputs of the AND circuit 91m and the transmission unit 91k are supplied to a switching unit 91n that sends out a signal for switching the changeover switch 91g. The output of the receiver 91e and the input signal to the transmitter 91k are given to the transmission controller 85A and sent out.

The LAN configured as described above requires two types of signals, a token signal and a frame signal, as shown in FIGS. 12A, 12B and 13.
And that distinction is necessary. Further, when the "token" indicating the transfer of the voice shown in FIG. 14 disappears, the reproduction procedure is required. In that case, if "tokens" are injected from multiple locations, multiple "tokens" will circulate, and "frames" will be injected from multiple locations, thus confusing communication. Therefore, in the past, the "token" was from only one place.
There is an annoyance that the procedure for injecting is necessary.

[0007]

In the conventional data collection method by LAN, the total extension distance is long, for example, 100 k.
When m and the number of nodes is large, for example, 1
When it is applied to the case where there are as many as 000 items, since one round of data is monitored for each contact, the response time becomes as follows when information is exchanged with all nodes. The time required for an electric signal to make one round through the total extension distance (0.5 mS at 100 km) x number of nodes (1000) is 0.5 seconds. Therefore, 0.1
There is a problem that the response time is delayed and it cannot be applied to applications such as updating data every second. In addition, the conventional L
The AN has a complicated transmission protocol. As a complicated example, for example, the acquisition of the floor, the transfer procedure, the reproduction procedure when the floor transfer signal disappears, the infinite cyclic prevention procedure of the same signal, the address duplication detection procedure, the detection procedure when the node disappears,
There are procedures for correcting lost or duplicated data and for configuring a loopback system when a failure occurs. For this reason, an integrated circuit must be developed in order to reduce the size of the LAN structure, but there is a problem in that the development of the integrated circuit requires a huge cost because the transmission protocol is complicated as described above.

In addition, it is difficult to detect the cause of the intermittent failure, and the amount of heat generated increases when the integrated circuit becomes complicated, and cooling equipment is required for outdoor installation, which makes it difficult to use outdoors. There is a problem that ends up. The present invention has been made in view of the above circumstances, and has made it possible to speed up the response, simplify the transmission protocol, and facilitate the detection of an intermittent failure, so that it can be easily used outdoors. It is an object to provide a LAN and a data collection method in the LAN.

[0009]

In order to achieve the above-mentioned object, the present invention provides a master in which a master node and a plurality of slave nodes are connected in a duplicated transmission path in a ring shape. The master node is connected to the supervisory control unit via the transmission control unit, each slave node is connected to the monitored control unit via the transmission control unit, and the master node and the slave nodes are connected to the bypass transmission line and the loopback transmission line. L is provided respectively, and when a failure occurs in the transmission line, the transmission line having the failure is separated and data is transmitted using the loopback transmission line.
In the AN, the loopback transmission lines of the master node and the slave node are omitted, and a bypass transmission line is provided only in the slave node.

In the second aspect of the invention, in the LAN, the master node transmits a frame signal addressed to all slave nodes, and then transmits an injection invitation signal, and the downstream slave node directly receives the signal received from the upstream slave node. To the slave node further downstream after resetting the injection solicitation signal, and the slave node also processes the signal in the same manner and repeats the same processing in sequence. It is characterized in that the frame signal is returned to the master node.

A third aspect of the invention is characterized in that a frame signal addressed to all slave nodes is directly provided with an injection invitation signal from the master node.

A fourth aspect of the present invention is characterized in that the master node stores the injection frame signals of all the nodes that are sequentially added, and transmits the stored signal again after receiving the last injection invitation signal. It is what

According to a fifth aspect of the invention, the slave node injects a signal addressed to the master node and another slave node when the line abnormality on the receiving side continues for a certain period of time or intermittently detects an abnormality, and the slave node outputs the information in the information. Is characterized by including occurrence of continuous reception abnormality or intermittent abnormality detection.

[0014]

[Operation] In the initial transmission stage, a frame signal for each slave node addressed to all slave nodes is injected from the master node, and the next slave node relays the frame signal from the upstream node to the downstream side, and then the master node and other Inject the frame signal addressed to the slave node. By repeating this, the fum injection signals of all the nodes added one by one are 1
Cycle back to the master node. By controlling in this way, it is possible to send signals from the master node to all slave nodes and signals from all slave nodes to the master node in the initial transmission stage.

In the retransmission step, the injection signals of all the nodes in the initial transmission step are injected again from the master node, and all slave nodes make a round. After this, after a certain period of time, the process returns to the initial delivery stage. By controlling in this way, it is possible to send a signal addressed to all slave nodes from the slave node at the retransmission stage.
If control is performed in the initial transmission stage and the retransmission stage as described above, transmission communication from all nodes can be performed in two cycles.

By transmitting the continuous abnormality detection slave node, transmission from all slave nodes to the master node, transmission from all slave nodes to other slave nodes, transmission from the master node to all slave nodes, and transmission of all nodes are possible. The intermittent failure detection node can be compared from the contact contents to limit the cause point in the loop.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, one master node 11 and a plurality of slave nodes 12A, 12B, and 12C are connected in a ring shape by transmission lines 13 and 14 of route 1 and route 2, and the master node 11 forms ring-shaped transmission lines 13 and 1.
Disconnect 4 connection. That is, the master node 11 is configured not to include a bypass circuit or a loopback circuit. Also, the slave nodes 12A to 12
A bypass circuit is provided in C, but a loopback circuit is not provided. Therefore, the transmission lines 13 and 1 shown in FIG.
Even when a failure occurs at the position indicated by X in FIG. 4, the loopback configuration is not used.

Therefore, in the LAN configured as described above, from the master node 11 to all slave nodes 1
Signals addressed to 2A to 12C are injected at regular intervals. The injection invitation signal of the next node is added to the end of the injection signal. The next node relays the upstream node signal to the downstream, but resets the received injection solicitation signal, and its own master node 11
And the signals addressed to the other slave nodes 12A to 12C are injected. Then, the injection invitation signal of the next node is added to the end of the signal to be injected.

FIG. 3 is a specific configuration diagram of the master node. Since the configurations connected to the transmission lines 13 and 14 of route 1 and route 2 are the same, the case of route 1 will be described. In FIG. 3, reference numeral 31 is a photoelectric converter, and the output of this photoelectric converter 31 is input to the receiving unit 32. The output of the reception unit 32 is input to the OR circuit 34 via the delay unit 33. The output of the OR circuit 34 is input to the storage unit 36 via the switch 35 that is switched during the initial transmission. The output of the storage unit 36 is supplied to the retransmission unit 37. The output of the retransmitting unit 37 is supplied to the transmission path of route 1 from the electro-optical converter 39 via the switch 38.

The output of the receiving section 32 is inputted to the injection invitation signal detecting section 40 and then given to the AND circuit 41 and the first switching section 42 for transmitting the switching signal of the switch 35. The AND circuit 41 outputs the AND output when the AND of the injection unnecessary signal and the output of the detection unit 40 is taken.
Is supplied to. Reference numeral 43 denotes a control unit, to which the outputs of the detection unit 40 and the retransmitting unit 37 are given, and the control output is sent from the control unit 43 according to the given outputs. One of the control outputs is given to the first switching unit 42 and the initial transmission unit 44, and the other control output is given to the retransmission unit 37 and the second switching unit 4.
Given to 5. The output of the retransmission unit 37 is also given to the second switching unit 45. Reference numeral 46 is an abnormality detection unit, and the intermittent and continuous outputs of the abnormality detection unit 46 are supplied to the transmission control unit 47. Reference numeral 48 is a processing unit, and 49 is a monitoring control unit.

FIG. 4 is a diagram for explaining the specific configuration of the slave node. Since the configurations connected to the transmission lines 13 and 14 of the route 1 and route 2 are the same, the case of route 1 will be described. In FIG. 4, 51a and 51b are optical path changeover switches, 52 is a bypass transmission path formed of an optical fiber, 53 is a photoelectric converter, and 54 is an electro-optical converter. The output of the photoelectric converter 53 is supplied from the receiving unit 55 to the first OR circuit 57 via the delay unit 56. The output of the first OR circuit 57 is relayed and injected via the injection switch 58 to the electro-optical converter 5
4 is input. The output of the reception unit 55 is input to the injection invitation signal detection unit 59 and then applied to the first input of the AND circuit 60 and also input to the second OR circuit 61. An injection unnecessary signal is input to the second input of the AND circuit 60,
When both inputs are ANDed, their outputs are supplied to the electro-optical converter 54 via the first OR circuit 57. Reference numeral 62 denotes an abnormality detection unit, and the continuous output of the abnormality output of the abnormality detection unit 62 is supplied to the second OR circuit 61. Second OR circuit 61
When either the abnormal output or the output of the injection solicitation signal detecting portion 59 is input, the switch 58 outputs the output.
The switching control output is sent to the switching unit 63 and the transmission unit 64. A transmission end signal is given from the transmission unit 64 to the switching unit 63. A transmission control unit 65 is supplied with the output of the reception unit 55 and the intermittent and continuous outputs of the abnormality detection unit 62, and the transmission signal to the transmission unit 64. Reference numeral 66 is a processing unit, and 67 is a monitored control unit.

In the master node and slave node configured as described above, the frame signal having the format shown in FIG. 5 is used. In FIG. 5, SD
Is a start signal and ED is an end signal, which requires special discrimination signals at the beginning and end, but since it is the same as the conventional method, detailed description thereof will be omitted. DA is the destination address signal, SA
Is a source address signal, I is information, and FCS frame check signal. The injection invitation signal uses the bit in the end signal ED.

Next, the operation of the above embodiment will be described with reference to FIGS. 6A and 6B. First, the case of normal operation will be described. At the initial sending stage, the master node 11 is all slave nodes 12
After injecting a slave node-specific frame signal addressed to A to 12C, an injection invitation signal is injected. The injected signal is received by the downstream slave node 12A, and the slave node 12A relays the received signal to the downstream as it is, but the final injection invitation signal is reset and then transmitted to the downstream slave node 12B. . A signal whose address signal AD is addressed to its own node is taken in by a method similar to the token ring method. After that, a signal addressed to the master node 11 and a signal addressed to another slave node are injected, and finally an injection invitation signal is injected and transmitted downstream. Furthermore, the next downstream slave node also performs the same operation, and repeats in sequence. By repeating this, the injection signals (frames) of all the nodes that have been sequentially added return to the master node 11 in one cycle.

If the injection invitation signal is set to "0" and the injection unnecessary signal is set to "1", the AND circuit 41 shown in FIG.
After the required delay time is secured, the OR circuit 34 sets "1" corresponding to the injection unnecessary signal and "0" corresponding to the injection solicitation signal to "1" to become the injection unnecessary signal. That is,
The injection invitation signal has been reset. Further, the required delay time may be only the time for detecting the end signal ED, that is, the ED signal as shown in FIG.

On the other hand, in the conventional method, as shown in FIG. 13, when there is a transmission, if the received signal is a frame signal, it is relayed as it is, and if it is a token signal, it is switched to injection of its own transmission signal frame. Therefore, a delay time corresponding to the token signal detection time is required. This delay time is three times that of this embodiment as shown in FIG. 12A.

Next, the retransmission step will be described. The master node 11 resets and stores the injection solicitation signal in the same manner as in the initial transmission step, receives the last injection solicitation signal, and then injects the stored circulation signal again. In addition,
The signal addressed to the master node 11 is taken in as described above. However, the injection invitation signal is not injected. The downstream slave node 12A relays the signal received from the upstream to the downstream as it is.

At this time, the signal addressed to its own node, especially the signal from the slave node, is fetched. However, since it does not receive the injection solicitation signal, it does not inject it from its own node. The next downstream slave node also performs the same operation as above, and repeats in sequence. By this repetition, the loop signal injected from the master node 11 makes one round and returns to the master node 11. After this operation, the master node 11 returns to the initial sending stage after a certain time has elapsed.

From the above, in the initial sending stage in a fixed time period,
A signal from the master node to all slave nodes, a signal from all slave nodes to the master node, and a signal from a slave node to another slave node can be sent in the retransmission stage.

FIG. 6A is a time chart in the embodiment of the present invention. By comparing this time chart and the time chart in the conventional example (shown in FIG. 14), the transmission time in the embodiment of the present invention is shortened as compared with the conventional example. I understand. As is clear from the time chart of the embodiment of the present invention, in the present invention, all nodes are transmitted, whereas in the conventional example, one node is transmitted.

Next, the abnormal operation will be described. FIG. 6B is a schematic overall time chart at the time of abnormal operation. First, a case where continuous abnormal detection is transmitted to a slave node will be described. The slave node injects signals to the master node and other slave nodes when the line abnormality on the receiving side continues for a certain time or longer. At this time, the time is set shorter toward the downstream side closer to the master node. Finally, the injection solicitation signal is injected. In this case, "continuous reception error occurrence" is included in the information.

The downstream slave node performs the same operation as in the normal state, and injects signals addressed to the master node and other slave nodes. The next downstream slave node also performs the same operation, and repeats in sequence. By repeating this,
After that, the injection signals (frames) of all the nodes that are sequentially added are returned to the master node. The master node stores the one-round signal in advance, receives the last injection solicitation signal, and then injects the stored one-round signal again. The signal addressed to the master node is taken in as in the normal operation. The injection invitation signal is not injected. Hereafter, the operation at the retransmission stage during normal operation is performed.

The case where the master node originates will be described below.
The master node performs the "master node injects signals addressed to all slave nodes and then injects injection solicitation signal" operation at a constant time interval regardless of whether there is an abnormality in the receiving line in the initial transmission stage in normal operation. The next downstream slave node also performs the same operation as in the initial sending stage during normal operation, and the sequence is repeated thereafter until the slave node immediately upstream of the detected slave node. The signal stops here due to an obstacle.

As described above, it is not necessary to perform loopback as in the conventional example. That is, the transmission to the master node from all the slave nodes (the symbols a, b, c, d shown in FIG.
(E, f), transmission from all slave nodes to other slave nodes (symbols a, d, and e shown in FIG. 2) becomes possible, and transmission from the master node to all slave nodes (Fig. (2, b, c, f)
Will be possible.

To describe the intermittent abnormality, the node that has detected the intermittent abnormality inserts (intermittent abnormality detection) in the information to be injected. It is difficult to find the cause of abnormalities that usually occur intermittently. However, as in the embodiment of the present invention, if all nodes make transmission contact at regular intervals and make detection communication at that time, by comparing the intermittent failure detection nodes from the contact contents of all nodes, the cause in the loop The location can be easily limited.

By configuring as in the above embodiment,
The following effects can be obtained. a. Acquisition and Transfer Procedure of Speaking Right In the conventional example, as shown in FIGS. 12 and 13, two types of “token signal” and “frame signal” are required and the discrimination is necessary, but in the embodiment of the present invention, the injection invitation signal Only a bit gets better.

B. Reproduction procedure when the floor transfer signal is extinguished In the conventional example, the "token" indicating the floor transfer shown in FIG.
If it disappeared, it required its regeneration procedure. In this case, if you inject "token" from multiple places,
Since the "token" is circulated and frames are injected from multiple points, communication is confused. Therefore, it is necessary to make the procedure of injecting the token only at one point. As shown, the "token" signal is not required and is activated in a fixed cycle, so this procedure is unnecessary.

C. Infinite cyclic prevention procedure for the same signal In the conventional example, when a node into which a frame signal is injected goes into a bypass state, other nodes simply repeat the relay. As a result, it will endlessly travel. Therefore, the countermeasure was needed. However, in this embodiment, since the master node does not perform the relay (breaks the loop), the infinite round does not occur.

D. Procedure for detecting address duplication In the conventional example, a frame is injected at only one location, so a complicated procedure is required to detect address duplication. However, in this embodiment, all nodes are injected every time, so that it can be immediately detected as the same source address (SA) duplication.

E. Detection procedure when a node disappears In the conventional example, even if a node goes into a bypass state, the disappearance of that node cannot be detected as it is. Therefore, a procedure to detect it was needed. However, in this embodiment, since all nodes are injected every time as in the case of the above item e, it can be immediately detected as a missing source address.

F. Correction procedure when data is lost or duplicated In the conventional example, when data was lost or duplicated, a countermeasure procedure was required. However, in this embodiment, no measures are required because the transmission is periodically repeated.

G. Loopback system configuration procedure when failure occurs In the conventional example, it was necessary to configure the loopback system by changing the line configuration when a transmission line failure occurs. However, in this embodiment, it is not necessary to change the line configuration.

H. Detecting the Cause of Intermittent Failure In the conventional example, there is no direct means to detect where the cause of the loop line is because it occurs intermittently. However, in this embodiment, all nodes inject signals at regular intervals, so that the cause points can be limited by comparing the detection nodes of intermittent failures.

In addition to the above, it is easy to detect the cause of an intermittent failure, the LAN can be applied outdoors, and the temperature rise due to the simplification of the integrated circuit can be reduced. Further, since the injection solicitation signal is used in this embodiment, the token signal "T" and the control signal "C" are unnecessary, and in particular, "C" is for controlling the complicated transmission protocol of the conventional system. The feature of this embodiment is that it is unnecessary.

[0044]

As described above, according to the present invention,
The advantage is that the response time can be shortened, the transmission protocol can be simplified, and the intermittent failure can be detected easily, and the device can be used outdoors.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration when a failure occurs in the above embodiment.

FIG. 3 is a specific configuration explanatory diagram of a master node unit.

FIG. 4 is a specific configuration explanatory diagram of a slave node unit.

FIG. 5 is a format showing the frame contents of the above embodiment.

FIG. 6A is a time chart during normal operation of the above embodiment, and B is a time chart during continuous abnormal operation of the above embodiment.

FIG. 7 is a time chart describing the detailed operation of the above-described embodiment.

FIG. 8 is a structural explanatory view showing a conventional example.

9 is an explanatory diagram of a configuration when a failure occurs in FIG.

FIG. 10 is a configuration explanatory view showing a configuration of a supervisory control system and a communication line.

FIG. 11 is an explanatory diagram of a specific configuration of a node of a conventional example.

FIG. 12 is a format showing a frame content of a conventional example, where A is a token signal and B is a frame signal.

FIG. 13 is a time chart describing the detailed operation of the conventional example.

FIG. 14 is a time chart describing a normal operation in a conventional example.

[Explanation of symbols]

 11 ... Master node 12A, 12B, 12C ... Slave node 13, 14 ... Transmission path

Claims (5)

[Claims] 1. A master node and a plurality of slave nodes are connected in a ring-shaped transmission line, and a monitoring control unit is transmitted to the master master node via a transmission control unit and is transmitted to each slave node. The monitored control unit is connected via the control unit, the bypass transmission line and the loopback transmission line are respectively provided in the master node and the slave node, and when a fault occurs in the transmission line, the faulty transmission line A LAN in which the loopback transmission line is separated and data is transmitted using the loopback transmission line, and the loopback transmission line of the master node and the slave node is omitted and a bypass transmission line is provided only in the slave node. 2. The LAN according to claim 1, wherein after transmitting a frame signal addressed to all slave nodes from the master node, an injection invitation signal is transmitted, and the downstream slave node directly receives the signal received from the upstream slave. It relays to the node, resets the injection solicitation signal, and then sends it to the slave node further downstream, and the slave node also processes the signal in the same manner and repeats the same processing in sequence. A method for collecting data in a LAN, characterized in that an injection frame signal is returned to a master node. 3. A data collection method in a LAN according to claim 2, wherein the frame signal addressed to all slave nodes is directly provided with the injection solicitation signal from the master node. 4. The master node stores the injection frame signals of all the nodes that are sequentially added, and transmits the stored signal again after receiving the last injection invitation signal. Item 2. A data collection method in a LAN according to Item 2. 5. The slave node injects signals to the master node and other slave nodes and continuously receives information when the line abnormality on the receiving side continues for a certain period of time or intermittently detects an abnormality. 4. The method of collecting data in a LAN according to claim 2, wherein the occurrence of abnormality or the detection of intermittent abnormality is included.