JP2000324150A - Optical double loop management switch circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical double loop management switch circuit reduced in interference of system operations. SOLUTION: Nodes 8 having a communication module 7 are connected through an optical fiber 9 and only one ring master node 10 is in existence in the nodes 8. A node 8 transmits a control signal with an address of its own node added thereto to its adjacent node 8, and then the adjacent node 8 confirms the connection of the node 8 adjacent to the adjacent node 8, the adjacent node 8 stores a node address of the first node 8, and informs the ring master node 10 about the confirmed connection together with the node address of the adjacent node by means of a frame. Thus, the node can inform the ring master node 10 about the confirmation of the adjacent node without giving adverse effect on the system operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical double-loop management switch circuit connected to a plurality of stations by optical fibers so as to enable bidirectional communication between the stations.

[0002]

2. Description of the Related Art In an optical double loop network using an optical fiber as a transmission line, there is one ring master,
Nodes other than the ring master send frame transmissions in both directions (both systems) and repeat downstream transmission frames from upstream transmission frames, but do not repeat downstream transmission frames from upstream transmission frames. As a result, communication in the form of a bus has been substantially enabled.

[0003]

However, in such a communication system, if communication becomes impossible due to disconnection or the like at any one place, a state where communication is impossible occurs because the ring master node is terminated. Conventionally, when such a communication-disabled state occurs or when a node joins / leaves,
A reset notification is sent to all connected nodes, the operation of the system is temporarily suspended, and it is determined whether the ring master node repeats or not, and the processing is performed. SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional point, and an object of the present invention is to provide an optical double loop management switch circuit in which system operation is less interrupted.

[0004]

To achieve the above object, an optical double loop management switch circuit according to the present invention, in which all nodes are not repeated between two adjacent stations, is not repeated. A control signal can be sent out. In an optical double loop network where there is one ring master and the ring master terminates both systems when it is a ring, and the end node terminates when it is not a ring. By transmitting the control signal transmitted between adjacent nodes with the own node address added thereto, when it is confirmed that the adjacent node is connected, the node address of the adjacent node is stored. And that the ring master is notified of the connection confirmation together with the node address of the adjacent node by a frame. With such a configuration, it is possible to notify the ring master of the adjacent node confirmation without affecting the operation of the system.
According to a second aspect of the present invention, in the optical double loop management switch circuit according to the first aspect, received frame signals from both systems are received, and if there is a received frame signal at the same time, the first-come-first-served basis is provided. It is characterized in that a received frame signal is selected and transmitted to transmission control software.

[0005] Such a configuration is characterized in that occurrence of reception errors can be prevented when the signal systems are unified. According to a third aspect of the present invention, in the optical double loop management switch circuit according to the second aspect, when the reception frame signal from another system arrives after the reception frame signal from one system is completely received, the transmission control is performed. It is characterized in that the interval between received frame signals transmitted to the software is maintained for a predetermined time or more. With such a configuration, it is possible to prevent a malfunction due to a delay in the reception processing. According to a fourth aspect of the present invention, in the optical double loop management switch circuit according to the second aspect, the received system identification data is automatically incorporated into a received frame transmitted to the transmission control software. It is characterized by. With such a configuration, the address analysis processing by the transmission control software can be made unnecessary. In the optical double loop management switch circuit according to the present invention, all nodes can transmit a non-repeat control signal exchanged between two adjacent stations, there is one ring master, and a ring is formed. In the optical duplex loop network where the ring master terminates both systems when there is a ring, and when the node is not a ring, the synchronization control code signal on the system that has the property of being periodically interrupted When a predetermined number of times have occurred consecutively, an abnormal condition is determined to be transmitted to the transmission control software.

With such a configuration, it is possible to detect a malfunction of the internal circuit without affecting the operation of the system. In the optical double loop management switch circuit according to the present invention, all nodes can transmit a non-repeat control signal exchanged between two adjacent stations, there is one ring master, and a ring is formed. In the optical duplex loop network where the ring master is terminated when there is a ring and the end node is terminated when the ring is not a ring, the ring master notifies all connected nodes whether or not it is currently a ring By doing so, when each node detects that communication with an adjacent node is not possible when it is a ring, it notifies the ring master of the occurrence of an abnormality with a break signal indicating suspension of system operation, and When communication failure is detected, the ring master is notified of the occurrence of an error by a frame, and the break signal is repeated one after another while it is occurring. Characterized in that so as to reach the Gumasuta. With such a configuration, the communication disabled state can be processed without affecting the operation of the system. According to a seventh aspect of the present invention, in the optical double-loop management switch circuit according to the first aspect, when a transmission frame transmitted from the transmission control software and a transmission frame to be repeatedly relayed occur simultaneously, the first-arrival is performed. The transmitted transmission frame is transmitted to the network, and an abnormal situation is transmitted to the transmission control software as occurrence of a collision abnormality.

With this configuration, the processing load on the transmission control software can be reduced. According to the present invention as set forth in claim 8, in the optical double loop management switch circuit according to claim 1 or 6, when a transmission frame transmission and a code transmission request occur simultaneously, the higher priority is given to the network. It is characterized in that it is transmitted and the occurrence of the lower priority is made to wait. With such a configuration, the processing load on the transmission control software can be reduced. In the optical double loop management switch circuit according to the present invention, all nodes can transmit a non-repeat control signal exchanged between two adjacent stations, there is one ring master, and a ring is formed. In the optical duplex loop network where the ring master terminates both systems when there is a ring and the end node terminates when it is not a ring, a part of the discrimination code of the received frame received after the synchronization code is missing In this case, data missing from the remaining discrimination codes is complemented. With such a configuration, malfunction and omission of reception due to noise of the reception signal can be prevented. In the optical double-loop management switch circuit according to the present invention, all nodes can transmit a non-repeat control signal exchanged between two adjacent stations, there is one ring master, and a ring is formed. In the optical duplex loop network where the ring master terminates both systems when it is present, and when it is not a ring, the end node terminates, the number of consecutive occurrences of the received code is counted, and it has exceeded the predetermined number. In this case, it is characterized in that the code is determined to be received and transmitted to the transmission control software.

With such a configuration, it is possible to prevent malfunction due to noise in the received signal.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following drawings, the same symbols indicate the same or corresponding parts.

(First Embodiment) First, a first embodiment of an optical double loop management switch circuit according to the present invention will be described. FIG. 1 is a diagram showing a configuration of a communication processing function of each node according to the first embodiment of the present invention. As shown in the figure, the communication processing function includes a loop management function 1, a network management function 2, a data link layer function 3, a transmission / reception driver 4, a transmission / reception control circuit 5, and a switch circuit 6. FIG. 2 is a diagram illustrating a system configuration according to the first embodiment. As shown in the figure, a node 8 having a communication module 7 is connected by an optical fiber 9. Only one ring master node 10 exists in the node. FIG. 3 is a diagram illustrating a detailed configuration of the communication module 7. As shown in FIG.
The transmission / reception control circuit 5, switch circuit 6, and CPU 1 shown in FIG.
1, an internal bus 12, a memory circuit 13, and a host interface circuit 14. The CPU 11 performs processing of the loop management function 1, the network management function 2, the data link layer processing function 3, and the transmission / reception driver 4. The transmission / reception driver 4 passes the frame requested to be transmitted from the data link layer function 3 or the frame requested to be transmitted from the loop management function 1 to the transmission / reception control circuit 5, and passes the received frame to the data link layer function 3 or Pass to loop management function 1.

The switch circuit 6 generates and transmits a non-repeat control signal exchanged between two adjacent stations.
Receive. The loop management function 1 issues a control signal transmission instruction. The received control signal is not recognized as a received frame by the transmission / reception control circuit 5, and is not notified of reception through the transmission / reception control circuit 5. When receiving the control code signal, the switch circuit 6 notifies the CPU 11 by an interrupt. When this interrupt occurs, the loop management function 1 performs processing according to the reception control code signal and the state of the loop management. FIG. 4 is a diagram showing a detailed internal configuration of the switch circuit 6. As shown in FIG.
Interface 15, transmission / reception interface circuit 16,
It comprises a transmission system block A17, a transmission system block B18, a reception system block A19, a reception system block B20, and a LAN interface 21. LAN interface 2
In step 1, a data signal from the LAN is input, and a LAN reception signal 29 is extracted and transmitted to the reception system block A19 and the reception system block B20. Also, the transmission system block A17,
LAN transmission signal 2 received from transmission system block B18
8 on the LAN. In the receiving system block A19 and the receiving system block B20, control code discrimination, frame synchronization, reception error processing, and frame extraction processing are performed, and are transmitted to the CPU interface 15 as reception status 24 such as reception control code contents and error results. The received information frame signal 25 is transmitted to the transmission / reception control circuit interface 16. Further, a repeat reception signal 27 is transmitted from the reception system block A19 to the transmission system block B18, and from the reception system block B20 to the transmission system block A17.

The transmission / reception control circuit interface 16 transmits the reception frame signal 25 from the reception system block A19 and the reception system block B20 to the transmission / reception control circuit 5. Further, it receives the transmission signal sent from the transmission / reception control circuit 5 and transmits it as a transmission frame signal 26 to the transmission system block A17 and the transmission system block B18. In the present embodiment, A
The signals for the system and for the system B are separated and connected to the transmission / reception control circuit 5. The CPU interface 15 receives the reception status 24 from the reception system block A19 and the reception system block B20 and notifies the CPU 11 of the reception status. Also, it receives the transmission status 23 from the transmission system block A17 and the transmission system block B18 and notifies the CPU 11 of the reception. Also CPU
The transmission system block A1 uses the repeat control signal / control code output signal received from the
7. Send to the transmission system block B18. Transmission system block A1
7. In the transmission system block B18, the transmission control command 22 from the CPU interface 15 and the reception system block A1
9. Repeat reception signal 2 from reception system block B20
7. Receiving the transmission frame signal 26 from the transmission / reception control circuit interface 16 and transmitting the LAN transmission signal 28 to the LAN
The information is transmitted to the interface 21.

FIG. 5 is a diagram showing a detailed internal configuration of a transmission system block. As shown in FIG.
1 (transmission system block A17, transmission system block B1 in FIG. 4)
8) The transmission frame selection circuit 32 and the FIFO circuit 3
3, a transmission selection circuit 34, a transmission control circuit 35, and a control code generation circuit 36. Transmission frame selection circuit 3
2, the transmission frame signal 26 from the transmission / reception control circuit interface 16 and the repeat reception signal 27 (frame) from the reception system block A19 and the reception system block B20
And the transmission frame selection result signal 37 is FIFO
Send to circuit 33. Also, it transmits the transmission unit status 23 to the CPU interface 15. In the FIFO circuit 33,
In response to the FIFO output control signal 38 from the transmission control circuit 35, the transmission selection circuit 34 sends the FIFO output frame signal 4
Transmit 0. The presence / absence of information stored in the FIFO is transmitted to the transmission control circuit 35 as a FIFO status signal 39. In the transmission selection circuit 34, in accordance with the transmission selection signal 44 transmitted from the transmission control circuit 35, the FIFO circuit 33
Of the FIFO output frame signal 40 transmitted from the control code generation circuit 36 and the control code generation result signal 43 transmitted from the control code generation circuit 36, and transmits the LAN transmission signal 28 to the LAN interface circuit 21.

In the transmission control circuit 35, the transmission control command 22 from the CPU interface 15, the repeat reception signal 27 (code) from the reception system block A 19 and the reception system block B 20, and the FIFO from the FIFO circuit 33
The state signal 39 is received and the transmission state is determined.
If it is determined that the output is the FIFO, the FIFO circuit 33
An O output control signal 38 is issued. When it is determined that the control code is output, a control code generation control signal 41 is transmitted to the control code generation circuit 36. Further, F from the FIFO circuit 33
It takes in the IFO status signal 39 and the control code generation status signal 42 from the code generation circuit 36 and performs an output destination switching operation. Further, the type of the transmission data is transmitted to the transmission selection circuit 34 as a transmission selection signal 44. The control code generation circuit 36 receives the control code generation control signal 41 from the transmission control circuit 35 and transmits a control code generation result signal 43 to the transmission selection circuit 34. Further, a control code generation status signal 43 indicating whether or not control code generation has been completed is transmitted to the transmission control circuit 35. Also, the transmission code information is created inside the control code, and in the case of a repeat code, it is created from the repeat reception signals 27 from the reception system block A19 and the reception system block B20. In the case of another code transmission request, the code information data included in the transmission control command 22 from the CPU interface 15 is used.

FIG. 6 is a diagram showing a detailed internal configuration of a receiving system block. As shown in FIG.
(Reception system block A19 and reception system block B2 in FIG. 4)
0) comprises a reception control code detection circuit 46, a control code count circuit 47, a frame synchronization detection circuit 48, an information frame detection circuit 49, a reception FIFO circuit 50, and a reception abnormality detection circuit 51. Receive control code detection circuit 46
Receives the LAN reception signal 29 and detects the control code. In the case of detecting the synchronization processing code, the synchronization code detection signal 52 is transmitted to the frame synchronization detection circuit 48. The control code receiving signal 53 is transmitted to the information frame detecting circuit 49.
To communicate. Further, the control code type signal 54 is transmitted to the control code count circuit 47 and the reception abnormality detection circuit 51.
A control count end signal 55 is received from the control code count circuit 47, and the reception status 24 is transmitted to the CPU interface 15. Further, the information frame detection circuit 49
, An information frame receiving signal 56 is received, and the code discrimination timing is distinguished. As for the break reception signal, the repeat reception signal 27 is transmitted to the transmission system block A17 and the transmission system block B18.

The control code count circuit 47 receives the control code type signal 54 from the reception control code detection circuit 46 and performs a count process to determine whether or not the control code type signal 54 is generated continuously. The count value is cleared when another code is received during the counting and when the information frame receiving signal 56 is received from the information frame detecting circuit 49. When the count value exceeds the set number, a control code count end signal 55 is generated and transmitted to the reception control code detection circuit 46. The frame synchronization detection circuit 48 receives the synchronization code detection signal 52 from the reception control code detection circuit 46 and transmits a frame synchronization establishment signal 58 to the information frame detection circuit 49. In the information frame detection circuit 49, the LAN interface 21
Receiving the received signal 29, the start of frame reception is detected using the time interval obtained from the frame synchronization establishment signal 58 from the frame synchronization detection circuit 48 and the control code receiving signal 53 from the reception control code detection circuit 46. When the frame reception is detected, the information frame receiving signal 56 is transmitted to the control code counting circuit 47, the reception control code detection circuit 46, and the reception FIFO circuit 50.
Further, an information frame extraction signal 57 is created, and the reception F
The signal is transmitted to the IFO circuit 57. When an information frame lacking information is determined, a frame data reproduction instruction 59 is transmitted to the reception FIFO circuit 50.

The reception FIFO circuit 50 receives the information frame reception signal 56 and the reception frame extraction signal 57 from the information frame detection circuit 49, and transmits the reception frame signal 25 to the transmission / reception control circuit interface 16 in the order of reception. The repeat reception signal 27 (frame) is transmitted to the transmission system block A17 and the transmission system block B18.
To communicate. When the frame data reproduction command 59 is received, a frame reproduction process is performed. The reception abnormality detection circuit 51 receives the LAN reception signal 29 from the LAN interface 21 and detects abnormal data. If an error has occurred, the reception status signal 24
The information is transmitted to the interface 15. Next, a normal operation will be described. FIG. 7 shows control codes used in this embodiment. In the figure, (a) shows the Quiet signal 6
0, (b) shows the code of the Ack signal 61, (c) shows the code of the Break signal 62, and (d) shows the code of the Idle signal 63. The Quiet code is used as a connection request to an adjacent node. The Ack code is used as a connection acceptance request for the Quiet code. The Break code is used as a disconnection request due to the occurrence of an abnormality.

Quiet code, Ack code, and B
The three types of leak codes are “header code +
It has a format of "code type code + code information". The header code indicates the control code, the code type code indicates the control code type, and the necessary information (code transmission source address, etc.) is included in the code information. Put and use. The Idle code is a signal synchronization establishment signal at the time of establishing a connection. This code is composed only of a code for identifying Idle. FIG. 8 shows the configuration of the information frame. The information frame has a plurality of recognition codes (Pre codes) at the beginning, a control code indicating a frame type,
It consists of a destination address code, a source address code, data, and a check code.

[Adjacent Node Confirmation Operation] FIG. 9 is an example of an adjacent node confirmation transaction in this embodiment. The adjacent node confirmation is a process performed by the loop management function 1, and is performed when the node starts up or when communication with the adjacent node cannot be performed due to a signal interruption or the like. The Quiet signal 60, the Ack signal 61, and the Idle signal 63 are non-repeated control signals exchanged between two adjacent stations. The Ack signal 61
This is a response to the t signal 60. During normal operation, the idle signal 62 is transmitted when there is nothing to transmit or repeat the frame. Information is added to the Quiet signal 60 and the Ack signal 61 and the signals are transmitted. The information is set by the loop management function 1 for the switch circuit 6. In the adjacent node confirmation, the node address of the own station is set as information. When the Ack signal 61 corresponding to the Quiet signal 60 is obtained, the loop management function 1 determines that communication with the adjacent node is possible, and transmits the Idle signal 62.
The Idle signal 62 is a signal that flows after the confirmation of the adjacent node is performed. The operation inside the switch circuit 6 is as follows. The loop management function 1 of the node N1
It sets its own address value and a Quiet signal transmission request to the N2 system side (B system side in this case) of the interface 15. The CPU interface 15 transmits a Quiet transmission request transmission control command 22 to the transmission system block B18.

Transmission control circuit 3 in transmission system block B18
In step 5, the transmission control command 22 is received and a control code generation control signal 41 for a Quiet transmission request is sent to the control code generation circuit 36. Further, a transmission selection signal 44 for code transmission selection is sent to the transmission selection circuit 34. The control code generation circuit 36 generates the transmission data of the Quiet signal including the address value as the control code generation result signal 43,
The signal is sent to the transmission selection circuit 34. The transmission selection circuit 34 sends the received control code generation result signal 43 to the LAN interface 21 as the LAN transmission data 28. The LAN interface 21 sends a LAN transmission signal 28 as B-system transmission data. In node N2, LAN A
The Quiet signal 60 is sent to the system. L on system A
The LAN signal is received by the LAN interface 21 and sent to the receiving system block A19 as the LAN reception signal 29. In the reception control code detection circuit 46 in the reception system block A19, the Quie included in the LAN reception signal 29
t, and if the code matches the code detection pattern, Quiet reception is set in the reception status 24 and C
Notify the PU interface 15. From the information output by the CPU interface 15, the loop management mechanism 1 of the node N2 determines that the Quiet signal is received in the A system.

In response to this, the loop management mechanism 1 of the node N2 transmits an Ack code to the A system. Node N2
The loop management function 1 of N1 of the CPU interface 15
The system side (in this case, the system side) is set with its own address value and an Ack signal transmission request. The CPU interface 15 transmits the transmission control command 22 of the Ack transmission request to the transmission system block A17. Thereafter, the Ack signal 61 is transmitted on the LAN similarly to the Quiet transmission described above. Thereafter, the LAN interface 21 of the node N1 receives the Ack signal 61, and
0 is sent as a LAN reception signal 29. The reception control code detection circuit 46 in the reception system block B20 determines the Ack determination code included in the LAN reception signal 29,
If the code matches the code detection pattern, Ack reception is set in the reception status 24 and the CPU interface 15 is notified. The loop management mechanism 1 of the node N1 determines from the information output from the CPU interface 15 that the B system has received the Ack signal. In response to this, the loop management mechanism 1 of the node N1 transmits an Idle code to the B system.
The loop management function 1 of the node N1 sets an Idle signal transmission request to the B-system side of the CPU interface 15. From the CPU interface 15, the transmission system block B
The transmission control command 22 of the Idle transmission request is transmitted to 18. In this case, only the idle code is transmitted.

At the N2 node, an Idle signal 63 is sent on the LAN A system. The LAN interface 21 receives the LAN signal on the system A and sends it to the receiving system block A19 as a LAN reception signal 29. In the reception control code detection circuit 46 in the reception system block A19, L
The Idle determination code included in the AN reception signal 29 is determined, and if it matches the code detection pattern, the reception status 24 is set to Idle reception and notified to the CPU interface 15. From the information output from the CPU interface 15, the loop management mechanism 1 of the N2 node
It is determined that the e signal is received. Here, the node N2
Completes the confirmation that N1 exists as a node on the A side. Finally, the Idle signal 6 is sent from the node N2 to the node N1.
3, the node N1 completes the confirmation that the node N2 is adjacent to the system B as a node. At this point Id
The le signal 63 is sent to both sides. Id
The detailed operation when the le signal 63 is received will be described below. When the reception control code detection circuit 46 detects the idle code, a synchronization code detection signal 52 is sent to the frame synchronization detection circuit 48. The frame synchronization detection circuit 48 confirms that the synchronization code detection signal 52 is transmitted periodically at the timing of receiving Idle, and sends a frame synchronization establishment signal 58 to the information frame detection circuit 49. This frame synchronization establishment signal 58 is used when receiving a frame.

The node N1 notifies the ring master node by transmitting a frame that the confirmation of the adjacent station has been completed. The detailed operation of the switch circuit 6 is as follows. The loop management function 1 transmits a frame to a system participating in the system operation (A system in this case). Transmission frame data is transmitted from the transmission / reception control circuit 5 to the switch circuit 6 via the data link layer function 2. The transmission / reception control circuit interface 16 sends the received transmission frame data to the transmission frame selection circuit 32 as a transmission frame signal 26. The transmission frame selection circuit 32 inputs a signal to the FIFO circuit 33. In the FIFO circuit 33, the FIFO
The O state signal 39 is sent to the transmission control circuit 35 as having a FIFO input. The transmission control circuit 35 transmits the FIFO output control signal 38 to the FIFO circuit 33 with the FIFO output enabled. Further, the transmission selection signal 44 is transmitted to the transmission selection circuit 34 as a FIFO output. Here, the FIF circuit 33
Receives the FIFO output control signal 38 as output permission, and sends the FIFO output frame signal 40
Send. The transmission selection circuit 34 creates a LAN transmission signal 28 and transmits it to the LAN interface 21. A frame is transmitted from the LAN interface 21 to the A system.

The ring master node receives the information frame sent to the B system. The signal received by the LAN interface 21 is transmitted to the reception system block B20 as a LAN reception signal 29. An information frame detection circuit 49 in the reception system block B20 detects a reception frame by detecting a Pre code match. This coincidence detection is performed using the timing of the frame synchronization establishment signal 58 output from the frame synchronization detection circuit 48. When a reception frame is detected, an information frame receiving signal 56 and an information frame extraction signal 57 are sent to the reception FIFO circuit 50. The reception FIFO circuit sends the received signal to the transmission / reception control circuit interface 16 as a reception frame signal 25. A reception signal is sent from the transmission / reception control circuit interface 16 to the transmission / reception control circuit 5, the transmission / reception control circuit 5 receives a frame, and notifies the CPU 11 of the reception. The adjacent station confirmation is transmitted to the loop management function 1 via the transmission / reception driver 4 and the data link layer 3. At the node between the node N1 and the ring master node, the adjacent station confirmation frame is relayed (repeat).
Is done. The data received by the system B
20 as a transmission reception block 27 as a repeat reception signal 27
It is conveyed to 17. The data is received by the transmission frame selection circuit 32 in the transmission system block A17, and thereafter, processed in the same manner as the transmission frame signal 26 from the transmission / reception control circuit interface 16, and transmitted to the A system.

The above-mentioned adjacent node check is performed independently for each system. Even if a node is operating in a state where only one system has been added to the system operation and terminated, the other system has no effect on the system operation. Can be performed without impact. Also, for the loop management function 1 of the ring master node, the system participating in the system operation is used,
The fact that communication with the adjacent node is possible together with the address of the adjacent node can be notified through the processing of the data link layer function 2, so that the notification to the ring master node can be executed without affecting the system operation.

[Abnormality Detection Operation] FIG. 10 shows an example of a transaction for detecting an idle code generation abnormality. When the confirmation of the adjacent node is completed and the idle code is continuously transmitted, the receiving side counts the number of continuous receptions. When the count number n exceeds a predetermined number NE, the CPU 11 is notified to the CPU 11 that an abnormality has occurred. C
The PU 11 performs notification processing as occurrence of a circuit failure. On the transmission side, idle transmission is automatically stopped every NE / 2 so that no abnormality occurs. Regarding this operation, a detailed operation inside the switch circuit 6 will be described. A transmission control circuit 35 in the transmission system block A17 and a transmission control circuit 35 in the transmission system block B18 have an idle continuous transmission counter, and a code generation control signal to be transmitted to the control code generation circuit 36 when the idle continuous transmission number becomes NE / 2. The transmission of Idle is stopped by eliminating 41 from Idle, and the operation is not to send a one-character time signal. On the receiving side, the reception error detection circuit 47 in the reception system block A19 and the reception system block B20 counts the idle detection of the control code type signal 54 from the reception control code detection circuit 46 at the time of continuous occurrence (reception of other codes). And resets the reception status 24 to the CPU interface 15 when the NE value is reached. The CPU 11 receives the information from the CPU interface 15 and performs an abnormal process.

By incorporating the above-described abnormality detection operation, it is possible to detect the occurrence of a circuit failure without generating a system interruption process for abnormality detection. In this example, the idle transmission interruption interval is set to NE / 2, but other values equal to or less than NE do not matter.

[Notification of Communication Impossibility] FIG. 11 is a diagram showing a communication impossibility notification in the case of a ring in this embodiment, and FIG. 12 is a view showing a communication impossibility notification of a bus in this embodiment. FIG. 13 shows a node array table.
(A) shows an A-system node array table, and (b) shows a B-system node array table. The loop management function 1 of the ring master node creates the node arrangement table 64 of FIG. 13 to determine whether the ring is a ring terminated by the ring master node or a bus terminated by another node, and is connected thereto. It notifies the loop management function 1 of all the nodes performing the broadcast frame. As a result, all nodes memorize the current ring or bus. When each node detects that communication with an adjacent node is not possible when it is a ring,
As shown in FIG. 11, a Break signal 62 having a signal disconnection identifier and a source node address as information is transmitted. Br
When the eak signal 62 flows, System_Start indicating that the system operation is restarted from the ring master node
Until the broadcast frame flows, the system operation is suspended. The operation inside the switch circuit 6 in this case will be described below. The reception abnormality detection circuit 51 detects that communication is disabled on the reception system block B20 side of the switch circuit 6 of the node N2. More specifically, the status of the LAN reception signal 29 is monitored, and if a signal-free state continues for a certain period of time or more, the reception status 24 is notified to the CPU interface 15 as a signal interruption. This status is transmitted from the CPU interface 15 to the CPU 11, and a signal disconnection process is performed by the loop management function 1.

In the case of a ring configuration, in response to this, the loop management mechanism 1 of the node N2 transmits a Break code to the A system. The loop management function 1 of the node N2 is a CPU
It sets its own address value and a Break signal transmission request to the N1 system side (A system side in this case) of the interface 15. The CPU interface 15 transmits a transmission control command 22 for a Break transmission request to the transmission system block A17. Thereafter, the above Quiet / Ac
The Break signal 62 is transmitted on the LAN in the same manner as the k transmission. Also, the code / frame repeat transmission at this node is stopped. The Break code is repeated at a node on the way from the N2 node to the ring master node. The B-system side LAN signal is input from the LAN interface 21 and transmitted to the receiving system block B20. Reception control code detection circuit 46 in reception system block B20
Then, the break code is detected and the code information included in the received code (in this case, the address N2 is included) is included in the repeat reception signal 27 upon receiving the Break code detection.
Is transmitted to the transmission system block A17. The Break reception status is reset when the Break reception is completed.

In the transmission system block A17, the repeat reception signal 27 is passed to the transmission control circuit 35 and the control code generation circuit 36. In the transmission control circuit 35, Break repeat transmission is set in the control code generation control signal 41 and is sent to the control code generation circuit 36. The control code generation circuit generates a Break code including the code information and sends it to the transmission selection circuit 34 as a control code generation result signal 43. In the transmission selection circuit 34, a Break code is transmitted to the LAN transmission signal 28 as code transmission, and is transmitted from the LAN interface 21 to the A side of the LAN. The ring master node receives the Break code transmitted in a repeated manner, and performs the above bus change processing. That is, in the ring master node, the A system and the B system are connected so that a repeat-through operation is performed. (Stop_Break.re
On the other hand, if it is detected that communication with the adjacent node is impossible when the connection configuration is a bus, the node N2 terminates and the frame transmission / reception is performed only by the node N1 side system as shown in FIG. Report_Status. To the loop management function 1 of the ring master node having information indicating that communication between the node N2 and the node N3 is disabled. req
To the data link layer function 3.

By having the transmission function / switch function as described above, it is possible to process the communication disabled state without interrupting the system operation. Thereby, interruption of the system operation can be reduced.

[Pre Code Reproduction Operation] FIG. 14 is a time chart showing the Pre Code reproduction operation at the time of frame reception. In the same figure, (a) shows when a reproducing operation occurs, (b)
Indicates a normal operation. In the information frame detection circuit 49, the LAN reception signal 29 is stored in an internal shift buffer, and when the frame synchronization establishment signal 58 is ON, it is determined whether or not the content of the shift buffer is a Pre code. Is being detected. If the LAN reception signal 29 is present prior to the detection of the Pre code as in (a), the frame data reproduction instruction 59 is turned ON at the determined timing and the reception FIFO is set.
Reproduce the Pre code in the circuit 50, and then
The received frame extracting signal 57 from the information frame detecting circuit 49 stored in the received frame signal is output to the received frame signal 25. In the normal state of (b), the received frame extraction signal 5
7 are extracted to the received frame signal 25 in the same order. By providing the code reproducing function as described above, it is possible to reduce missed information frames due to the influence of noise or the like, and to reduce interruption of the system operation caused by unreached information.

[Code Continuous Counting Process] FIG. 15 is a time chart of the code continuous counting process. Here, the processing content will be described by taking Quiet detection as an example. In the figure, (a) shows an example of code detection operation, and (b) shows an example of operation when no code is detected. The reception control code detection circuit 46 receives the reception frame signal 25 and enters the internal shift register. When this matches the code detection pattern, the control code type signal 54 is transmitted to the control code count circuit 47. When the control code type signal 54 is input, the control code counting circuit 47 counts up an internal counter. In this example, as shown in (a), when there are three consecutive occurrences, it is determined that there is a code, and the control code count end signal 55 is sent to the reception control code detection circuit 46.
Conveyed to. If the code content changes less than three times as in the example of (b), the control code count end signal 55 is not output. When the control code count end signal 55 is received by the reception control code detection circuit 46, the status of continuous control code generation is entered in the reception status 24. By providing the code continuous counting process as described above, it is possible to eliminate the interruption of the system operation caused by erroneously receiving a code due to the influence of noise or the like.

In this example, three consecutive detections are used as the delimiter value for detection. However, other values may be used without any problem.

[Collision Detection Operation] FIG. 16 is a timing chart of the transmission frame selection operation in the transmission frame selection circuit 32. 14A shows a case where the transmission frame signal 26 is selected, and FIG. 14B shows a case where the reception repeat signal 2 is selected.
7 is selected. (C) is a case where the transmission frame signal 26 and the reception repeat signal 27 are simultaneously generated and the transmission frame signal 26 is selected. The first arrived frame is selected and sent to the transmission frame selection result signal 37. If they occur simultaneously, (c)
As shown in FIG. 7, in this embodiment, the transmission frame signal 26 is prioritized. When a transmission frame occurs at the same time, the occurrence of a collision is set in the transmission unit status 23 and transmitted to the CPU interface 15. By using the above-described transmission collision detection operation, when transmitting a transmission frame, perform an advance arbitration process with a repeat transmission frame,
Since the occurrence of collision can be detected, the load of the judgment of the transmission control program can be reduced.

[Code / transmission frame priority processing] FIG.
FIG. 7 shows a time chart of the code / transmission frame priority processing. In the figure, (a) shows a state in which a frame is being transmitted and code transmission is waiting. (B) shows a state in which frame transmission has been completed and an idle code is being transmitted. (C) shows a state in which a repeat break signal request having a higher priority during the idle transmission is transmitted. (D) shows a state in which the transmission of the Repeat Break signal ends and the transmission of the idle signal that has been waiting has been performed. In this case, there is a frame transmission request, but waiting for code transmission completion. First, the signal operation inside the transmission system block 31 in the part (a) will be described. FIFO circuit 33
The transmission frame selection result signal 37 is output from the transmission frame selection circuit 32. In the FIFO circuit 33, since the transmission frame has occurred, the FIFO state signal 39
Is set to "with frame" and data is stored in the FIFO. The transmission control circuit 35 performs transmission control judgment in accordance with the transmission synchronization timing (（in FIG. 17), and
Accepts transmission request and turns on FIFO output control signal 38
(FIFO output permission). The transmission selection signal 44 is a FIFO transmission selection. In the FIFO circuit 33, the FIFO
When the O output control signal 39 becomes FIFO output enabled, the stored transmission frame data is inserted into the FIFO output frame signal 40. In the transmission selection circuit 34, FI
The FO output frame signal 40 is selected and the LAN transmission signal 28 is selected.
Output to

When all the frame signals stored in the FIFO circuit 33 are output, the FIFO state signal 39 becomes no frame. Upon receiving this signal, the transmission control circuit FI
The F output control signal 39 is set to disable FIFO output. While the frame transmission is being performed, the transmission control command 22 indicates that the idle code is transmitted, but waits until the frame transmission is completed. Next, the operation in the part (b) will be described. The transmission control circuit 35 transmits a control code generation control signal 41 to the control code generation circuit 36 at the timing when the frame transmission ends, in the form of the idle code transmission. In response to this, the control code generation circuit 36 generates an Idle code and outputs it to the control code generation result signal 43. The transmission control circuit 35 sets the transmission selection signal 44 to code transmission selection. At the timing of transmitting the next idle, a repeat break request having a high priority is included in the repeat reception signal 27, and the transmission control circuit 35 stops idle transmission. Next, the operation in the part (c) will be described. The transmission control circuit 35 sends the control code generation control signal 41 to the control code generation circuit 36 at the timing when the idle transmission stops.
Is transmitted in the content of the repeat Break code transmission. In response to this, the control code generation circuit 36 repeats Break
A code is created and output to the control code generation result signal 43. Further, the transmission control circuit 35 continues the transmission selection signal 44 with the code transmission selection. When the control code generation status 42 indicates that the code generation has been completed, the control circuit 35 stops the repeat Break transmission.

Finally, the operation in the part (d) will be described.
The transmission control circuit 35 transmits the control code generation control signal 41 to the control code generation circuit 36 at the timing when the repeat Break transmission is stopped in the form of the idle code transmission. In response, the control code generation circuit 36 outputs Id
A le code is created and output to the control code generation result signal 43. In the transmission control circuit 35, the transmission selection signal 44 is continued with the code transmission selection. At the timing of transmitting the next Idle, a high-priority frame presence request is included in the FIFO status signal 39, and the transmission control circuit 35
Stop dle transmission. Thereafter, frame transmission is started. By providing the above code / transmission frame priority processing, priority can be given to frame transmission processing and command transmission processing, so that it is not necessary to perform discrimination processing in the transmission control program, and processing speed is improved. I do.

(Second Embodiment) Next, a second embodiment of the optical double loop management switch circuit according to the present invention will be described. FIG. 18A shows a connection configuration between the transmission / reception control circuit 5 and the switch circuit 6 in the second embodiment. The unified transmission frame signal 65 and the unified reception frame signal 66 are connected by one system. The connection configuration of other parts is the same as that of the first embodiment. FIG. 18B shows a connection configuration used in the first embodiment, and is independent for the A system and the B system. The A system is a transmission frame signal 67 for the A system and an A system.
The transmission / reception control circuit 5 and the switch circuit 6 are connected to the system reception frame signal 68 and the system B by a system B transmission frame signal 69 and a system B reception frame signal 70.

[Received frame unification operation]
Since a single frame is transmitted to the AN irrespective of the A system and the B system, there is no problem if only one transmission frame signal is sent to the switch circuit 6. The unified transmission frame signal 65 sent from the transmission / reception control circuit 5 is transferred to the transmission frame signal 26 by the transmission control circuit interface 16 inside the switch circuit 10 and sent to the transmission system block A17 and the transmission system block B18. The data is transmitted from the transmission system block A17 and the transmission system block B18 to the LAN interface 21 and transmitted. In this case, a frame transmission prohibition / permission setting function is provided in the CPU interface 15 as necessary, so that frame transmission can be determined for each system.
On the other hand, since there is a possibility that the received frame is transmitted independently in the A system and the B system, the operation of unifying the received frame shown in FIG. 19 is required. FIG. 7A shows a case where the A-system reception frame signal 71 is selected, and FIG. 7B shows a case where the B-system reception frame signal 72 is selected. Also, FIG.
This is a case where the system reception frame signal 71 and the system B reception frame signal 72 are simultaneously generated and the system A reception frame signal 71 is selected.

In the transmission / reception control circuit interface 16,
The first received frame is selected and the unified received frame signal 6
6 will be sent. In the case of simultaneous occurrence, as shown in (c), in this embodiment, the A-system received frame signal 71 is prioritized. Received frames that have not been selected will be discarded. By having the receiving frame unifying operation described above, the number of signals connected to the transmission / reception control circuit 5 can be reduced since the receiving frame signals are grouped from two systems into one system inside the switch circuit 6, In addition, even if a reception frame signal is generated at the same time, it is possible to prevent the transmission of the erroneous reception signal to the transmission / reception control circuit 5 due to the mutual influence.

[Reception Interval Adjustment Function] FIG. 20 is a time chart of the reception interval adjustment function. In addition to the above-described reception frame unifying operation, this is a function of transmitting a reception frame signal to the transmission / reception control circuit 5 with a certain time interval or more. In the time chart of FIG. 20, (a) shows the operation when the reception frame signal arrival interval is equal to or greater than a specified value (b).
Is an operation when the reception frame signal arrival interval is smaller than a specified value. As in the case of (a), when the signal generation interval of the B-system received frame signal 72 arriving after the termination of the A-system received frame signal 71 is larger than the minimum interval value T, the unified received frame signal 66 has arrived as it is. A B-system received frame signal 72 is output. On the other hand, when the signal generation interval of the B-system reception frame signal 72 arriving after the termination of the A-system reception frame signal 71 is smaller than the minimum interval value T, as in the case of (b), the unified reception frame signal 66 includes a direct signal. The data is not output but is stored in the internal FIFO data 73. When the time T elapses after the end of the A-system reception frame signal 71, the operation is output from the internal FIFO data 73 to the unified reception frame signal 66. In this case, the signal generation interval output to the unified reception frame signal 66 is T.

If the above-mentioned signal generation interval is kept at T and the time when the B-system reception frame signal 72 is output to the unified reception frame signal 66 is delayed, then the processing of the A-system reception frame signal 71 starts to be accepted. At the time when the output of the unified reception frame signal 66 is completed. Thereafter, the signal generation interval output to the unified reception frame signal 66 is T or more in the same manner. By having the reception interval adjusting function described above, the reception frame output is set to a certain interval or more, so that it is not necessary to secure a signal processing time interval in the transmission / reception control circuit 5, and the circuit can be simplified.

[Transmission Channel Information Addition Function] FIG.
The time chart of the transmission channel information addition function is shown in FIG. This is a function of adding transmission channel information to the unified reception frame signal 66 and transmitting it to the transmission / reception control circuit 5 in addition to the above-described reception frame unification operation. 21A shows a case where the A-system reception frame signal 71 is selected, and FIG. 21B shows a case where the B-system reception frame signal 72 is selected. When creating the unified reception frame signal 66, the transmission / reception control circuit interface 16 adds connection channel information to the frame. This addition information is put in a fixed position in the frame. The frame information is transmitted to the CPU 11 via the transmission / reception control circuit 5, and the transmission control program uses the information to determine the reception channel. Without this information, it would be necessary to search the address table to determine the receiving channel,
Processing time will be longer than necessary.
By having the transmission channel information addition function described above, the reception channel information is embedded in the reception frame, so that there is no need to perform the reception channel determination processing in the transmission control program, and the processing speed is improved.

[0045]

As described above, the optical double loop management switch circuit according to the present invention according to the first, second, third, fourth, seventh, and eighth aspects of the present invention has the following advantages. , Adjacent node confirmation processing, terminate connection processing,
Since the repeat through connection process is performed independently for each system using a signal, the other system can perform connection with an adjacent node without affecting system operation. Further, in the optical double loop management switch circuit according to the present invention as set forth in claim 5, when the synchronization control code signal on the system having the property of being periodically interrupted continues more than a predetermined number of times, a continuous abnormality is generated. Since the abnormal state can be transmitted to the transmission control software, there is no need to interrupt the system operation for the abnormality diagnosis. Further, in the optical double loop management switch circuit according to the present invention, when the ring master terminates from the repeat state, the change timing can be determined, so that the system operation is interrupted. Can be reduced. Further, in the optical double loop management switch circuit according to the ninth aspect of the present invention, it is possible to reduce missed information frames due to the influence of noise and the like, and to reduce interruption of system operation caused by unreached information. .

Further, in the optical double loop management switch circuit according to the present invention, it is possible to eliminate the interruption of the system operation caused by erroneously receiving a code due to the influence of noise or the like. Also, in the optical double loop management switch circuit according to the present invention described in claims 2, 3 and 4, the received frame signals are combined in a system for selecting a signal from two systems to one system inside the switch. Therefore, it is possible to unify connection signals to the transmission / reception control circuit and to prevent an error from occurring at the time of simultaneous reception. In the optical double loop management switch circuit according to the third aspect of the present invention, since the reception frame output is set to a predetermined interval or more, it is not necessary to secure a signal processing time interval in the transmission / reception control circuit, thereby simplifying the circuit. it can.
Further, in the optical double loop management switch circuit according to the present invention, since the received frame discriminating data such as the received channel information is embedded in the received frame, the receiving channel discriminating processing is performed in the transmission control software. Need not be performed, and the processing speed is improved.
Furthermore, in the optical double-loop management switch circuit according to the present invention, when transmitting a transmission frame, first-arbitration processing with a repeat transmission frame is performed, and collision occurrence can be detected. Can be reduced.

In the optical double loop management switch circuit according to the present invention, the frame transmission processing and the command transmission processing can be performed with a priority.
It is not necessary to perform the determination processing in the transmission control software, and the processing speed is improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a communication processing function of a node according to a first embodiment.

FIG. 2 is a diagram showing a configuration of a system according to the first embodiment.

FIG. 3 is a diagram illustrating a configuration of a communication module according to the first embodiment.

FIG. 4 is a diagram illustrating a configuration of a switch circuit according to the first embodiment.

FIG. 5 is a diagram showing a configuration of a transmission system block according to the first embodiment.

FIG. 6 is a diagram showing a configuration of a transmission system block according to the first embodiment.

FIG. 7 is a diagram showing a configuration of a control code according to the first embodiment.

FIG. 8 is a diagram showing a configuration of an information frame according to the first embodiment.

FIG. 9 is a view showing an example of an adjacent node confirmation transaction according to the first embodiment;

FIG. 10 is a diagram showing an example of detecting an idle code generation abnormality in the first embodiment.

FIG. 11 is a diagram showing a communication disable notification in the case of a ring according to the first embodiment.

FIG. 12 is a diagram illustrating a communication disable notification in the case of a bus according to the first embodiment.

FIG. 13 is a diagram showing an example of a node array table according to the first embodiment.

FIG. 14 is a diagram illustrating a state Pr when receiving a frame according to the first embodiment;
6 is a time chart showing an e-code reproducing operation.

FIG. 15 is a time chart illustrating a code counting process according to the first embodiment.

FIG. 16 is a time chart illustrating a transmission frame selection operation in the first embodiment.

FIG. 17 is a time chart illustrating a transmission code / frame priority operation according to the first embodiment;

FIG. 18 is a diagram illustrating a connection configuration between a transmission / reception control circuit and a switch circuit according to the second embodiment.

FIG. 19 is a time chart showing a received frame selecting operation in the second embodiment.

FIG. 20 is a time chart illustrating a reception frame interval holding operation according to the second embodiment;

FIG. 21 is a time chart showing an operation of attaching received frame channel information in the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Loop management function 2 ... Network management function 3 ... Data link layer function 4 ... Transmission / reception driver 5 ... Transmission / reception control circuit 6 ... Switch circuit 7 ... Communication module 8 ... Node 9 ... Optical fiber 10 ... Ring master node 11 ... CPU 12 ... Internal bus 13 ... Memory circuit 14 ... Host interface circuit 15 ... CPU interface 16 ... Transmit / receive interface circuit 17 ... Transmit system block A 18 ... Transmit system block B 19 ... Receive system block A 20 ... Receive system block B 21 ... LAN interface 31 ... Transmission system block 32 ... Transmission frame selection circuit 33 ... FIFO circuit 34 ... Transmission selection circuit 35 ... Transmission control circuit 36 ... Control code generation circuit 45 ... Reception system block 46 ... Reception control code detection circuit 47 ... Control code count circuit 48 ... Frame Sync detection Road 49 ... information frame detection circuit 50 ... reception FIFO circuit 51 ... receiving the abnormality detection circuit 64 ... node arrangement table

Claims (10)

[Claims] 1. All nodes can transmit a non-repeat control signal exchanged between two adjacent stations. If there is one ring master and the ring is used, the ring master terminates both systems. In an optical duplex loop network in which the end node terminates when it is not a ring, the control signal transmitted between adjacent nodes is added to the local node address and transmitted, so that adjacent nodes are connected. When the connection is confirmed, the node address of the adjacent node is stored, and the fact that the connection has been confirmed is notified to the ring master together with the node address of the adjacent node in a frame by using an optical duplex loop. Management switch circuit. 2. The optical double loop management switch circuit according to claim 1, wherein receiving frame signals from both systems are received, and if there is a receiving frame signal at the same time,
An optical double loop management switch circuit for selecting a first-arrived received frame signal and transmitting the selected signal to transmission control software. 3. The optical double-loop management switch circuit according to claim 2, wherein when a received frame signal from another system arrives after completion of reception of a received frame signal from one system, reception transmitted to the transmission control software. An optical double loop management switch circuit, wherein an interval between frame signals is maintained for a predetermined time or more. 4. The optical double-loop management switch circuit according to claim 2, wherein received system identification data is automatically incorporated into a received frame transmitted to said transmission control software. Heavy loop management switch circuit. 5. All the nodes can transmit a non-repeat control signal exchanged between two adjacent stations, and if there is one ring master and it is a ring, the ring master terminates both systems. In an optical duplex loop network where the end node is terminated when it is not a ring, if the synchronization control code signal on the system that has the property of being periodically interrupted continues more than a predetermined number of times, it will be regarded as an abnormality and an abnormal situation will occur. Transmission to the transmission control software. 6. All nodes can transmit a non-repeat control signal exchanged between two adjacent stations, and if there is one ring master and a ring, the ring master terminates and the ring becomes In an optical duplex loop network where the end node terminates if not, the ring master notifies all connected nodes whether or not it is currently a ring so that each node If the communication failure with the adjacent node is detected, the ring master is notified of the occurrence of an abnormality by a break signal indicating the suspension of the system operation. The occurrence of an abnormality is notified to the ring master while the break signal is being generated. Heavy loop management switch circuit. 7. The optical double loop management switch circuit according to claim 1, wherein when a transmission frame sent from the transmission control software and a transmission frame to be repeated are simultaneously generated, the transmission frame received first is transmitted to the network. And transmitting an abnormal condition to the transmission control software as occurrence of a collision abnormality. 8. The optical double loop management switch circuit according to claim 1, wherein, when a transmission frame transmission and a code transmission request occur simultaneously, a higher priority is transmitted to the network, and An optical double-loop management switch circuit, wherein the occurrence of the lower one is made to wait. 9. All nodes can transmit a non-repeat control signal exchanged between two adjacent stations, and if there is one ring master and it is a ring, the ring master terminates both systems. In an optical double-loop network where the end node terminates when it is not a ring, if a part of the discrimination code of the received frame received after the synchronization code is missing, the missing data is supplemented from the remaining discrimination code. An optical double-loop management switch circuit. 10. All nodes can transmit a non-repeat control signal exchanged between two adjacent stations. If there is one ring master and the ring is used, the ring master terminates both systems. In the optical double loop network where the end node terminates when it is not a ring, the number of consecutive occurrences of the received code is counted, and when the number exceeds a predetermined number, it is determined that the code is received and transmitted to the transmission control software. An optical double-loop management switch circuit.