JPS6181047A - Communication system - Google Patents

Abstract

PURPOSE:To improve the availability of a communication system by providing a means which generates communication frames and transmits them to a circular communication line, a means which constitutes a loop back path from prescribed one of communication lines of two systems to the other if the abnormality of the signal on one of said communication lines is detected at least, and a means which releases the loop back path. CONSTITUTION:Each of communication controllers of terminal stations 2-3, 2-4, and 2-5 is provided with the communication frame generating function and the function which provides a compensation delay time to repeat communication frames, namely, the function by which the communication controller can be a master station. If the abnormality of reception signals from one or both of communication lines of two systems is detected, the loop back path through which the output of one communication line is turned back to the other is constituted in accordance with a prescribed system, and the number of the station which sets the loop back path is indicated in communication frames which are generated or repeated and transmitted. Thus, frames where the station number of reception frames of both systems or the station number of the station itself is indicated are received by the system which transmits loop back signals, and the station releases the loop back path.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a control method for a communication system using an original transmission line. A plurality of communication control devices that communicate with each other are connected in a ring by a transmission line, and three transmission lines are used to transmit data. Nostem systems that communicate by means of predetermined formats of communication frames are well known.

In such a communication system, the transmission path is monitored, and if a communication frame is lost due to an obstacle such as a river, the communication frame is activated, and the transmission path is monitored and the communication frame is activated. To make this possible, there must always be one so-called mask station in one ring transmission line, which has a monitoring control function such as compensating for the transmission delay time of the ring transmission line.

[Conventional technology]

FIG. 2 (al is a diagram showing an example of the communication nostem configuration of a ring transmission path, in which mask station 1 and general OL'ff 12-1
~2-7 are connected in a ring through two systems of transmission lines shown in 3.4 (hereinafter, these two systems will be referred to as 0 system and 1 system, respectively).

Here, as is well known, transmission line systems 3 (0 system) and 4 (1 system) are two systems that are provided to constitute an alternative transmission facility in the event of a terminal station or transmission line failure.・During normal operation, communication is performed using one system (system 0 and 3 in the figure).

Reference numeral 5 in the 7th station IU indicates a frame generation unit that generates a communication frame in a predetermined format and compensates for the transmission time of the circular transmission path.

FIG. 3 is a block diagram showing an example of the configuration of a communication control bag I serving as a terminal station of the above-described circular transmission line.

The communication control device of mask station 1 is switch 10.11.12.
By connecting each switch to the side shown in the figure, the signal of the O system 3 is connected from the switch 12 to the frame generation section 13, and the transmission delay time of the entire ring transmission path is at least 1i[ Compensate so that it does not become shorter than the length of one transmission frame.

The control unit 14 receives the output of the frame generation unit 13, and
The format of the communication frame is checked, and the communication frame is relayed to the adjacent terminal station 2-1 by the O system 3 via the switch 10.

The same signal is also sent to the 1st system 4 via the switch 11, and is transmitted to both sides.

The adjacent general terminal station 2-1 also relays communication frames through the same route as the mask station, but the function corresponding to the frame generation unit 13 in the case of a mask station is that communication frames on the transmission path system 3 are transmitted and received. For processing, the signal only passes through the control i1J section 14 and is relayed, and the signal of the l system 4 is directly connected. This situation is the same for the terminal station 2-7.

In this configuration, if terminal station 2-2 and terminal station 2-6
g is disconnected, the mask station 1 uses the control unit 14 to prevent the communication frames received from the 0 system 3 from arriving.
When detected, a new communication frame is generated and sent.

In addition, as is well known, the general terminal station operates to form a loopback path from the transmission line system that can receive signals to the transmission line system that cannot receive signals, so that the terminal station 2.1 switches the switch 11 to send the communication frame received from the transmission line 3 through the control section 14,
Relay to 1 system 4.

In addition, the terminal station 2-7 switches the switches 11 and 12 to the opposite side, and transfers the communication frame received from the transmission line system 4 to the control unit 1.
Since it is connected to the transmission line system 3 through 4, in the end, the
As shown in , terminal station 2-7, mask station 1 and terminal station 2 = 1
The partial circular transmission path is reconfigured and communication continues.

[Problem that the invention seeks to solve]

As mentioned above, even if a failure occurs such as a power cut at a terminal station, communication can be continued in some areas by partially reconfiguring the transmission path, but as illustrated in Figure 2(b), Terminal station 2-3~2-
5 is in a state where it can be operated, but the power-off terminal stations 2-2 and 2-6 are intervening and are disconnected from mask station 1, making it impossible to resume communication at all. There is.

[Means for solving problems]

The above-mentioned problem is that in a two-system circular communication path in which a plurality of communication devices t and ii are connected in series through a transmission path, and the transmission directions are opposite to each other, the communication control 1111 device transmits communication frames. means for generating and transmitting to the circular communication channel;
means for configuring a loopback path from a predetermined one of the communication paths of the two systems to the other when an abnormality in a signal of at least one of the communication paths of the two systems is detected; means for displaying the configured station number;
'A'+'/P by the communication node system of the present invention having means for canceling the set loopback route according to a predetermined condition of the station number display of the communication frame received from the communication path of the second system. , areru.

[Effect]

All communication control devices of each terminal station are provided with a function of generating a communication frame and a function of relaying the communication frame with a compensated delay time, that is, a function of functioning as a mask station.

In addition, when an abnormality (including no signal) is detected in the received signal from one or both of the communication paths of the second system, a loopback path is established in which the output of one communication path is looped back to the other communication according to a predetermined method. The number of the station that has set the loopback route is displayed in the communication frame that is generated or relayed and transmitted.

In this way, if the received frames of both systems have the same station number display, or if the frame that has the station number display of its own station (originated from its own station) is transmitted by a loopback signal, The station releases the loopback path.

By executing the above procedure at each station, when the power is turned on individually for each round and the communication system starts J use, or when the power is cut off as described above, etc., the section where the transmission line is continuous A partial ring channel is constructed for each channel and can be expanded automatically.

(Embodiment) FIG. 1 (al is a block diagram showing the configuration of a communication control device according to an embodiment of the present invention. In the figure, the same parts as in FIG. 3 are designated by the same reference numerals.

The figure shows the communication control device of the terminal stations 2-3.2-4.2-5, and the switches 10, 11, 12 and 20 of each terminal station are connected to the terminal stations 2-2 and 2-6 as before. A power cut occurred in /'
It shows the state as a result of the partial transmission paths being reconfigured by the terminal stations 2-3 to 2-5 after j.

In this embodiment, the communication control devices of the mask station 1 and the terminal stations 2-1 to 2-7 in FIG. 2 ta+ are all in FIG.
The terminal stations 2-1 to 2-7 have the same configuration as each station illustrated in FIG.
shall be given.

Using FIG. 1, the operation when the power is turned on will be explained first.

Assuming that terminal stations 2-3 and 2-4 start operating when the power is turned on, since there is no normal reception signal, both stations temporarily operate as mask stations and send communication frames to, for example, O system 3. .

For example, as shown in FIG.
S, and a plurality of time slots TSO=TSn.

When each station has the status shown in the table above, the number display section 05TS and l5 of the communication frame to be generated or relayed.
Set the appropriate value for Ts.

At this stage, both stations have switched switches 10.11.12.
20 to the state shown in the terminal station 2-3 of Fig. 1 ta+ (however, the switch 12 is connected to the side shown by the broken line), and the terminal station 2-
In step 3: 03 is set for 05TS and FF is set for l5TS of the communication frame sent to thread 1 through the 0 system and the loopback route, and 04 is set for 0STS and FF is set for l5Ts at the terminal station 2-4.

Since terminal station 2-4 receives the communication frame transmitted from terminal station 2-3 using the 0 system, it maintains the 5-loop back.
The 05TS of that frame is changed to 0422 and relayed.

The terminal station 2-3 receives the communication frame looped back by the abusive station 2-1 on the 1st system, so it reconfigures the loopback route from the 1st system to the 0th system, and
Set s↓ko03 and relay.

As a result of the above, a partial circular communication path is established between terminal stations 2-3 and 2.4, and a new clause (') is established between 0STS・04 and 15Ts・03 communication. The frame becomes stable as it flows.

In this state, when terminal station 2.5 starts operating, it receives communication frames from terminal station 2-4 on the 0-system communication path, but
Since there is no signal on the system communication path, the terminal station 2-5 purchases a loopback path from the O system to the 1 system, receives and relays the 0STS of 10 communication frames as 05.

This communication frame (O5TS=05, l5TS・03)
arrives at terminal station 2-4 on the 1st line. When the terminal station 2-4 receives this communication frame, it relays it to the 1-system 4 communication path.

The terminal station 2-3 also receives this communication frame (O3TS=05,
When 15TS・03) is received on l system 4, it is relayed to 1 system 4 and O system 3, so when terminal station 2-4 receives it on the communication path of 0 system 3, it sends the same station number to both systems. By receiving the indication, it is recognized that the relayed communication frame has been looped back, and the loopback from the O system to the 1 system of the local station is eliminated.

This message frame is looped back to the oM communication channel at the terminal station 2-3. Therefore, the circular communication path is broken between the three terminal stations 2-3 to 2-5, 05TS=05, l5TS・0
The situation in which the third communication frame flows continues.

Furthermore, when the terminal station 2-6 or 2-2 starts operating,
The I-interval communication channel is constructed by a procedure similar to the above, and in this way, the constituent section of the circular communication channel can be automatically and successively expanded.

As a result of the above, the setting of the circular communication channel for a certain section is stabilized,
At the point when the setting values of 05TS and l5TS do not change, for example, the terminal station whose station number is set to l5TS (terminal stations 2 to 3 in the case of the upper side) retains its function as a mask station and other stations It is assumed that the terminal station bypasses the frame ordering section 13 by the switch 20 and becomes a single ship terminal station.

As described above, if we consider the case where the ring communication channel setting section is expanded and all end stations are connected, the end station that joins last receives signals in both systems, so there is no need to create a loop hack. Relays communication frames of each system.

Therefore, the terminal station that had previously configured the loopback path at both ends of the section will now transmit the communication frames sent by itself on the same system, and the detection of this state will be By dividing by 67, it is possible to construct a communication path in a normal state in which all terminal stations are connected in a ring in one system.

In this way, the terminal station that has canceled the loop; sets its own station number to 0 in the 05TS or 15TS of the communication frame.

During communication operation in the IE normal state, as in the above example, terminal station 2-2
Assume that the power is cut off in 2-6.

When each station except terminal stations 2-2 and 2-6 detects that the received signal disappears, each station generates a communication frame and transmits it in the state shown in Figure 1+C) in the same way as when the power is turned on. . As a result, according to the procedure described above when turning on the power, 3
A circular communication path as shown in FIG. 1 (d+) is constructed between the stations.

Similar operations are performed at terminal station 2-1, mask station 1, and terminal station 2-7, and in the end, the configuration is as shown in Figure 1, and all terminal stations except the new station whose power is cut off can communicate. can become a state.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, even in the event of a failure that disrupts the communication system of a circular transmission line, the transmission line is automatically reconfigured for each section and the section is expanded. There is a significant industrial effect of improving the availability of communication systems.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the configuration of a communication system, and FIG. 3 is a configuration block diagram of a conventional communication control device. In the figure, 1 is a mask station, 2-] to 2-7 are terminal stations, and 3.
4 is a transmission system, 10.11.12.20 is a switch, 13 is a frame generation section, and 14 is a control section. Agent Patent Attorney Examination Koshibu Part 1 Figure 26

Claims (1)

[Claims] In a two-system ring communication path in which a plurality of communication control devices are connected in series through a transmission path and have mutually opposite transmission directions, the communication control device generates a communication frame and sends it to the ring communication path. , means for configuring a loopback path from a predetermined one of the communication paths of the two systems to the other when an abnormality in a signal of at least one of the communication paths of the two systems is detected; and a means for canceling the set loopback route according to a predetermined condition for displaying the station number of the communication frame received from the communication path of the second system. communication system.