JPH02250538A - Multiplex transmission network communication system - Google Patents

Abstract

PURPOSE:To unnecessitate a special monitor station by using two transmission lines to secure the double loop type connection among plural stations and transmitting the same signals to both transmission line, at one time and in the directions opposite to each other. CONSTITUTION:A communication system consists of the stations 2-6, the transmission lines 10 and 11, and the transmission devices 122-128. Then the double loop type connection is secured among stations 2-6 via both lines 10 and 11, and the same signals are transmitted to these lines 10 and 11 at one time and in the directions opposite to each other. As a result, the transmission of signals is attained with no trouble even when the lines 10 and 11 are disconnected or the devices 122-128 have troubles. Then no special monitor station is required.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a multiplex transmission network communication system in which a plurality of stations are connected via multiple transmission paths and data is transmitted between these stations.

"Prior Art" Fig. 7 is a block diagram showing an example of the configuration of a conventional multiplex transmission network communication system. 8 is a main transmission line such as an optical fiber cable through which data is transmitted, and 9 is a subsidiary transmission line such as an optical fiber cable through which a monitoring signal is transmitted.

In such a configuration, if a disconnection fault occurs in the main transmission line 8 between stations 4 and 5, the main station 1 changes the transmission line for data transmission to the main transmission line 8, as shown in FIG. After switching to the secondary transmission line 9 to continue data transmission, an interrupt is made to notify the switching of the transmission line and the address of the station adjacent to the disconnection fault (station 5 in this case).

In addition, in Figure 7, if a failure such as a power outage or failure occurs in station 4 during data transmission (see Figure 9), or if both transmission lines 8 and 9 between stations 3 and 5 When a disconnection fault occurs, the main station 1 creates a loopback configuration by connecting the main transmission line 8 and the slave transmission line 9 at stations 3 and 5 adjacent to these faults, respectively, as shown in Figure 1O. By creating this command, station 4 is disconnected and data transmission continues, and then an interrupt is performed to notify that loopback has been performed and the addresses of the stations performing loopback (in this case, stations 3 and 5). do.

In addition, in FIG. 1θ, if a failure such as a power outage or failure occurs in yet another station 5 while loopback is being performed, the main station 1, as shown in FIG. 41,
By connecting the main transmission line 8 and the secondary transmission line 9 in the station 6 adjacent to these failures to create a loopback configuration, the station 5 is disconnected and data transmission continues, and then an interrupt is performed to terminate the loop. Notify that the loopback has been performed and the address of the station (in this case, station 6) that is performing the loopback.

When data transmission is performed using the loopback configuration shown in FIG. 10, the main station 1 periodically makes inquiries about failure recovery to stations 3 and 5, which are performing loopback, at a cycle of about 10 seconds, for example. I do. Meanwhile, stations 3 and 5
constantly monitors failure recovery, and when the failure is recovered, returns a recovery response to inquiries from main station 1 (first
(See Figure 2).

As a result, the main station l receives this recovery response and the 13th
As shown in the figure, after station 4 joins this multiplex transmission network, an interrupt is performed to notify that station 4 has joined this multiplex transmission network.

In addition, in FIG. 7, station 4 and station 5
If only station 5 recovers after a failure such as a power outage or failure occurs in both stations (see Figure 14), main station l will not be able to detect that station 5 has recovered, so station 5 will station 1
A command is sent to notify the user that the device has recovered.

As a result, main station 1 receives this command and causes station 5 to join this multiplex transmission network.

Next, the case of adding stations in the multiplex transmission network communication system shown in FIG. 15 will be explained. In this diagram,
Components corresponding to those in FIG. 7 are given the same reference numerals, and their explanations will be omitted.

In such a configuration, in order to add more stations, first remove the main transmission line 8 and the secondary transmission line 9 connecting stations 3 and 5, as shown in FIG. , the main transmission line 8 and the secondary transmission line 9 are connected to form a loopback configuration. Next, as shown in FIG. 17, station 4 is added, and stations 3 and 4 and stations 4 and 5 are connected by main transmission line 8 and secondary transmission line 9, respectively. .

Then, as shown in FIG. 18, the power of station 4 is turned on, and the main transmission line 8 and secondary transmission line
The station 4 joins this multiplex transmission network by disconnecting the station 4 and canceling the loopback configuration.

``Problems to be Solved by the Invention'' By the way, in the conventional multiplex transmission network communication system described above, a main station constantly monitors the multiplex transmission network and switches the transmission path for data transmission if a failure occurs. The drawback was that it required supervision.

Another drawback is that it is necessary to notify each station of the occurrence of a failure, etc. by means of an interrupt or the like.

Furthermore, in order to perform the above-described loopback, there is a drawback that the location where the failure has occurred must be detected and identified.

In addition, there is a drawback in that various procedures are required to return the multiplex transmission network to a normal state after the fault has been recovered.

Furthermore, since the main station 1 constantly monitors this multiplex transmission network, there is a drawback that if the main station 1 breaks down, it becomes impossible to switch the transmission path. Therefore, there are disadvantages in that it is necessary to increase the reliability of the main station and to install a sub-station to take over the monitoring duties. Additionally, in this case, there is the problem that the delegation of authority between the main station and the sub-stations becomes complicated.

The present invention has been made in view of the above-mentioned circumstances, and therefore does not require a special monitoring station, a special transmission line switching procedure, or a special failure recovery procedure. The purpose is to provide a multiplex transmission network communication system that does not require .

A multiplex transmission network communication system according to the first invention is a multiplex transmission network communication system that connects a plurality of stations in a double loop through first and second transmission paths, and transmits data between the stations. In a transmission network communication system, a transmission device that simultaneously transmits a signal output from a predetermined station among a plurality of stations in opposite directions via first and second transmission paths, and first and second transmission It is characterized by comprising a first-come-first-served priority circuit that selects and outputs the signal that arrived earliest among the two signals transmitted through the channel.

Further, the multiplex transmission network communication system according to the second invention includes the first
In the invention, at least one of the first and second transmission paths is a multiple transmission path, and the transmission device transmits a signal output from a predetermined station among the plurality of stations to the multiple loop transmission path and the second transmission path. The signals are simultaneously transmitted in the opposite direction via the first or second transmission path, and the first-come-first-served priority circuit selects the first among the plurality of signals transmitted through the multi-loop transmission path and the first or second transmission path. It is characterized by selecting and outputting the signal that arrived earlier.

"Operation" According to the first invention, when transmitting a signal from a predetermined station to another station, this signal is transmitted to the transmission device. Thereby, the transmission device simultaneously transmits this signal in opposite directions via the first and second transmission paths. Then, the first-come-first-served priority circuit selects and outputs the signal that arrived earliest among the two signals transmitted via the first and second transmission paths.

This allows other stations to receive the earliest signal transmitted from a given station.

According to the second invention, when transmitting a signal from a predetermined station to another station, the signal is transmitted to the transmission device. Thereby, the transmission device simultaneously transmits this signal in the opposite direction via the multiple transmission paths and the first or second transmission path. Then, the first-come-first-served priority circuit selects and outputs the hacksaw signal that arrives earliest among the plurality of signals transmitted via the multiplex transmission path and the first or second transmission path. This allows other stations to receive the earliest signal transmitted from a given station.

"Embodiment" Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a multiplex transmission network communication system according to an embodiment of the present invention. In this figure, parts corresponding to those in FIG. 7 are given the same reference numerals,
The explanation will be omitted.

In FIG. 1, 10 and 11 are outer loop and inner loop transmission lines, such as optical fiber cables, through which data is transmitted, respectively, and 12t to t2. 1 is a transmission device that transmits signals output from each station via transmission lines IO and 11, and 13 is a twisted pair cable that connects each station 2 to 6 and the transmission device 12t=12g.

Next, FIG. 2 shows a more detailed block diagram of the transmission device 12. In this figure, 4 is an optical data link that mutually converts optical signals and electrical signals, and 15 is an optical data link 14.
i6 is a signal switching circuit that switches and outputs two human input signals; 17 is an interface circuit that connects stations 2 to 6 and this transmission device 12 via twisted pair cable 13; It is.

In addition, 18 is a first-come-first-served priority circuit that selects and outputs the signal that arrives earliest among the two received signals and the transmitted signal of the local station;
[9 is the first-come, first-served priority circuit! First-come-first-served detection signal S output from 8
A reception detection circuit 20 inputs T and outputs a reception detection signal Sg, and a transmission detection circuit 20 detects a transmission signal of its own station and switches the signal switching circuit 16.

Next, FIG. 3 shows the first-come-first-served priority circuit 18 and the reception detection circuit 1.
An example of a specific circuit of No. 9 is shown below. In this figure, 21
- 23 are input terminals into which the two received signals S I and S' and the own station's transmission signal S'3 are respectively input;
24 are latches that hold the signals S°1 to S's, respectively;
25 is a selector (the logic diagram is shown in FIG. 4) which selects and outputs the earliest arriving signal among the output signals of the latch 24.

Further, 26 is an input terminal into which the reception detection signal S6 is input;
27 to 29 are the output signal of the selector 25 and the reception detection signal S
a logic element that outputs a signal at the "L" level when t is manually input and both the two human input signals are at the °L level; 3;
0 to 32 are input with the output signals of the logic elements 27 to 29 and the reception detection signal Stt, respectively, and the reception detection signal St is "I".
(“level signal, or logic elements 27 to 2
When the output signal of 9 is an "L" level signal, logic elements 33 to 35 output a "high" level signal; 33 to 35 are the signal S°
1 to S' and the output signals of logic elements 30 to 32 are respectively input, and when both input signals are at the "high" level, a logic element 36 outputs a signal at the 'L' level. 35 is input, and when any signal is at the "L" level, a logic element outputs a signal at the !, " level. 37 is an output terminal to which the output signal of the logic element 36 is output.

Further, 38 to 40 are logics that output signals at the "yes" level when the signals S'1 to S'3 and the output signals of the logic elements 27 to 29 are manually input, and when both of the two human input signals are at the "yes" level. Element 4I receives the output signals of logic elements 38 to 40, and when any signal is 1L level,
A logic element 42 outputs an "L" level signal, and is an output terminal to which the output signal of the logic element 41 is output.

Further, 43 is an input terminal to which signal Sr is input, 44 is triggered by signal ST, and reception detection signals St and S
Mono multivibrator outputting R, 45 and 46
are a capacitor and a resistor that respectively set the time constant of the mono-multivibrator 44, 47 and 48 (output terminals from which the reception detection signals SI! and S8 are output, respectively), and 49 are shown in the figure when power is turned on to the transmission device 12. This is the input terminal to which the initialization signal output from the power supply circuit is input manually.Therefore, when the 71i power is turned on, the reception detection signal SE is at the "[" level.

In such a configuration, it is assumed that a signal is transmitted from station 2 to station 4 in a state where no signal is being transmitted within this multiplex transmission network communication system.

First, station 2 sends a signal S' corresponding to predetermined data to be transmitted.
a to the transmission device 12.a via the twisted pair cable 13 and the interface circuit 17. to be transmitted. As a result, the signal S' 3 is manually input to the two signal switching circuits I6, the first-come-first-served priority circuit 18, and the transmission detection circuit 20. In this case, since no data is being transmitted from other stations, the first-come-first-served priority circuit 18 sends the signal S' as signal S, 1.
is outputted and inputted again to the station 2 via the interface circuit 17 and the twisted pair cable 13.

On the other hand, since the signal S° is detected in the transmission detection circuit 20, the signal switching circuit 16 is switched and the signal S's is output from the signal switching circuit 16, and the optical signals Sl and S, respectively are outputted in the optical data link 14. and is transmitted through the outer loop and inner loop transmission lines IO and 11+.

Next, the signals S1 and S2 that have reached the transmission device +24 are converted into electrical signals S'1 and S't, respectively, in the optical data link 14, then waveform-shaped in the waveform shaping circuit 15, and then sent to the signal switching circuit 16, respectively. At the same time, it is input to the first-come, first-served priority circuit 18.

In this case, it is assumed that the transmission line 11 in the inner loop is shorter between the stations 2 and 4. On the other hand, at this time, the first-come-first-served priority circuit 18 receives the transmission signal S's from the station 4 via the twisted pair cable 13 and the interface circuit 17.
It is assumed that S°1 and So are input later than the signals S°1 and So. That is, it is assumed that among the signals 81 to S', the signal S° reaches the first-come-first-served priority circuit 18 earliest. The waveforms of the signals 81 to S' at this time are shown in FIG.
) to (c).

Next, in the first-come-first-served priority circuit 18, the signals S'1 to S3 are inputted from the input terminals 21 to 23, respectively, and the logic element 3
3 to 35 are respectively input, and are also input to the latch 24. At this time, since the reception detection signal S8 is an "H" level signal, the signals S to S° should be held. Further, the logic elements 30 to 32 both output "L" level signals. Therefore, from the logic element 36, the signal St
A signal S'1 is output as (see FIG. 5(d)).

Next, the signal S° is transmitted to the output terminal 37 and the input terminal 43
The signal is inputted to the reception detection circuit 19 through the , and then inputted to the mono multivibrator 44 . As a result, the reception detection circuit 1
9 outputs the reception detection signal SE shown in FIG.
SQl is output respectively (Fig. 5(f) to (h)
reference). Next, the selector 25 selects the signal SQL according to the logic diagram in FIG. 4, and outputs the signal 5sq (see FIGS. 5(i) to 5(k)). The reception detection signal SE is now “L”
Since the signals 5sQ1 to S8Q3 are output as they are, the logic elements θ to 32 and the logic elements 38 to
40 respectively. Next, logic elements 38 to 40
In this case, the output signals of the logic elements 27 to 29 become gate signals, and in this case, the signal S'1 is outputted from the logic element 38 and outputted as the signal SR via the logic element 41 and the output terminal 42. (See Figure 5 (1)). As a result of the above, among the signals transmitted from the station 2 to the station 4, the signal S'1 transmitted through the inner loop transmission line 11 is transmitted. In this case, the signals are transmitted by the transmission lines 10 and +1 of both the inner loop and the outer loop, but the first-come-first-served priority circuit 18 causes only the first-come-first-served signal to be output from the transmission device 124, so the two signals Interference due to delay differences will not occur.

Next, as shown in FIG. 6, when transmitting a signal from station 2 to station 4, if both transmission lines IO and 11 between stations 3 and 4 are disconnected, transmission device 12. The optical signal transmitted through the inner loop transmission line 1 is transmitted to the transmission device 12.
．． does not reach the transmission device 12. The optical signal transmitted from the transmission line 10 of the outer loop reaches the transmission device 24.

Furthermore, when transmitting a signal from station 2 to station 4 in FIG. If transmission device 1 is out of order,
2. The optical signal transmitted via the inner loop transmission line 11 from the transmission device 12. does not reach the transmission device 12. The optical signal transmitted from the transmission line 10 of the outer loop reaches the transmission device 12°. In this case, since there is no problem with signal transmission even if the transmission device 12a is removed for repair, the same applies even if the station 3 breaks down.

As explained below), the stations are connected in a loop through two transmission lines 10 and 11, and the same signal is simultaneously transmitted in the opposite direction to each transmission line.
The transmission lines 10 and 11 in the middle are disconnected and the transmission device 1
．． 2. ~12. Even if something goes wrong, signals can be transmitted without any problems. Therefore, as before,
The reliability, availability, and maintainability of transmission network communication systems are improved for dedicated stations for monitoring and switching transmission paths, and for failure recovery.

In the embodiment described above, the transmission line is a double loop of the transmission lines 10 and 1.1, but at least one of these transmission lines is configured as a multiple loop, and the transmission device 12
The first-come, first-served priority circuit I8 may be configured to transmit a plurality of signals and determine the first-come, first-served basis. This further improves the reliability, availability, etc. of this multiplex transmission network communication system.

"Effects of the Invention" As explained above, the present invention has the advantage of not requiring a special monitoring station. Another advantage is that no special transmission path switching procedure or special failure recovery procedure is required. However, it has the effect that there is no need for delegation of authority between the main station and the sub-stations.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a multiplex transmission network communication system according to an embodiment of the present invention, FIG. 2 is a detailed block diagram of the transmission device 12, and FIG. 3 is a first-arrival first-arrival circuit 8 and a reception detection circuit. Figure 4 is a logic diagram of the selector 25, and Figure 5 is a waveform diagram of signals S°1 to S゛3 and signals output from each part of the circuit in Figure 3. ,
Figure 6 shows the transmission line lO between stations 3 and 4 in Figure 1.
Block diagram when 11 and 11 are disconnected, Figures 7 to 1
FIG. 8 is a block diagram showing a configuration example of a conventional multiplex transmission network communication system. 2-5...station, 10.11...transmission line, 12. ~12...Transmission device, 18...
・First-come, first-served priority circuit. Shujin Shinko Electric Co., Ltd. Figure 1 Figure 6 Figure 5 Figure 7 Figure 8 Figure 9 Figure 10 Figure 12 Figure 13 Figure 14 Exit

Claims (2)

[Claims] (1) Two or more stations are connected by the first and second transmission paths.
In a multiplex transmission network communication system connected in a double loop and transmitting data between the stations, a signal output from a predetermined station among the plurality of stations is transmitted via the first and second transmission paths. A transmission device that simultaneously transmits data in opposite directions;
A multiplex transmission network communication system comprising a first-come, first-served priority circuit that selects and outputs the signal that arrives earliest among the two signals transmitted via the first and second transmission paths. (2) At least one of the first and second transmission paths
one transmission path is a multi-loop transmission path, and the transmission device transmits a signal output from a predetermined station among the plurality of stations via the multiple-loop transmission path and the first or second transmission path. At the same time, the signals are transmitted in opposite directions, and the first-come, first-served priority circuit selects the signal that arrives earliest among the plurality of signals transmitted via the multiple loop transmission path and the first or second transmission path. 2. The multiplex transmission network communication system according to claim 1, wherein the multiplex transmission network communication system outputs a signal.