JPS5923650A - Backup system - Google Patents

Abstract

PURPOSE:To perform effective backup operation by performing automatic switching to a receivable route for communication if one route is cut off or in case of such abnormality that either slave station loses its repeating function. CONSTITUTION:When slave stations 2 and 3 are unable to receive call signals even after the elapsed time of polling through an A route 6, a time monitoring circuit 28 sends a signal to inverts the contents of a route selection memory 29, and a selector 25 receives the call signal from a B route 7. A master station 1, on the other hand, is able to receive answer signals from the slave stations 2 and 3 from the A route 6 and an answer station from a slave station 5 from the B route 7, so the time monitoring circuit does not receive the signal even the specific elapsed time later so far as the other route is selected. In this case, the contents of the selection memory are rewritten into the A route 6 for the slave stations 2 and 3 and the B route 7 for the slave station 5 to perform automatic recovery, so that there is no hindrance to communication.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention provides an optical loop network in which a master station and a slave station with t rotations are duplicated, connected in a loop through a transmission path, and using a polling method. The present invention relates to a bank-up system that automatically recovers from an abnormality with a small-scale circuit configuration.

(b) Technical Background In Figure 1, the number of slave stations is four. 1 is a conceptual diagram of an optical loop network to which the present invention is applied; FIG.

In the figure, 1 is the master station, 2 to 5 are slave stations, and 6 is the A route.

Seven B routes are shown, and each route includes an optical transmission line, a master station, and a slave station.

In an optical loop network system that is connected in a loop with a duplicated optical transmission line, as shown in Figure 1, a master station 1 and slave stations 2 to 5 are connected by a duplicated optical transmission line. Normally, one route, for example A route 6, is used, and route 13 is reserved as a backup.

Furthermore, if each slave station does not select data, it enters a relay state and transmits the data in a loop. Also, between the optical transmission line and the master station 1 and slave stations 2 to 50, there is an optical/electrical converter and
, are connected via an air/light converter. In the polling method, when master station 1 sends data, it adds the slave station number of the destination to the data format and sends it, and each slave station 2 to 5 identifies this slave station number and sends the data addressed to it. Import only data.

In addition, the master station 1 sequentially calls the slave stations 2 to 5 at predetermined time intervals, and the slave stations that want to send data transmit data only when they receive this call, and the slave stations that do not have data to send in send a message to that effect. Returns a notification response. Furthermore, each slave station is in a relay mode in which it sends human data as is to the next station, except when it is transmitting data. Now, if we consider the case where slave station 4 is powered off and relay mode is no longer possible, this loop network system will be unable to transfer data between master station 1 and slave stations 2 to 5 in all °C. υSystem goes down. Also, when the point f is disconnected, the loop is disconnected and the system goes into a run. The present invention provides an automatic trowel 1 with a small-scale circuit configuration so that the system does not go down during the first stage of such abatement.

(c) Prior Art and Problems In the conventional backup method, the master station IKij shown in FIG. If it cannot be received, a special alert signal is sent to the line monitoring device using the route used by the first official or another route. If slave station 4 on both sides is unable to use relay mode due to power outage, etc., slave stations 3 and 5 on both sides
A loopback command signal is sent to the slave station 5 to create a loop by operating the loopback switch function possessed by each slave station as indicated by the dotted line C1, and the signal is transmitted to the slave station 5 using the A route 6 and received. (Broux) 7 is used, and the slave station 2,
3, use B route 7 to send, and receive via A route 6.
I use this to make backups to avoid system downtime.

However, this method requires a line monitoring device at the parent station 1, and a monitoring signal and loopback command signal receiving device and a loopback switch function at the parent and child stations 2 to 5, requiring a large-scale circuit as a system. There are drawbacks.

(d) Object of the Invention The object of the present invention is to provide a backup system that eliminates the above-mentioned drawbacks and allows automatic recovery in the event of an abnormality with a small-scale circuit configuration.

(e) Structure of the Invention In order to achieve the above-mentioned object, the master station simultaneously sends out a calling signal to the right from one route and to the left from the other route. Response from station 48
The call signal is simultaneously sent to each route from which the call signal is received, and the master station and slave stations can select which route to receive the call signal from at their own discretion, thereby enabling automatic recovery in the event of an abnormality. It is characterized by

(f) Embodiment of the Invention An embodiment of the invention will be described below with reference to the drawings. Second
The figure is a block diagram of the main part of the main station according to the embodiment of the present invention.
The figure is a block diagram of the child Jr.'s flight 141 according to the embodiment of the present invention.

In the diagram, 8.9.19.20 are drivers, 10, 11, 21
．． 22 is a receiver, 12, 23, 24.25 are selectors, 13.26 is a data reproducing circuit v14, and 26 is a data check circuit.

Reference numerals 16 and 29 indicate route selection memories, which are configured by flip-flop circuits. 17.18.30 shows an AND circuit.

To explain the master station subcommittee in FIG. 2 with reference to FIG. 1, if there is a transmission request, the transmission data is sent to the A route 6 shown in FIG. Simultaneously send out t to B route 7 counterclockwise. Reception of received data is valid only when there is no transmission request, and the reception route is stored for each slave station 2 to 5. According to the contents of the selection memory 16, the reception route is stored for each slave station 2 to 5. , the selector 12 selects the data received from the A route 6 and the B route 7 via the receiver 10.11. The selected data is subjected to bit synchronization frame synchronization in the data reproducing circuit 13 via the AND circuit 18 and becomes received data. This received data is checked by the data check circuit 14 to see if correct data has been returned from the called slave station, and only when correct data has been returned, a signal is sent to the time monitoring circuit 15.

On the other hand, when the call is activated, the time monitoring circuit 15 is activated by the transmission request signal, and it is monitored whether the above-mentioned correct data can be received within a predetermined time. If correct data cannot be received even after a predetermined period of time has elapsed, the route selection information of the corresponding slave station in the route selection memory 16 is inverted and the subsequent reception route is changed. Further, in FIG. 3, the case of a slave station will be explained with reference to FIG. 1. Child station also parent/
The operation is almost the same as that of 1iij, but when the transmitter is not turned on, the data received via the A route 6 and the receiver 21 is selected by the selector 23 and sent to the driver 1.
9 to A route 6, B route 1-71 receiver 2
The data received via 2 is selected by the selector 24, and the relay mode is set in which the data is sent to the route 7 via the driver 20. Also, a time monitoring circuit 28 monitors whether or not a correct calling signal is received at the periodic time when the own station is called. If the own station is not called even after the calling time has elapsed, the route selection memory 29 is reversed and the subsequent reception route is changed. If there is a transmission request, the transmission data is selected by the selectors 23 and 24, and sent via the drivers 19 and 20 to the A route 6 at the same time using the same route as the call signal.
and send it to B route 7. Reception of received data is valid only when there is no transmitted data. Data received from l route 6 and I3 route 7 via receivers 21 and 22 is sent by selector 25 to route selection memory 29 that stores the received route. is selected according to the contents of , and the bit synchronization frame period is taken by the data reproducing circuit 26 via the AND circuit 30 to become received data. This received data is checked by a data check circuit 27 to see if the data from the called parent station is correct or not, and only when it is correct is a signal sent to the time monitoring circuit 28.

Next, with reference to FIG. 1, an automatic recovery operation will be explained in the case where the slave station 4 loses its relay function due to power cut-off or the like. Master station 1 is A route 6
For example, a call signal is simultaneously sent to the clockwise direction and to the B route 7 to the counterclockwise direction. Since the slave station 2.3 can only receive a calling signal from the B route 7, the route selection memory 29 is configured to receive the call signal from the A route 6, and the selector 25
If the selection is made in , the calling signal cannot be received even after the polling cycle time has elapsed, so the time monitoring circuit 28 sends a signal, inverts the sirut selection memory 29, and selects the selector 2.
5 so that the calling signal from the B route 7 is received. Conversely, since the slave station 5 can only receive the calling signal from the A route 6, if the route is selected to receive from the B route 7, the slave station 5 can receive the calling signal from the A route. 6. On the other hand, the master station 1 can receive the response signals from the slave stations 2 and 3 from the A route 6, and the response signal from the slave station 5 from the B route 7. Please choose the other route.
``H15 does not receive the signal even after the predetermined response time has elapsed, so the ``t4f slave station 2.3'' location in the route one selection memory 16 is placed in the A/L/-toro slave station 5, and 1, +1 ru)
7, after the VI is changed, the selector 12 selects the received data from this route. As a result, the system will automatically recover and there will be no problem in communication. For child station 4, the receiving route is switched from A route 6 to B route 7 every time it is called.Since no correct response signal is returned even after calling a certain number of times, child station 4 determines that there is a failure. . Also, even if both routes or one of the optical transmission lines is cut off, it can be automatically restored using the same procedure as above. In other words, the master station 1 does not require the line monitoring device W, and the parent and child stations 2 to 5 do not need the monitoring, loopback command signal receiving device UR, and loopback switch function, so the system is small-scale. Automatic recovery is possible with the circuit. Also, a data check circuit 14.27, a time monitoring circuit 15.28, and a route selection memory 16.
The functions of No. 29 can also be implemented in software, and in this way the circuit scale can be further reduced.

(g) Effects of the Invention As can be explained in detail above, according to the present invention, as a system, Kozuki 1. This has the effect of enabling automatic recovery in the event of an abnormality with a similar circuit configuration.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of an optical loop network to which the present invention is applied, Fig. 2 is a block diagram of the main parts of a master station in an embodiment of the present invention, and Fig. 3 is a main part of a slave station in an example of the present invention. FIG. In the figure, 1 is the master station, 2 to 5 are slave stations, and 6 is the A route. 7 is] 3 routes, 8, 9, 19.20 is the driver,
10,11°21.22 is the receiver, 12.23~25
is a selector. 13.26 is a data reproducing circuit, 14.26 is a data check circuit + 15.28 is a time monitoring circuit, 16.
29 indicates route selection memo 1c. 17.18.30 indicates an AND circuit.

Claims (1)

[Claims] In an optical loop network system using a polling method in which a master station and multiple slave stations are connected in a loop through a duplicated optical transmission path, the master station transmits a paging signal from one route clockwise to the other. A means for simultaneously transmitting counterclockwise signals from the route, a time monitoring means for monitoring the return time of a response signal to this calling signal, and a route for receiving the response signal are stored for each of the plurality of slave stations. and means for switching the receiving route by inverting the contents of the route selection memory corresponding to the slave station that is to emit the response signal if the response signal is not returned within a predetermined time; The father and son stations each have a means for simultaneously transmitting a response signal on the route from which they each received the paging signal when they receive a call, and a relay means for transmitting the paging signal to the same route when the own station does not receive the paging signal. It also has a time monitoring means for monitoring the polling cycle time, and if the station is not called within a predetermined time, the contents of the route selection memory storing the route for receiving the calling signal are sent to the station. It has a means for switching the receiving route by reversing the route, and when the route is disconnected, one of the slave stations loses the relay function, but when the abnormality occurs, the communication is automatically switched to the route that can receive the communication. A backup method characterized by making it possible to perform