JP2522492B2 - Loop network integration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for integrating a loop network when a failure occurs.

(Prior Art) Conventionally, there is a loop network in which a plurality of control stations and a plurality of transmission stations are connected in a loop by an internal / external duplex transmission path, and a frame is circulated on the transmission path for communication.
FIG. 7 shows such a loop network, in which the control stations 1 and 3 and the transmission stations 5 and 7 are connected in a loop by transmission lines 9 and 11. Frames are periodically circulated on the transmission paths 9 and 11, and each station acquires the frame and adds data to each other, whereby communication is performed between the stations.
The above-mentioned frame is, for example, as shown in FIG. 8, a frame synchronization area 12a, a control area 12b, a data communication area 12c.
Consists of

In such a loop-type network, as shown in FIG. 9, when trouble occurs at a plurality of locations 13 and 15, loopback is performed as trouble handling. This loopback connects the transmission line 11 outside the obstacle points 13 and 15 and the transmission line 9 inside to cut off the obstacle points 13 and 15. 2 by this
Two closed loops are formed. In order to recover this state, two closed loops are integrated. In order to perform this integration, the communication is artificially stopped before the restoration process, the wiring is connected, and then the procedure similar to the network startup process is performed.

However, when integrating the two separated closed loops, there has been a problem in that work efficiency is poor and communication of the loop network is interrupted for a long time because fault processing is conventionally performed artificially. In addition, if it is carried out from the initial start-up, there is a problem in that all kinds of information held in each station regarding communication carried out immediately before the restart processing are all initialized and it takes a long time to reproduce the information.

(Problems to be Solved by the Invention) As described above, in the conventional loop network, the same process as the initial startup process is required for the integration of the closed loop in the recovery process after the trouble occurs at a plurality of points. In addition, since there are many manual operations, communication interruption time is long and information is often destroyed.

The present invention has been made in view of the above problems, and an object thereof is a loop capable of integrating closed loops separated in a short time without destroying various kinds of retained information during loop separation operation with little artificial operation. To provide a method of network integration.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention has a plurality of transmission stations and a control station having a function of generating a transmission frame signal, which have different signal transmission directions. Controls the function to select only one station to operate as a control station in one closed loop by connecting in a loop with an internal / external duplex transmission line, configured to circulate frames around the transmission line for communication The station itself has, the transmission station has a function to connect the transmission line in a loopback inside, and when a trouble point occurs in the loop, it is separated by the trouble point by the loopback to form a plurality of closed loops including the control station. In the loop network integration method, when normal stations on both sides of the faulty point detect a signal due to restoration of the faulty point, a loopback cancellation request signal is sent to each control station, and this is received. The control station sends a loopback cancellation permission signal to the transmission line, the transmission station receives this signal and cancels the loopback, and the two closed loops separated at the trouble point are reconnected as one closed loop. One control station judges the priority by comparing the setting values in the frames transmitted by the other party, leaves the only control station, and repeats these loops every time multiple trouble points are restored. And

(Operation) When trouble occurs at multiple points in the transmission line, loopback is performed and multiple closed loops are formed. When the one place is restored, the closed-loop comrades are fused, the true control station among the plurality of control stations is determined, and the closed-loop comrades are fused. After that, when the other trouble points are restored, the same operation is repeated.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

FIGS. 1 (a) and 1 (b) show a control station, which includes a reception logic unit (RL) 21 and a frame aligner buffer (B).
F) 23, a frame transmitter (FT), and a carrier detector 29. FIG. 1 (a) shows a state in which the control station is incorporated between two loop back stations, and FIG. 1 (b) shows a state in which the control station prompts the reconfiguration of the loop.
FIGS. 1 (c) and 1 (d) show the configuration of the transmission station. The transmission station has a logic unit 31 and a carrier detection unit 33. FIG. 1 (c) shows the state of the transmission station in a normal state. FIG. 1 (d) shows a case where a loopback station is configured at the time of loopback.

As shown in FIG. 2, control stations 35, 37 and transmission stations 39, 41, 4
In a loop network in which 3 and 45 are connected in a loop by transmission lines 47 and 49, two points A of transmission lines 47 and 49,
If B fails, loopback is performed in this loop network. That is, the transmission stations 39, 41, 43, 45 were in the state as shown in FIG. 1 (c) before the trouble occurred, but the transmission stations 39, 41, 43, 45 are shown in FIG. 1 (d). As shown, two separate closed loops C and D are formed by making the own station a loop back station. When the trouble point B is restored, frames are transmitted to the transmission stations 39 and 41, so that the carrier is detected and the transmission station 39 is controlled by the control station 35.
Then, the transmission station 41 sends a loopback recovery request frame to the control station 37.

Next, when this frame is received by the control stations 35 and 37 as shown in FIG. 3, the state shifts to the state shown in FIG. 1 (b). Then, the control stations 35 and 37 transmit the simultaneous loopback cancellation frame. This broadcast loopback release frame is transmitted to the transmitting station 39,
When 41, 43, 45 are received, the transmission stations 39, 41, 43, 45 shift from the state shown in FIG. 1 (d) to the state shown in FIG. 1 (c). In this state, the two loops fuse.

Next, as shown in FIG. 4, the only control station is determined from the two control stations 35 and 37. In the following, the true control station is called the master station. At that time, after the two closed loops are fused, the control stations 35 and 37 do not perform the process of determining the only master station immediately, but the control stations 35 and 37 first determine the frame on the loop shown in FIG. The master station number display in the control area 12b is checked to recognize the existence of a master station other than the own station, and then the master station determination process is performed. When it is recognized that there is no other master station, the master station determination process is not performed. Therefore, the complicated processing described below becomes unnecessary,
Communication interruption time can be shortened. Also, when the presence of another master station is recognized, a value called the Bid frame indicating the priority of the own station is put in a frame, and the control stations 35 and 37 transmit to each other and receive a Bid frame from the other party. If the priority value is lower than that of the own station, that value of the own station is overwritten and transmitted. Next, the return of the Bid frame is detected and this B
Check the priority described in advance on the id frame. When the priority of the return Bid frame is equal to or lower than the value of the own station, the Bid frame is transmitted again and this operation is continued until the Bid frame of the own station is received twice. In this case, the own station becomes the master station. Conversely, if the priority value of the Bid frame is greater than the value of its own station, the control station relinquishes its parental authority and functions as a transmission station. That is, in the case shown in FIG. 4, the control station 35 becomes the only master station and the control station 37 shifts to the transmission station. After that, the control station 35 detects the carrier disconnection of both loops because the trouble location A exists, and transmits the simultaneous loopback support frame.

Sending a simultaneous loopback instruction frame to each transmitting station 39, 41, 3
When 7, 43 and 45 receive, each transmission station shifts from the state of FIG. 1 (c) to the state of FIG. 1 (d) (FIG. 5).

Further, as shown in FIG. 6, finally, the transmission stations 39, 41, 37
Detects the carriers of both systems, releases the loopback state, and returns to the state of FIG. 1 (c) again. Further, the control station 35 returns to the state of FIG. 1 (a) by detecting the carriers of both systems.

In this state, the two separated closed loops are integrated into one closed loop, and thereafter, a normal single-point disconnection loopback state is established, and thereafter, conventional restoration processing is performed.

As described above, in this embodiment, a trouble occurs at two points in the loop network, loopback is performed on both sides of the trouble point, two closed loops are formed, and one of them is restored, the closed loop is automatically integrated. Therefore, the communication is not stopped for a long time, and the same processing as the start-up processing is not required, so that the retained information is not lost.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to integrate closed loops that have been separated in a short time without destroying various kinds of holding information at the time of loop separation, regardless of human operation except for repair of troubled parts. It can be carried out.

[Brief description of drawings]

1 (a) and 1 (b) are diagrams showing a configuration of a control station, FIGS. 1 (c) and 1 (d) are diagrams showing a configuration of a transmission station, and FIGS. 2 to 6 show the present embodiment. 7 is an explanatory diagram showing the integration method in FIG. 7, FIG. 7 is a configuration diagram of a loop network, FIG. 8 is an explanatory diagram of a frame format, and FIG. 9 is an explanatory diagram when a plurality of trouble points occur in the loop network. 35, 37 ...... Control station 39, 41, 43, 45 ...... Transmission station 47, 49 ...... Transmission path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Yahagi 70 Yanagicho, Sachi-ku, Kawasaki-shi, Kanagawa Stock company Toshiba Yanagimachi plant (72) Inventor Toshiyuki Nakaji 70, Yanagicho, Saiwai-ku, Kawasaki-shi, Kanagawa Stock company Toshiba Yanagimachi Factory (56) Reference JP-A-60-191539 (JP, A) JP-A-63-26050 (JP, A) JP-A-60-86945 (JP, A)

Claims (1)

(57) [Claims] 1. A plurality of transmission stations and a control station having a function of generating a transmission frame signal are connected in a loop by dual internal and external transmission lines having different signal transmission directions, and a frame is circulated in the transmission line. The control station itself has a function of selecting only one station to operate as a control station in one closed loop, and the transmission station has a function of loopback connecting the transmission path therein. In the integrated method of a loop network where multiple closed loops including control stations are separated by a loopback when a trouble point occurs in a loop, normal stations on both sides of the trouble point interfere with each other. When a signal is detected by the restoration of, the loopback cancellation request signal is transmitted to each control station, and the control station receiving this signal transmits the loopback cancellation permission signal to the transmission path, and the transmission station Received and released the loopback, the two closed loops separated at the trouble point were reconnected as one closed loop,
Two control stations judge the priority by comparing the setting values in the frames transmitted by the other party, leave the only control station, and repeat these loops each time multiple trouble points are restored. A method of integrating loop networks that features.