JPS62221237A - Transmission primary station equipment in multipoint optical transmission system - Google Patents

Abstract

PURPOSE:To minimize the influence of abnormality by double connecting a primary station for optical communication transmission and plural secondary stations into a loop clockwise and counterclockwise and judging a trouble to switch the used communication destination if a reception response is not returned. CONSTITUTION:A primary station 20 and plural secondary stations A-I are double connected into a loop by a clock wise line 18 and a counterclockwise line 19 of optical fibers. If the line 18 between secondary stations C and D is disconnected, the secondary station D judges the trouble because of no reception response and switches the secondary station of the transmission destination from the station C to the station E. The signal from the station D is broken in the station C, and the station C switches the station of the transmission destination from the station D to the station B. If the station D is faulty, stations C and E detect the break of the signal from the station D and switch stations of transmission destinations from the station D to stations B and F respectively. Thus, the influence of abnormality of the system is minimized with simple equipments.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a transmission primary station device in a multipoint optical transmission system.

(Summary of the invention) In this invention, two pairs of transmitting and receiving optical boats are provided, and a double loop for optical transmission is formed between them, sequentially passing through each secondary station. The secondary stations are designated one after another, and a transmission path abnormality is detected based on the presence or absence of a reception response. If a transmission path abnormality is detected, the port pair to be used is set to the port pair opposite to the port pair currently in use. It is designed to switch between port pairs, which prevents transmission line abnormalities (2
This is designed to minimize the impact on the entire system due to power outages at the next station or optical transmission line interruptions midway.

(Prior art and its problems) Conventionally, this type of primary transmission station equipment is provided with only one optical boat pair for transmission and reception, and therefore, the configuration of a multipoint optical transmission system is as follows. We had no choice but to adopt only two configurations.

In the first configuration, the transmission E10 port 3 constituting port pair 2 of the primary station 1 is sequentially routed through each secondary station A, B, C... Shun made a U-turn on the signal at secondary station I by connecting it with optical fiber 4 as shown in Figure 4, and vice versa.

The optical fibers 5 are used to connect the signals via F...A, and the signals are finally returned to the receiving 0/E port 6 of the primary station 1.

Moreover, as shown in FIG. 4, each secondary station has the same configuration, and guides the signal from the receiving 0/E port 10°11 to the receiving system RX via the OR gate 7, and The signal from the TX is transmitted via the OR gates 8 and 9 to the outside via the transmitting E10 ports 12 and 13.

As a second configuration, as shown in FIGS. 6 and 7, the transmitting E10 port 3 constituting port pair 2 of the primary 81 is connected to each secondary station as shown in FIG. A, B,
Optical fiber 14.14 passes through C...I sequentially.
The two terminals are connected to form a single loop that ultimately returns to the receiving 0/E port 6 of the primary station 1.

Moreover, each secondary station has the same configuration, and as shown in FIG. , to the E10 boat 16 for transmission.

However, in the configuration of the multipoint optical transmission system described above, if an optical fiber disconnection occurs between any of the secondary stations or a power outage occurs at any of the secondary stations, the system will no longer function. There was a problem in that subsequent transmission to the secondary station became impossible, which seriously affected the entire system.

(Objective of the Invention) The object of the invention is to minimize the impact on the entire system due to power outage at any secondary station, disconnection of optical fibers, etc. in this type of multipoint optical transmission system. The object of the present invention is to provide a transmission primary station device that can perform the following functions.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention provides two pairs of transmitting and receiving optical ports between which a double loop for optical transmission passing through each secondary station is formed. and an abnormality detection means that sequentially specifies each secondary station from the optical port pair in use and detects a transmission path abnormality based on the presence or absence of a reception response; The present invention is characterized by comprising a used port pair switching means for switching between port pairs.

According to such a configuration, even if a power outage occurs at any secondary station or an optical fiber breaks midway, transmission is immediately performed from the opposite direction, thereby preventing the entire system from being affected. The impact can be kept to a minimum.

(Description of Embodiments) FIG. 1 is a circuit diagram showing a main part of a multi-point optical transmission system using a primary transmission station device according to the present invention.

In this system, the configuration of the secondary station is as follows:
Since it is completely the same as the conventional example shown in FIG. 4, the same reference numerals will be given and the explanation will be omitted.

Two optical port pairs, namely a first port pair 21 and a second port pair 22, are provided on the primary circumference 20, which is the essential part of the present invention.

The first port pair 21 consists of a reception 0/E port 21a and a transmission E10 port 21b, and the second port pair 22 consists of a reception 0/E port 22a and a transmission E10 port 22b. There is.

Further, gates 23a, 2 connected to the first port pair 21
3b, and a gate 24a leading to the second pair of ports 22,
24b is configured to open and close alternately depending on the content of the gate control signal by the action of the inverter 25, and the receiving 0/E port 21a and the receiving 0/E port 22a are configured to selectively open and close the receiving port 24b. Along with being introduced to the system RX,
The transmission system TX signal is selectively output to the transmission E10 port 21b and the transmission E10 port 22b.

In addition, as shown in FIG. 2, the primary station 20 and each secondary station A, B...I are connected via two optical fibers 18 and 19, and the transmission A double loop is formed.

On the other hand, the control device built into the primary station 20 executes the process shown in FIG.

It is designed to deal with problems such as disconnection of optical fibers 18 and 19).

Therefore, the operation of the apparatus of this embodiment will be systematically explained below with reference to flowcharts 1 to 1 in FIG.

Assume now that the first boat pair 21 is selected for transmission and reception, and that data transmission is performed in a clockwise route as shown in FIG.

The transmission procedure in this type of multipoint optical transmission system is well known, so it will not be explained in detail.In short, the primary station sequentially addresses and polls each secondary station, and each secondary station performs polling. In response to this, the station sends its own data to another station, and the other station receives the sent data.

On the premise of the above transmission process, the primary station 20 side updates the station address by +1 (step 308), determines whether the corresponding station response is abnormal based on the contents of the flag described later (step 300), and if normal (Step 300: No), the state of the gate control signal is set to "H" and is switched to the first port pair 21 side in order to maintain clockwise data transmission (Step 301).

Next, send the new station address to the E10 port 21b for transmission.
and waits for a reception response thereto (step 304).

Here, if a reception response is received from the corresponding station (step 305, negative), the no-response abnormality flag of the corresponding station is cleared (step 307), and the above operations are repeated.

On the other hand, if a power outage occurs at any of the secondary stations or a break in the optical fiber occurs between any of the secondary stations, the reception response is interrupted (step 305 affirmative), and in this case A flag is set to indicate that the corresponding station has no response abnormality (step 306).

Therefore, in the next execution cycle, when the corresponding station no-response abnormality determination is made, the determination result is abnormal (step 300 affirmative), and the state of the gate control signal is switched to L'', so that the gate 23a, Instead of 23b 1. :
24a and 24b are opened and the second boat pair 22 is selected, thereby setting the transmission direction to counterclockwise (step 302).

Therefore, if we assume that a power outage occurs at secondary station B, transmission to secondary stations C, D...I would become impossible in clockwise rotation, but the result would be that the transmission would immediately switch to counterclockwise transmission. , I, H, G, . . . , C can be transmitted normally in this order.

Furthermore, if the flowchart in FIG. 3 is continuously executed after the above-mentioned counterclockwise switching, no reception response is detected when transmitting to the secondary station A or B, and the The transmission direction is switched from counterclockwise to clockwise, and as a result of repeating the above process, it is possible to continue data transmission to all other stations except for secondary station B, which has lost power. .

In addition to minimizing the impact on the entire system in the event of a power outage or fiber disconnection as described above, the configuration of the secondary stations A, B, C...I is as shown in Figure 4. As shown, it is completely the same as the conventional example, and therefore the reliability of the system can be improved without causing any particular cost increase.

Although the above embodiments have been described using one optical fiber for each round trip, it is of course applicable to the case where data transmission is performed in parallel using a plurality of optical fibers.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the main parts of the multi-point optical transmission system according to the present invention, Fig. 2 is an explanatory diagram showing the wiring system of the entire system, and Fig. 3 is the processing content executed at the primary station. 4 is a block diagram showing the configuration of the primary station and secondary station in the conventional system. FIG. 5 is an explanatory diagram showing the wiring system in the conventional system. FIG. 7 is a block diagram showing the configuration of the primary station and the secondary station, and an explanatory diagram showing the wiring system in another system. 20・・・・・・・・・・・・・・・・・・・Primary station 21・・・・・・・・・・・・・・・・・・・First station Boat vs. 21a・・・・・・・・・・・・・・・
・・Receiving 0/E boat 21b・・・・・・・・・・・
......E10 port 22 for transmission...
.....Second port pair 22a.
・・・・・・・・・・・・・・・・・・Reception 0/E port 22b・・・・・・・・・・・・・・・・・・Transmission E10 port 23a, 23b, 24a, 24b--Gate 25...
Inverter RX・・・・・・・・・・・・・・・・・・
・・・Receiving system TX・・・・・・・・・・・・・・・・・・
...Transmission system 18.19...Optical fibers A, B, C...■...Secondary station Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 Procedural amendments May 26, 1986 Director General of the Patent Office Mr. Uga Torubu Eguchi 1, Indication of the case Patent application No. 1983-65367 2, Title of the invention Transmission in a multi-point optical transmission system Primary station equipment 3, name of person making the correction (294) Tateishi Electric Co., Ltd. Representative Takao Tateishi 4, agent 101

Claims (1)

[Claims] (1) Two transmitting/receiving optical port pairs between which a double loop for optical transmission is formed that passes through each secondary station sequentially, and the optical port pairs in use are sequentially designated to each secondary station. an abnormality detection means for detecting a transmission path abnormality based on the presence or absence of a reception response; and a port pair switching means for switching a port pair to be used when a transmission path abnormality is detected. A transmission primary station device in a multipoint optical transmission system characterized by: