JPS63175551A - Optical network system - Google Patents

Abstract

PURPOSE:To constitute a network by means of the optical fiber cable of a minimum length by connecting plural communication equipments with a relay circuit in a loop by an optical fiber cable and providing a function such as addition of a code and erasure of a data packet signal to the relay circuit. CONSTITUTION:The relay circuit 1 and plural data terminal equipments 5a-5e are connected in a loop via optical fiber cables 2, 2a-2e, and the relay circuit 1 adds a code representing the passing of the relay circuit 1 to the data packet signal 21 in receiving the data packet signal 21 sent from any of the data terminal equipments 5a-5e to the optical fiber cable 2, and has a function erasing the data packet signal 21 in receiving the data packet signal 21 added with the code. Thus, the optical signal is not oscillated in the optical fiber cable 2. Thus, the fault of the communication controller is not given to the entire network and the length of the optical fiber cable 2 is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical network system using a T-coupler for branching optical signals.

[Conventional technology]

Conventionally, as this type of optical network system, one shown in FIG. 3 or 4 has been proposed.

In the system shown in FIG. 3, a plurality of communication control bags N 32 a to 32 C are connected to an optical fiber cable 33 in a loop under the control of a network main controller 31 . In addition, the system shown in FIG. 4 has a star coupler 41
The communication control bags W42a to 42e are connected in the form of branches via optical fiber cables 432 to 43e, respectively.

[Problem that the invention seeks to solve]

In the conventional network system described above, each law such as r! A problem has arisen.

That is, in the configuration shown in FIG.
Since the information is converted into an electrical signal within the network and then sent out over the optical fiber cable, a failure in one communication control device affects the entire network. For this reason, although the spread of the failure is minimized by duplicating the loop and taking measures to bypass the communication control unit, even with this, there is a problem that the network system may temporarily go down.

In addition, in the configuration shown in FIG. 4, optical fiber cables 432 to 43e are connected to each communication control device 42a from the star coupler 41.
Since it is necessary to pull out each of the optical fiber cables 42e to 42e, there is a problem that the total amount of optical fiber cable used increases. especially,
When the communication control devices 42a to 42e are installed as shown in FIG.
d needs to be pulled out independently from the star coupler 41, and the length of the fiber cable becomes longer in the portion where these optical fiber cables are arranged in parallel.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical network system in which a failure in one communication control device does not affect the entire network, and in which the length of the optical fiber cable can be shortened.

[Problem that the invention seeks to solve]

The optical network system of the present invention connects a relay circuit and a plurality of data terminal devices in a loop via an optical fiber cable, and connects the relay circuit to a length of the optical fiber cable from any data terminal device. When a data packet/node signal is received, a code indicating that it has passed through the relay circuit is added to this data packet signal, and when a data packet signal with a code is received, this data packet signal is configured to delete.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of an optical network system according to the present invention, and FIG. 2 is a format diagram of a data packet signal used when transmitting and receiving data.

The optical network system in this embodiment connects a relay circuit 1 and T couplers 3a to 3 through an optical fiber cable 2.
3e in a loop, and connect each T coupler 3a to 3e.
Data terminal devices 5a to 5e are connected to the network via communication control devices 4a to 4e, respectively.

The relay circuit 1 receives the data packet signal 21 sent onto the optical fiber cable 2 from any of the data terminal devices 5a to 5e via the communication control devices 4a to 4e, and then passes through the relay circuit 1. A code indicating the data packet signal 21 is added to the control field 22 of the data packet signal 21 and then sent onto the optical fiber cable 2.

Furthermore, when the data packet signal 21 with the code added is received again by the relay circuit 1, this data packet signal 2
Configure to erase 1.

Next, the operation of the system will be explained.

For example, the data packet signal (electrical signal) 21 output from the data terminal device 5C is transmitted to the communication control device 4C.
is converted into an optical signal by The data packet signal 21 converted into an optical signal is sent from the communication control device 4C to the T-coupler 30 after confirming that no optical signal is flowing on the optical fiber cable 2.

To confirm this, the signal from the optical fiber cable 2 is input to the T-coupler 30 and is branched into two, one signal traveling straight on the T-coupler 3C and the other.
A method of determining whether or not an optical signal is flowing on the optical fiber cable 2 by branching two signals toward the communication control device 4C and determining the presence or absence of this branched signal within the communication control device 4C. will be adopted.

The data packet signal 21 sent to the T coupler 30 is sent onto the optical fiber cable 2 at the T coupler 30 and reaches the relay circuit 1 via the T couplers 3d and 3e. At this time, even if this data packet signal 21 is data addressed to the data terminal device 5e, since the control field 22 of the data packet signal 21 sent from the communication control device is not given a relay circuit passage code, The communication control device 4e does not receive this data packet signal 21 even though it is addressed to its own station.

Next, in the relay circuit 1, a relay circuit passing code is added to the control field 22 of the data packet signal 21 sent out from the communication control device 4C, and the signal is output onto the optical fiber cable 2.

This data packet signal 21 is transmitted to the T couplers 3a to 3e.
The data packet signal 21 returns to the relay circuit 1 again while being branched off, but this time it is given a relay circuit passage code, so the communication control device 4e connected to the T coupler 3e receives this data packet signal 21 and electrically transmits it. It is converted into a signal and sent to the data terminal device 5C, and at this point the data from the data terminal device 5C is transmitted to the data terminal device 5.
This means that it was received at e.

On the other hand, the data bucket signal number 21 that has returned to the relay circuit 1 is erased in the relay circuit 1 because it is given a relay circuit passage code, and as a result, an optical signal oscillates on this optical fiber cable 2. There isn't.

If you install a spare T-coupler in the appropriate position of the optical fiber cable loop in advance, you can easily add a communication control device to the network by simply pulling out the optical fiber cable from this T-coupler during expansion. can.

〔Effect of the invention〕

As explained above, the present invention provides a communication control device.

Multiple communication devices consisting of data terminal equipment and relay circuits are connected in a loop using optical fiber cables, and the relay circuits are equipped with functions such as adding codes and erasing data packet signals, so each communication device There is no need to draw in the optical fiber cables that make up the internal loop, and it is possible to construct a network with the minimum length of optical fiber cables, and the failure of one communication control device does not affect the entire network. It has the effect of not giving anything.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the optical network system of the present invention, Fig. 2 is a formant diagram of its data packet signal, Fig. 3 is a block diagram of a conventional optical network system, and Fig. 4 is a conventional optical network system. FIG. 5 is a block diagram of another optical network system, and FIG. 5 is a plan layout diagram showing an example of the system of FIG. 1... Relay circuit, 2, 2a to 2e, 33.43a to 4
3e...Optical fiber cable, 3a-3e...T coupler, 4a-4e, 32a-32c, 42a-4, 2
C... Communication control device, 5a to 5e... Data terminal device, 21... Data packet signal, 41...
・Star coupler. Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] (1) Consisting of a relay circuit and a plurality of T couplers connected in a loop via an optical fiber cable, and a data terminal device connected to each of these T couplers via a communication control device, the relay circuit is When a data packet signal transmitted from a data terminal device onto an optical fiber cable is received, a code indicating that it has passed through a relay circuit is added to this data packet signal. An optical network system characterized in that the optical network system is configured to erase this data packet signal when the signal is received.