JPH06132966A - Triplex loop data transmission system - Google Patents

Abstract

PURPOSE:To improve the reliability of a transmission line in a loop type data transmission system. CONSTITUTION:A master station data transmitter is connected respectively to plural slave station data transmitters in a loop shape via the transmission lines 1 and 2 through which the signals are transmitted in the mutually different directions. Thus a duplex loop data transmission system of such constitution performs the data transmission among the stations. In one-fold loop data transmission system, a master station data transmitter is connected to plural slave station data transmitters in a loop shape via a transmission line 3 where the signals are sent in one direction. Furthermore the duplex loop data transmission system includes the selection parts 12 and 13, and one-fold loop data transmission system includes the selection parts 14 and 15 respectively.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a triple loop data transmission system.

[0002]

2. Description of the Related Art A conventional loop data transmission system is composed of a loop in which a transmission line is duplicated. When a single failure occurs in the transmission line, the loop is reconfigured by loopback control, and a node is used. In the event of a failure occurring in the system, loop reconstruction is performed by bypassing the failed node to improve the reliability of the line.

[0003]

In this conventional loop data transmission system, when a double fault occurs on the transmission line of the double loop, the loop reconfiguration as described above cannot be performed and data communication becomes impossible. Is likely to be.

[0004]

According to the triple loop data transmission method of the present invention, one master station data transmission apparatus and a plurality of slave stations are provided in each of the first and second transmission lines through which signals are sent in different directions. A dual loop data transmission system that connects data transmission devices in a loop to perform data transmission between stations, and a single master station data transmission device and a plurality of data transmission devices by a third transmission line through which signals are sent in one direction. A single loop data transmission system for connecting a slave station data transmission device in a loop to perform data transmission between stations, and a reception alarm detected by the data transmission device at each station of the duplicated loop data transmission system. First selection means for selecting transmission / reception data from the normal transmission path according to presence / absence, transmission / reception data selected by the first selection means in each station of the single loop data transmission system, and its own system Sending And a second selecting means for selecting the reception data from the normal the transmission path in accordance with the presence or absence of the reception alarm is detected by the own-system data transmission apparatus from among the signal data.

[0005]

The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. The terminal stations A and B send two signals in different directions, and two transmission paths 1 and 2, and send a signal in the same direction as the transmission path 1.
It is connected in a loop by the book transmission line 3. The transmission lines 1 and 2 form an N-system system, and the transmission line 3 forms an E-system loop-type data transmission system, and the terminal device 4 and the terminal device 5 mutually transmit data via the triple loop data transmission network. I do.

In the terminal station A, of the transmission / reception data of the transmission lines 1 and 2 which form the N system, the data transmission devices 6 and 8 are used.
The selection unit 12 selects the transmission / reception data of the normal transmission path according to the presence / absence of the reception alarm detected in step S6. This selection unit 1
Of the transmission / reception data of the N system selected in 2 and the transmission / reception data of the transmission line 3 constituting the E system, normal selection is performed by the selection unit 14 according to the presence or absence of a reception alarm detected by the data transmission device 10. Select the transmission and reception data of the road.

The terminal interface unit 16 includes a selection unit 14
Is connected to the bus to transmit and receive data, and exchange data with the terminal device 4. Similarly, the terminal station B also selects transmission / reception data on a normal transmission line.

[0009]

As described above, according to the present invention, a triplex loop is constituted by a double loop for transmitting signals in different directions and a single loop for transmitting signals in one direction. By providing the redundant loop selection means, even if a double failure occurs in the transmission line, the operation system can be switched and data can be transmitted and received by the system that is operating normally, so the reliability of the transmission line can be improved. Has the effect.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

 1,2,3 Transmission line 4,5 Terminal device 6,7,8,9,10,11 Data transmission device 12,13,14,15 Selection unit 16,17 Terminal interface

Claims (1)

[Claims] 1. The first signals are sent in different directions.
And a dual loop data transmission system in which one master station data transmission device and a plurality of slave station data transmission devices are connected in a loop on the second transmission path to perform data transmission between stations, and the signal is unidirectional A single loop data transmission system in which one master station data transmission device and a plurality of slave station data transmission devices are connected in a loop through a third transmission line sent to the station to perform data transmission between stations; First selecting means for selecting transmission / reception data from the normal transmission line according to the presence / absence of a reception alarm detected by the data transmission device at each station of the duplex loop data transmission system; and the single loop data transmission system. From the transmission line that is normal depending on the presence / absence of a reception alarm detected by the data transmission device of the own system from the transmission / reception data selected by the first selecting means and the transmission / reception data of the own system at each station Triple loop data transmission system, characterized in that it comprises a second selection means for selecting the transmitted and received data.