JPS61120545A - Loop transmission equipment - Google Patents

Abstract

PURPOSE:To improve remarkably the reliability of the entire system by providing the 2nd transmission line transmitting a data in opposite direction in addition to the 1st transmission line transmitting data normally and forming a new loop with the 1st and 2nd transmission lines when a station existing just at the downstream position of an open line fault detects the open line fault so as to continue communication. CONSTITUTION:A CPU 4 controls a transmission/reception switch circuit 2 and an error signal generating circuit 13, an error signal is being outputted during the open line fault from the error signal generating circuit 13 and the signal is transmitted to an upperstream station Ti-1 through a transmission circuit 8 and a transmission line Li-1. Through the constitution above, if an open line fault takes place between stations ST 2 and ST 3, a signal from a transmission line R1 is reflected on the station ST 2 and transmitted in the part of ST2 L1 ST1 Ln - L3 ST3, while the data signal from a transmission line L3 is reflected on the station ST 3 and transmitted in the path of ST3 R3 ST4 - R1 ST2, finally a new loop subject to loopback by the stations STs 2, 3 is constituted to continue the communication.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a loop transmission device that achieves fM control of the entire system [Prior Art] An automatic control system that is divided over a wide area, etc.? In order to control it, it is necessary to control each structure fR element through a friendly process.

#146 figure is 5 like this! FIG. 2 is a conceptual diagram showing the configuration of a loop transmission device suitable for compensation. In this figure.

The stations STN i (i=1, 2·”n) are connected by a unidirectional @transmission route i, and the data tM is transmitted to the stations 8TN 1-esTN2-+...S'I"Nn-+5
It is connected to TN1, and communication between each station is performed.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned loop transmission device S,
Since there was only one transmission line i connecting each station 8TNi, if this transmission line ratio i was disconnected for some reason, or if the transmitting/receiving circuit in one station 5TNi broke down, the entire system would be damaged. The problem was that it was possible.

In addition, in order to solve the above problem, the transmission line is completely dual-enriched, and if one of the transmission lines is disconnected.

A method of switching I and rl to the other transmission line is also considered, but in this method, the gJ of the line at all stations STN 1 to 5TNn
Another drawback is that the control becomes complicated.

[Means for resolving gaps]

In order to solve the above problems, the present invention provides, in addition to the first transmission line through which data is normally transmitted, an iA2 transmission line through which data is transmitted in the opposite direction to this first transmission line, so that disconnection can occur. When a station downstream of a point detects a disconnection a, it notifies the station upstream of the disconnection (this communication is via the second transmission path), and the upstream station described in III Is the data signal sent from The station detects the disconnection and returns the signal sent from the second transmission path to the first transmission path and transmits it again. do.

[Effect]

According to the above-mentioned means IC, as shown in FIG. 3, a loop is formed by the first transmission line excluding the broken line and the second transmission line, and the communication continues. . This dramatically increases the reliability of the entire system. 1 ≧ Even when switching between lines, only two stations adjacent to the disconnection point can be used, i! IJ- becomes extremely easy.

[Husband example]

An actual IM example of the invention will be described below with reference to one drawing.

In Figures i1 and 2, transmission ll! connects each station dTi!
r1-Rn forms the transmission line L1 of S□1, and the transmission line L1
-Ln is the second transmission wrLt shaped bottom.

The first transmission path ratio is 1 station ST for data signals: 1
-* Fd 'r2-+...°d Tn -+ d'
The transmission path between l' l and transmission aL, gz is station ST n-+8
T n -1-+・-8'I'34ST2→S'I
It is designed to transmit in the opposite direction: 'l→f9Tn.

Here, the internal purchasing of the station 8Ti will be explained with reference to FIG. A receiving circuit engineer is connected to the transmission path K i-1, and the receiving circuit 1 switches the transmitting/receiving switching circuit 2 to receive fl! to the communication control circuit 3! The communication control circuit 3 that supplies the 1fPr signal converts the received stone signal into serial and parallel signals and supplies it to the CPU 4, and also converts the received signal into a transmission/reception @ switching circuit Ml' and supplies it to the transmission @ circuit 6.
The s-containing circuit 6 sends the signal to the transmission path ratio i.

On the other hand, the signals on the transmission line LInb, etc. flow in the opposite direction to that described above, are received by the receiving circuit 7, and then transmitted/received II! rgJ
Replacement circuit 5.2ffi control circuit 3. The transmission/reception switching circuit 2 is sequentially switched off, and the signal is sent from the retransmission circuit 8 to the transmission line Li-1.

The above is the flow of data signals during normal operation, and if the transmission path ratio is either -10,000 or 2, tracking is performed by LK.

Next, a line error detection circuit 11 is connected to the receiving circuit 1, and the receiving groove transmits signals according to the signal level (16) t, i-.
1 lfrMA check is performed to detect a disconnection, and when the lfr line is used, it outputs a line error detection signal and a line error release signal.

And these ff! The number is I10 boat 127a' Benshite Gl' U 4? Ij1+lL6t, CP
U 44-j,, affi [switching circuit 12N and error signal generation circuit 130 are suppressed, error signal generation circuit 1
3 outputs an error signal indicating that the wire is disconnected, and this sends 1i! IOjM8, legend? s%Li-1 and is sent to the upstream station 8''J:'i-1.The details of these controls will be described later.On the other hand, the transmission lines kLi,L
In the same way as above, for the i-measurement receiving circuit 7 and transmitting circuit 6,
A line error detection circuit 15 and an error signal generation circuit 17 are connected to each other, and these are connected to C1 via I10 port 16.
-'Connected to U4.

9) With the L configuration and H-・Mitsutomi is the traditional fs route (f2
A data signal is transmitted by L), and alternating and directing between each station STi is performed. One example is the sea urchin shown in Figure 3.
When a disconnection occurs in the dark between stations 8T2 and ST3, the transmission step 11) Rari 1gi is turned back at station 8T2, and 8T
2→f, l→dT1→Ln→・・・・・・→L3→8T
3, while the data signal from the transmission line L3 is turned back at the station 8T3 and is transmitted from ST3→几3→ST4→...
...→Bon 1→ST2, and in the end, 1st station 8 'r 2
In ST3, a new loop is constructed and the relationship continues.

Hereinafter, the operations when a disconnection occurs and when it is repaired will be explained with reference to the flowcharts of FIGS. 4 and 5.

(This is the case when the phase system transmission line (here referred to as transmission line) is disconnected (Fig. 4).

As shown in FIG. 3, suppose that a disconnection occurs in the transmission line 2 between stations 8T2 and 8T3.

The station 5T30 line error detection circuit 11 detects this and supplies a 1 line error detection signal to the CPU 4 (step MP1 in FIG. 4). As a result, the CPU 4 sends a loopback L command to the transmission/reception switching circuit 5 on the downstream side, and the receiving circuit 7
Sends the received @ 虡 number output from the f11 circuit 6 and returns it (
Along with loopback L; step 5P2), an error signal generation indication is sent to the error signal generation circuit 13 on the upstream side.
? The error signal is sent to the upstream station S'L'2 by the S concealment circuit 8 and the transmission line L2 (step 5P3).

The above error signal is received by the downstream receiving circuit 7 of the station 8'r2, and is sent to the transmitting/receiving switching interval g5 and the communication control circuit 3.
Station 5T20UPLJ4” is supplied (step SP
4). In response to this, eL'U4 of station ST2 is the transmitter/receiver I on the upstream side? ! A loop buckle finger is supplied to the switching circuit 2, and the received signal output from the receiving @1ollNr11'1% is looped back to the transmitting circuit 8 and transmitted to the transmission path L1 (step SP5).

In this way, the loopback Ls mechanism shown in FIG. 3 is executed, a loop is formed, and communication continues.

(2) If the regular transmission line is repaired during loopback (see Figure 5).

When the disconnection between stations 1M'L'' 2 and 8'r3 shown in FIG. Resolve the change and output a line error release signal. CP of station S'f'3
After confirming that its own station is in loopback and loopback L (step 5P11.12J, U4 valves I10 port 12 and reads the line error release signal (
Step 5P13], upstream error signal generation time M13
While stopping the error signal by issuing a stop/stop fN signal,
f on the downstream side issues a loopback L release command to the receiving UjJ switching circuit 5 to switch the line: and connects the transmission line 2 and line 3 (step 5P14J).

As a result, the sending of the error number 1M to the upstream station 8T2 is stopped, but the CPU 4 of the first station, dT2, confirms that its own station is in loop puncture and loop buckle (step i: !pH, SL'12), to detect this step 5P15), own station +7) upstream transmission/reception compensation switching circuit'116
Issue a loop buckle release command to 2 and connect transmission lines kLl and R.
2 and retransmit the data [100] of stations ST1n) and others to station ST3.

Thus, looseback R of station ST2 and station S'lf'3σ
] The loop bank L is divided by S, and the data signal is transmitted through the regular transmission line.

In the non-embodiments, the transmission line has been described as being a skin type, but it goes without saying that the transmission line may be a regular type.

Further, as the transmission line, either a metal cable ty= such as a coaxial cable or an optical fiber can be used.

〔Effect of the invention〕

As explained above, the present invention provides two transmission lines for transmitting data signals in opposite directions, and transmits the data signals back and back to two stations adjacent to the location where a line error has occurred. Forms a '#z transmission loop and sends one ff! Since the process is continued for a long time, the following effects can be achieved.

(11) The reliability of the entire system is dramatically improved.

(2) Since line switching only needs to be performed by the two stations mentioned above, control is simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of station STi according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing the overall configuration of the same example, and FIG. 3 is a block diagram for explaining the loopback. Conceptual diagrams, Figures 5g4 and 5 are flowcharts for explaining the operation of the above embodiment, and Figure 6 is a conceptual diagram showing the groove bottom of Takumi's loop transmission device. 2.5... Transmission/reception switching circuit (switching means). 11.15... Line error detection circuit (failure detection means included) 13.17... Error signal generation 1 error. Generally, L... Transmission line ( 1i6 and second transmission line). 8Ti, 8TNi... stations.

Claims (1)

[Claims] In a loop transmission device that circulates a data signal through a plurality of stations connected in a loop and performs mutual communication between the stations, first and second stations connect the stations and transmit the data signal in opposite directions. A transmission line is provided, and the data signal is normally circulated through the first transmission line, and each station has a failure detection means for detecting a failure in the first transmission line, and a failure detection means for detecting the failure. an error signal generating means for generating an error signal to be transmitted to an immediately upstream station when the error occurs, and a switching means for switching the connection relationship between the first and second transmission paths, and the station receiving the error signal is provided with: The data signal received from the first transmission path is transmitted to the second transmission path.
The loop transmission device is characterized in that the station detecting the failure returns and transmits the data signal received from the second transmission path to the first transmission path. .