JPS6058744A - System for separating faulted remote device - Google Patents

Abstract

PURPOSE:To prevent the entire system from being into the state of system-down by separating a faulted remote device from a digital line if a fault occurs in the remote device in a loop communication system to limit the range of the affect due to the fault. CONSTITUTION:Information is transmitted from a preceding RE to a succeeding RE in the path of L3i-reception side digital line interface RIF200-dropper/inserter D/I203-transmission side digital line interface SIF206-relay contact rl2-L3j in each remote device RE normally. As being well known, each channel of a digital line has a signal bit, by which each corresponding digital line is controlled and information required for state supervision is transmitted. Since a relay RL1 is operated and a normally ON relay RL2 is restored by the relay contact rl1 at fault, a relay contact rl2 is selected in solid lines in the figure, and a circuit of L3i-relay contact rl2-L3j is formed. That is, REj 2j is separated from the digital line and the signal from the L3i is transmitted to the L3j through the REj 2j.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a faulty remote device isolation method, and more particularly to a faulty remote device isolation method in a loop communication system in which a master station and a plurality of remote devices are connected in a loop through digital lines.

Generally, if subscribers are scattered, for example in a depopulated area,
A loop communication system is used in which these subscribers are divided into several groups, remote devices are provided corresponding to each group, and a master station and each remote device are connected in a loop through digital lines and concentrating and multiplexing the connections.

In this system, each remote device extracts the signal carried on one channel of the digital line assigned by the master station to a certain subscriber accommodated in its own device, and puts the subscriber's signal on that channel. The function is to transmit the data to the master station.

Although this system is economically extremely effective in the depopulated areas mentioned above, all signals pass through all remote devices connected by digital lines, so if a failure occurs in any remote device, it will affect the entire system. Once such a situation occurs, control from the master station becomes impossible, making system reconfiguration difficult.6 The purpose of the present invention is to ensure that the master station receives normal signals from each remote device To provide a failure remote device isolation method which eliminates the above drawback by separating the remote device from a digital line when no reception is received within a certain period of time, and prevents the influence of a remote device failure from affecting the entire system.

According to the present invention, in a loop communication system in which a master station and a plurality of remote devices are connected in a loop through digital lines, each of the remote devices determines whether the digital line is drawn into the own device or passes through the own device. and a failure monitoring means for monitoring a reset signal periodically transmitted from the master station, and the master station monitors the normality of its own device periodically transmitted from each remote device. and a remote monitoring means for monitoring a normal signal indicating a normal signal, and when the remote monitoring means does not receive the normal signal within a certain period of time, the remote monitoring means stops transmitting the reset signal to the remote device, and the fault monitoring means for the remote device stops transmitting the reset signal to the remote device. A failure remote device isolation system is obtained, characterized in that the switching means switches to a state where the digital line company's own device passes when the reset signal stops.

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

FIG. 1 is a block diagram showing an embodiment of a loop communication system using the failure remote device separation method of the present invention, and FIGS. 2 and 3 show an example of the configuration of the remote device and master station in FIG. 1, respectively. It is a circuit block diagram showing.

In Figure 1, the loop communication system is a master station (hereinafter referred to as Pg).
) t and a plurality of remote devices (hereinafter referred to as RE) BE.

20 + RD 121 to REn 2 n are connected in a loop through digital lines (hereinafter referred to as L) 30, 31. 321 to 3n, and RE 620 + "El
21 + to REn2n each have a plurality of subscribers 40
41/.

~4 nm is accommodated. Communication between subscribers, for example between subscriber 40 and 4nm, is between subscriber 40 and -BEo20L31.
aElzi L+32·-RE, 2n-subscriber 4nm and subscriber 4nm-REt12 n -L3n-PH
I-L30-R[o20-to subscriber 40]. When each box E is normal, the RE periodically transmits a normal signal tl-L indicating the normality of its own device to the PEI via the subsequent RE.

PEx monitors the normal signal from the PEx, and if it cannot receive it within a certain period of time, it determines that the BE that is the source of the normal signal is at fault, and stops the reset signal that was periodically sent to that BE. . Since the failure BE detects the stoppage of this reset signal and separates itself from L, subsequent loop communication is performed in a state where this failure Et has passed.

Next, in FIG. 2, RE, 2j is a receiving side digital line interface (hereinafter referred to as hole IF) 200 that performs bipolar/unipolar conversion of the signal from L3i, clock reproduction, and frame synchronization monitoring.

A clock generator (hereinafter referred to as CKG) 201 that generates a stable clock synchronized with the recovered clock using the F200 and generates its own clock in the event of a digital line failure, and a
Control of the subscriber circuits LC1, to LCP based on signals received from E1 (shown in FIG.
A remote device control unit (hereinafter referred to as RCTL) 202 that controls an inserter (hereinafter referred to as D/I) 203, and an RC'I'L
202, the RIF 200/sending side digital line interface (hereinafter referred to as 8IF) 206t extracts/inserts signals from/to the channel on the digital line assigned to the communicating subscriber accommodated in the own device.
- said D/I 203 and CKG 201,
A fault monitoring circuit (hereinafter referred to as 5UP) that is connected to the C'I'L 202 and outputs a timeout signal when a reset cannot be applied for a certain period of time, and urges periodic transmission of a normal signal to the PFit when the own device is normal. 204, and the timeout signal causes relay 'fLL□ (relay contact ri1
), a constantly operating relay RL2 (relay contact fiz), and a relay contact r/1.
The 5I is connected to L3j via 2 and performs unipolar/dipolar conversion of the signal from D/I2O3 or 6-.
F206 and subscribers 4il to 4t, respectively.

and the subscriber circuits LC1 to LCp with a digital/analog conversion function connected to D/I2O3. Note that when the own device is normal, relay contact r12 is in the state shown by the broken line, and L3i and 3j are R and lP2O, respectively.
0,8 IF206, but in the event of a failure, relay RL1 operates and its relay contact cl□ restores the normally operating relay RL2, so the relay contact rl is in the state shown by the solid line, and La1 - relay contact rlz - L3j
A circuit is formed. That is, BE,2j is separated from the digital line, and the signal from L3i passes through BE,2j and is transmitted to L3j.

Next, in FIG. 3, Pg is a digital interface (hereinafter referred to as DIP) that interfaces with a central processing unit (hereinafter referred to as CPU) 100 that controls the entire master station, a switching network (hereinafter referred to as NW) 101, and L3n and 30, respectively.
loz , 103 and La via D IF 103
A control information transmitting circuit (hereinafter referred to as 5ND) 104 that transmits a remote device control signal to L3 via DIF 102
An information receiving circuit (hereinafter referred to as REC) 105 that receives remote device information such as a normal signal from n, and an interrupt generation circuit (hereinafter referred to as IRP) 106 that periodically generates an interrupt signal necessary for monitoring the normality of R and E. CPU100.5ND104,
Connected to RgC105, IR, P106 and CPU100
The master station control unit (hereinafter referred to as PCT) controls information exchange between RE and digital lines, and monitors the normality of RE and digital lines.
L) Consists of 107.

Next, the operation of this embodiment will be explained using FIGS. 2 and 3. Usually in each BE L3i-RIF200-D
/I 203-8IF206-Relay contact ri12-T
, 3j, information is transmitted from the preceding If to the succeeding RE. As is generally known, each channel of a digital line has signal bits and is capable of transmitting information necessary for controlling and monitoring the status of each corresponding digital line. For example, the primary group digital line of the CBPT system consists of 32 time slots for a communication capacity of 30 channels, and 16
Each frame forms one multiframe. Three bits are assigned to each channel as message bits in #1 to #15l multiframe slots of this l multiframe. Plagiarize these (bit steal) and P
Control information is transmitted between EI, R, and Ej2j. For example, out of 90 signal bits (3 bits x 30) in a multiframe, one bit is allocated to each channel (therefore, 30 bits in one multiframe) to shorten the status of the subscriber line using each channel. Send at regular intervals, 6 remaining
Address and transmission control procedure data so that one order can be transmitted for each multiframe with 0 bits.

The control information is transmitted by adding a transmission error check pattern. Control information including PEL is transmitted from j5cPU100 to PCTL107.8ND using the above transmission method.
104, is placed on a signal bit position by DIF 103, and is sent to La0. In REj2j, RIF from L3 i
When the address information received by the D/I2O3K via 200 indicates the own device, it is extracted and exchanged with the data sent to PEL9-, but when it does not indicate the own device, the information is 5IP206.
, relay contact r7!2. It is sent to the rear BB via L3j. In this way, control information is transmitted and received between Pgt and each R and E, but in PH1, PCTL 107
The reset signal is set to 5N every time a periodic interrupt is received from
It is sent to La0 via D104 and DIF103. R
, E, 2j from L3i to RIlli'200, RC
The reset signal received via TL202 is
P204 monitors, and when the 80P204 does not receive a reset signal for a period sufficiently longer than the period of the reset signal (
In other words, when the reset is not applied, a timeout occurs and the relay driver 205 operates the relay L1. As a result, the always-operating relay RL2 is restored and L3i and 3j are connected by the relay contact rJ2, so it is RE.

2j is formed. If this state occurs due to a failure in a certain BE, the subsequent BE cannot receive the reset signal, so it operates to allow its own device to pass, but when the faulty E enters the passing state, it receives the reset signal again. I can do io- in Kotoka. Therefore, only the fault 'fLE' will be isolated. - D/I2O3゜5 from RCTL202 in Yongyo RE
A normal signal indicating the normality of the own device is sent to L to the rear BE via IF206 and relay contact r/, and P
In H1, the normal signal on LBn is connected to DIF102, RE
It is monitored by PCTL 10γ via C105. If a failure occurs in the transmission system of a BE, this failure BE
The normal signals including those from earlier REs are PEl
You will not be able to receive data. In PRl, when a normal signal is not received for a certain period of time at PCTI 107, it is possible to isolate the RE by stopping sending a reset signal to the rearmost RE to which the normal signal does not arrive.

Note that at this time, since the reset signal from PEI does not reach R and E downstream of the faulty RE, a path for passing the digital line is formed by the operation of 5UP 204.
Since the BE at the earlier position is capable of sending a normal signal to the FBI, there is a difference in the timeout of time monitoring in the PEN, and the relevant R and E can be distinguished.

As is clear from the above explanation, according to the faulty remote device isolation method of the present invention, when a fault occurs in a remote device in a loop communication system, the faulty remote device is isolated from the digital line, so that the range affected by the fault is This has the effect of preventing the entire system from going down.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a loop communication system using the failure remote device separation method of the present invention, and FIGS. 2 and 3 show an example of the configuration of the remote device and master station in FIG. 1, respectively. It is a circuit block diagram showing. In the figure, l... Master station (Pg), 20, 21
゜~2n, 2j-...-Remote device (ago, B
El, ~几E,,R,E,),30,3],32.
-3n. 3i, 3j... Digital line, 40,
41/. "-4nm, 4 j 1 + 4 i, ・=-・-
subscriber, ioo... central processing unit (CPU),
lot...exchange network (NW), 102
．． 103...Digital interface (DI
F), 104, old... control information transmission circuit (SND), 1
05... Information receiving circuit (R, FiC), 106
...Interrupt generation circuit (IRP), 107...
... Master station control unit (PCTL), 200 ... Receiving side digital line interface (RIp), 20
1-...Clock oscillator (CKG), 202...
...Remote device control unit (R, CTL), 203...
...dropper/inserter (D/I), 204 ・-
・-Fault monitoring circuit (SUP). 205... Relay driver, 206...
・Sending side digital line interface (SIF),
LC□. ~LCP...Subscriber circuit, RL,...
Relay, RL2... Continuously operating relay. Part l Figure 2

Claims (1)

[Claims] In a loop communication system in which a master station and a plurality of remote devices are connected in a loop through digital lines, each of the remote devices has a switching means for selecting whether to draw the digital line into the own device or to pass the digital line through the own device; failure monitoring means for monitoring a reset signal periodically transmitted from the master station, and the master station monitors a normal signal indicating the normality of its own device periodically transmitted from each remote device. comprising remote monitoring means, when the remote monitoring means does not receive the normal signal within a certain period of time, it stops transmitting the reset signal to the remote device, and the fault monitoring means of the remote device detects the stop of the reset signal; 1. A failed remote device isolation method, characterized in that the switching means switches the digital line to a state where the device passes through the own device.