JPH01114137A - Fault monitoring system - Google Patents

Abstract

PURPOSE:To recognize the production of a fault of a communication path by transmitting a specific pattern signal at a prescribed period from a relay node to a bus type transmission line and displaying it externally as the occurrence of a fault when the specific pattern is not received and detected at a prescribed period. CONSTITUTION:When a specific pattern is detected by a specific pattern detection circuit 2 from a signal 1 received by each terminal accommodation equipment ST, a detection signal is sent to a timer circuit 3 and comparator 4. In being started by a detection signal, the circuit 3 sends a signal to the circuit 4 after a setting time (corresponding to a transmission period of a specific pattern signal), and the circuit 4 compares the timing of the signals from the circuits 2 and 3, and the result of comparison is sent to a fault alarming circuit 5. The circuit 5 monitors whether or not a specific pattern signal is received accurately at a prescribed time interval from the result of comparison and if the signal is not received, it is discriminated as the occurrence of the fault in the transmission path and a signal is sent to a fault alarm transmission circuit 6 to inform the fault.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fault monitoring method in a data transmission system, and particularly to a fault monitoring method in which faults on a transmission path are actively detected and displayed. It is.

[Conventional technology]

In data transmission systems, data is generally transmitted using wired transmission lines, but in some cases, spatial transmission using radio waves or light is also being considered. Regardless of the method used, it is necessary to effectively detect and promptly eliminate various types of failures that occur on the transmission path.

By the way, when performing optical communication through atmospheric space, it is necessary to establish a transmission path in the atmospheric space in advance prior to optical communication. A method for confirming the establishment of a transmission path is shown.

[Problem that the invention seeks to solve]

Various methods have been considered to detect failures on wired transmission lines, but in the case of communication using radio waves or light that uses atmospheric space as a transmission line, there are cases where the transmission line is not established once it has been established, It is easy to imagine that communication may be interrupted due to the temporary presence of an obstacle in the transmission path.

If such a situation occurs, it is necessary to detect and display it externally, but so far, only the confirmation that the transmission path has been established has been considered, and the Communication interruptions were not actively disclosed to the outside world.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fault monitoring system that can display communication interruptions due to failures in transmission lines, particularly spatial transmission lines, or temporary interference of obstacles on the route.

Means for Solving Problem C] The above purpose is to perform time division multiplexing from a preceding relay node or a control node serving as a central synchronizer at each of one or more relay nodes predeterminedly placed in the middle of a transmission path. After inserting and removing time slots for the frame signal, the frame signal is transmitted to a subsequent relay node or control node, and is connected to a bus-type transmission line connected to the relay node. In a data transmission system configured to exchange data related to insertion and removal between devices in a time-division multiplex frame format, a relay node transmits a specific pattern signal on a bus-type transmission path at regular intervals, while a terminal accommodation device In each case, this is achieved by externally indicating the occurrence of a failure by not receiving or detecting a specific pattern signal at a fixed period.

[For production]

At each relay node, the previous relay node, or
When a time-division multiplex frame signal is received from a control node, the data is output onto a bus-type transmission path, and a specific pattern signal is also output onto the bus-type transmission path at regular intervals.

Therefore, each terminal accommodating device receives a specific pattern signal at regular intervals. If,
If a specific pattern signal is not received and detected at regular intervals, it is displayed externally as a failure. This will allow the necessary measures to be taken promptly.

〔Example〕

The present invention will be explained below with reference to FIGS. 1 and 2.

First, the data transmission system according to the present invention will be described. FIG. 2 shows an example of the system configuration. In this case, a loop network is configured such that a control node CSA and a plurality of relay nodes SAT are connected by a loop-shaped transmission path l, but among these, the control node C3A converts a predetermined transmission frame format into a loop It operates as a central synchronizer that causes the transmission path E to circulate in a fixed direction. Further, each relay node SAT is connected to the loop-shaped transmission path β.

It operates as a relay device that receives data, exchanges the data in time slot units, and then outputs the data on the loop-shaped transmission line l toward the downstream relay node SAT or control node C3A. There is. on the other hand,
The bus network is configured such that a relay node SAT in a loop network and a plurality of terminal accommodation devices ST are connected in a bus-like manner through a bus-type transmission line.

Now, the time-division multiplexed frame signal from the control node C5A is received by each relay node SAT via the loop-shaped transmission path l, and from each relay node SAT is sent to each terminal accommodation device ST via a bus-type transmission maze. A specific pattern signal is transmitted periodically, and each R8T that does not accommodate an end uses the signal to send data of an arbitrary time slot to a terminal device (not shown) as received data. Data from each terminal device is also transmitted from the relay node to the subsequent relay node via the reverse route.

FIG. 1 shows the main structure of an example of the terminal accommodating device according to the present invention, and the processing of a specific pattern signal will be explained as follows.

That is, when a specific pattern signal is detected by the specific pattern detection circuit 2 from the signal 1 received in each terminal accommodation device ST, the detection signal is sent to the timer circuit 3 and the comparison circuit 4. ing. Timer circuit 3
When activated by a detection signal, it sends a signal to the comparison circuit 4 after a set time (corresponding to the sending cycle of the specific pattern signal), but the comparison circuit 4 receives the signal from the detection circuit 2 and the signal from the timer circuit 3. The timing of the comparison is compared and the comparison result is sent to the fault alarm circuit 5. The fault alarm circuit 5 monitors whether or not the specific pattern signal is accurately received at regular time intervals based on the comparison results, and if it is not received, it is determined that a fault has occurred in the transmission path, and a fault alarm is sent out. By sending a signal to the circuit 6, the terminal operator is notified of the occurrence of a fault.

As described above, the operator can quickly learn of a failure in the transmission path, which is the most important part of a data transmission system, and can take necessary measures at an early stage.

〔Effect of the invention〕

As explained above, according to the present invention, an operator can quickly and reliably know the occurrence of a failure in a communication path, and can take necessary measures at an early stage, thereby improving reliability and transmission efficiency in a data transmission system. Effective for improvement.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a main part configuration of an example of a terminal accommodating device according to the present invention, and FIG. 2 is a diagram showing a system configuration of an example of a data transmission system according to the present invention. SAT...Relay node, C3A...Control node, S
T...terminal housing device! ... loop-shaped transmission line, b.
... Bus type transmission line, 1 ... Terminal accommodation device reception signal, 2
...Specific pattern detection circuit, 3...Timer circuit, 4
. . . comparison circuit, 5 . . . fault alarm circuit, 6 . . . fault alarm sending circuit. Illustration 112 Teitosakune 10th Book (Volunteer) December 4, 1986

Claims (1)

[Claims] 1. In each of one or more relay nodes predeterminedly placed in the middle of a time division multiplex transmission path on which time division multiplex frame signals are transmitted, control is performed as a preceding relay node or as a central synchronization device. A bus-type transmission line that inserts and removes time slots for time-division multiplexed frame signals from a node, transmits them to a subsequent relay node or control node, and connects to the relay node, and a plurality of terminals accommodated on the transmission line. This is a fault monitoring method in a data transmission system configured to exchange data related to insertion and removal between each terminal via an accommodation device in a time division multiplex frame format, in which a constant amount of data is sent from each relay node on a bus-type transmission path. While the specific pattern signal is transmitted at regular intervals, each terminal accommodation device does not receive or detect the specific pattern signal at regular intervals.
A fault monitoring method characterized by displaying the occurrence of a fault externally. 2. The fault monitoring system according to claim 1, wherein at least some or all of the time division multiplex transmission paths and bus-type transmission paths are wirelessly transmitted using radio waves or light as a data transmission medium.