JPS6347380B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to an overhead cable monitoring device, and in particular, for each section of an overhead cable developed in the form of branches,
This invention relates to an overhead cable monitoring device that allows for economical centralized monitoring.

Prior Art There are two types of communication lines: overhead cables and underground cables.Since overhead cables are installed in the air, they are easily affected by the natural environment such as temperature, wind and rain, lightning, earthquakes, and damage from birds and insects. It is necessary to keep it in perfect condition. Therefore, when a failure occurs, in order to discover it early and restore it,
We are constantly monitoring.

Conventionally, continuous monitoring has been carried out for line sections that do not tolerate momentary interruptions, but for other line sections that do not require continuous monitoring, monitoring checks every few tens of seconds to several minutes are considered sufficient. There is. In such a monitoring system, separate cable cores are used between the monitored section and the central monitoring display device, or multiple monitor devices are connected in parallel to the same cable core. However, in the latter case, continuous signals of different frequencies were used and multiplexed for each monitor device. Therefore, in the former method, the same number of cable cores as the number of monitoring sections is used, which is expensive, and if there are many branches to be monitored, the ratio of cable cores for monitoring increases, making it impractical. The latter requires transmitting devices with different frequencies, and the centralized receiving side requires the same number of receiving circuits as the number of monitoring sections, including filters to separate and identify signals from each child device, making it expensive. There were flaws.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an overhead cable monitoring device that can mass-produce the entire monitoring system and reduce costs in order to improve the conventional drawbacks.

General Description of the Invention The overhead cable monitoring device of the present invention shares the cable core by multiplexing the unique pulse train signals from each monitoring device, and the receiving device on the centralized side also receives each unique pulse train signal. The feature is that the receiving circuit for decoding and decoding is shared.

Embodiment 1 of the Invention FIG. 1 is an overall schematic diagram of an overhead cable monitoring device showing an embodiment of the present invention.

1 is a reception display device for intensive monitoring; 2, 4, 6, 8 to 11 are sections of the overhead cable to be monitored; 3, 5, and 7 are 2, 4, and 6, respectively.
If a cable section exists, this is a monitor device that sends a unique pulse train signal to a pair of cable core wires that share each other at respective transmission timings. The monitor devices 5 and 7 also monitor the lower cable sections 8, 9 and 10, 11, respectively, and if they are present, the corresponding unique pulse train signals are transferred to the active signals of cable sections 4 and 6, respectively. It is sent at the timing following. With this configuration, the total number of fibers in each cable section is the same as that required for other main purposes, but only one pair of fibers is used in each section for the monitoring system.
A necessary number of monitor devices are inserted in accordance with the number of sections to be monitored, which is determined based on the deployment status of the cable. If this viewing system is installed every 30 seconds as a monitoring cycle, if the receiving display device 1 cannot receive the unique pulse train signal from each child device 3, 5, 7 even once during this 30 seconds, the monitoring system will It is identified that an abnormality has occurred in the monitoring section of the child devices 3, 5, and 7, and this is displayed for monitoring.

FIG. 2 is a configuration diagram of a monitor device showing an embodiment of the present invention.

Reference numeral 12 denotes a group of monitoring systems, each of which is a programmable frequency divider including a clock crystal controlled oscillator of the same frequency, and outputs a transmission start timing pulse of a predetermined period under control from the controller 13. . This transmission start timing uses random timing for each group of monitoring systems. In this case, random transmission start timing can be obtained by incorporating a randomizer 131, which is a combination of a shift register and a gate, into the control section 13, and controlling the programmable frequency dividing section 12 with its random output. The pulse train generator 14 is activated at this random timing.

The bit rate of the pulse train signal is set to 4800 b/s, for example, so that it can be sufficiently transmitted through the overhead cable core, and 10 bits are set for each monitor device.
It is assumed that a word-sized unique pulse train signal is assigned, and one child device transmits three words in one pulse train transmission. The dedicated time for the shared cable core is only 1/160 seconds for one transmission. For example, if 10 child devices send data every second on average,
In this case, 1/16 per second is a chance of competing with other child devices, and if the receiving device cannot receive three words correctly, it will be rejected, and the probability is that 15/16 words per second can be successfully received. If the monitoring cycle is, for example, every 30 seconds, it is not necessary to transmit every second on average, and if the random timing is selected appropriately according to the total number of child devices, it is possible to receive all the active signals. It is fully possible.

In FIG. 2, reference numeral 16 denotes an interface section, which sends and receives signals to and from the receiving device 1 via the upper monitor device. That is, when the pulse train generator 14 is activated at the timing of the start of transmission from the crystal controlled clock oscillation/programmable frequency divider 12, an assigned unique pulse train signal is generated, which is amplified by the amplifier 15, and then output to the interface. It is sent out to the overhead cable core via section 16.

On the other hand, the unique pulse train signal from the monitor device at the lower part of the branch is inputted to the lower interface section 17 and passed through the control section 13 to the pulse generation section 1.
4, passes through the interface section 16, and is transmitted following the unique pulse train signal from the monitoring child device.

FIG. 3 is a block diagram of a reception display device on the central monitoring side showing an embodiment of the present invention.

The pair of shared cable cores are drawn into the interface section 18, and unnecessary surges and the like induced in the overhead cable are removed. Reference numeral 19 denotes a control section including a clock crystal controlled oscillator of the same frequency as that of the child device, a frequency dividing circuit, etc., which supplies timing pulses necessary for the overall operation and controls each section. The received pulse train signal that has passed through the interface circuit 18 is applied to the receiver 20, which has a built-in filter that matches the bit rate of the pulse train signal and an amplifier circuit that reduces the level, converts and translates the serial pulse train input, and converts and translates the serial pulse train input. A parallel binary output uniquely determined by the unique pulse train of each child device is obtained.
21 is a part that decodes this output and expands it to correspond to each child device, and turns on the latch memory 22 corresponding to each child device every time a pulse train arrives during one monitoring cycle. The display unit 23 detects something that does not turn on during the monitoring cycle and displays it as an LED.
Notify the abnormal section by displaying a lamp or other means and at the same time by ringing a bell. 24
is the power supply required for each circuit, and supplies power to the child device.

In the above embodiment, the transmission start timing of each monitor device is set at random, but other methods may be used as the transmission start timing for each group of monitoring systems.

Next, second and third embodiments using other methods as the transmission start timing will be described.

Embodiment 2 of the Invention In this embodiment, the monitoring system having the configuration shown in FIG. 1, the monitor device having the configuration shown in FIG. 2, and the reception display device shown in FIG. 3 are used as they are.
The difference from the above-mentioned embodiment is that the transmission interval times of each monitor device use timings having a relationship of prime numbers.

In Fig. 1, for example, slave device 3 transmits data every 3 seconds, slave device 5 transmits data every 5 seconds, child device 7 transmits data every 7 seconds, and so on, at intervals that are prime numbers. The programmable frequency dividing section 12 is fixed and made so that the control section 13 repeatedly controls the programmable frequency dividing section 12. The pulse train from each child device sequentially arrives at the reception display device 1 via the common core wire.
Because the intervals are each a prime number of seconds, even if they overlap at one timing, they will always deviate at the next timing.If the monitoring cycle is long enough compared to each interval, a normal pulse train will be received and it will be possible to identify that the pulse train is healthy. It becomes possible. In this example, the unit of the interval is seconds, but since the bit rate that can be transmitted by the pulse train is large and the time for exclusive use of the shared core is short, the unit of the prime number can be as small as seconds or less. child devices can be assigned.

Embodiment 3 of the Invention FIG. 4 is a block diagram of a monitor device showing another embodiment of the invention.

In this embodiment, after starting power supply all at once,
Each child device determines its transmission start timing after a different amount of time has elapsed.

In the monitoring system shown in FIG. 1, each child device 3,
5 and 7, power supply is started simultaneously from the central monitoring reception/display device 1 via the shared core. That is, power is supplied to each child device at once from the power supply circuit 24 of the receiving display device shown in FIG. 3 via the interface 18 (indicated by broken lines).
The control unit 19 sends a control signal (indicated by a broken line) to the interface unit 18 to turn on and off the power supply. When power is received, each child device starts up at the same time, but the initial control of the programmable frequency divider 12 by the control circuit 13 shown in FIG. 4 is fixed, and the transmission start timing is given to each child device only after different times have passed. Make it like this. In FIG. 1, for example, if we assign transmission start timings such as 1 second later for slave device 3, 2 seconds later for slave device 5, and 3 seconds later for slave device 7, then Since the pulse train, which is health information, arrives one after another, it is possible to identify and display the health status.
After going through all the connected child devices, the power supply is turned off each time and the next monitoring cycle is started by restarting the power supply.Also, the clock that is the reference timing is stable because it is based on a crystal controlled oscillator. A method that automatically repeats retransmission from each child device at regular intervals longer than the time required for one cycle of the child device, and synchronizes the timing by turning off the power and turning it on once every multiple monitoring cycles. You can also.

In FIG. 4, when power is supplied through the interface section 16, initial control of the programmable frequency dividing section 12 is started at a different time for each child device, and after a certain period of time, transmission start timing 1 is started.
21 is given to the control section 13. On the other hand, since the initial starting pulse 161 is given from the interface section 16 to the control section 13, an AND operation of these signals causes the starting signal 1 to be sent to the pulse generating section 14.
32 is output. Based on this output, the unique pulse generator 14 generates a unique pulse train signal. That is, the pulse generation section 14 generates a pulse train of about 10 bits and one word unique to each monitor device based on the transmission start timing pulse from the frequency division section 12.

The pulse train signal from the pulse generator 14 is amplified by the pulse amplifier 15 and is then sent to the interface circuit 16.
to the shared core of the cable. The interface circuit 16 includes a circuit that converts the power supplied via the common core wire into the power required by the child device, and also supplies a pulse to the control unit 13 indicating initial activation.

If a plurality of sections below the insertion point are monitored, as in the child devices 5 and 7 in FIG. 1, a lower interface section 17 is added. Here, for example, a pair of lower monitoring core wires is connected in a rectangular manner on the terminal side, and if it is confirmed that a loop is formed, it is determined that the core wires are alive and well, and the wires are passed through the control section 13' to the pulse generation section 14.
Start. The timing is set to follow the first unique pulse train signal transmission, so that there is no need to separately prepare a control section 13' for determining the transmission start timing. The number of monitored signals at the bottom are sequentially generated as unique pulse train signals different from each other.

Effects of the Invention As explained above, according to the present invention, it is possible to monitor a plurality of monitoring sections by sharing each pair of cable cores in chronological order, and to use a low-cost digital digital camera that can be mass-produced. A monitoring system such as a reception display device and a monitoring child device can be configured by combining ICs and LSIs, and since the reception section, which is the main part of the reception display device, can also be shared, it is possible to reduce the cost of the entire monitoring system. .

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an overhead cable monitoring system showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a monitor device showing an embodiment of the present invention, and FIG. 3 is a centralized monitoring diagram showing an embodiment of the present invention. FIG. 4 is a block diagram of a side receiving display device, and FIG. 4 is a block diagram of a monitor device showing another embodiment of the present invention. 1: Reception display device for centralized monitoring, 2: Overhead cable monitoring section, 3: Monitoring device, 4: Overhead cable monitoring section, 5: Monitoring device, 6: Overhead cable monitoring section, 7: Monitoring device Devices, 8 to 11: Overhead cable monitoring section, 12: Crystal control clock generation/programmable frequency division section, 13: Control section, 1
4: Unique pulse generation section, 15: Amplification section, 16: Interface section, 17: Lower interface section, 18: Interface section, 19: Crystal control clock transmission/frequency division/control section, 20: Receiving section, 2
1: Decoder section, 22: Latch memory section, 23:
Display section, 24: Power supply section.

Claims (1)

[Scope of Claims] 1. In an overhead cable monitoring device that detects faulty sections of overhead cables deployed in the form of branches, a monitoring device that is inserted in each monitored section and sends out a unique pulse train signal if the assigned section is normal. a child device;
The above-mentioned system has a pair of cable core wires for transmitting signals from the monitoring device, and a reception display device for intensive monitoring that receives signals from each monitoring device and displays the status of each monitoring section. An overhead cable monitoring device characterized in that the monitor device repeatedly sends out pulse train signals at random time intervals. 2. The overhead cable monitoring device according to claim 1, wherein each of the monitoring device devices sets the time intervals of transmission repetition so that they are in a prime number relationship with each other. 3. Each of the monitor devices has a starting timing when the power supply from the reception display device for intensive monitoring starts all at once, and transmits the unique pulse train signal after mutually different times have elapsed from the starting timing. An overhead cable monitoring device according to scope 1.