JP2020061624A - Signal transmission device and determination device - Google Patents

Abstract

To efficiently determine whether a service line is in use or not.SOLUTION: A signal transmission device 1 applies a normal mode test signal to a communication line which has an open end on a concentrator 914 of a communication center building 901 and measures a common mode voltage generated in a service wire 912 with a probe 2. A determination device 3 determines whether the service wire 912 is in use or not based on the measured common mode voltage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for determining whether a service line is in use or not.

  With the spread of optical fibers, unused metal service lines may remain in facilities such as houses without being removed. If the unused service wire is left, there is a problem that an accident may occur due to the service wire hanging down. For example, if a drop-in line that is placed over the sky of the road hangs down, it is very dangerous because it obstructs the passage of vehicles and pedestrians.

  Removal of unused service lines is in progress.

JP-A-7-50618

  When removing the service line, it is necessary to confirm whether the target service line is in use or not in use, that is, whether or not it is in use.

  I visit the lead-in place to check if the lead-in line is used or not, but if the lead-in place is out, I cannot confirm whether it is active or not.

  The present invention has been made in view of the above, and an object thereof is to efficiently determine whether the service line is in use or not in use.

  A signal transmission device according to the present invention is arranged in a facility where communication lines electrically connected to a service line are concentrated, and outputs a test signal to a determination device that detects a common mode voltage generated in the service line. A signal transmitting device for transmitting, comprising: a generating unit that generates a test signal having a predetermined frequency; and an applying unit that applies the test signal to the communication line in a normal mode.

  The determination device according to the present invention is a determination device that can be attached to a service wire in a non-contact manner and detects a common mode voltage generated when a test signal having a predetermined frequency is applied to the service wire in a normal mode. There is a measuring unit that measures the common mode voltage of the lead-in wire and obtains the voltage value of the common mode voltage having the same frequency as the frequency of the test signal among the measured common mode voltage, the voltage value and the threshold value. And a determination unit that determines whether the service line is used or not.

  According to the present invention, it is possible to efficiently determine whether the service line is in use or not.

It is a figure which shows the specific example of the environment where the determination system of 1st Embodiment is used. It is a functional block diagram which shows the structure of the signal transmission apparatus of 1st Embodiment. It is a functional block diagram which shows the structure of the determination apparatus of 1st Embodiment. It is a flow chart which shows a flow of processing of a judgment device. It is a functional block diagram which shows the structure of the signal transmission apparatus of 2nd Embodiment. It is a figure which shows a mode that the signal transmission apparatus of 3rd Embodiment was connected to the concentrator.

[First Embodiment]
The first embodiment will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a specific example of an environment in which the determination system of the first embodiment is used. The determination system shown in the figure includes a signal transmission device 1, a probe 2, and a determination device 3.

  The communication center building 901 and the target building 902 are connected by an overhead cable 911 and a drop line 912. The overhead cable 911 and the drop wire 912 are metal wires for communication, and are, for example, telephone lines. The overhead cable 911 and the lead-in wire 912 are connected by the connection terminal 904 attached to the telephone pole 903. The lead-in wire 912 is fixed by the L-shaped metal piece 905, the branch metal piece 906, the C-shaped metal piece 907, and the wiring cleat 908, and connects the connection terminal 904 and the protector 909. The protector 909 is connected to the ground rod 910 by a ground line 913.

  The communication center building 901 is a facility that manages communication. In the communication center building 901, communication devices such as the signal transmission device 1, the concentrator 914, and an exchange (not shown) are installed. The distribution board 914 collects each communication line of the aerial cable 911 (connected to the service line 912 arranged in each of the installed structures 902). Among the communication lines concentrated on the distribution board 914, the active communication line is connected to the exchange and the non-active communication line is open.

  The signal transmission device 1 is connected to a non-working communication line on the concentrator 914. Like the communication signal, the signal transmission device 1 applies a test signal of a predetermined frequency to the communication line in the normal mode. The applied test signal flows through the overhead cable 911 and the drop wire 912.

  The installed structure 902 is a facility to which the lead-in line 912 is drawn in, and is, for example, a detached house. The L-shaped metal piece 905 and the line metal piece 906 are metal fittings for fixing the lead-in wire 912 to the electric pole 903. The C-shaped hardware 907 is a metal fitting for fixing the lead-in wire 912 to the installed structure 902. The wiring cleat 908 is a pottery or ebonite tool for fixing the service wire 912 to the installed structure 902. The protector 909 is connected to the ground rod 910 via the ground line 913 to protect the terminal in the home from overvoltage / overcurrent due to lightning, surge current, or the like.

  The current service line 912 is connected to a terminal such as a telephone at the service destination. The terminal of the non-working service line 912 is basically not connected to the terminal, but the terminal may remain connected.

  The probe 2 includes a detection probe 21, a support rod 22, and a clamp lever 23. The detection probe 21 is arranged at the tip of the support rod 22. The detection probe 21 is attached in a non-contact state to the service wire 912 whose working / non-working is desired to be determined. A voltage and a current are induced in its own electrode by an electromagnetic induction phenomenon caused by a common mode voltage generated by applying a test signal to the lead-in wire 912. The clamp lever 23 is a lever operated when the detection probe 21 is attached to the lead-in wire 912.

  The determination device 3 is connected to the probe 2, detects the voltage induced in the probe 2 by the test signal transmitted by the signal transmission device 1, and determines whether the service wire 912 is in use or not.

  FIG. 2 is a functional block diagram showing the configuration of the signal transmission device 1 of the first embodiment. The signal transmission device 1 shown in the figure includes a signal application unit 11, a signal generation unit 12, and a storage unit 13.

  The signal applying unit 11 applies the test signal generated by the signal generating unit 12 to the communication line connected to the concentrator 914. More specifically, the test signal is sent in the normal mode between the communication lines L1 and L2.

  The signal generation unit 12 generates a test signal having a predetermined frequency, amplitude, and waveform based on the information on the test signal stored in the storage unit 13. The frequency of the test signal may be selected in the range of 220 Hz to 100 kHz. Since the low frequency has a long wavelength and the coupling due to the stray capacitance is small, the signal can be transmitted to a distant place. The waveform of the test signal may be a sine wave or a rectangular wave.

  The test signal may be, for example, a single-frequency continuous wave having a frequency of 1 kHz, or may be a single-frequency intermittent wave having a frequency of 1 kHz that repeatedly turns on and off every second. When the test signal is characterized as an intermittent wave having a predetermined pattern, the determination device 3 can more easily distinguish the noise from the common mode signal generated by the test signal, and can suppress erroneous determination.

  The storage unit 13 stores information on the test signal generated by the signal generation unit 12. As the information of the test signal, for example, the frequency and amplitude of the test signal, the time and timing of transmitting the test signal, the ON period and the OFF period when the test signal is an intermittent wave, and the waveform of the test signal are stored.

  When the test signal applied by the signal transmission device 1 flows through the lead-in wire 912, a common mode voltage is generated in the lead-in wire 912. When the signal transmission device 1 loses the balance of the L1 and L2 lines of the drop line 912, the normal mode component of the test signal is converted to the common mode. The balance of the test signals flowing through L1 and L2 is lost due to the rising and falling timings of the waveform, the deviation of the speed, the deviation of the amplitude, and the like. Therefore, when the signal transmission device 1 applies the test signal to the lead-in wire 912, a weak common mode voltage is generated in the lead-in wire 912.

  FIG. 3 is a functional block diagram showing the configuration of the determination device 3 of the first embodiment. The determination device 3 shown in the figure includes a voltage measurement unit 31, a bandpass filter (BPF) 32, an amplification unit 33, an A / D conversion unit 34, a storage unit 35, a detection unit 36, a setting unit 37, a comparison unit 38, and The display unit 39 is provided. The determination device 3 is connected to the detection probe 21.

  The detection probe 21 has a hollow cylindrical shape, and the lead-in wire 912 can be passed through the hollow portion. The detection probe 21 induces a voltage in its own electrode by an electromagnetic induction phenomenon caused by the common mode voltage generated in the lead-in wire 912.

  The voltage measurement unit 31 outputs the voltage signal induced in the detection probe 21 to the BPF 32.

  The BPF 32 extracts a voltage signal in the same frequency band as the test signal.

  The amplification unit 33 amplifies the amplitude of the voltage signal extracted by the BPF 32.

  The A / D converter 34 converts the input voltage signal into a digital signal.

  The storage unit 35 stores the same test signal information as that stored in the storage unit 13 of the signal transmission device 1.

  The detection unit 36 detects the voltage value at the timing when the test signal is transmitted, based on the information of the test signal stored in the storage unit 35. For example, when the test signal is an intermittent wave, the voltage value in the ON period is detected. The voltage value in the off period may be detected in advance.

  In the setting unit 37, a threshold serving as a reference for determining whether the service line 912 is in use or not is set.

  The comparing unit 38 compares the voltage value detected by the detecting unit 36 with the threshold value set in the setting unit 37, determines that the detected voltage value is the current value or more, and determines that the voltage value is less than the threshold value. To determine. When the test signal is an intermittent wave, the ratio or difference between the voltage value in the off period and the voltage value in the on period may be used.

  The display unit 39 displays the determination result of the comparison unit 38. For example, if the service line 912 is currently in use, “currently used” is displayed, and if the service line 912 is not currently used, “not currently used” is displayed.

  Next, the operation of the determination device will be described.

  FIG. 4 is a flowchart showing the flow of processing of the determination device.

  The signal transmission device 1 is connected to the communication line, which is an open end, by the concentrator 914, and the test signal is continuously applied for a predetermined period (for example, a period for removing the service line such as one week).

  During the period of removing the service line, the worker attaches the probe 2 to the service line 912 to be investigated and causes the determination device 3 to execute the following process.

  The voltage measurement unit 31 detects the voltage signal induced in the detection probe 21 and outputs the voltage signal to the BPF 32 (step S11).

  The BPF 32 acquires the voltage signal detected by the voltage measuring unit 31, extracts the voltage signal in the same frequency band as the frequency of the test signal (step S12), and the amplifying unit 33 amplifies the amplitude of the voltage extracted by the BPF 32. (Step S13).

  The A / D converter 34 converts the voltage amplified by the amplifier 33 into a digital signal (step S14).

  The detection unit 36 detects the voltage value at the timing when the test signal is transmitted, and the comparison unit 38 compares the detected voltage value with the threshold value and determines whether the service line 912 is in use or not (step S15). .

  The display unit 39 displays the determination result of the comparison unit 38 (step S16).

  As described above, according to the present embodiment, the signal transmission device 1 applies the normal mode test signal to the communication line which is the open end in the concentrator 914 of the communication center building 901, and the probe 2 is used. A line between L1 and L2 of the service line 912 is determined by measuring the common mode voltage generated in the service line 912 and determining whether the service line 912 is in use or not based on the measured common mode voltage. Since the test signal is detected without measuring the inter-terminal voltage, it is possible to determine whether the service line 912 is in use or not in use from the ground without the ascending pole work even if the service destination is an absence house.

  According to the present embodiment, by applying the test signal in the normal mode instead of the common mode, it is possible to propagate the test signal to a longer distance than in the common mode and prevent signal leakage to the adjacent line. Since the test signal is not detected except for the target line, the risk of misjudgment can be reduced.

  If the number of active communication lines connected to the exchange is extremely smaller than the number of open active non-active communication lines among the communication lines concentrated on the distribution board 914, the signal transmission device 1 may be connected to the working communication line and a test signal may be applied to the working communication line to determine the working drop line 912.

[Second Embodiment]
Next, a second embodiment will be described.

  The second embodiment is different from the first embodiment in that a test signal obtained by multiplexing signals having a plurality of frequencies that are not in a constant multiple relationship with each other is used.

  FIG. 5 is a functional block diagram showing the configuration of the signal transmission device 1 of the second embodiment. The signal transmission device 1 shown in the figure includes the signal multiplexing unit 14 in the configuration of the first embodiment.

  The storage unit 13 stores information on signals of a plurality of frequencies to be combined. The plurality of frequencies are frequencies that are not in a constant multiple relationship with each other. For example, 1 kHz and 10.1 kHz. The number of frequencies may be three or more.

  The signal generation unit 12 generates a signal having each of a plurality of frequencies based on the information of the signals of a plurality of frequencies stored in the storage unit 13. Each of the signals having a plurality of frequencies may be a continuous wave, or at least one of them may be an intermittent wave. A plurality of signal generation units 12 that generate signals having frequencies that are not in a constant multiple relationship may be provided.

  The signal multiplexer 14 multiplexes the signals of the plurality of frequencies generated by the signal generator 12 to generate a test signal.

  The signal applying unit 11 applies the test signal combined by the signal combining unit 14 to the communication line on the concentrator 914.

  In addition, regarding the determination device 3, the BPF 32 is assumed to be able to extract the signals in the respective frequency bands of the combined multiple frequencies.

  The storage unit 35 stores information on signals of a plurality of frequencies.

  The comparing unit 38 compares the detected voltage value with the threshold value set in the setting unit 37 for each of the plurality of frequencies, and the voltage value is equal to or higher than the threshold value in a predetermined number of frequencies among the plurality of frequencies. In this case, the lead-in line 912 is determined to be the working line. For example, when the number of frequencies is two, it is determined to be in use when the voltage value becomes equal to or higher than the threshold value at one of the frequencies. Alternatively, when the number of frequencies is 3, and when the voltage values at the two frequencies are equal to or higher than the threshold value, it is determined to be in use. If the voltage value is equal to or higher than the threshold value at all of the plurality of frequencies, it may be determined to be the current use, or if the voltage value is equal to or higher than the threshold value at at least one frequency, it may be determined to be the current use.

  According to the present embodiment, it is possible to suppress erroneous determination due to noise by using a test signal obtained by multiplexing signals having frequencies that are not a constant multiple.

[Third Embodiment]
Next, a third embodiment will be described.

  FIG. 6 is a diagram showing a state in which the signal transmission device 1 according to the third embodiment is connected to the concentrator 914.

  In the third embodiment, the signal transmission device 1 is connected to a plurality of communication lines of the concentrator 914, and a test signal is applied to each of the plurality of communication lines in a time division manner. It may be combined with any of the first and second embodiments.

  The signal transmission device 1 may apply the test signal to the plurality of communication lines at the same time, but the number of the test signals that are simultaneously output by applying the test signal to each of the plurality of communication lines in a time division manner. Suppress. The timing and cycle of applying the test signal to each communication line are recorded in the storage unit 13 of the signal transmission device 1.

  The signal transmission device 1 is arranged in the communication center building 901, and is connected to each of the communication lines, which are open ends, on the concentrator 914. The signal transmission device 1 continues to apply the test signal during the work of removing the non-working service wire.

  The worker determines whether each service line is active or non-active in the area where the service line removal work is to be performed, and removes the service line not in service.

  According to the present embodiment, by applying the test signals to the plurality of communication lines in a time division manner, the number of test signals output at the same time can be suppressed and the output level of the signal transmission device 1 can be reduced.

DESCRIPTION OF SYMBOLS 1 ... Signal transmission device 11 ... Signal application part 12 ... Signal generation part 13 ... Storage part 14 ... Signal combining part 2 ... Probe 21 ... Detection probe 22 ... Support rod 23 ... Clamp lever 3 ... Judgment device 31 ... Voltage measurement part 32 ... BPF
33 ... Amplification section 34 ... A / D conversion section 35 ... Storage section 36 ... Detection section 37 ... Setting section 38 ... Comparison section 39 ... Display section

A signal transmission device according to the present invention is arranged in a facility where communication lines electrically connected to a service line are concentrated, and outputs a test signal to a determination device that detects a common mode voltage generated in the service line. A signal transmitting device for transmitting, comprising: a generator for generating a test signal having a predetermined frequency; and an applying unit for applying the test signal to the communication line in a normal mode , wherein the test signals are mutually It is characterized in that it is a signal obtained by combining signals having frequencies that are not a constant multiple .

The determination device according to the present invention is a determination device that can be attached to a service wire in a non-contact manner and detects a common mode voltage generated when a test signal having a predetermined frequency is applied to the service wire in a normal mode. There is a measuring unit that measures the common mode voltage of the lead-in wire and obtains the voltage value of the common mode voltage having the same frequency as the frequency of the test signal among the measured common mode voltage, the voltage value and the threshold value. And a determination unit that determines whether the service line is used or not, and the test signal is a signal having a frequency that is not a constant multiple of each other. It is a signal .

Claims (6)

A signal transmission device for transmitting a test signal to a determination device for detecting a common mode voltage generated in the service line, which is disposed in a facility where a communication line electrically connected to the service line is concentrated.
A generator for generating a test signal having a predetermined frequency,
An applying unit for applying the test signal to the communication line in a normal mode,
A signal transmission device comprising: A storage unit that stores test signal information including the frequency of the test signal and the timing of transmitting the test signal;
The signal transmission device according to claim 1, wherein the generation unit generates the test signal based on the test signal information.   The signal transmitting apparatus according to claim 1 or 2, wherein the test signal is a signal obtained by multiplexing signals having frequencies that are not a constant multiple of each other.   The signal transmission device according to claim 1, wherein the test signal is an intermittent wave.   The signal transmitting apparatus according to claim 1, wherein the applying unit applies the test signal to a plurality of communication lines in a time division manner. A determination device which can be attached to the service wire in a non-contact manner, and which detects a common mode voltage generated when a test signal having a predetermined frequency is applied to the service wire in a normal mode,
A measurement unit that measures the common mode voltage of the lead-in wire and obtains a voltage value of the common mode voltage having the same frequency as the frequency of the test signal among the measured common mode voltages,
A determination unit that compares the voltage value and a threshold value to determine whether the service line is used or not,
A determination device having:

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