JP3230941B2 - Subscriber line measurement method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention aims at confirming normality / abnormality on a subscriber line including a subscriber terminal, and a composite including a resistance component and a capacitance component on the subscriber line. The present invention relates to a subscriber line measuring method and an apparatus for measuring impedance from a non-subscriber terminal side with high accuracy, quickly and economically.

[0002]

2. Description of the Related Art In recent years, each of a plurality of subscriber terminals is temporarily housed in a subscriber interface device installed remotely from a switching center via a terminal-compatible metallic subscriber line, and further (for uplink / downlink multiplex transmission). At present, a mode of being housed in an exchange office via an optical fiber cable is being adopted. By the way, as long as each subscriber terminal is accommodated directly and indirectly in the exchange building side via the terminal corresponding metallic subscriber line, for the purpose of confirming normality / abnormality in each of the metallic subscriber lines, A composite impedance including a resistance component and a capacitance component on a metallic subscriber line must be measured at any time or periodically by a subscriber interface device or a subscriber line measuring device in a switching center. It has become. Generally, when the subscriber terminal is on-hook, 1-3
Since a capacitance of about μF is shown, therefore, when the capacitance value is measured to be about 1 to 3 μF in the impedance measurement on the subscriber line including the subscriber terminal, the subscriber line Is determined to be normal, but if the capacitance value is zero, the subscriber line can be determined to be in a disconnected state or an inter-line short-circuit state.

Here, a subscriber line measuring apparatus according to the prior art will be described. FIG. 4 shows an example of the configuration. In this case, the impedance on the subscriber line is measured with the subscriber line measuring device connected to the subscriber line connection terminal 1 as the non-subscriber terminal side end of the subscriber line. Has become. That is, in order to measure the capacitance Cx on the subscriber line side including the subscriber terminal, the capacitance Cx is sufficiently charged up to the constant voltage Vs via the (high constant) resistor Rs and the switch SW, and then the switch SW is switched to the reference capacitance. By switching to the Cs side, the accumulated charge is discharged to the reference capacitance Cs, so that the reference capacitance Cs is charged. After the charge / discharge, the charge Cx can be calculated by measuring the charge voltage (divided voltage) at the reference capacitance Cs by the voltage measurement unit 2. The capacity Cx is charged via the resistor Rs. This is because the charging current flows to the subscriber terminal due to the capacity measurement, but in order to prevent the subscriber terminal from being erroneously sounded. It is provided for current limitation. For example, using a -48V power supply and a current sensitivity of 0.5 mA
In order to prevent erroneous ringing of the telephone when set to, it is necessary to charge through a resistor of 100 kΩ or more. As a technique relating to this kind of technology, for example, "Measurement unit for subscriber line test using electronic circuit" (National Meeting of Information and System Division, Institute of Electronics, Information and Communication Engineers, 1981, 408) can be mentioned.

[0004]

By the way, when an impedance measurement is performed by the subscriber line measuring apparatus according to the prior art, it is indeed necessary to charge a maximum of 3 μF to 99% through a 100 kΩ resistor. It takes 1.5 seconds. In addition to such a defect, the accuracy of the capacitance measurement at that time also depends on the reference capacitance C.
depends on the accuracy of s itself and the residual charge,
To measure the capacitance with high accuracy, a high-precision reference capacitance Cs
Needless to say, sufficient time is required for charging and discharging.

[0005] The first object of the present invention, the capacitance components on a subscriber line including the subscriber terminal, as a reference capacity required, with high accuracy from a non-subscriber terminal end, and quickly, yet economical It is an object of the present invention to provide a subscriber line measuring method and an apparatus for measuring the subscriber line. A second object of the present invention, the capacitance components on a subscriber line including the subscriber terminal, as a reference capacity required, the non-subscriber terminal end, with a best constant voltage corresponding to the subscriber line length Another object of the present invention is to provide a subscriber line measuring method and apparatus capable of measuring with high accuracy, quickly and economically.

[0006]

A first object of the present invention is to apply a constant voltage Vs to a subscriber line via a resistor Rs,
In a state where the voltage on the subscriber line is continuously measured, by integrating the measured voltage from the subscriber line over a period T from a predetermined integration start time,
While obtaining the voltage integration value S _A , a time point delayed by the time δt from the integration start time point is set as a new integration start time point.
By integrating the measured voltage from the said subscriber line over a period T from the integrating start time, so as to obtain a voltage integral value S _B, the resistor Rs, the voltage integral value S _A, S _B,
Constant voltage Vs, the period T and time .DELTA.t, capacitance component Cx
Is Cx = | δt / (Rs · log ((S _A −Vs · T) /
(S _B −Vs · T))) . Further, the subscriber line measuring device includes, as its components, a constant voltage source for generating a constant voltage Vs, a resistor Rs connected in series to the constant voltage source, and a constant voltage Vs from the constant voltage source. A switch for enabling application on a subscriber line via a resistor Rs, a voltage measuring unit for continuously measuring a voltage on the subscriber line, and a state in which a constant voltage Vs is applied on the subscriber line An integrator that integrates the measured voltage from the voltage measuring unit over a period T from a predetermined integration start time to hold and output a voltage integrated value S _A as an integration result; In the state where the constant voltage Vs is applied, a time point delayed by the time δt from the integration start time is set as a new integration start time, and the measured voltage from the voltage measurement unit is applied over a period T from the integration start time. By integrating, the voltage product And min value S delay _{integrator B} is kept output as an integration result, a holding portion for fixedly holding outputs the constant voltage Vs and the resistor Rs as a constant, the resistor Rs, the voltage integral value S _A, S _B, a constant voltage Vs, the period T and time .DELTA.t, the capacitive component Cx, Cx = | δt /
_{(Rs · log ((S A} -Vs · T) / (S B -Vs · T)))
This is achieved by configuring at least a computing unit that computes as | .

[0007] The second object is also to respond to the subscriber line length.
Prior to optimally mark <br/> pressurized to a subscriber line on the set constant voltage Vs and Flip, measured the constant voltage Vs, and through Thereafter, the resistor Rs on the subscriber line constant While the voltage Vs is applied, while the voltage on the subscriber line is continuously measured, the measured voltage from the subscriber line is integrated over a period T from a predetermined integration start time. Thus, while obtaining the voltage integrated value S _A , a time point delayed by the time δt from the integration start time is set as a new integration start time, and the time from the integration start time to the period T from the subscriber line. By integrating the measured voltage, the voltage integrated value S
_B to obtain the resistance Rs, the voltage integrated values S _A , S
_B, and the constant voltage Vs, the period T and time .DELTA.t, capacitance component
Cx becomes Cx = | δt / (Rs · log ((S _A −Vs · T) /
(S _B −Vs · T))) . Further, the subscriber line measuring device includes, as its components, a constant voltage source for generating a constant voltage Vs according to the subscriber line length, and a resistor Rs connected in series to the constant voltage source.
A switch for applying a constant voltage Vs from the constant voltage source to the subscriber line via the resistor Rs, a voltage measuring unit for continuously measuring a voltage on the subscriber line, In the state where the constant voltage Vs is applied, the measured voltage from the voltage measuring unit is integrated over a period T from a predetermined integration start time to obtain a voltage integrated value S _A
And the integration start time, with the time delayed by the time δt from the integration start time when the constant voltage Vs is applied to the subscriber line, as a new integration start time. by integrating the measured voltage from the voltage measuring unit for a period T from the time, a delay integrator for holding output voltage integral value S _B as an integration result, pressurized
Subscriber line prior to sign pressurized to a subscriber line on the optimally set the constant voltage Vs depending on the length, a variable constant voltage holding unit for holding output a constant voltage Vs measured at the voltage measuring unit, A resistance holding unit that holds and outputs the resistance Rs as a constant as a constant, the resistance Rs, the voltage integrated values S _A and S _B , and the constant voltage V
s, the period T and time .DELTA.t, the capacitive component Cx, Cx =
| Δt / (Rs · log ( (S A -Vs · T) / (S B -Vs ·
T))) This is achieved by configuring to have at least an operation unit that operates as | .

[0008]

The purpose of the present invention is to measure the impedance (particularly the capacitance component) on the subscriber line without the need for the reference capacitance. That is, the voltage measured from the subscriber line is converted to the time δt.
By integrating successively over the period T with only the shift, only two types of voltage integrated values SA and SB are obtained. These voltage integrated values SA and SB are used to determine the impedance and various constants on the subscriber line. Since the voltage integration values SA and SB and other known constants are used as functions, the impedance on the subscriber line can be determined with high accuracy.
It can be measured quickly and economically. At that time, even if the constant voltage for measurement (part of various constants) needs to be set optimally according to the subscriber line length,
If the constant voltage is measured in advance, the impedance on the subscriber line can be measured with high accuracy, quickly, and economically regardless of the value of the constant voltage.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, the principle of the subscriber line measuring method according to the present invention will be described with reference to FIG. In FIG. 1, 1 is a subscriber line connection terminal (non-subscriber terminal side end of the subscriber line), S
W is a switch, Rs is a (high constant) resistor, Vs is a constant voltage (source), 2 is a voltage measurement unit, and 21 is a voltage measurement result output terminal. Here, for the sake of simplicity, the operation will be described assuming that the impedance on the subscriber line including the subscriber terminal is a pure capacitance Cx. When the capacitance Cx is grounded by the switch SW, The charge stored in the capacitance Cx is zero, and therefore the voltage on the subscriber line is also zero. In this state, if the switch SW is switched to the resistor Rs side, the constant voltage Vs is applied to the subscriber line via the resistor Rs, so that the capacitance Cx is gradually charged with the passage of time. At the time, the subscriber line connection terminal 1
The above voltage is continuously measured by the voltage measuring unit 2 as the charging voltage of the capacitor Cx. From the voltage measurement unit 2, the time when the constant voltage Vs is applied is set as a time reference.
The measured voltage Vm is obtained as the following equation 1.

[0010]

(Equation 1)

Accordingly, a voltage integrated value S _{A obtained} by integrating the measured voltage Vm from the time base to the period T is given by the following equation (2).
And the measured voltage Vm is _converted from the time reference to the time δ
The time point delayed by t is set as a new integration start point, and the voltage integration value S _B integrated over the period T from this integration start point
Is obtained as Equation 3 below.

[0012]

(Equation 2)

[0013]

(Equation 3)

Accordingly, the following equation (4) is obtained from the above equations (2) and (3).

[0015]

(S _A −Vs · T) / (S _B −Vs · T) = exp (−δt / (Rs · Cx))

Since the values other than the capacitance Cx are known constants, the capacitance Cx can be easily obtained from the equation (4). In the above description, the case where the charge stored in the capacitor Cx is zero in the initial state, that is, the case where the initial voltage on the subscriber line is zero, has been described. Similarly, impedance on the subscriber line is required.

The principle of the subscriber line measuring method according to the present invention has been described above. Next, the subscriber line measuring device according to the present invention will be described in detail. FIG. 2 shows a configuration of an example of the subscriber line measuring device. In FIG. 2, 1 is a subscriber line connection terminal (non-subscriber terminal side end of the subscriber line), SW is a switch, Rs is a resistor, Vs
Is a constant voltage (source), 2 is a voltage measuring unit, 3 is an integrator, 4 is a delay integrator, 51 is a constant voltage (Vs) holding unit, and 6 is a resistor (R
s) A holding unit, 7 is an (impedance) calculating unit, 8 is a subscriber line impedance measurement result output terminal, and 9 is a subscriber line including a subscriber terminal.

For the sake of simplicity, the operation will be described assuming that the impedance on the subscriber line 9 is the pure capacitance Cx. In the same manner as in the previous case, the capacitance Cx is grounded by the switch SW. In this state, the electric charge stored in the capacitance Cx is zero, and the voltage on the subscriber line is also zero. In this state, if the switch SW is switched to the resistor Rs side, the constant voltage Vs is applied to the subscriber line via the resistor Rs, so that the capacitance Cx is gradually charged with the passage of time. At this time, the voltage on the subscriber line connection terminal 1 is continuously measured by the voltage measurement unit 2 as the charging voltage of the capacitance Cx. From the voltage measuring unit 2, the measured voltage Vm is obtained as the following equation 5 with respect to the time when the constant voltage Vs is applied.

[0019]

(Equation 5)

The measured voltage Vm is integrated by the integrator 3 from the time base to the period T, and the voltage integrated value S _A as the integration result is obtained as Expression 6.

[0021]

(Equation 6)

On the other hand, in the delay integrator 4, the measured voltage V
m as a new integration start point a point which is delayed by the time δt from the time reference, the voltage integral value S _B obtained by integrating over a period T from the integration start time will be obtained as Equation 7.

[0023]

(Equation 7)

[0024] After all, the arithmetic unit 7, when the voltage integral value S _B obtained, various constants in Equation 8 below, i.e., the voltage integral value S _A from the integrator 3, from the delay integrator 4 The voltage integrated value S _B and the constant voltage Vs from the constant voltage (Vs) holding unit 51
, The resistance Rs from the resistance (Rs) holding unit 6 and the period T and the time δt are substituted to obtain the capacitance Cx.
Is required.

[0025]

(Equation 8)

By the way, in the above configuration, the voltage is measured digitally by the voltage measuring unit 2, the integrator 3, the delay integrator 4, the constant voltage (Vs) holding unit 51, and the resistance (Rs) holding. When the control function for the switch SW, including the functions of each of the unit 6 and the arithmetic unit 7, is realized by a digital signal processor (DSP), the subscriber line measuring device can be realized with a small amount of hardware. It is.

Finally, the configuration of another example of the subscriber line measuring apparatus according to the present invention will be described with reference to FIG. As shown in FIG. 3, the present embodiment is practically different from the one shown in FIG. 2 in that the variable setting of the constant voltage Vs is considered in this embodiment, and the impedance measurement on the subscriber line is performed. Prior to the measurement, the voltage value of the constant voltage Vs is measured by the voltage measurement unit 2 and the variable constant voltage holding unit 5
2 and the other circumstances are almost the same as those in FIG. If the constant voltage Vs is not fixed and the value of the constant voltage Vs needs to be set optimally according to the length of the subscriber line, the subscribing is performed based on the optimally set constant voltage Vs. It suffices if the impedance on the user line is measured. Also in this example, as in FIG. 2, the arithmetic unit 7 and the like use a digital signal processor (DS).
In the case of realizing P), the subscriber line measuring device can be realized with a small amount of hardware.

[0028]

Effect of the Invention] As described above, the case of the claims 1 and 2, the capacitance component on the subscriber line including a subscriber terminal, a reference capacity required, high from the non-subscriber terminal end accuracy, and quickly, yet economically measured may subscriber line measuring method and apparatus, also in the case of claims 3 and 4, capacitance component on the subscriber line including a subscriber terminal
And a reference capacity required, the non-subscriber terminal end, the subscriber
Thus, a subscriber line measuring method and an apparatus thereof that can be measured with high accuracy, quickly, and economically with an optimum constant voltage according to the subscriber line length can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of a subscriber line measuring method according to the present invention;

FIG. 2 is a diagram showing a configuration of an example of a subscriber's line measuring apparatus according to the present invention;

FIG. 3 is a diagram showing a configuration of another example of the subscriber line measuring device according to the present invention.

FIG. 4 is a diagram showing a configuration example of a subscriber line measuring apparatus according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Subscriber line connection terminal, 2 ... Voltage measurement part, 3 ... Integrator, 4 ... Delay integrator, 51 ... Constant voltage holding part, 52 ... Variable constant voltage holding part, 6 ... Resistance holding part, 7 ... Calculation part , 9 ... subscriber line

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-271266 (JP, A) JP-A-3-262975 (JP, A) JP-A-5-172877 (JP, A) JP-A-3-271 163369 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04M 3/30

Claims (4)

(57) [Claims] 1. A for the purpose of confirming the normality of the subscriber line including a subscriber terminal, capacitance component on the subscriber line
A subscriber line measuring method for measuring Cx from a non-subscriber terminal side end, wherein a constant voltage Vs is applied on a subscriber line via a resistor Rs.
While integrating the measured voltage from the subscriber line over a period T from a predetermined integration start time while the voltage on the subscriber line is continuously measured. While obtaining the voltage integrated value S _A , the time point delayed by the time δt from the above-mentioned integration start time is regarded as a new integration start time, and the measured voltage from the subscriber line over the period T from the integration start time is obtained. By integrating
So as to obtain a voltage integral value S _B, the resistor Rs, the voltage integral value S _A, S _B, the constant voltage Vs, or the period T and time δt
From the above, the capacitance component Cx becomes Cx = | δt / (Rs · log
_{((S A -Vs · T)} / (S B -Vs · T))) | subscriber line measurement method to be measured <br/> constant as. Wherein for the purpose of confirming the normality of the subscriber line including a subscriber terminal, capacitance component on the subscriber line
A subscriber line measuring device for measuring Cx from a non-subscriber terminal side end, comprising: a constant voltage source for generating a constant voltage Vs; a resistor Rs connected in series to the constant voltage source; A switch for applying a constant voltage Vs to the subscriber line via the resistor Rs, a voltage measuring unit for continuously measuring the voltage on the subscriber line, and a constant voltage Vs on the subscriber line. An integrator that holds and outputs the voltage integration value S _A as an integration result by integrating the measured voltage from the voltage measurement unit over a period T from a predetermined integration start time while the voltage is being applied; When the constant voltage Vs is applied to the subscriber line, a time point delayed by the time δt from the integration start time is set as a new integration start time, and the voltage measurement unit is extended over the period T from the integration start time. By integrating the measured voltage from A delay integrator for holding output voltage integral value S _B as an integration result, a holding portion for fixedly holding outputs the constant voltage Vs and the resistor Rs as a constant,
The resistor Rs, the voltage integral value S _A, S _B, the constant voltage Vs, the period T and time .DELTA.t, the capacitive component Cx, Cx = |
δt / (Rs · log (( S A -Vs · T) / (S B -Vs ·
T))) A subscriber line measuring device configured to include a calculation unit that calculates as | . 3. In order to confirm the normality of a subscriber line including a subscriber terminal, a constant power is supplied according to the subscriber line length.
In a state where the pressure Vs are optimally set, a subscriber line measuring method for measuring the capacity <br/> weight component Cx on the subscriber line from a non-subscriber terminal end, depending on the subscriber line length Optimally set
The prior to sign pressurized onto the subscriber line of the constant voltage Vs, the
Measuring the constant voltage Vs, and thereafter, while applying a constant voltage Vs and through the resistor Rs on the subscriber line, in a state where the voltage on the subscriber line is continuously measured, predetermined By integrating the measured voltage from the subscriber line over a period T from the integration start time thus obtained, the voltage integration value S
On the other hand, while obtaining _A , the time point delayed by the time δt from the integration start point is set as a new integration start point, and the measured voltage from the subscriber line is integrated over a period T from the integration start point. so as to obtain a voltage integral value S _B, the resistor Rs, the voltage integral value S _a, S _B, a constant voltage Vs
From the period T and time .DELTA.t, the capacitive component Cx is, C
x = | δt / (Rs · log ((S A -Vs · T) / (S B -V
s · T))) A subscriber line measurement method that is measured as | . 4. A constant power supply according to a subscriber line length for the purpose of confirming the normality of a subscriber line including a subscriber terminal.
In a state where the pressure Vs are optimally set, a subscriber line measuring apparatus for measuring the capacity <br/> weight component Cx on the subscriber line from a non-subscriber terminal end, depending on the subscriber line length A constant voltage source for generating the constant voltage Vs, a resistor Rs connected in series with the constant voltage source, and a constant voltage Vs from the constant voltage source.
And a voltage measuring unit for continuously measuring the voltage on the subscriber line, and a state where a constant voltage Vs is applied on the subscriber line. An integrator that holds and outputs a voltage integration value S _A as an integration result by integrating the measured voltage from the voltage measurement unit over a period T from a predetermined integration start time, With the voltage Vs applied, a time point delayed by the time δt from the integration start point is set as a new integration start point, and the measured voltage from the voltage measurement unit is integrated over a period T from the integration start point. By
A delay integrator for holding output voltage integral value S _B as an integration result, a constant voltage V, which is optimally set depending on the subscriber line length
s prior to sign pressurized to a subscriber line on the variable constant voltage holding unit for holding output a constant voltage Vs measured at the voltage measuring unit, the resistance holding for fixedly holding outputs the resistor Rs as a constant , The resistor Rs, the voltage integrated values S _A , S _B ,
Constant voltage Vs, the period T and time .DELTA.t, the capacitance component
Cx is calculated as follows: Cx = | δt / (Rs · log ((S _A −Vs · T) /
(S _B −Vs · T)))) .