JP2001197220A - Terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ring the bell of a telephone set without answering any call other than one from a monitor center and also to automatically answer calling from the monitoring center without ringing the bell of the telephone set to make it possible to communicate with monitor center with respect to a terminal device connected to a terminal adapter to be connected to an ISDN telephone line. SOLUTION: Relating to this terminal device having a control 2 installed on an ordinary home side of a system in which the monitor center collects the information of a meter 29 installed in the ordinary home or the like by utilizing a telephone line 25, the control 2 is provided with a line state monitoring part 5 monitoring the polarity inversion or the unused and used states of the line 25 and a call signal monitoring part 3 monitoring a call signal from the line 25, and when the part 5 detects the state change of the line 25, the call signal monitoring part 3 measures the ringing period of the call signal and its non-ringing period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal device installed at a terminal side for collecting meter readings of gas, water, electricity, etc. at a monitoring center using a telephone line.

[0002]

2. Description of the Related Art Conventionally, this type of terminal apparatus has two methods of collecting data such as meter readings: a center starting method for starting a terminal apparatus from a monitoring center, and a terminal starting method for starting a monitoring center from a terminal apparatus. According to the method described above, the monitoring center and the terminal device are connected via a telephone line, and data of a meter connected to the terminal device is collected by the monitoring center.

[0003] Generally, a terminal device that can operate both methods is provided.

As a method of activating a terminal device from a monitoring center, a method of using a no-ringing service provided by NTT is generally used. The no-ringing service, as described in, for example, a technical document published by the Telecommunications Association of Japan, processes and controls a call by no-ringing when the line voltage is inverted and the line voltage becomes 35 V, It has the characteristic that it can be connected without ringing the bell of the telephone connected to the line, so that meter reading can be performed without inconvenience to the customer even in the middle of the night.

As another method, there is a method of calling a terminal device from a monitoring center by a normal call (hereinafter, called a ringing call) without using a special service called no ringing.

[0006] This method is based on the principle of an answering machine, and is a method in which, when a calling signal continues for a set number of times, a telephone line is automatically caught and brought into a communication state.

On the other hand, the terminal activation method is such that the terminal device automatically captures the line when a preset date and time or when a communication request from the meter is detected, and sends a selection signal to the monitoring center. To connect to the monitoring center.

As described above, there has been proposed a terminal device capable of performing both the operation of starting the center by the no ringing service or the ringing call and the operation of starting the terminal.

[0009] Against this background, in recent years, the spread of ISDN lines has been expanding due to the advancement of electronic technology, and the situation is becoming more and more widespread in the future.

[0010] Since this ISDN line is a digital line,
When connecting an analog telephone or a terminal device for an automatic meter reading system, a connection method is usually adopted via a terminal adapter.

This terminal adapter has been commercialized to have a function of registering a specific caller telephone number and outputting a specific call signal when a call is made from the caller. (See, for example, JP-A-08-237385)

[0012]

As described above, in order to call a terminal device from a monitoring center, a method using a no-ringing service is excellent. However, when the terminal side is an ISDN line, a no-ringing call cannot be made. There is a problem that a separate fee is required every month.

A particular problem is that a terminal cannot be called from a monitoring center, and a ringing calling method utilizing the principle of answering machine has conventionally been used.

However, this method has a problem that when a call is made, it cannot be known until a call from a monitoring center, a call from a third party such as an acquaintance, or a line has been captured.

[0015] Therefore, when a person in the house answers the telephone, if the call is from the monitoring center, it is necessary to reconnect to the terminal device, and it is necessary to start the device manually or perform complicated control by the terminal device. was there.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a system for collecting information such as a meter installed in a general home at a monitoring center using a telephone line at a general home. In the terminal device having the control unit, the control unit includes a line state monitoring unit that monitors a polarity inversion of the telephone line, or an unused state or a used state, and a call signal monitoring unit that monitors a call signal from the telephone line. Provided,
When the line state monitoring unit detects a change in the state of the telephone line, the ringing signal monitoring unit measures the ringing time and non-ringing time of the calling signal.

The control unit has a storage unit for setting and storing a predetermined ringing time and a non-ringing time in advance, and a network control unit for capturing / opening control of a telephone line and a data transmitting / receiving unit for transmitting / receiving data. If the ringing time and the non-ringing time measured by the call signal monitoring unit after detecting the state change of the telephone line by the line state monitoring unit are the same as the stored ringing time and non-ringing time, the network control unit It automatically captures the line and controls the data transmission / reception unit to communicate with the calling party.

Further, the control unit is provided with a connection switching unit for connecting and disconnecting a terminal device such as a telephone, and when the line status monitoring unit detects a change in the state of the telephone line, the connection switching unit is controlled immediately. While disconnecting the terminal device, the ringing time and non-ringing time of the ringing signal are measured by the ringing signal monitoring unit, and the measured ringing time and non-ringing time,
When the stored ringing time and non-ringing time are the same, the network control unit automatically captures the line, controls the data transmitting / receiving unit, and performs communication with the calling side.

Further, the control unit is provided with a connection switching unit for connecting and disconnecting a terminal device such as a telephone, and when the measured ringing time and non-ringing time are different from the stored ringing time and non-ringing time, The connection switching unit is controlled to connect the terminal device to the telephone line.

Further, the control unit is provided with a paging signal monitoring unit for monitoring a paging signal from a telephone line, and the paging signal monitoring unit measures a ringing time and a non-ringing time with a signal not subjected to waveform shaping. did.

Further, the control unit is provided with a paging signal monitoring unit for monitoring a paging signal from a telephone line, and the paging signal monitoring unit measures a ringing time and a non-ringing time with a signal subjected to waveform shaping. did.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The control unit includes a line state monitoring unit for monitoring a change in the state of a telephone line, a call signal monitoring unit for monitoring a call signal from the telephone line, and a network control for capturing / opening the telephone line. Unit, a data transmitting and receiving unit for transmitting and receiving data is provided, and when a line state change is detected by a line state monitoring unit, the ringing signal monitoring unit measures a ringing time and a non-ringing time of a ringing signal. If the set ringing time and non-ringing time are the same, the network control unit automatically captures the line and controls the data transmitting / receiving unit to communicate with the calling side.

[0023]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic configuration diagram of the automatic meter reading system.

A monitoring center 101 includes a telephone line 102,
General home 105 via exchange 103 and telephone line 104
Is connected to Similarly, general household 107,..., N
+1 are also connected to the telephone lines 106,..., N.

Each telephone line 102, 104, 106, and N is an ISDN line.

On the monitoring center 101 side, a terminal adapter 11 for converting a digital signal into an analog signal
0, which processes and stores data sent from the network control device 111 or a general household which comprises a data transmission / reception unit for controlling a telephone line and transmitting / receiving data or a selection signal transmission unit for dialing. Computer 112 and the like are installed.

On the other hand, as shown in FIG. 3, a general home side has a terminal adapter 113 for converting a digital signal into an analog signal, a terminal device 114 for communicating with a center, a terminal device 115 such as a telephone, Meter 116
And so on.

An embodiment of the terminal device 1 of the present invention having the above-described configuration will be described with reference to the block diagram shown in FIG.

Reference numeral 1 denotes a terminal device, which includes a connection portion 20 such as a modular connector or a terminal block and a terminal adapter 2.
6 and a telephone line 25 of ISDN.

Reference numeral 2 denotes a control unit which controls or processes the operation of the terminal device 1. In general, a one-chip microcomputer (hereinafter referred to as a microcomputer) is used, and a program for performing a predetermined operation is stored therein. RO
M2-1, a RAM 2-2 for storing data, an arithmetic processing unit 2 for processing, judging, or giving control instructions for data
-3, etc., which operate according to a program stored in the ROM 2-1. Note that the ROM 2-1 and the RAM 2-2 are collectively referred to as a storage unit 2-
A.

Reference numeral 3 denotes a call signal monitoring unit which detects the input of a call signal from the terminal adapter 26 and measures the ringing time and non-ringing time of the calling signal. On the other hand, it checks the presence or absence of a call at the time of calling from the terminal.

Reference numeral 4 denotes a line voltage rectifier which converts the polarity of the line voltage into a fixed polarity, and uses a diode bridge or the like.

Reference numeral 5 denotes a line state monitoring unit which monitors the line voltage at a specified threshold voltage and detects a change in state due to reversal of the polarity or input of a calling signal at the time of calling to activate the circuit.

Further, it is determined whether or not the terminal device 1 is connected to the telephone line 25, and the terminal device 2 such as a telephone is determined.
Reference numeral 7 determines whether the line is in use.

Reference numeral 6 denotes a network control unit, which is connected via a line voltage rectification unit 4 and controls capture / release of a telephone line. When the line is captured, a closed circuit is formed with the specified terminal impedance,
Communication with the monitoring center is performed according to a predetermined procedure.

Reference numeral 7 denotes a selection signal transmitting unit for dialing the telephone number of the monitoring center when calling the monitoring center from the terminal side. A method using a dial pulse signal and a method using a DTMF signal are automatically selected according to the type of line or according to the setting.

Reference numeral 8 denotes a data transmitting / receiving unit for transmitting / receiving data to / from the monitoring center according to a predetermined procedure.

Reference numeral 9 denotes a connection switching unit for disconnecting or connecting the terminal equipment 27 from the line.
-1 or the like. While the terminal device 1 is using the line, the terminal device 27 is disconnected from the line.

Reference numeral 10 denotes an off-hook detection unit. When the use of the terminal device 27 is interrupted while the terminal device 1 is communicating with the monitoring center, this is detected and the terminal device 1 interrupts the communication with the monitoring center to establish a connection. The switching unit 9 is controlled to connect the line to the terminal equipment 2.
7 and preferentially handles the line use of the terminal device 27.

Reference numeral 11 denotes a data setting interface unit, which is data necessary for operating the terminal device 1, such as a telephone number of the monitoring center, a selection signal transmission mode, a customer number of a home where the terminal device 1 is installed, and a periodic monitoring center. It is for setting and confirming data such as the date and time of notification to. The setting is performed by connecting the data setting device 28 to the connection terminal 22.

Since the data setting device 28 is used only for setting or checking data, the data setting device 28 has a detachable structure for commuting. After the data setting, the data setting device 28 is removed.

Reference numeral 12 denotes a meter interface unit for transmitting and receiving data such as a measured value and information inside the meter to and from the meter 29 connected to the connection terminal 23 of the terminal device 1.

The meter 29 includes a gas meter, a water meter and a power meter, and is connected to each business.

Reference numeral 13 denotes an external device interface unit, which is a contact type sensor 3 connected to the connection terminal 24 of the terminal device 1.
This is an interface unit for monitoring the state of 0 or the state output of the gas leak alarm. Hereinafter, a contact type sensor will be described. However, even when a voltage type sensor, such as a gas leak alarm, that outputs a different voltage depending on the state is connected, monitoring can be performed in the same manner.

Further, a power supply for operating the terminal device 1 is required, but is omitted because it is not directly related to the present invention.

Next, the operation of the above configuration will be described.

When the terminal device 1 sends a report to the monitoring center, it operates as follows.

In this case, a predetermined monthly report, a report when a change in the state of the externally connected sensor 30 is detected, or a report from the meter 29 connected to the connection terminal 23 is provided. There is a report by detecting a communication request signal.

When the communication request signal from the meter 29 is detected, communication with the meter 29 is performed before receiving the notification operation to the monitoring center, the status data of the meter 29 is received, and the RAM 2 of the control unit 2 is received. -2.

The notification operation starts with the line state monitoring unit 5 monitoring the use state of the telephone line 25.

The signal from the line state monitoring unit 5 is the telephone line 2
If the telephone number 5 is not in use, or if no call signal is detected from the call signal monitoring unit 3, the network control unit 6 is controlled to capture the telephone line 25.

On the other hand, when the telephone line 25 is in use of the terminal device 27, the line state monitoring unit 5 continues monitoring until the telephone line 25 becomes unused.

When a call signal is detected, the call signal monitoring unit 3 and the line state monitoring unit 5 continue monitoring until the call signal disappears and the line becomes unused.

Next, when the network control unit 6 is controlled by the control unit 2 and the telephone line 25 is captured, the connection switching unit 9 is controlled to disconnect the terminal device 27 from the telephone line 25.

After a predetermined time elapses after the line is captured, the telephone number of the monitoring center is read from the storage unit of the microcomputer, converted into a dial pulse signal or a DTMF signal, and the selection signal transmitting unit 7 is controlled to transmit the selection signal. As the selection signal mode, a preset mode is automatically selected.

When the transmission of the selection signal is completed, the control unit 2
Controls the data transmission / reception unit 8 and starts monitoring the response signal from the monitoring center. When a response signal is detected, the data transmission / reception unit 8 is controlled according to a predetermined procedure to transmit / receive data. When communication is completed, the network control unit 6 is controlled to control the telephone line 2
Release 5. At the same time, it controls the connection switching unit 9 to connect the terminal device 27 to the telephone line 25.

During communication with the monitoring center, communication with the meter 29 can be performed via the terminal device 1 at the request of the monitoring center.

On the other hand, if the response signal from the monitoring center cannot be detected within a predetermined time after the transmission of the selection signal, the network controller 6 is controlled to release the telephone line 25. At the same time, the connection switching unit 9 is controlled to connect the terminal device 27 to the telephone line 25. Thereafter, after a lapse of a predetermined time, the terminal transmission is repeated again, and is repeated a predetermined number of times until the communication with the monitoring center ends normally.

During communication with the monitoring center, the use state of the terminal device 27 is monitored by the off-hook detection unit 10, and when the start of use is detected, communication with the monitoring center is interrupted and the network control unit 6 is stopped. Control is performed to release the telephone line 25. After the opening, after a lapse of a predetermined time, the connection switching unit 9 is controlled to connect the terminal device 27 to the telephone line 25, and the terminal device 27 gives priority to using the telephone line 25. The terminal device 1 monitors the line status monitoring unit 5 and waits for the terminal device 27 to finish using the telephone line 25.

Next, the communication operation by calling from the monitoring center is as follows.

For the call from the center, the following settings are required in advance.

For the terminal adapter 26, a telephone number of the monitoring center and a specific calling signal (for example, ringing time T1, non-ringing time T2) when calling from the monitoring center.
Set to output

For the terminal device 1, the ringing time T1 and the non-ringing time T2 of the specific calling signal set by the terminal adapter 26, and the number of ringing times and non-ringing times measured are set. Here, one ringing time, one non-ringing time
The case where two times are set will be described below.

First, the operation at the time of calling from the monitoring center will be described.

When there is a called call, the terminal adapter 2
6 outputs a polarity inversion signal or a call signal. When this signal is detected by the line state monitoring unit 5 or detected by the call signal monitoring unit 3, the connection switching unit 9 is immediately controlled and the terminal equipment 27 is connected to the telephone line 25. Disconnect.

As a result, the person at home does not notice that the terminal device 27 is in the calling state because the calling signal is not input to the terminal device 27 despite the presence of the calling signal.

In this state, the terminal device 1 immediately starts measuring the ringing time and the non-ringing time of the calling signal in the calling signal monitoring unit 3.

In the case of a call from the monitoring center, the call signal output from the terminal adapter 26 is a signal of the ringing time T1 and the non-ringing time T2. Terminal device 1
Monitors the ringing signal by the ringing signal monitoring unit 3 and terminates the measurement of one preset ringing time and one non-ringing time (assuming that the preset number of measurements is two times). The measured ringing time T1 and non-ringing time T2 are compared with the preset ringing time T1 and non-ringing time T2, and if they are the same, it is determined that the call is from the monitoring center, and the network control unit 6 is controlled to control the telephone line. 25 is captured automatically. (See FIG. 4) After capturing the telephone line, the data transmission / reception unit 8 is controlled and communicated with the monitoring center according to a prescribed communication procedure.

On the other hand, when calling from other than the monitoring center,
The ringing time and the non-ringing time are measured in the same manner as the above procedure.

However, when the telephone number of the calling side is other than the monitoring center set in the terminal adapter 26, the calling signals output by the terminal adapter 26 are the ringing time T3 and the non-ringing time T4. The ringing time T1 and the non-ringing time T2 set to 1 are different.
Therefore, the terminal device 1 does not shift to the communication state because the measured value and the set value are different, but controls the connection switching unit 9 to switch the relay contact 9-1, and connects the terminal device 27 to the line 25 side. Connect to As a result, since the call signal output from the terminal adapter 26 is input to the terminal device 27, a ring of a telephone or the like is sounded to notify that there is a call.

In this case, the time required for the terminal device 1 to measure the ringing time and the non-ringing time varies depending on the setting, but it can be recognized if the time is about 1 second, so that there is no problem about the delay of the telephone call to the person at home. Range.

FIGS. 6 and 8 show specific circuit examples of the call signal monitoring section 3. FIG.

FIG. 6 is an example of a circuit without a waveform shaping section.
Resistance 151, Zener diode 15 reversely connected
2 and 153, a capacitor 154, and a primary side of a bidirectional type photocoupler 155 connected in series are connected to a line portion in the terminal device 1.

The secondary side is connected to the power supply via the resistor 156 on the collector side of the photocoupler 155, and the emitter side is connected to the ground.

In this circuit, the Zener diode 15
In the state lower than the Zener voltages of 2 and 153, the output signal is "H" without turning on the photocoupler 155.

On the other hand, in a state higher than the Zener voltage,
Since the photocoupler 155 is turned on, the output signal is “L”.

FIG. 7A shows a waveform of a calling signal input to the calling signal monitoring unit 3, and FIG. 7B shows an output waveform of the photocoupler 155. In the output waveform, part A is a ringing period,
Part B is a non-ringing period.

That is, the ringing period is "H / L" and the non-ringing period is "H".

FIG. 8 is a circuit example of the call signal monitoring unit 3 having a built-in waveform shaping unit 159. The circuit is the same as that of FIG. 6 except for the waveform shaping unit 159.

In this circuit, the resistor 157 and the capacitor 15
The waveform shaping section 159, which is a time constant circuit made up of eight, is added, and the output waveform of the calling signal is as shown in FIG. 9B. In the output waveform, part A is a ringing period, and part B is a non-ringing period.

Next, a method of monitoring the ringing time and the non-ringing time of the call signal will be described.

The monitoring starts when the line state monitoring unit 5 or the paging signal monitoring unit 3 detects a state change.

For the waveform shown in FIG. 7B, the following processing is performed.

FIG. 10 is an enlarged view of the output signal of the call signal monitoring section 3 in FIG. 7B, and the signal is monitored at regular time intervals (Td). During the ringing period, the output signal repeats the “L” and “H” states at predetermined intervals,
On the other hand, the output signal during the non-ringing period is fixed at “H”.

The monitoring starts with the measurement of the ringing time, and then repeats the non-ringing time and the ringing time.

The monitoring is terminated when a preset number of times have been measured.

The measurement is performed by using a measurement counter and a monitoring counter.
This is performed using the number of counters.

After detecting the output signal = “L”, the measurement counter increments by one each time monitoring is performed, and the monitoring counter is cleared when the read state is different from the previous state.

The ringing time starts after the output signal becomes "L", and continues for a predetermined number of "H" s (here, Z).
+1) and the ringing period can be treated as having ended, so that the ringing time can be obtained by the following formula: ringing time = measurement counter value-(monitoring counter value + 1).
Do one.

Subsequently, the monitoring counter value is temporarily stored in advance to measure the non-ringing time, and after the calculation, the temporarily stored monitoring counter value is copied to the measurement counter. As a result, the monitoring time from when the state becomes “H” is stored in the measurement counter.

On the other hand, since the non-ringing time can be measured by the time from the end of the measurement of the ringing time to the detection of the output signal = L, the non-ringing time is obtained by the following formula: non-ringing time = measurement counter value-1. This can be stored, and the storage count
Do one.

Thereafter, the same processing is performed, and when the number of measurements set by the storage counter has reached, the monitoring processing of the call signal is ended.

FIG. 11 is a schematic flowchart for the above processing.

When the monitoring starts, the monitoring timer starts,
The monitoring first set and the number of times of measurement are set (S1).

Next, the control waits for the monitoring timing (S2). At the monitoring timing, the input state is read and stored (S2).
3).

Next, it is determined whether or not it is the first monitoring (S4).
In the case of the first monitoring, it is determined whether the input state is "L" (S5). If the input state is "H", the process returns to monitoring timing waiting (S2). On the other hand, when the input state is "L", the monitoring first clear, the measurement counter = 0, the monitoring counter = 0, and the sound monitoring set are set (S6).

If it is not the first monitoring in S4, it is determined whether the state input this time is the same as the previous state (S7). If they are different, the previous state is stored, and the measurement counter is set to +1 and the monitoring counter is set to 0 (S8).

Next, it is checked whether or not ringing is currently being monitored (S9). If ringing is being monitored, the process returns to (S2) and waits for monitoring timing. When ringing is not being monitored, “measurement counter value −1” is stored as the non-ringing time, and
The number of storage times is incremented by one. Further, the monitoring counter value is copied to the measurement counter value, and the sound monitoring is set (S1).
0).

Next, it is checked whether the set number of times has been measured or not (S16). If the set number of times has been measured, the monitoring process ends. If the measurement of the set number of times has not been completed, the process returns to (S2) and waits for the monitoring timing.

On the other hand, if the state read this time is the same as the previous state (S7), the measurement counter and the monitoring counter are each incremented by one (S11).

Next, it is checked whether or not ringing is currently being monitored (S12). If ringing is not being monitored, the process returns to (S2) and waits for a monitoring timing.

If sound monitoring is being performed, the current state is checked (S13), and if "L", the flow returns to (S2) to wait for monitoring timing. If it is "H", the monitoring counter is checked (S14). If it is smaller than the specified value Z, the process returns to (S2) and waits for the monitoring timing. If it is equal to or greater than the specified value Z, “measurement counter− (Z + 1)” is stored as the ringing time, and the number of times of storage is incremented by one. Further, the monitoring counter value is copied to the measurement counter value, and the sound monitoring is cleared (S15).

Next, it is checked whether the set number of times has been measured or not (S16). If the set number of times has been measured, the monitoring process ends. If the measurement of the set number of times has not been completed, the process returns to (S2) and waits for the monitoring timing.

The specified value Z is a value for judging the end of the ringing period, and satisfies "Z> (Ta / sampling period)" with respect to the time Ta of the state "H" during the ringing period. Value.

On the other hand, the following processing is performed for the waveform shown in FIG.

In FIG. 12, when monitoring is started, a monitoring timer is started, monitoring is first set, and the number of measurements is set. (S50) Wait for the monitoring timing in S51, and when the monitoring timing comes, the input state is read and stored. (S52) Subsequently, it is compared whether the current input state is the same as the previous state (S53), and if it is the same, the monitoring counter is incremented by 1 (S54), and the monitoring timing is waited (S51).

If it is different from the previous time, the input state is determined (S55). If it is "L", the monitoring counter value is stored as the ringing time, monitoring is cleared for the first time, and the number of storages is incremented by 1 (S56). The counter is set to 0, and it is determined in step 58 whether or not the storage of the counter value for the specified number of times has been completed.

If the specified number of times has been stored, the monitoring of the calling signal is terminated.

If the storage of the specified number of times has not been completed,
It returns to step 51 and waits for the monitoring timing.

On the other hand, if the input state is "H", it is determined whether or not it is the monitoring first set. In the case of the first monitoring, the process proceeds to the monitoring counter = 0.

If the monitoring is not the first time, the monitoring counter value is stored as the non-ringing time, the number of storage times is incremented by 1, the monitoring counter is set to 0, and it is determined whether or not the storage of the counter value for the specified number of times is completed. If the specified number of times has been stored, the monitoring of the call signal is terminated.

If the storage of the specified number of times has not been completed,
It returns to step 51 and waits for the monitoring timing.

[0114]

As described above, by using the function of the terminal adapter connected to the ISDN telephone line, a setting is made to output a specific call signal when a call is made from a specific calling number. By measuring the ringing time and non-ringing time of the specific call signal and comparing the measured value with the set value, the terminal device automatically identifies whether the calling side is the monitoring center or not. I do.

Further, the terminal device is disconnected from the telephone line as soon as the call signal is detected. Therefore, when a call is made from the monitoring center, the terminal device such as a telephone does not receive a call signal, so that the bell does not ring and the person at home does not hear the bell. There is no answer to calls for communications that do not need to be answered.

[Brief description of the drawings]

FIG. 1 is a block diagram of a terminal device showing one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an automatic meter reading system showing one embodiment of the present invention.

FIG. 3 is a schematic configuration diagram illustrating a terminal device according to an embodiment of the present invention.

FIG. 4 is a characteristic diagram of a call signal measurement from a monitoring center according to an embodiment of the present invention.

FIG. 5 is a characteristic diagram of a call signal measurement from a source other than the monitoring center according to the embodiment of the present invention.

FIG. 6 is a specific circuit example of a call signal monitoring unit without a waveform shaping unit according to an embodiment of the present invention.

FIGS. 7A and 7B are input / output waveform diagrams (a) and (b) of a call signal without a waveform shaping unit according to an embodiment of the present invention.

FIG. 8 is a specific circuit example diagram of a call signal monitoring unit having a waveform shaping unit according to an embodiment of the present invention.

FIGS. 9A and 9B are input / output waveform diagrams (a) and (b) of a call signal having a waveform shaping unit according to an embodiment of the present invention.

FIG. 10 is a diagram illustrating a principle of measuring a ringing time according to an embodiment of the present invention.

FIG. 11 is a schematic processing flowchart of a call signal monitoring unit without a waveform shaping unit according to an embodiment of the present invention.

FIG. 12 is a schematic processing flowchart of a call signal monitoring unit having a waveform shaping unit according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Terminal device 2 Control part 3 Ringing signal monitoring part 4 Line voltage rectification part 5 Line state monitoring part 6 Network control part 7 Selection signal sending part 8 Data transmission / reception part 9 Connection switching part 10 Off-hook detection part 11 Data setting interface part 12 Meter interface Unit 13 External device interface unit

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideaki Kitagawa 3-1, Shinjuyoji, Kashiwa-shi, Chiba F-term in Hitachi Home-Tech Corporation 2F073 AA07 AA08 AA09 AB02 BB09 BC01 CC01 CC11 DD02 DE11 GG01 GG02 GG07 GG08 5K048 BA36 CA12 EA22 5K101 KK12 PP06 QQ01 UU01 UU05 UU20

Claims (6)

[Claims] 1. A terminal device having a control unit (2) installed on an ordinary household side of a system for collecting information such as a meter (29) installed in an ordinary household at a monitoring center using a telephone line (25). A line state monitoring unit (5) for monitoring the polarity inversion of the telephone line (25) or an unused state or a used state, and a telephone line (2).
A call signal monitoring unit (3) for monitoring a call signal from the telephone line (2) is provided by the line state monitoring unit (5).
A terminal device characterized in that upon detecting the state change of (5), the ringing signal monitoring unit (3) measures a ringing time and a non-ringing time of a calling signal. 2. A network control unit having a storage unit (2-A) for setting and storing a predetermined ringing time and a non-ringing time in the control unit (2), and for controlling the capture / release of a telephone line (25). (6) and a data transmitting / receiving unit (8) for transmitting / receiving data
And the line status monitoring unit (5) provides the telephone line (2).
If the ringing time and non-ringing time measured by the ringing signal monitoring unit (3) after detecting the state change of 5) are the same as the stored ringing time and non-ringing time, the network control unit (6) automatically 2. A communication system for capturing a line and controlling a data transmitting / receiving unit to communicate with a calling side.
The terminal device as described in the above. 3. The control unit (2) is provided with a connection switching unit (9) for connecting and disconnecting a terminal device (27) such as a telephone, and the line status monitoring unit (5) controls the telephone line (25). As soon as the state change is detected, the connection switching unit (9) is controlled to disconnect the terminal device (27).
The ringing time and non-ringing time of the ringing signal are measured by the ringing signal monitoring unit (3), and if the measured ringing time and non-ringing time are the same as the stored ringing time and non-ringing time, the network control unit (6) 3. The terminal device according to claim 2, wherein the terminal automatically acquires the line and controls the data transmission / reception unit to communicate with the calling side. 4. The control unit (2) is provided with a connection switching unit (9) for connecting and disconnecting a terminal device (27) such as a telephone, and measures a measured ringing time and a non-ringing time.
4. The terminal device according to claim 3, wherein when the stored ringing time and non-ringing time are different, the connection switching unit (9) is controlled to connect the terminal device (27) to the telephone line (25). 5. The control unit (2) is provided with a call signal monitoring unit (3) for monitoring a call signal from a telephone line (25),
5. The terminal according to claim 1, wherein the ringing signal monitoring unit measures ringing time and non-ringing time using a signal that is not subjected to waveform shaping. 6. apparatus. 6. The control unit (2) is provided with a call signal monitoring unit (3) for monitoring a call signal from a telephone line (25),
5. The terminal according to claim 1, wherein the ringing signal monitoring unit (3) measures a ringing time and a non-ringing time with a signal having undergone waveform shaping. apparatus.