JP4214589B2 - Terminal network controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a terminal network control device that connects a gas meter meter in each household and an automatic meter reading device of a central management center via a telephone line and communicates between them, and more particularly, an improvement in a circuit for detecting a telephone off-hook. Regarding technology.
[0002]
[Prior art]
FIG. 4 shows a block diagram of an off-hook detection circuit of a conventional terminal network control apparatus. The conventional off-hook detection circuit 111 of the terminal network control device is located inside the main body of the terminal network control device 101, is electrically coupled, and raises the voltage of the power source 113 of the main body of the terminal network control device. A converter circuit 116 is provided so as to be a power source 111.
[0003]
Further, in FIG. 4, the interface circuit unit 109 is electrically insulated from the main body control unit 110 of the terminal network control device by the optical communication circuit components and the like, and the power supply unit 112 is also configured independently.
[0004]
Next, the operation of the conventional off-hook detection circuit will be described with reference to FIGS.
The converter circuit 116 operates only when the main body control unit 110 of the terminal network control device operates, such as communication between the gas metering meter in each household and the automatic metering device in the central management center, in order to reduce power consumption. The operating voltage range of the off-hook detection circuit 111 is such that the power supply voltage of the main body power supply 113 of the terminal network control device decreases due to current consumption or environmental changes, or voltage loss occurs due to the internal circuit of the telephone 107 during operation. In consideration of the case where the power supply becomes narrow and does not operate, a voltage that is constant and higher than the main power supply 113 of the terminal network control device is generated so that the off-hook detection circuit 111 operates stably.
[0005]
Next, when the telephone 107 is connected to the telephone line 102 via the telephone line connection terminal 106 by the switch 114, such as when communication is not performed or requested by the central monitoring center as shown in FIG. The line voltage is monitored and compared with a specified value to detect the off-hook of the telephone 107.
[0006]
Next, as shown in FIG. 5, when the telephone 107 is disconnected from the telephone line 102 by the switch 114, such as communication by a request from the external equipment 105 connected to the external equipment connection terminal 104, the telephone 107 The off-hook is detected by monitoring the resistance value and comparing it with the specified value.
[0007]
Next, an off-hook detection signal is transmitted to the terminal network control device main body control unit 110 in the electrically connected state, and the switch 114 is switched to the telephone line 102 side so that the telephone 107 can be used.
[0008]
In addition, as shown in FIG. 4, the conventional terminal network control device includes a power supply voltage detection circuit 117 that detects when the power supply voltage falls below a specified value in the terminal network control device main body 101. 109 is not equipped.
[0009]
[Problems to be solved by the invention]
Such a conventional off-hook detection circuit requires a converter circuit, resulting in a significant increase in cost, and noise generated from the converter circuit affects the performance of the terminal network control device. In some cases, it is applied to the terminal network control device main body via the off-hook detection circuit, causing a problem in a control system such as a microcomputer.
[0010]
In addition, even if the interface circuit power supply voltage drops below the specified value due to abnormal use or external factors, it cannot be detected, and even if the power supply voltage of the terminal network control device exceeds the specified value, communication cannot be performed. Had.
[0011]
[Means for Solving the Problems]
In the present invention, a telephone line connection terminal, a telephone connection terminal, an external connection terminal, an interface circuit unit that is connected to the external device and performs data communication in an electrically insulated state, and a terminal network control body are controlled. A power supply for the main body, a single power supply for the interface circuit section, and off-hook detection means that operates with the single power supply and detects that the telephone is off-hook.
[0012]
According to the present invention, for example, static electricity charged on the human body does not adversely affect a control system such as a microcomputer via the off-hook detection circuit.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
A circuit for detecting an off-hook of a telephone that operates with an independent power source is provided in the interface circuit unit that has an independent power supply unit with respect to the terminal network control unit main body, and is electrically insulated. And connected to the main body control unit of the terminal network control device.
[0014]
The off-hook detection circuit unit can be electrically insulated from the terminal network control device main unit, and an operating voltage that is not affected by the power supply voltage of the main unit is ensured.
[0015]
In addition, the power supply voltage of the interface circuit unit is configured to be higher than the power supply voltage detection level of the terminal network control device main unit by the off-hook operation detection voltage of the telephone, and this is used as the power supply of the off-hook circuit, so that the terminal network control device Even when the power supply voltage of the main body is lowered, it is detected that the telephone connected to the telephone connection terminal of the terminal network control device is off-hook.
[0016]
Further, in the terminal network control apparatus, the telephone connected to the telephone connection terminal is detected based on a request from an external device connected to the external connection terminal to detect the off-hook operation of the telephone connected to the telephone connection terminal. It is configured to be performed in a state separated from the line.
[0017]
The off-hook detection circuit including the telephone can be completely separated and independent from the main body control unit of the terminal network control device, and the off-hook operation can be determined by the telephone alone, so that the off-hook detection circuit can be simplified.
[0018]
In addition, the terminal network control device includes means for operating with the power supply of the interface circuit unit, electrically insulating and connecting to the terminal network control device body, and comparing and determining the power supply voltage of the interface circuit unit with a specified value. Yes.
[0019]
When the power supply voltage of the interface circuit is monitored and falls below the specified value, a signal is sent to the main body control unit of the terminal network control device while being electrically insulated by optical communication circuit components, etc. Etc.
[0020]
【Example】
Preferred embodiments of the present invention will be described with reference to the drawings.
[0021]
Example 1
FIG. 1 shows a configuration block diagram of a terminal network control apparatus according to the first embodiment.
[0022]
In the figure, reference numeral 1 denotes a terminal network control device that is connected to a center device 3 via a telephone line 2 and performs data communication with an external device 5 such as a meter-reading meter connected to an external connection terminal 4. Yes, 6 is a telephone line connection terminal for connecting the telephone line 2, and 7 shows a telephone on-hook state connected to the telephone line 2 via the telephone connection terminal 8 of the terminal network control device 1.
[0023]
Reference numeral 9 denotes an interface circuit unit that electrically insulates the main body control unit 10 of the terminal network control device 1 from the external device 5 and performs data communication. 11 is electrically insulated from the inside of the interface circuit unit 9 and is configured such that the power supply voltage is higher than the detection level of the power supply voltage detection circuit 17 of the terminal network control device main body power supply 13 by the off-hook operation detection voltage of the telephone set 7 or more. This is an off-hook detection circuit that operates with the interface circuit unit power supply 12 and detects the off-hook of the telephone 7 by being electrically insulated in the same manner as the interface circuit unit.
[0024]
Reference numeral 14 denotes a switch for connecting or disconnecting the telephone 7 to or from the telephone line 2, and FIG. 1 shows a state at the time of standby and at the time of communication in response to a request from the center apparatus 3. FIG. 2 shows a state in which the terminal network control device 1 is in communication with a request from the external device 5. The telephone 7 is disconnected from the telephone line 2 by the switch 14 and connected to the off-hook detection circuit 11. It represents an off-hook state.
[0025]
Next, the operation will be described. When the telephone 7 is off-hooked by the switch 14 as shown in FIG. 2 while being connected to the off-hook detection circuit 11, the off-hook detection circuit 11 detects changes in the impedance or voltage drop of the telephone 7, and optical communication components, etc. The signal is sent to the main body control unit 10 of the terminal network control device 1 in a state where it is electrically insulated by the terminal network control unit 10, and the main body control unit 10 receiving the signal terminates communication in accordance with a preset program. The switch 14 is switched so that it can be used.
[0026]
(Example 2)
FIG. 3 is a block diagram showing the configuration of the terminal network control apparatus according to the second embodiment.
[0027]
In FIG. 3, reference numeral 15 denotes a voltage drop detection circuit for the interface circuit power supply 12 configured in the interface circuit unit 9, which detects when the voltage drops below a specified value and is electrically connected by a photocoupler or the like, similar to the off-hook detection circuit 11. The signal is transmitted to the main body control unit 10 of the terminal network control device 1 while being insulated from the mobile phone, and is transmitted to the center device 3 via the telephone line 2.
[0028]
【The invention's effect】
As is clear from the above description, the terminal network control apparatus of the present invention has the following effects.
[0029]
Further , according to the present invention, since the off-hook circuit is configured to be electrically insulated, static electricity charged on the human body is applied to the terminal network control device main body via the off-hook detection circuit when the telephone is operated, In particular, there will be no problems with control systems such as microcomputers.
[0030]
In addition, according to the present invention, the power supply voltage of the interface circuit unit is set higher than the power supply voltage of the main body of the terminal network control device so that the voltage can be sufficiently driven as a substitute for the converter circuit in the conventional off-hook detection circuit. By using the interface circuit power supply in an insulated state, a significant cost reduction can be achieved, and the occurrence of noise when the converter circuit is used eliminates the influence on the performance of the terminal network control device. It becomes unnecessary.
[0031]
Further , according to the present invention, the off-hook detection function of the telephone is performed in a state where the telephone connected to the telephone connection terminal is separated from the terminal network control device and the telephone line based on a request from an external device connected to the external connection terminal. By limiting to the case, the telephone can be detected as a simple resistance value or a voltage drop, and the circuit configuration can be simplified.
[0032]
Further, according to the present invention, operating in the power supply of the interface circuit portion, and means for comparing determines that the specified value electrically insulating the power supply voltage of the interface circuit portion connected to the terminal network controller body By providing, when the power supply of the terminal network control device main body exceeds the specified value, abnormal use of the power supply of the interface circuit section or voltage drop due to external factors is detected, and the terminal before the interface circuit operation becomes impossible It is possible to take measures such as reporting to the center device through the network control device main body control unit and the telephone line.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a terminal network control apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a state where a telephone is off-hooked in the apparatus. FIG. 4 is a block diagram of a conventional terminal network control device. FIG. 5 is a block diagram of the configuration when the telephone is disconnected from the telephone line by a switch.
DESCRIPTION OF SYMBOLS 1 Terminal network control apparatus 2 Telephone line 3 Center apparatus 4 External connection terminal 5 External apparatus 6 Telephone line connection terminal 7 Telephone 8 Telephone connection terminal 9 Interface circuit part 10 Main body control part 11 Off-hook detection circuit 12 Interface circuit part power supply 13 Main part power supply 14 Switch 15 Voltage drop detection circuit 16 Converter circuit 17 Voltage detection circuit of main body power supply section

Claims (1)

A telephone line connection terminal to which a telephone line is connected, a telephone connection terminal to which a telephone is connected, an external connection terminal to which an external device such as a meter-reading meter is connected, and a state in which the external device is connected and electrically insulated The interface circuit unit for data communication, the main unit power source for controlling the terminal network control main unit, the single power source for the interface circuit unit, and the off-hook detection that operates with the single power source and detects that the telephone is off-hook. With means ,
The single power supply is set to be higher than the voltage detection level of the main body power supply by a voltage for detecting the off-hook operation of the telephone, and the off-hook detection means is electrically insulated from the interface circuit section. Terminal network controller.

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