JPH1084429A - Terminal network controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid having effects from being made onto terminal equipments after a digital service unit(DSU) by connecting the controller between a protector and the DSU (at point LI). SOLUTION: The controller is provided with a 1st LI point connection means 9 connection to an interface LI point of an ISDN line, a 2nd LI connection means 10 connecting to an interface point LI of a DSU 2, a terminal connection means 11 connecting to a terminal equipment 8 for communication, and an exchange means 12 that exchanges frames arbitrarily among the 1st LI point connection means 9, the 2nd LI point connection means 10 and the terminal connection means 11. Thus, the comunicatin between the ISDN line and the terminal equipment 8 is made, via the 1st LI point connection means 9 and the terminal connection means 11 and the communication between the terminal equipment at the DSU side and the terminal equipment 8 is made via the 2nd LI point connection means 10 and the terminal connection means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal network control device for connecting a meter sensor or equipment to a remote management device via an ISDN line for communication.

[0002]

2. Description of the Related Art Automatic meter reading of an energy supply management device (for example, a gas meter, a water meter, an electric power meter) from a remote management device using a telephone network, notification of a gas leak to the remote management device, and failure notification of equipment. Systems for performing remote diagnosis and the like are becoming widespread.

[0003] Further, ISDN telephone lines have begun to spread, and introduction to general households for accessing personal computer communication and the Internet has also become active. As shown in FIG. 10, a general system configuration is such that a digital line termination unit (hereinafter referred to as DSU) 2 is connected to a two-wire metal cable drawn into a house from a public switched telephone network (ISDN) via a security device 1. Transmission line termination such as wire-to-wire conversion is performed, and a digital telephone 3 for ISDN is connected to the four wires, and a terminal adapter (hereinafter referred to as TA) 4 is connected.
To perform protocol conversion, and connect to a terminal device 5 such as a personal computer using an RS-232C cable or the like. N
In TT (Nippon Telegraph and Telephone Corporation), DS
The interface up to U2 is the reference point LI, and the interface from DSU2 to the telephone 3 or TA4 is the reference point S /
The interface from T and TA 4 to the terminal device 5 such as a personal computer is referred to as a reference point R. The S / T point is TT
ISDN user / network interface points defined in C.I.411, and point R is an existing user / network interface point defined in ITU-T Recommendations V, X series, etc.

[0004] The ISDN line has a 16 kbit / s signal channel called a D channel, and controls the start and stop of communication and sends and receives information. A plurality of terminals can be connected to the S / T point by bus, and the connected terminals can access the D channel in order, and even if two or more terminals try to access the D channel at the same time, The D-channel access procedure that ensures that only one terminal always performs normal information transmission is adopted. However, at the LI point, only one DSU is connected.

[0005] As an example of communication between the remote management device and the energy supply management device via the ISDN public network,
JP-A-5-7259 discloses an automatic meter reading system. The system configuration is as shown in FIG. 11. In FIG. 11, reference numeral 6 denotes a remote management device, which is also called a center device in an automatic meter reading system, and is installed in a gas company or a security company to install each customer's home and the ISDN public network. Connected through. Reference numeral 7 denotes a terminal network control device, which is connected to the S / T point and is a gas meter 8 as an energy supply management device.
It relays communication between the remote management device 6 and the remote management device 6, and controls connection and disconnection of a line.

[0006] In the automatic meter reading system using the ISDN line, a procedure until the remote management device obtains the meter reading data of the gas meter is shown in FIG. 11 and FIG.

(1) The remote management device 6 establishes connection with the customer's home in response to a call setting request including the telephone number of the customer's home where the meter is to be read. At this time, in order not to activate the telephone 3 at the customer's home, a sub address unique to the gas meter is given as a telephone number (for example, the telephone number 9-876 at the customer's home).
5 with a sub-address 123).

(2) The DSU 2 connected to the ISDN public network by the LI point has a line inversion (SI) at the LI point.
Start-up is performed by receiving a predetermined start-up signal (SIG4) following G3), and the start-up acknowledge signal (SIG2) is set to L.
Send to point I. Here, the activation signal (SIG4) is a synchronization establishment signal for synchronizing reception.

(3) When the switch of the public network receives the activation acknowledge signal (SIG2), it transmits a line system activation indication signal (SIG6) to the DSU2.

(4) When DSU2 receives the line system activation signal (SIG6) from the LI point, it transmits a predetermined terminal activation signal (INFO2) to the S / T point.

(5) The terminal network control device 7 connected to the S / T point receives the terminal activation signal (INFO2) from the S / T point, activates the terminal activation signal, and issues a terminal activation completion signal (INFO3) to the S / T point. Send to point T.

(6) The DSU 2 receives the terminal start-up completion signal (INFO3) from the S / T point and sends out the INFO3 reception display signal (SIG8) to the LI point. A network control device 7 is connected to the public network.

(7) The terminal network control unit 7 returns a call setting response only when the call setting information data received via the public network and the DSU 2 is provided with the sub-address of the terminal itself, and the remote management device 6 and the terminal A call with the network control device 7 is established.

(8) After connection with the remote management device 6, the terminal network control device 7 relays the data received from the remote management device 6 to the gas meter 8.

(9) If the received data is a meter reading request, the gas meter 8 transmits meter reading value data.

(10) The terminal network control device 7 transmits the meter reading data from the gas meter 8 to the S / T point.

(11) The DSU 2 transmits data from the terminal network control device 7 to the remote management device 6 via the ISDN public line.
Send to

Also, as disclosed in Japanese Patent Application No. 8-131530, a terminal network control device has been devised which is connected in parallel with the DSU at an LI point between the protector and the DSU to relay communication between the ISDN line and the terminal device. I have. According to this device, the remote management device and the terminal device connected to the LI point of each customer's house are connected to the DSU.
Communication can be performed only when subsequent terminals are not communicating.

[0019]

The above-mentioned conventional system has the following problems.

(1) In a device such as a TA that is connected between a DSU and a terminal device, the installation position of the device is easily influenced by the installation position of the DSU.

(2) When a device is attached between the protector and the DSU (LI point), the terminal after the DSU cannot recognize the collision of the D channel communication with the device connected to the LI point.

(3) Further, the DSU attempts to transmit the D channel signal of the terminal after the DSU irrespective of the communication status of the device connected to the LI point.

(4) Terminals after the DSU cannot directly communicate with devices connected to the LI point.

(5) When the terminal network controller operates on an external power supply such as a commercial power supply, if the power supply is turned off, it is not possible to make an abnormality report such as gas leak from a meter sensor or equipment, so that emergency is required. Is impaired.

(6) Since the equipment connected to the LI point starts and stops the communication operation by reversing the line polarity of the LI point, communication becomes impossible if the connection to the terminal of the protector is incorrect.

(7) Also, since the DSU also performs the start and stop processing of the communication operation according to the polarity of the LI point, if the connection to the terminal of the DSU is incorrect, the terminals after the DSU cannot communicate.

(8) When the terminal network control device is installed indoors, it is difficult to perform wiring work to a terminal device such as a gas meter outdoors, and it may be necessary to drill a hole in a house.

(9) Protector and D of equipment connected to LI point
If the connection with the SU can be easily disconnected, the connection will be disconnected due to mischief or the like, and communication within the customer's house will not be possible.

(10) The equipment connected to the LI point must be installed outdoors in order to communicate with an outdoor meter sensor and equipment.

[0030]

In order to solve the above-mentioned problems, the present invention provides a first LI point connecting means connected at an interface LI point of an ISDN line and a second LI point connecting means connected at an interface LI point to a DSU. LI connection means, terminal connection means for connecting and communicating with a terminal device, and the first LI
And a switching means for exchanging frames between any of the point connection means, the second LI point connection means and the terminal connection means.

According to the above invention, the terminal network control device is connected between the protector and the DSU, and the communication between the ISDN line and the terminal device can be performed via the first LI point connection means and the terminal connection means. D via the second LI point connection means and the terminal connection means
Communication between the terminal on the SU side and the terminal device can be performed.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a first LI point connecting means connected at an interface LI point of an ISDN line,
A second LI connection unit connected at an interface LI point to the SU, a terminal connection unit connected to and communicating with a terminal device, the first LI point connection unit, the second LI point connection unit, and the terminal Exchange means for exchanging frames between any of the connection means and the connection means. Then, the connection between the protector and the DSU enables communication between the ISDN line and the terminal device via the first LI point connection means and the terminal connection means.

Further, the switching means includes connection and disconnection means for connecting and disconnecting the first LI point connection means and the second LI point connection means, and impedance matching means for matching the impedance of the LI point to the impedance at the time of communication. When,
In-communication detecting means for detecting the line voltage of the ISDN line to detect that communication is in progress, polarity inversion detecting means for detecting inversion of the polarity of the ISDN line, and signals from the in-communication detecting means and the polarity inversion detecting means. Controlling the connection and disconnection means by the first LI point connection means and the second LI point connection means.
And a communication control means for transferring a frame between the point connection means and the terminal connection means. And I
Since the second LI connecting means is disconnected from the ISDN line by the disconnecting means while the terminal device is communicating with the SDN line, unnecessary communication data does not flow to the DSU.

Further, the switching means extracts the first information on the D channel in the frame received via the first LI point connection means, and extracts the second information on the other channels.
The first channel receiving and transferring means for transferring to the LI point connecting means, and the second information relating to the D channel in the frame received via the second LI point connecting means are extracted and the other information is used for other channels. A second channel reception and transfer unit for transferring to the first LI point connection unit; and a terminal connection unit when the first information is predetermined information, and a second LI when the first information is not predetermined information. First D-channel receiving means for notifying information to the point connection means, and third information and the second information requested to be transmitted from the terminal connection means are transmitted to the D channel via the first LI point connection means. And first D-channel transmitting means for transmitting as information. Since the first D channel receiving means does not transfer the information to the terminal device to the second LI point connecting means,
The data to be transferred to the terminal device in the received data from the SDN line does not flow to the DSU side, so that the terminal on the DSU side does not needlessly start up,
Only when there is no transmission data from the terminal, the transmission data from the terminal device is transferred to the first LI point connection means, so that the transmission data from the terminal device is transmitted to the ISDN line without colliding with the transmission data of the terminal on the DSU side. It is possible to

Further, the switching means extracts the first information on the D channel from the frame received via the first LI point connection means, and extracts the second information on the other channels.
The first channel receiving and transferring means for transferring to the LI point connecting means, and the second information relating to the D channel in the frame received via the second LI point connecting means are extracted and the other information is used for other channels. A second channel receiving and transferring means for transferring to the first LI point connecting means; and a terminal connecting means for transmitting the first LI when the second information is not the predetermined information when the second information is the predetermined information. A second D channel transmitting means for notifying the information to the point connection means, a third information requested to be transmitted from the terminal connection means and the first information of the D channel via the second LI point connection means. And a second D-channel receiving means for notifying as information. The second D-channel receiving means is ISDN
Since the transmission data from the terminal device is transferred to the second LI point connection means only when there is no reception data from the line, the transmission data from the terminal device is transmitted to the DSU without colliding with the reception data from the ISDN line. Since the second D-channel transmitting means does not transfer the predetermined information to the first LI point connecting means, the data transmitted from the DSU to the terminal device does not flow to the ISDN line, but the ISDN line. Unnecessary data is not transmitted.

Further, a first LI point connecting means connected to the LI point of the ISDN line, and an S / T for connecting to the interface S / T point and connecting to the ISDN line via the first LI point connecting means. T point connection means, terminal connection means for connecting a terminal device and connecting to the S / T point interface for communication, the first LI point connection means, the S / T point connection means, and the terminal connection means And line power supply means for supplying power supplied from the exchange to the LI point via the ISDN line as a power source.
When the terminal network control device is connected to the ISDN line, the line power supply supplies power to each unit, so that communication with the terminal device can be performed at any time via the ISDN line.

Further, the first LI point connecting means and the ISDN
It is provided with line polarity determining means for determining the connection polarity of the two metal cables to the line, and line connection switching means for switching the connection of the two metal cables. When the terminal network control device is connected to the ISDN line, the line connection switching unit can switch the line connection so that the line polarity can be recognized and communication can be performed by the line polarity determination unit. It is not necessary to consider the connection polarity at the time of wiring.

Further, D is connected via the second LI point connection means.
DSU connection determination means for determining the connection polarity with the SU, and DSU for switching the connection polarity of the second LI point connection means
Connection switching means. When the terminal network control unit is connected to the DSU, the DSU connection switching unit can switch the DSU connection so that the DSU connection determination unit can determine whether the connection with the DSU is correct or not and perform communication. It is not necessary to consider the connection polarity at the time of wiring.

Further, the terminal connection means includes a wireless communication means for communicating with the terminal device wirelessly. Even if the terminal network control device is installed indoors, there is no need to make a hole in the wall of a house or perform wiring work for connection with a terminal device installed outdoors.

Further, the first LI point connection means and the ISDN
The connection with the line, the connection between the second LI point connection means and the DSU, and the connection between the terminal connection means and the terminal device by respective metal cables are made by screws.
And even if the terminal network control device is installed outdoors, mischief such as disconnection of wiring can be prevented.

Furthermore, since it is housed in a waterproof case, it can be operated safely even if it is installed outdoors with much rain or moisture.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a terminal network control apparatus according to Embodiment 1 of the present invention. In the figure, reference numeral 9 denotes first LI connection means, which is connected to an LI point of an ISDN line. Reference numeral 10 denotes second LI point connection means, which is connected to the DSU 2. 1
Reference numeral 1 denotes a terminal connection unit, which is connected to a gas meter 8 which is an example of a terminal device. Reference numeral 12 denotes an exchange unit, which includes a first LI point connection unit 9, a second LI point connection unit 10, and a terminal connection unit 1.
Exchange frames between any one and one.

In the above configuration, the signal from the ISDN line is transmitted to the terminal network control device 7 by the first LI point connection means 9.
Is received. The exchange means 12 reads out the destination address from the signal received by the first LI point connection means 9 and transfers it to the second LI point connection means 10 or the terminal connection means 11. Similarly, a signal received via the DSU 2 is also received by the second LI point connection means 10 and transmitted to the ISDN line via the first LI point connection means 9 or transmitted to the terminal according to the destination address of the signal. The signal is sent to the gas meter 8 via the connection means 12. The same applies to the signal transmitted from the gas meter 8 and received by the terminal connection means 12.

With the above configuration, the ISDN line and the DS
A terminal network control device is connected to the U and communication with the gas meter can be performed from the ISDN line or the terminal on the DSU side.

(Embodiment 2) FIG. 2 is a block diagram of a terminal network control apparatus according to Embodiment 2 of the present invention. In the figure, a switching means 12 of a terminal network control device includes a connection / disconnection means 13 for connecting / disconnecting a first LI point connection means 9 and a second LI point connection means 10, and an impedance at the LI point for communication. Communication between impedance matching means 14 for matching impedance, communication detecting means 15 for detecting line voltage of the ISDN line to detect that communication is being performed, and polarity inversion detecting means 16 for detecting polarity inversion of the ISDN line. The connection and disconnection means 13 is controlled by signals from the middle detection means 15 and the polarity inversion detection means 16 to transfer frames between the first LI point connection means 9, the second LI point connection means 10, and the terminal connection means 11. And communication control means 17 for performing the above.

The operation of the above configuration will be described below with reference to FIG. (1) When the polarity inversion (SIG3) is received from the ISDN line via the first LI point connection means 9, the polarity inversion detection means 16 detects it and notifies the communication control means 17.

(2) When the polarity inversion (SIG3) is sent to the DSU 2 via the connection / disconnection means 13 and the second LI point connection means 10 at the same time, the DSU 2 connects the second LI point connection means 10 and the connection / disconnection means. , An activation acknowledge signal (SIG2) to the ISDN line via the first LI point connection means 9
Is sent.

(3) A line system activation display signal (SIG) from the ISDN line via the first LI point connection means 9
6) is received, this signal is sent to the disconnection means 13
Is transferred to DSU2 via

(4) In the DSU2, when the INFO3 signal is received at the S / T point in the same manner as in the conventional example after the line system start-up display signal (SIG6) from the ISDN line, the INFO3 reception display signal (SIG8) ) IS
Send to DN line.

(5) Upon receiving the INFO3 reception indication signal (SIG8), the ISDN line sends out call setting information data including the destination address.

(6) When receiving the call setting information data via the first LI point connection means 9, the communication control means 17 reads out the destination address and, if the communication is to the gas meter, the communication detecting means 15 After confirming that the terminals after DSU2 are not communicating, the communication unit requests the impedance matching unit 14 to perform impedance matching for communication, requests the disconnection unit 13 to disconnect the second LI point connection unit 10, and connects the terminal. The UUI information element of the D channel data received via the means 11 is transferred to the gas meter 8.

Although the data transferred from the terminal network controller to the gas meter is used as the UUI information element, the information contained in the subaddress or the D channel packet itself may be transferred. According to the above procedure, the impedance matching unit 14 matches the communication impedance, so that the second LI point connection unit 10 is disconnected and the ISDN line is connected in a state where impedance matching is achieved even when the DSU 2 is not connected. Can be used to communicate with the gas meter 8.

(Embodiment 3) FIG. 3 is a block diagram of a terminal network control apparatus according to Embodiment 3 of the present invention. In the figure, the switching means 12 of the terminal network control device extracts the D channel data of the frame received via the first LI point connection means 9 as the first information, and the second channel is used for the other channels.
The first channel receiving and transferring means 18 for transferring the data to the LI point connecting means 10 and the D channel data of the frame received via the second LI point connecting means 10 are extracted as the second information, and the other channel is extracted. Is transferred to the first LI point connection means 9 for the second channel reception and transfer means 19
A first D-channel receiving means 20 for notifying the terminal connection means 11 when the first information includes the destination address addressed to the gas meter, and for notifying the information to the second LI point connection means 10 otherwise; A configuration including first D-channel transmitting means for transmitting the third information or the second information requested to be transmitted from the terminal connecting means as D-channel transmission data via the first LI point connecting means; And

The operation of the above configuration will be described below with reference to FIG. (1) The first channel reception and transfer means 18 extracts the D channel reception data from the frame received via the first LI point connection means 9 from the ISDN line, and the other channels are connected to the second LI point connection. Transfer to means 10. At this time, the content of the D channel transferred to the second LI point connection means 10 is assumed to be no signal.

(2) The first D channel receiving means 20
When the destination address included in the D channel reception data from the first channel reception transfer unit 18 is addressed to the gas meter 8, the UUI information element of the D channel data is transferred to the gas meter 8 via the terminal connection unit 11. The destination address included in the D channel reception data is the gas meter 8
If not, the first channel receiving and transferring unit 18 returns the frame to the D channel of the frame to be transferred to the second LI point connecting unit 10.

(3) The gas meter 8 is connected to the terminal connecting means 11
Analyze the received data and if it is a meter reading request,
Send the meter reading.

(4) The first D channel transmitting means 21
When data is received from the gas meter 8 via the terminal connection means 11, a D-channel packet using this data as a UUI information element is generated, and the second channel reception and transfer means 19
If the D-channel data extracted from is no signal,
It is inserted as a D channel of a frame to be transferred from the second channel reception and transfer means 19 to the first LI point connection means 9.

(5) The first LI point connection means 9 converts the frame data from the second channel reception and transfer means 19 into IS
Send to DN line.

As in the second embodiment, the data transferred from the terminal network controller to the gas meter may be the information contained in the subaddress or the D channel packet itself.

According to the above procedure, data to be transferred to the gas meter as received data from the ISDN line does not flow to the DSU side, so that the terminal on the DSU side is not activated unnecessarily, and transmission data from the gas meter is not transmitted to the DSU side. When the terminal does not transmit the transmission data, it is possible to transmit the transmission data to the ISDN line.

(Embodiment 4) FIG. 4 is a block diagram of a terminal network control apparatus according to Embodiment 4 of the present invention. In the figure, the switching means 12 of the terminal network control device extracts the D channel data of the frame received via the first LI point connection means 9 as the first information, and the second channel is used for the other channels.
The first channel receiving and transferring means 18 for transferring the data to the LI point connecting means 10 and the D channel data of the frame received via the second LI point connecting means 18 are extracted as the second information, and the other channels are extracted. Is transferred to the first LI point connection means 9 for the second channel reception and transfer means 19
Terminal connection means 11 when the second information is predetermined information
When the second information is not the predetermined information, the second D channel transmitting means 2 for notifying the information to the first LI point connecting means 9
2 and a second D channel receiving means 23 for notifying the third information and the first information transmitted from the terminal connection means 11 as D channel data via the second LI point connection means 10
And a configuration including:

The operation of the above configuration will be described below with reference to FIG. (1) The first channel reception and transfer means 18 extracts D channel reception data from the frames received via the first LI point connection means 9 from the ISDN line, and simultaneously converts all the frames into the second LI point. Transfer to connection means 10.

(2) The second D channel receiving means 23
When data is received from the gas meter 8 via the terminal connection means 11, a D channel packet using this data as a UUI information element is generated, and the first channel reception and transfer means 18
If the D-channel data extracted from is no signal,
It is inserted as a D channel of a frame to be transferred from the first channel reception and transfer means 18 to the second LI point connection means 10.

(3) Second channel receiving and transferring means 19
Extracts the D-channel received data from the frame received from the DSU 2 via the second LI point connection means 10 and transfers the other channels to the first LI point connection means 9. At this time, the content of the D channel to be transferred to the first LI point connection means 9 is set to no signal.

(4) The second D channel transmitting means 22
When the destination address included in the D channel reception data from the second channel reception transfer unit 19 is addressed to the gas meter 8, the UUI information element of this D channel data is transferred to the gas meter 8 via the terminal connection unit 11. The destination address included in the D channel reception data is the gas meter 8
If not, the second channel reception / transfer unit 19 returns the frame to the D channel of the frame transferred to the first LI point connection unit 9.

As in the second embodiment, the data transferred from the terminal network controller to the gas meter may be the information contained in the subaddress or the D channel packet itself.

According to the above procedure, the transmission data from the gas meter can be sent to the DSU when no reception data is received from the ISDN line, and the data to be transferred to the gas meter by the transmission data from the DSU flows to the ISDN line. Therefore, it is possible to perform communication between the terminal on the DSU side and the gas meter without transmitting unnecessary data to the ISDN line.

(Embodiment 5) FIG. 5 is a block diagram of a terminal network control apparatus according to Embodiment 5 of the present invention. In the figure, reference numeral 24 denotes an S / T point connection means, which connects TA4 with an S / T point interface and IS via a first LI point connection means 9.
Connect the DN line to TA4. Also, the terminal connection means 11
Is connected to the gas meter 8 as a terminal device and S
Communicates by connecting to the / T point interface. 25 is a line power supply means, which is connected to the first LI point connection means 9, the S / T point connection means 24 and the terminal connection means 11 by the ISDN from the exchange.
The power supplied to the LI point via the line is supplied as a power supply.

With the above configuration, the terminal network control device is
Since the operation is performed as long as power is supplied from the DN line, communication with the gas meter can be performed via the ISDN line at any time.

(Embodiment 6) FIG. 6 is a block diagram of a terminal network control apparatus according to Embodiment 6 of the present invention. The difference from the fifth embodiment is that a line polarity determining unit 26 and a line connection switching unit 27 are added.
Of the connection between the LI point connection means 9 and the ISDN line by two metal cables, and determines the line connection switching means 2
7 switches the connection of the two metal cables.

In the above configuration, the terminal network controller is
The operation for wiring to the SDN line will be described below with reference to FIG. In the drawing, when a two-wire metal cable of an ISDN line is connected to the terminal network control device 7, a line polarity determining means 26 detects the voltage polarity between the two wires. The line polarity determining means 26 determines whether the voltage polarity between the two lines is
Determines that the polarity is not communicable, it sends a connection switching request signal.

Upon receiving the connection switching request signal, the line connection switching means 27 replaces the two lines connecting the ISDN line and the first LI point connection means 9 with each other, and
Is switched so that the LI point connection means 9 is connected to the ISDN line with a polarity that allows communication. As a specific configuration of the line polarity determination unit 26, a voltage comparator that compares two input voltages and outputs a result is conceivable. Further, as a specific configuration of the line connection switching means 27, a two-circuit relay that switches contacts according to an input voltage can be considered.

With the above configuration, communication can always be performed without considering the connection polarity when wiring the ISDN line and the terminal network control device.

(Embodiment 7) FIG. 7 is a block diagram of a terminal network control apparatus according to Embodiment 7 of the present invention. The difference from the first embodiment is that the line polarity determining means 26 and the line connection switching means 2
7. The addition of the DSU connection determining means 28 and the DSU connection switching means 29 allows the line polarity determining means 26 and the line connection switching means 27 to have the same functions as in the sixth embodiment. The DSU connection determination means 28 determines the connection polarity of the two metal cables to the DSU 2 and the DSU connection switching means 29 switches the connection of the two metal cables to the DSU 2.

In the above configuration, the terminal network control device is
The operation for wiring to the SDN line is as described in the sixth embodiment. The operation of wiring the terminal network control device to the DSU will be described below with reference to FIG.

First, the terminal network controller 7 and the DSU 2
Connected by wire metal cable. Terminal network controller 7
Applies a voltage of 60 V to the DSU 2 from the second LI point connection means 10 via the DSU connection switching means 29. When the DC resistance of the DSU 2 becomes 812 Ω, the DSU connection determination means 28 determines that the voltage polarity is not the polarity with which the terminal network control device 7 can communicate, and sends a connection switching request signal.

When the DSU connection switching means 29 receives the connection switching request signal, the DSU connection switching means 29 interchanges the two lines connecting the DSU 2 and the second LI point connection means 10 respectively, and
Is switched so that the LI point connecting means 10 is connected to the DSU 2 with the communicable polarity. DSU2 connection switching means 2
As a specific configuration of No. 9, the contact is switched by the input voltage.
Circuit relays are conceivable.

With the above configuration, when the terminal network control device is connected between the protector and the DSU, communication can always be performed without considering the connection polarity between the protector and the DSU.

(Eighth Embodiment) FIG. 8 is a block diagram of a terminal network control device according to an eighth embodiment of the present invention. The difference from the fifth embodiment is that the terminal connection unit 11 is configured by a wireless communication unit 30, and the communication between the gas meter 8 as a terminal device and the terminal network control device 7 is performed wirelessly by the wireless communication unit 30. .

With the above configuration, even if the terminal network control device is installed indoors, it is not necessary to make a hole in a wall of a house or perform wiring work for connection with a gas meter installed outdoors.

(Embodiment 9) FIG. 9 is a connection diagram of a terminal network control apparatus according to Embodiment 9 of the present invention. The internal configuration of the terminal network control device 7 is the same as that of the first embodiment. The connection of the wiring extending from the first LI point connection means 9 to the ISDN line as the LI point in FIG. 1 is performed by screwing at the L1 and L2 terminals. The connection of the wiring extending from the second LI point connection means 10 to the DSU 2 is performed by screwing at terminals D1 and D2. The connection of the wiring extending from the terminal connection means 11 to the gas meter 8 as the terminal device is performed by screwing the terminals M1 and M2. Further, as shown in FIG. 9, the terminal network control device 7 is installed outside a customer's house, and the internal components and terminals are housed in a waterproof housing.

With the above configuration, even if the terminal network control device is installed outdoors, it is possible to prevent mischief such as disconnection of wiring and to operate safely.

[0083]

According to the terminal network control device of the present invention as described above, the following effects can be obtained.

(1) Since the connection can be made between the protector and the DSU (LI point), the installation position can be selected regardless of whether the device is indoors or outdoors.

(2) Since the DSU can be separated while communication with the terminal device is performed using the ISDN line, the DSU
Signals from devices connected to the LI point do not affect subsequent terminals.

(3) Since the D channel from the DSU is extracted by the second channel reception and transfer means and the transmission data and transmission adjustment from the terminal device are performed by the first D channel transmission means, regardless of the communication status of the terminal device, DSU to D
Even if a channel signal is transmitted, I
No collision occurs on the SDN line.

(4) The transmission data from the DSU to the terminal device is transferred to the terminal device via the second channel receiving and transferring means and the second D channel transmitting means, and is transmitted from the terminal device to the D device.
The transmission data to the terminal after the SU is transmitted to the DS via the second D channel receiving means and the first channel receiving and transferring means.
Since the data is transferred to the U, the terminal after the DSU can directly communicate with the terminal device connected to the LI point.

(5) Since the terminal network control unit supplies power from the ISDN line to each unit by the line power supply means, it is possible to always report an abnormality such as gas leak from the terminal device such as a meter sensor or equipment. So the urgency is not compromised.

(6) The line polarity judging means judges the connection polarity between the terminal network control device and the protector and the line connection switching means can switch the line connection polarity, so that the connection with the terminal of the protector is considered. No need to do.

(7) Since the DSU connection determining means determines the connection polarity between the terminal network controller and the DSU and the DSU connection switching means can switch the connection polarity with the DSU, the connection with the terminal of the DSU is considered. No need to do.

(8) Even if the terminal network control device is installed indoors, communication with the terminal device located outdoors can be performed by the wireless communication means, so that wiring work to the communication terminal is not required.

(9) Since each wiring connected to the terminal network control device is screwed, the protector and the DSU do not come off easily.
There is no possibility that communication in the customer's house cannot be disabled due to disconnection due to mischief or the like.

(10) Since the terminal network control device is housed in a waterproof housing, operation is not hindered even if the terminal network control device is installed outdoors for communication with an outdoor terminal device such as a meter sensor or equipment.

[Brief description of the drawings]

FIG. 1 is a block diagram of a terminal network control device according to a first embodiment of the present invention;

FIG. 2 is a block diagram of a terminal network control device according to a second embodiment of the present invention;

FIG. 3 is a block diagram of a terminal network control device according to a third embodiment of the present invention;

FIG. 4 is a block diagram of a terminal network control device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a terminal network control device according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram of a terminal network control device according to a sixth embodiment of the present invention.

FIG. 7 is a block diagram of a terminal network control device according to a seventh embodiment of the present invention.

FIG. 8 is a block diagram of a terminal network control device according to an eighth embodiment of the present invention.

FIG. 9 is a block diagram of a terminal network control device according to a ninth embodiment of the present invention;

FIG. 10 is a general terminal configuration diagram using an ISDN line.

FIG. 11 is a configuration diagram of a conventional automatic meter reading system using an ISDN line.

FIG. 12 is a diagram showing a signal flow of the system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Protector 2 DSU (Digital Line Termination Unit) 4 TA (Terminal Adapter) 6 Remote Management Device 7 Terminal Network Controller 8 Gas Meter (Terminal Device) 9 First LI Point Connection Means 10 Second LI Point Connection Means 11 Terminal connecting means 12 Switching means 13 Disconnecting means 14 Impedance matching means 15 Communication detecting means 16 Polarity inversion detecting means 17 Communication control means 18 First channel receiving and transferring means 19 Second channel receiving and transferring means 20 First D channel Receiving unit 21 First D-channel transmitting unit 22 Second D-channel transmitting unit 23 Second D-channel receiving unit 24 S / T point connection unit 25 Line power supply unit 26 Line polarity determination unit 27 Line connection switching unit 28 DSU connection Determination means 29 DSU connection switching means 30 wireless communication means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shiro Honma 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] 1. A first LI point connecting means connected at an interface LI point of an ISDN line, a second LI connecting means connected at an interface LI point with a DSU, and a terminal connection for connecting to and communicating with a terminal device. A terminal network control device comprising: means for switching frames between any of the first LI point connecting means, the second LI point connecting means, and the terminal connecting means. 2. The exchange means comprises a first LI point connection means and a second LI point connection means.
Connection / disconnection means for connecting / disconnecting the LI point connection means, impedance matching means for matching the impedance of the LI point to the impedance at the time of communication,
Communication detecting means for detecting that the line is being communicated by detecting the line voltage of the N line; polarity inversion detecting means for detecting the polarity inversion of the ISDN line; and signals from the communication detecting means and the polarity inversion detecting means. 2. The communication device according to claim 1, further comprising communication control means for controlling the connection and disconnection means to transfer frames between the first LI point connection means, the second LI point connection means, and the terminal connection means. Terminal network controller. 3. The switching means extracts the first information on the D channel in the frame received via the first LI point connection means, and transfers the other information to the second LI point connection means for the other channels. To the first channel receiving and transferring means and the second information relating to the D channel in the frame received via the second LI point connecting means, and to the first LI point connecting means for other channels. A second channel receiving and transferring unit for transferring, and notifying the terminal connecting unit when the first information is the predetermined information, the second LI point connecting unit when the first information is not the predetermined information. First D-channel receiving means, third information requested to be transmitted by the terminal connection means, and the second information
2. The terminal network control device according to claim 1, further comprising: first D-channel transmission means for transmitting as D-channel information via the LI point connection means. 4. The switching means extracts the first information on the D channel in the frame received via the first LI point connection means, and transfers the other information to the second LI point connection means for the other channels. To the first channel receiving and transferring means and the second information relating to the D channel in the frame received via the second LI point connecting means, and to the first LI point connecting means for other channels. A second channel receiving and transferring unit for transferring, and notifying the terminal connecting unit when the second information is the predetermined information, the information to the first LI point connecting unit when the second information is not the predetermined information. Second D-channel transmitting means, and third information and the first information requested to be transmitted by the terminal connection means are transmitted to a second D-channel transmitting means.
2. The terminal network control device according to claim 1, further comprising: a second D-channel receiving means for notifying as D-channel information via the LI point connection means. 5. A first L connected to an LI point of an ISDN line.
An S / T point connecting means, an S / T point connecting means for connecting to an interface S / T point, and an ISDN line via a first LI point connecting means; Terminal connection means for connecting and communicating with an interface; ISDN from the exchange to the first LI point connection means, the S / T point connection means and the terminal connection means;
A terminal network control device comprising: line power supply means for supplying power supplied to an LI point via a line as power. 6. A line polarity judging means for judging the connection polarity between the first LI point connection means and the ISDN line using two metal cables, and line connection switching means for switching the connection of the two metal cables. The terminal network control device according to claim 1 or 5. 7. DSU connection determining means for determining the connection polarity with the DSU via the second LI point connection means, and DSU connection switching means for switching the connection polarity of the second LI point connection means. The terminal network control device according to claim 1. 8. The terminal network control device according to claim 1, wherein the terminal connection means comprises a wireless communication means for communicating with the terminal device wirelessly. 9. The connection between the first LI point connection means and the ISDN line, the connection between the second LI point connection means and the DSU, and the connection of the metal cable between the terminal connection means and the terminal device by means of screws. The terminal network control device according to claim 1. 10. The terminal network control device according to claim 1, wherein the terminal network control device is housed in a waterproof housing.