JPH11284760A - Line terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a communication with plural data terminal equipments through one public lines and by one line terminal equipment by providing a transmission part transmitting a starting telegraphic message consisting of fixed characters and a transmission part capable of transmitting a starting telegraphic message consisting of characters different from the starting telegraphic message. SOLUTION: The line terminal equipment is provided with the fixed starting telegraphic message transmitting part 16 transmitting the starting telegraphic message consisting of the fixed characters and the designated starting telegraphic message transmitting part 17 capable of transmitting the starting telegraphic message consisting of the characters different from the starting telegraphic message. In a case of judging that a received telegraphic message requests transmitting characters designated from a central monitoring device 5 as the starting telegraphic message as the result of analyzing by a telegraphic message analyzing part 15, the part 17 transmits the designated characters as the starting telegraphic message. Then, the line terminal equipment 20 can singularize a terminal for connecting the data terminal equipments and at the time of connecting the plural data terminal equipments 2, 18 and 19 onto a bus by this terminal, it is possible to communicate with the device 5 through a single public line 3 and by the single equipment 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a central monitoring device which collects data from a data terminal device such as a gas shut-off device by communication, performs a ringing communication service using a public line network, and a terminal calling system. The present invention relates to a line terminal device for transferring data to a home controller.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional line terminal device 1 is a device for connecting a data terminal device 2 to a public line 3.

Here, the data terminal device 2 is an automatic gas shut-off device with a communication function built in a microcomputer, which is connected to a gas meter to measure the gas flow rate and to detect the abnormality to shut off the gas supply. This is a device that performs data communication with the central monitoring device 5 via the line terminal device 1. The telephone 6 is also connected to the public line 3.

[0004] The data terminal device 2 is a communication protocol that starts communication by first receiving a start message notifying a start request, and ends communication operation by receiving a communication end message at the end.

[0005] This activation message is standardized in the industry, and a fixed character "number 1" is used. Reference numeral 7 denotes a network control unit which performs network control with the exchange 4 on the public line 3. A slow polarity reversal detection unit 8 which is a component of the network control unit 7 detects a slow polarity reversal which is activated by the no ringing service of NTT.

Reference numeral 9 denotes an impedance matching circuit for receiving a DTMF signal used for a no-ringing call signal in a first semi-closed circuit.

Reference numeral 10 denotes a DTMF receiving unit that receives a DTMF signal.

Reference numeral 12 denotes a second semi-closed circuit.
This is a matching circuit that makes a semi-closed state such that the impedance becomes smaller than that.

Reference numeral 13 denotes a circuit for transmitting the # of the DTMF signal as a response signal when the calling signal is addressed to itself in the DTMF transmitting unit 10.

Reference numeral 14 denotes a modem transmitting / receiving circuit that modulates and demodulates a modem signal in order to communicate with the central monitoring device 5.

Reference numeral 15 analyzes the message received by the message analyzer. When the activation message is requested by the analysis of the message analysis unit 15, the fixed activation message transmission unit 16 transmits a predetermined character.

Reference numeral 11 denotes a data terminal interface for converting a signal suitable for the data terminal device 2.

FIG. 6 shows a procedure for communicating between the central monitoring device 5 and the data terminal device 2 via the line terminal device 1 in the conventional example (a message is sent in the direction of the arrow).

The central monitoring device 5 issues a connection request to the exchange 4 to communicate using the no ringing service. The exchange 4 receives this connection request and performs gentle polarity reversal in order to call up no ringing for the corresponding line. In the line terminal device 1, the gentle polarity inversion detecting unit 8 detects the gentle polarity inversion.

Next, the line terminal apparatus 1 sets the first semi-closed circuit 9 to an impedance capable of receiving a DTMF signal used for a signal for a plurality of call no-ringing calls, and waits.

Next, the DT sent from the exchange 4
When the DTMF receiving unit 10 receives the MF signal and determines that it is addressed to itself, after the DTMF signal is interrupted, the DTMF transmitting unit 13 controls the second semi-closed circuit 12 to make the semi-closed state, and then responds by the DTMF transmitting unit 13. The # of the DTMF signal is transmitted as a signal.

Then, the exchange 4 responds to the central monitoring device 5 that the connection is normal. In response to this response, the central monitoring device 5 transmits a start request message by a modem signal in order to communicate with the data terminal device 2.

The modem transmission / reception circuit 14 of the line terminal device 1 receives the activation request message as a modem signal.

The modem signal received by the modem transmission / reception circuit 14 is demodulated and passed to a message analyzer 15. When the message analysis unit 15 analyzes that the request is an activation request, the fixed activation message transmission unit 16 transmits a predetermined activation message (STX 1 ETX BCC).

This activation message is converted into an appropriate signal via the data terminal interface 11 and transmitted to the data terminal device 2.

When the data terminal device 2 receives this activation message, it responds with a message with meter reading value data.

This response message from the data terminal device 2 is sent to the modem transmitting / receiving circuit 14 via the data terminal interface 11.

The signal is converted into a modem signal by the modem transmitting / receiving circuit 14 and transmitted from the exchange 4 to the central monitoring device 5. Thereafter, communication is performed between the central monitoring device 5 and the data terminal device 2.

[0024]

However, in the above-described configuration, when a plurality of data terminal devices are monitored by one line, a plurality of line terminal devices are installed and one for each line terminal device. There is a problem that the data terminal device must be connected.

[0025]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is connected to a plurality of data terminal devices and connected to an external device such as a central monitoring device via a public line to communicate between the two. A network control unit for matching communication conditions to connect to a public line, and a modem signal transmitting and receiving unit for modulating and demodulating signals from external devices such as a data terminal device and a central monitoring device. A message analysis unit that analyzes a received message received by the modem signal transmission / reception unit; and a fixed startup message transmission that transmits a fixed character determined in advance as a startup message when the message analysis unit analyzes the fixed startup request. And a designated activation message transmission unit that, when the message analysis unit analyzes that the character to be transmitted as the activation message is specified, transmits the character as the activation message. , Characterized by comprising a data terminal interface for converting the message to be transmitted from the fixed start message transmission unit and the designated start message transmission unit into a signal suitable for the data terminal equipment.

According to the invention, since the central monitoring device communicates with the designated data terminal device after the no-ringing call, the central monitoring device transmits the startup information message including the startup message information that can activate only the designated data terminal device to the modem. When transmitted by a signal, the modem transmission / reception circuit of the line terminal device receives this activation information telegram as a modem signal. The modem signal received by the modem transmission / reception circuit is demodulated and passed to the message analyzer. The character obtained as a result of the analysis by the message analysis unit is transmitted as the activation message from the designated activation message transmission unit. This activation message is converted into an appropriate signal via the data terminal interface and transmitted to the data terminal device. Other data terminal devices connected to this terminal interface receive no response even when receiving this activation message, and respond only to the data terminal device designated by the central monitoring device. The response message from the designated data terminal device is sent to the modem transmission / reception circuit via the data terminal interface. It is converted to a modem signal by the modem transmitting and receiving circuit,
Sent to the central monitoring device via the public line. Thereafter, communication is performed between the central monitoring device and the designated data terminal device. During that time, the other data terminal devices remain unanswered, so that this communication is not affected. Therefore, if one line terminal device is installed in one line, it is possible to communicate with a plurality of data terminal devices.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A line terminal device according to the present invention comprises a network controller for matching communication conditions for connection to a public line, and a modem for modulating and demodulating signals from external devices such as a data terminal device and a central monitoring device. A signal transmitting / receiving unit, a message analyzing unit for analyzing a received message received by the modem signal transmitting / receiving unit, and a fixed start request transmitted when the fixed start request is analyzed by the message analyzing unit as a start message. A fixed activation message transmission unit, a designated activation message transmission unit that transmits the character as a activation message when the character to be transmitted as the activation message is analyzed by the message analysis unit as being specified, and the fixed activation message transmission unit; A data terminal interface for converting a message transmitted from the designated activation message transmission unit into a signal suitable for the data terminal device.

Communication with a plurality of data terminal devices can be performed not only with one public line but also with one line terminal device. In addition, since only one terminal is required for connecting the data terminal device, a line terminal device can be realized at low cost.

If the message analyzer is required to start with an arbitrary character string, it is preferable to have an arbitrary character string transmitting unit for transmitting the character string.

Since a plurality of character strings can be transmitted as an activation message of the data terminal device, by giving meaning to the character strings, not only a simple response of the data terminal device but also various internal information can be taken at once. Communication control becomes possible.

[0031]

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

(Embodiment 1) FIG. 1 is a block diagram of a line terminal apparatus according to the present invention. Note that components having the same numbers as those in FIG. 5 are components having the same functions, and a description thereof will be omitted.

Reference numeral 17 denotes a designated activation message transmission unit which activates the designated character when the message received by the analysis of the message analysis unit 15 is a request to transmit the designated character from the central monitoring device 5 as the activation message. Send as a message.

Reference numeral 2 denotes a first data terminal, which is the same as the data terminal shown in FIG. Reference numeral 18 denotes a second data terminal device which is activated by “number 6”, and 19 denotes a third data terminal device which is activated by “number 7”. It is connected with the first data terminal device 2.

When these data terminal devices do not receive a start-up message addressed to themselves at the beginning of communication, the communication protocol does not respond to other messages. Reference numeral 20 denotes a line terminal device according to the present embodiment.

FIG. 2 shows a communication sequence of the line terminal device 20 according to the embodiment of the present invention.

The operation of the line terminal device 20 will be described with reference to FIG. 2 in terms of the flow of a message (a message is sent in the direction of the arrow). First, the central monitoring device 5 transmits to the exchange 4 to communicate using a no-ringing service. Make a connection request to it.

The exchange 4 receives the connection request and performs gentle polarity reversal in order to call up no ringing for the corresponding line.

In the line terminal device 20, the gentle polarity reversal detecting unit 8
Detects the gentle polarity inversion.

Next, the line terminal device 20 is connected to the first semi-closed circuit 9.
, And waits for a receivable impedance of the DTMF signal used for the signal of the multiple ringing no ringing call.

Next, the DT sent from the exchange 4
When the DTMF receiving unit 10 receives the MF signal and determines that it is addressed to itself, after the DTMF signal is interrupted, the DTMF transmitting unit 13 controls the second semi-closed circuit 12 to make the semi-closed state, and then responds by the DTMF transmitting unit 13. The # of the DTMF signal is transmitted as a signal. Then, the exchange 4 responds to the central monitoring device 5 that the connection is normal.

In response to this response, the central monitoring device 5
In order to communicate with the data terminal device 18, a start information message including “number 6” of the start message information capable of starting only the second data terminal device 18 is transmitted by a modem signal.

The modem transmitting / receiving circuit 14 of the line terminal device 20
Then, the start information message is received by a modem signal.

The modem signal received by the modem transmission / reception circuit 14 is demodulated and passed to the message analyzer 15.

The designated activation message transmission unit 17 transmits the character “numeral 6” obtained as a result of the analysis by the message analysis unit 15 as an activation message (STX 6 ETX BCC).

This activation message is converted into an appropriate signal via the data terminal interface 11 and transmitted to the first data terminal device 2, the second data terminal device 18, and the third data terminal device 19.

The first data terminal device 2 and the third data terminal device 19 receive no response even when receiving the activation message, and only the second data terminal device 18 responds to the meter reading with the meter value data-added message.

The response message from the second data terminal device 18 is sent to the modem transmitting / receiving circuit 14 via the data terminal interface 11.

The signal is converted into a modem signal by the modem transmitting / receiving circuit 14 and transmitted from the exchange 4 to the central monitoring device 5.

Thereafter, communication is performed between the central monitoring device 5 and the second data terminal device 18.

In the meantime, the other data terminal apparatuses, that is, the first data terminal apparatus 2 and the third data terminal apparatus 19 remain unresponsive, so that this communication is not affected.

Accordingly, since a single terminal for connecting the data terminal device can be provided, a plurality of data terminal devices can be connected to the bus by using these terminals. Can communicate with the central monitoring device 5 by itself.

Further, a mode in which data transmission between the line terminal device 20 and the data terminal device is performed wirelessly by attaching a device such as a wireless adapter to the data terminal interface 11 can be considered. In this case, if the activation message for activating the wireless adapter is set differently from that of the data terminal device, not only the data terminal device but also the wireless adapter can be activated from the central monitoring device 5, so that maintenance can be performed remotely, and You can reduce the frequency of going to.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 differs from the above-described embodiment in that when a message requesting transmission of a plurality of character strings as a start message from the central monitoring device 5 is received, the message analyzer 16
An arbitrary character string transmitting unit 21 for transmitting a plurality of character strings extracted in the above to the data terminal interface 11 as an activation message.

The third data terminal device 19 is set so as to be activated even with a plurality of character strings "XYZ".

FIG. 4 shows a communication sequence of the line terminal device 22 according to the second embodiment of the present invention. The operation of the line terminal device 22 will be described with reference to FIG. 4 using the flow of a message (the message is sent in the direction of the arrow). Same as the example. Thereafter, the central monitoring device 5 receiving this response transmits a character string transmission request message for activating the third data terminal device 19 by a modem signal.

The modem transmitting / receiving circuit 14 of the line terminal device 22
Then, this character string transmission request message is received by a modem signal.

The modem signal received by the modem transmission / reception circuit 14 is demodulated and passed to the message analyzer 15.

When the message analyzer 15 analyzes that the request is a "XYZ" character string transmission request, the arbitrary character string transmitter 21 transmits the received character string "XYZ" as a startup message.

This activation message is converted into an appropriate signal via the data terminal interface 11 and sent to the first data terminal device 2, the second data terminal device 18, and the third data terminal device 19 using an arbitrary character string message (STX XY). Z ETX
BCC).

The first data terminal device 2 and the second data terminal device 18 receive no response even when receiving this message, and only the third data terminal device 19 receives meter reading value data and a message with internal information such as a timer and a version number. To respond. This third
The response message from the data terminal device 19 is sent to the modem transmitting / receiving circuit 14 via the data terminal interface 11.

The signal is converted into a modem signal by the modem transmitting / receiving circuit 14 and transmitted from the exchange 4 to the central monitoring device 5.

Thereafter, communication is performed between the central monitoring device 5 and the third data terminal device 19.

In the meantime, the other data terminal apparatuses, that is, the first data terminal apparatus 2 and the second data terminal apparatus 18 remain unresponsive, so that this communication is not affected.

According to this configuration, since a plurality of character strings can be transmitted as an activation message of the data terminal device, not only a simple meter reading response but also various internal information of the data terminal device can be provided by giving the character strings meaning. Advanced communication control such that data can be captured at one time can be achieved.

[0067]

As described above, according to the line terminal device of the present invention, the following effects can be obtained.

(1) According to the first aspect of the present invention, a fixed activation message transmission unit for transmitting an activation message composed of predetermined fixed characters unified in the industry, and a predetermined fixed activation message Since it has both a designated activation message transmission unit that can transmit activation messages composed of characters different from those of the telegram, it is possible to respond to communication systems that have been used in the industry, and a single public It is possible to construct a system that communicates with a plurality of data terminal devices using one line terminal device.

Further, since the data terminal device can be connected to the bus, the line terminal device can be realized at low cost by using only one terminal for connection.

Further, it becomes possible to activate a communication device such as a wireless adapter which corresponds to an activation message different from that of the data terminal device interposed between the line terminal device and the data terminal device, thereby enabling remote maintenance of the entire system. Become.

(2) According to the second aspect of the present invention, in addition to the effect of (1), an arbitrary character string can be transmitted from an arbitrary character string transmitting unit.
A plurality of character strings can be transmitted as a start message of the data terminal device. Therefore, by giving meaning to the character string, not only the meter reading response by mere activation but also various internal information of the data terminal device can be taken at once, and the internal information can be changed by one message, so that communication costs can be increased. Communication time is shortened, and efficient communication is enabled.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a communication sequence of the line terminal device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a line terminal device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a communication sequence of a line terminal device according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a conventional line terminal device.

FIG. 6 is a diagram showing a communication sequence of a conventional line terminal device.

[Explanation of symbols]

 2 First data terminal device 3 Public line 4 Switch 5 Central monitoring device 7 Message analyzer 8 Slow polarity reversal detector 9 First semi-closed circuit 10 DTMF receiver 11 Data terminal interface 12 Second semi-closed circuit 13 DTMF transmission Unit 14 Modem transmission / reception circuit 15 Network control unit 16 Fixed startup message transmission unit 17 Designated startup message transmission unit 18 Second data terminal device 19 Third data terminal device 20 Line terminal device 21 Arbitrary character string transmission unit

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masahiro Yasui Osaka Gas Co., Ltd. 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka

Claims (2)

[Claims] 1. A line terminal device connected to a plurality of data terminal devices and connected to an external device such as a central monitoring device via a public line to communicate between the two terminals. A network controller for matching communication conditions, a modem signal transmitter / receiver for modulating and demodulating signals from external devices such as a data terminal device and a central monitoring device, and a message for analyzing a received message received by the modem signal transmitter / receiver. An analysis unit, a fixed activation request transmission unit that transmits a fixed character determined in advance as a activation message when the message is analyzed as a fixed activation request by the message analysis unit, and a character transmitted as a activation message by the message analysis unit is A designated activation message transmission unit that transmits the character as a startup message when it is analyzed to be designated, the fixed activation message transmission unit, and the designated activation message transmission unit And a data terminal interface for converting a message transmitted from the terminal into a signal suitable for the data terminal device. 2. The line terminal device according to claim 1, further comprising: an arbitrary character string transmitting unit for transmitting the character string when the message analysis unit requires activation with an arbitrary character string.