JPH05167727A - Terminal network controller - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a terminal network control device having a general-purpose connection terminal capable of connecting both a serial communication terminal and a contact device. [Structure] Application means 2 for supplying a DC voltage to a transmission line,
Intermittent detection means 3 for detecting connection and disconnection of the transmission line by the terminal, data transmission means 8 for transmitting serial data to the terminal by the intermittence generating means 4 for disconnecting the transmission line, and data receiving means for receiving the serial data. 9 and 9 are provided.
If the terminal is a serial communication terminal, the data transmitting means 8
And serial communication means 5 using the data receiving means 9
And the terminal is a contact device, the contact state notifying means 6 for notifying the center device of the state of the contact detected by the on / off detecting means 3.
In addition, operation switching means for switching between the serial communication means 5 and the contact state notification means 6 are provided.

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 used in a telecontrol system for automatic meter reading, gas leak notification, etc., and more particularly to an interface for connecting a gas meter or a contact device to the terminal network control device. ..

[0002]

2. Description of the Related Art There is a terminal network control device for automatic meter reading for connecting a terminal such as a gas meter and a center via a telephone line to perform data communication between the terminal and the center. The interface between the terminal network control device and the terminal connected thereto differs from terminal to terminal. The electrical interface condition of the water meter with the terminal network control device has been studied at the comprehensive telemeter system development conference of the Ministry of Posts and Telecommunications and has the interface configuration of FIG. In addition, the electrical interface condition of the LP gas with the terminal network control device is the same as that of the water meter as an industry standard.

In addition, a terminal has a contact device which notifies the terminal network control device of a state change by making a break in the contact.

In order to connect such a contact device, the terminal network control device is provided with a connection terminal dedicated to the contact device, which is independent of the water meter and the LP gas meter.

[0005]

However, in such a conventional technique, a water meter or an LP gas meter cannot be connected to a connection terminal dedicated to a contact device. Conversely, it is not possible to connect a contact device to the terminal that connects the water meter or the LP gas meter. Therefore, depending on the combination of the type and number of terminals connected to the terminal network control device, there are cases where several types of terminal network control devices must be prepared, and there is a problem that a general-purpose terminal network control device cannot be provided.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a terminal network control device having a general-purpose connection terminal to which any of a contact device, a water meter and an LP gas meter can be connected. To do.

[0007]

In order to solve the above problems, a terminal network control apparatus of the present invention is connected between a terminal and a line to connect the terminal to a communication line, and a pair of transmission lines. , A voltage applying means for supplying a DC voltage between the transmission lines, an intermittent generating means for connecting and disconnecting the transmission lines, and a voltage applied to the transmission line by the voltage applying means. Controls the interruption detecting means with the voltage applied to the transmission line by the interruption detecting means for detecting whether the DC loop circuit with the terminal used as the power source is closed or opened by the terminal. Data transmission means for generating a pulse signal between transmission lines and transmitting serial data to the terminal, and connection / disconnection of the DC loop circuit by the terminal by the disconnection detection means with the voltage applied to the transmission line by the voltage application means. Change of serial Data receiving means for receiving data as a data, serial communication means for performing communication between the center device and the terminal by the data transmitting means and the data receiving means, and notifying the center device of the detection state of the interruption detecting means via the communication line. The contact state notifying means and the operation switching means for setting which of the serial communication means and the contact state notifying means is used and switching the means.

[0008]

According to the present invention, when the contact switching device is connected as a terminal by the operation switching means, the contact state notification means is connected to the serial communication means when a terminal for serial communication is connected. To drive. The contact state notification means determines that the DC loop circuit with the terminal is opened by the interruption detecting means when the contact device breaks the contact, and the interruption detecting means when the contact device makes the contact. It is determined that the DC loop circuit with the terminal is closed. The serial communication means, when transmitting serial data to the terminal, the data transmitting means drives the interruption generating means to transmit serial data to the transmission line, and when receiving serial data from the terminal, the data receiving means,
A change in closing or opening of the DC loop circuit by the terminal is detected by the interruption detecting means and received as serial data.

Further, the contact state detection notifying means notifies the center device of the state of the contact. The serial communication means exchanges serial data between the center device and the terminal.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 1 is a terminal network control device of the present invention, which is connected to a terminal 13 via a transmission line 10 and is connected to a center device 12 via a communication line 11 such as a telephone network.

The terminal network control device 1 of the present invention comprises a transmission line 10
It is detected whether the DC loop circuit of the voltage applying means 2 for applying the DC voltage V to the terminal and the terminal 13 using the voltage V to the transmission line by the voltage applying means 2 as a power source is closed or opened by the terminal 13. The disconnection detecting means 3 and the disconnection generating means 4 for changing the voltage V applied to the transmission line by the voltage applying means 2 by connecting and disconnecting the transmission lines.

Further, serial data transmission / reception with the terminal 13 is performed using the data transmission means 8 and the data reception means 9, and the serial communication means 5 for realizing the communication between the center device 12 and the terminal 13 and the interruption detection means are detected. The contact state notifying means 6 for notifying the center device of the state of the transmission line to be transmitted to the center device, and the operation switching means 7 for setting whether to use the serial communication means 5 or the contact state notifying means 6 and switch the means. Constitute.

The data transmitting means 8 and the data receiving means 9 drive the voltage applying means 2, the interruption generating means 4 and the interruption detecting means 3 to transmit / receive serial data.

Next, the voltage applying means 2 of the embodiment of the present invention,
The circuit configuration of each part of the intermittence detecting means 3 and the intermittence generating means 4 will be described.

The voltage applying means 2 has a structure in which the transistor TR1 is turned on to supply a DC voltage to the transmission line 10 by setting the point A to the L level. The intermittence generating means 4 is configured to turn on the transistor TR3 by dropping the point C to the H level to drop the voltage supplied to the transmission line 10.
The resistor R1 of the voltage applying means 2 is a relatively small protective resistor that prevents an excessive current from flowing when the transistor TR3 is on. The intermittence detecting means 3 has a structure in which the transistor TR2 is turned on / off by a change in the voltage of the transmission line 10 and outputs a signal corresponding to the change in the voltage of the transmission line 10 to a point B.

When the transistor TR3 is off and the transmission line 10 is open, the voltage V of the transmission line supplied by the voltage applying means 2 is 5V.

When not communicating with the terminal 13, it is assumed that the point A is maintained at the H level and the point C is maintained at the L level.

Next, the operation of the embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. First, referring to FIG. 2, the terminal 13
As an example, the operation of connecting a conventional terminal represented by a water meter that performs serial communication will be described. This terminal is called a serial communication terminal 14.

The serial communication terminal 14 receives the serial data by terminating the transmission line 10 with a relatively large resistance R4 and continuously detecting changes in the voltage appearing across the R4. Further, the switch 15 is closed when the transistor TR3 of the intermittence generating means 4 is off, thereby closing the DC loop circuit formed through the transmission line 10 with the terminal network control device 1 of the present invention to thereby form a transmission line. The voltage V of 10 is dropped to a voltage close to 0 V. By continuously opening and closing the switch 15, serial data is transmitted to the terminal network control device of the present invention.

Normally, the serial communication terminal 14 is on standby for reception, and the switch 15 is open.

First, since the serial communication terminal device 14 is connected, the operation switching means 7 activates the serial communication means 4. Various methods can be considered for selecting which of the serial communication means 5 and the contact state notification means 6 the operation switching means 7 should activate, but here, it is set in advance by a setting switch or the like in the terminal network control device 1. Be present. There may be means for calling the terminal network control device 1 from the center device 12 and setting it by communication.

Next, a case where the serial communication means 5 transmits serial data to the serial communication terminal 14 in response to a request from the center device 12, for example, will be described.

When the serial communication means 5 sets the point A to the L level, the applying means 2 supplies a voltage to the transmission line 10 and the voltage V becomes 5V. Therefore, the resistance R of the serial communication terminal 14
A voltage of 5V is generated across both terminals of the communication terminal 4, and the serial communication terminal 14 detects that communication has started and starts the serial data receiving operation. Then, the serial communication means 5 activates the data transmission means 8 to continuously output the serial data signal to the point C. When the point C is at the H level, the transistor TR3 of the interruption generating means 4 is turned on and the voltage V across the resistor R4 changes from 5V to 0V. When the point C is at the L level, the transistor TR3 is turned off and the voltage across the resistor R4 is reduced. Since the voltage is 5V, the serial communication terminal 14 receives the serial data by detecting the change in the voltage across the resistor R4.

Next, the serial communication means 5 receives the serial data from the serial communication terminal 14, and receives the serial data from the center device 1.
The case of transmitting to No. 2 will be described. Normally, when the serial communication terminal 14 such as a water meter receives serial data such as a meter reading request, it continuously transmits a response such as a meter reading value as serial data.

After the serial communication means 5 has transmitted the serial data to the serial communication terminal 14, the points C and A are kept at the L level and the data receiving means 9 is activated this time. At this time, the voltage applying means 2 supplies a voltage to the transmission line 10 and the voltage V is 5V. Serial communication terminal 14
In order to transmit serial data, the switch 15 is continuously opened and closed so as to become a serial data signal. When the switch 15 is open, the voltage V of the transmission line is 5V, so that the transistor TR2 of the interruption detecting means 3 is turned on and outputs a signal of L level to the point B. On the contrary, when the switch 15 is closed, the voltage V of the transmission line becomes a value close to 0V, so that the transistor TR2 of the interruption detecting means 3 is turned off and an H level signal is output to the point B.

Therefore, by opening / closing the switch 15 so that the serial communication terminal 14 becomes a serial data signal, the interruption detecting means 3 outputs the signal to the point B, and the data receiving means 9 outputs the serial data. You will be able to receive. The serial communication means 5 receives the serial data from the serial communication terminal 14 by transmitting the serial data to the center device 12, and the center device 12 receives the serial data.
To complete a series of operations to send to.

Next, the operation when a contact device is connected as the terminal 13 will be described with reference to FIG. This terminal is the contact device 16.

The contact device 16 includes a contact switch 17. Here, an operation in which the contact switch is normally broken, and when the contact switch is made, it is detected to notify the center device that the contact switch has been made will be described.

First, since the contact device 16 is connected as a terminal, the contact state notifying means 6 is activated in the operation switching means 7. Various methods can be considered for selecting which of the serial communication means 5 and the contact state notification means 6 the operation switching means 7 should activate, but here, it is set in advance by a setting switch or the like in the terminal network control device 1. Be present. Center device 1
There may be means for calling the terminal network control device 1 from 2 and setting it by communication.

When activated, the contact state notifying means 6 sets point A to L level. Therefore, the voltage applying means 2 is connected to the transmission line 10
And the voltage V becomes 5V. Therefore, the transistor TR2 of the intermittence detecting means 3 is turned on, and the L point is connected to the B point.
Output level signal. The contact state notification means 6 monitors that the point B becomes H level. In this state, contact device 1
When 6 makes the contact switch 17, the voltage V of the transmission line
Becomes a value close to 0V, the transistor TR2 of the interruption detecting means 3 is turned off, and an H level signal is output to the point B. The H-level signal at the point B is detected by the contact state notifying means 6 and the center device 12 is notified that the contact is made by converting it to code information. The contact state notifying means 6 keeps the point C at the L level so that the contact device 16
The change in the state of the contact switch can be detected.

As described above, the terminal network control device 1 of the present invention is connected to both the terminal for serial communication and the terminal of the contact device through the same transmission line 10 to support the communication between the center device and the terminal.

[0032]

As described above, according to the terminal network control apparatus of the present invention, the following effects can be obtained. It is possible to provide a terminal network control device having a general-purpose connection terminal to which a contact device, a water meter, an LP gas meter, etc. can be connected. Therefore, it is possible to provide a terminal network control device having a plurality of such general-purpose connection terminals. For example, one terminal network control device can be used without worrying about the combination of types and numbers of terminals connected to the terminal network control device.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating an operation when a serial communication terminal of the same device is connected.

FIG. 3 is a diagram illustrating an operation when a contact device of the same device is connected.

FIG. 4 is a diagram illustrating an interface in a conventional terminal network control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Terminal network control device 2 Voltage application means 3 Interruption detection means 4 Interruption generation means 5 Serial communication means 6 Contact state notification means 7 Operation switching means 8 Data transmission means 9 Data reception means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Sakata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A connection unit connected between a terminal and a communication line for connecting the terminal using a pair of transmission lines, a voltage applying unit for supplying a DC voltage to the transmission line, and the transmission line. Intermittent disconnection generating means, intermittent connection detecting means for detecting whether or not the DC loop circuit with the terminal is closed by the terminal, and the voltage applying means in a state where voltage is applied to the transmission line, Data transmission means for controlling the interruption generating means to generate a pulsed signal between the transmission lines and transmitting serial data to the terminal, and the interruption detecting means in a state where a voltage is applied to the transmission line by the voltage applying means. The data receiving means for receiving as a serial data the change in the connection / disconnection of the DC loop circuit by the terminal, and the communication between the center device and the terminal are performed by the data transmitting means and the data receiving means. It is set which of the real communication means, the contact state notification means for notifying the center device of the detection state of the disconnection detection means via the communication line, the serial communication means or the contact state notification means. And a terminal network control device having an operation switching means for switching the means.