JP2943466B2 - Terminal network controller - Google Patents

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 performing automatic meter reading, gas leak notification, and the like, and more particularly to an interface for connecting a gas meter and 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 connecting to 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 for each terminal. The electrical interface condition of the water meter with the terminal network control device was examined by the Ministry of Posts and Telecommunications General Telemeter System Development Conference, and has the interface configuration shown in FIG. The electrical interface between the LP gas and the terminal network controller is the same interface as the water meter as an industry standard.

[0003] Further, there is a contact device that notifies a terminal network control device of a state change by making a contact break in the terminal.

In order to connect such contact devices, the terminal network control device is provided with a connection terminal dedicated to the contact device independent of the water meter or 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, a contact device cannot be connected to a terminal for connecting a water meter or an LP gas meter. Therefore, depending on the combination of the types and the 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.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a terminal network control device having a general-purpose connection terminal that can be connected to any of a contact device, a water meter, and an LP gas meter. I do.

[0007]

In order to solve the above-mentioned problems, a terminal network control device according to 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 is provided. A connection unit for connecting a terminal by using, a voltage applying means for supplying a DC voltage between transmission lines, an intermittent generating means for intermittently connecting the transmission lines, and a voltage applied to the transmission line by the voltage applying means. An intermittent detecting means for detecting whether the DC loop circuit with the terminal as the power supply is closed or open by the terminal, and controlling the intermittent generating means in a state where a voltage is applied to the transmission line by the voltage applying means. Data transmission means for generating a pulse-like signal between the transmission lines and transmitting serial data to the terminal, and closing and opening of the DC loop circuit by the terminal by the intermittent detection means with the voltage applied to the transmission line by the voltage application means Serial change Data receiving means for receiving data as data, a serial communication means for performing communication between the center device and the terminal by the data transmitting means and the data receiving means, and a detection state of the gating detecting means to the center device via a communication line. It comprises contact state notifying means and operation switching means for setting which of the serial communication means and the contact state notifying means is to be used, and for switching the means.

[0008]

According to the present invention, when the contact device is connected as a terminal by the operation switching means, the contact state notifying means is connected to the serial communication means by the operation switching means when the terminal performing serial communication is connected. Drive. The contact state notifying means determines that the DC loop circuit with the terminal is open by the disconnection detecting means when the contact device is breaking the contact, and determines the disconnection detecting means when the contact device makes the contact. Thus, it is determined that the DC loop circuit with the terminal is closed. When transmitting serial data to the terminal, the serial communication unit transmits serial data to the transmission line by driving the intermittent generating unit, and when receiving serial data from the terminal, the data receiving unit includes:
A change in the closing and opening of the DC loop circuit by the terminal is detected by the intermittent detecting means and received as serial data.

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

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 1 denotes a terminal network control device of the present invention, which is connected to a terminal 13 via a transmission line 10 and 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
Detects whether the DC loop circuit between the voltage applying means 2 for applying the DC voltage V to the terminal 13 and the terminal 13 powered by the voltage V to the transmission line by the voltage applying means 2 is closed or open by the terminal 13 And a disconnection generating means 4 for changing a voltage V applied to the transmission line by the voltage applying means 2 by disconnecting the transmission lines.

Further, serial data is transmitted / received to / from the terminal 13 by using the data transmitting means 8 and the data receiving means 9 to realize the communication between the center device 12 and the terminal 13; Contact state notifying means 6 for notifying the center device of the state of the transmission line to be performed via the communication line, and operation switching means 7 for setting whether to use the serial communication means 5 or the contact state notifying means 6 and switching the means. Constitute.

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

Next, the voltage application means 2 according to the embodiment of the present invention,
One circuit configuration of each part of the interruption detection means 3 and the interruption generation means 4 will be described.

The voltage applying means 2 is configured to supply a DC voltage to the transmission line 10 by turning on the transistor TR1 by setting the point A to the L level. The intermittent generating means 4 has a configuration in which the transistor TR3 is turned on by setting the point C to the H level to lower the voltage supplied to the transmission line 10.
The resistor R1 of the voltage applying unit 2 is a relatively small protection resistor that prevents an excessive current from flowing when the transistor TR3 is on. The intermittent detecting means 3 has a configuration in which the transistor TR2 is turned on / off by a change in the voltage of the transmission line 10 and a signal corresponding to the change in the voltage of the transmission line 10 is output 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 no communication is performed 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 FIGS.
This will be described with reference to FIG. First, referring to FIG.
The operation of connecting a conventional terminal typified by a water meter performing serial communication will be described. This terminal is referred to as a serial communication terminal 14.

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

Normally, the serial communication terminal 14 is waiting 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 notifying means 6 is activated by the operation switching means 7, but in this case, it is set in advance by a setting switch or the like in the terminal network control device 1. Shall be There may be a means for calling the terminal network control device 1 from the center device 12 and setting 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 application 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
When a voltage of 5 V is generated at both ends of the terminal 4, the serial communication terminal 14 detects that communication has started, and starts a serial data receiving operation. Subsequently, the serial communication unit 5 activates the data transmission unit 8 and continuously outputs a serial data signal to the point C. When the point C is at the H level, the transistor TR3 of the intermittent 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 turned off. Since the voltage is 5 V, the serial communication terminal 14 receives the serial data by detecting a 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
2 will be described. Normally, upon receiving serial data such as a meter reading request, the serial communication terminal 14 such as a water meter continuously transmits a response such as a meter reading value as serial data.

After transmitting the serial data to the serial communication terminal 14, the serial communication means 5 keeps the points C and A at the L level and activates the data receiving means 9 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
The switch 15 continuously repeats opening and closing so that the switch 15 becomes a serial data signal for transmitting serial data. When the switch 15 is open, the voltage V of the transmission line is 5 V, so that the transistor TR2 of the disconnection detecting means 3 is turned on, and an L-level signal is output to the point B. Conversely, when the switch 15 is closed, the voltage V of the transmission line becomes a value close to 0 V, so that the transistor TR2 of the disconnection detecting means 3 is turned off, and an H level signal is output to the point B.

Therefore, by opening and closing the switch 15 so that the serial communication terminal 14 becomes a serial data signal, the discontinuity detecting means 3 outputs the signal to the point B, and the data receiving means 9 transmits the serial data. It 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
Completes a series of operations for transmitting to.

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

The contact device 16 has a contact switch 17. Here, a description will be given of an operation of detecting when the contact switch is normally broken and making it, and notifying the center apparatus that the make is made.

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

When activated, the contact state notifying means 6 sets point A to L level. Therefore, the voltage applying means 2 is
And the voltage V becomes 5V. Therefore, the transistor TR2 of the disconnection detecting means 3 is turned on, and the L
Output level signal. The contact state notifying means 6 monitors that the point B becomes H level. In this state, the contact device 1
6 makes the contact switch 17, the transmission line voltage V
Becomes a value close to 0 V, the transistor TR2 of the discontinuity detecting means 3 is turned off, and an H level signal is output to the point B. The contact state notifying means 6 detects the H level signal at the point B, and notifies the center device 12 that the contact has been 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
Change in the state of the contact switch can be detected.

As described above, the terminal network control device 1 of the present invention connects either the terminal that performs serial communication or the terminal of the contact device via the same transmission line 10, and supports communication between the center device and the terminal.

[0032]

As described above, according to the terminal network control device 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 contact devices, a water meter, an LP gas meter, and the like can be connected. Therefore, it is necessary to provide a terminal network control device having a plurality of such general-purpose connection terminals. For example, one terminal network control device can cope with the combination of types and numbers of terminals connected to the terminal network control device.

[Brief description of the 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 device is connected.

FIG. 3 is a view for explaining the operation when the contact device of the 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 Disconnection detection means 4 Disconnection generation means 5 Serial communication means 6 Contact state notification means 7 Operation switching means 8 Data transmission means 9 Data reception means

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Sakata 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) H04M 11/00

Claims (1)

(57) [Claims] A connection unit connected between a terminal and a communication line for connecting the terminal using a pair of transmission lines; voltage applying means for supplying a DC voltage to the transmission line; Gating generation means for gating, gating detection means for detecting whether or not a DC loop circuit with the terminal is closed by the terminal, and the gating means in a state where a voltage is applied to the transmission line by the voltage applying means. Data transmitting means for controlling the on / off generating means to generate a pulse signal between the transmission lines and transmitting serial data to the terminal; and the on / off detecting means in a state where a voltage is applied to the transmission line by the voltage applying means. A data receiving means for receiving, as serial data, a change in the closing and opening of the DC loop circuit by the terminal, and a communication between the center device and the terminal by the data transmitting means and the data receiving means. A real communication unit, a contact state notifying unit for notifying the center device of the detection state of the disconnection detecting unit via the communication line, and setting which of the serial communication unit and the contact state notifying unit is used; And an operation switching means for switching the means.