JPH05207182A - Terminal network controller - Google Patents

Abstract

PURPOSE:To surely detect off-hook even to a telephone set or the like in the case of switching and connecting a telephone line to a data communication terminal and the telephone set, etc. CONSTITUTION:In the state of operating a line termination part 6 to terminate the telephone line at a specified resistance value in the case of no-ringing communication, a line voltage measurement part 19 measures a line voltage, subscriber line resistance is calculated from the measured value by a line resistance calculation part 20, and the detecting condition of an off-hook detection part 18 is changed from the calculated value by an off-hook detecting condition change part 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a system for calling a data communication terminal and collecting data by a ringing method using a subscriber telephone line from a center, and switching the telephone line between a data communication terminal and a telephone or the like. The present invention relates to a terminal network control device for connecting and detecting off-hook of a telephone or the like.

[0002]

2. Description of the Related Art A conventional terminal network control device 1 of this type is shown in FIG.
As shown in FIG. 3, the analog line (L1, L2) 2 is switched and connected to the data communication terminal 3 and the telephone 4 (connected to the terminals T1 and T2), and the telephone line 2 is connected to the telephone 4. An off-hook detecting section 5 for detecting an off-hook of the telephone 4 at this time, a line terminating section 6 for terminating the telephone line 2 with a prescribed resistance value during no ringing communication, and a signal for transmitting and receiving a communication message between the data communication terminal 3 and the center apparatus. The transmission unit 7 and the central control unit 8 that controls the above-mentioned units are included.

In the no-ringing communication system, the telephones 4 are connected in parallel with the line terminating unit 6 terminating the line, and the telephone 4 always connected to the telephone line 2 can be preferentially used. Since the configuration is required, the off-hook state of the telephone 4 is constantly monitored by the off-hook detector 5 even during no-ringing communication, for example. When the off-hook is detected, the central control unit 8 controls the line terminating unit 6 to release the termination of the telephone line 2 so that the telephone exchange can use the general line.

By the way, the off-hook detecting section 5 is often composed of a photocoupler or the like connected in series with the telephone 4, and at the time of off-hook, the direct current flowing through the line is also distributed to the light emitting element on the primary side. Had been detected by.

[0005]

However, with the above-described structure, accurate off-hook detection cannot be performed for the off-hook resistance of the telephone 4 which changes depending on the applied voltage. That is, some line terminal devices, such as the 601 type telephone, change the internal equivalent DC resistance value during off-hook depending on the voltage value applied between the connection terminals. For example, when the applied voltage is about 30 (V), about 2
Although there is a terminal device having a configuration in which it indicates 00 (Ohm) but reaches several (Kilo-Ohm) when it reaches about 10 (V), the conventional terminal network control device 1 does not consider these changes.

FIG. 4 shows how the voltage value applied to the line terminal device such as a telephone set which should detect the off-hook state changes depending on the line. In the figure, the exchange 9,
It is composed of three blocks, that is, a subscriber line 10 and a terminal device 11. In the exchange 9, a station power supply E (48V) 12 is supplied to the subscriber line 10 through an in-station resistor RA13. The capacitor 14 is inserted in order to cut off the DC communication between the terminal devices that communicate with each other. The station power supply 12 is further supplied to the terminal device 11 side via the subscriber line resistance RL15. A telephone is connected to the terminal device 11, and the line is terminated by the DC resistance RT16. As is clear from this figure, the line voltage value applied to the connection terminal of the terminal device 11 depends on the subscriber line resistance RL15 (about 0 to 1.5 kOhm) determined by the wire rod wired from the exchange 9 and its length. However, it is determined by the ratio of RA, RL, and RT.

In FIG. 4, during no ringing communication, the line termination unit 6 shown in FIG. 3 terminates the line with a prescribed resistance value instead of the telephone DC resistance 16, and at this time, the telephone 4 which should detect an off-hook state. Connection terminal T, etc.
The voltage applied to T1 and T2 is changed by the subscriber line resistance 15 as described above. Therefore, a telephone 4 or the like connected in parallel with the line terminating unit 6 whose internal equivalent DC resistance value changes depending on the applied voltage has a problem that its off-hook cannot be detected reliably.

SUMMARY OF THE INVENTION The present invention has been made to solve the above conventional problems, and an object of the present invention is to provide a terminal network control device capable of surely detecting an off-hook of a telephone or the like.

[0009]

In order to solve the above-mentioned problems, a terminal network control apparatus of the present invention terminates a telephone line with a prescribed resistance value during no-ringing communication and an off-hook detection unit for detecting off-hook of a telephone or the like. Line termination unit, a line voltage measurement unit that measures the line voltage when the line is captured by the line termination unit, and a line resistance calculation unit that calculates the subscriber line resistance from the measurement value of the line voltage measurement unit. And an off-hook detection condition changing unit that changes the detection condition of the off-hook detection unit based on the calculated value of the line resistance calculation unit, and a central control unit that controls each unit.

[0010]

According to the present invention, with the above configuration, the line voltage measuring unit measures the line voltage while the line terminating unit terminating the telephone line with the specified resistance value is operating during the no-ringing communication. Then, the line resistance calculation unit calculates the subscriber line resistance, and the off-hook detection condition changing unit changes the detection condition of the off-hook detection unit from the calculated value.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

Referring to FIG. 1, a terminal network controller 1 of the present invention.
Reference numeral 7 denotes an off-hook detecting section 18 for detecting an off-hook of the telephone set 4, etc., a line terminating section 6 for terminating the telephone line 2 with a prescribed resistance value during no ringing communication, and a line terminating section 6 when the line is captured. A line voltage measuring unit 19 that measures a line voltage, a line resistance calculating unit 20 that calculates a subscriber line resistance from the measured value of the line voltage measuring unit 19, and a detection value of the off-hook detecting unit 18 from the calculated value of the line resistance calculating unit 20. It is composed of an off-hook detection condition changing unit 21 that changes the condition and a central control unit 22 that controls the above-mentioned units.

With this configuration, the line voltage measured by the line voltage measuring unit 19 in the state in which the data communication terminal 3 terminates the telephone line 2 with the specified resistance value during no ringing communication with the center. From the value, the line resistance calculating unit 20 calculates the subscriber line resistance as shown in FIG. Then, the off-hook detection condition changing unit 21 changes the detection condition of the off-hook detection unit 18 from the calculated value. That is, the threshold value for determining off-hook is changed according to the line voltage value. For example, as described above, when the applied voltage is about 30 (V), it shows about 200 (ohm),
In a terminal device configured to reach several (kiloohms) at about 10 (V), a detection level estimated from the characteristics is set in the off-hook detection condition changing unit 21.

As described above, even for a line terminal device such as a telephone whose internal equivalent DC resistance value changes during off-hook depending on the voltage value applied between the connection terminals, the off-hook detection level is changed depending on the applied voltage value, so that malfunction occurs. It is possible to reliably detect the use (off-hook) of a telephone or the like without the presence of a telephone. Here, an example in which the resistance value at the time of off-hook depends on the applied voltage has been shown, but the same effect is also exerted on the line terminal device whose open resistance value at the time of on-hook changes depending on the applied voltage.

Next, another embodiment of the present invention will be described with reference to FIG. In the figure, components having the same numbers as in FIG. 1 have the same functions. The line terminating unit 24 has a terminating resistance at the time of no ringing communication and a terminating resistance at the time of calling a terminal, and changes the resistance value terminating in each operation mode. The second off-hook detection unit 25 has a function of detecting the off-hook of the telephone 4 by using the device power supply of the present device 23 when the terminal of the data communication terminal 3 is called, and the line switching unit 26 determines each operation mode. The connection line of the telephone 4 is switched to. The central control unit 27 controls each of the above units. Here, the second off-hook detection unit 25 that uses the device power supply detects the off-hook when the telephone line 2 is connected to the data communication terminal 3 side as described above, and the low-voltage power supply (about 5 V). ) Is often driven by.
Therefore, the detection resistance value is set higher than the off-hook determination level detected by using the telephone line voltage.

As described above, by setting the off-hook detection level according to the voltage applied to the network control device having the terminal calling function as well, it is possible to surely detect the off-hook including during no-ringing communication. is there. That is, the telephone priority function can be surely achieved.

[0017]

As described above, according to the terminal network control apparatus of the present invention, the following effects can be obtained. (1) An off-hook detection unit that detects an off-hook of a telephone, a line termination unit that terminates a telephone line with a prescribed resistance value during no ringing communication, and a line voltage when the line is captured by the line termination unit is measured. A line voltage measuring unit, a line resistance calculating unit that calculates the subscriber line resistance from the measured value of the line voltage measuring unit, and an off-hook detection condition changing unit that changes the detection condition of the off-hook detecting unit from the calculated value of the line resistance calculating unit. , A central control unit that controls each of the above-mentioned units, so that the applied voltage value is applied even to a line terminal device such as a telephone whose internal equivalent DC resistance value changes during off-hook depending on the voltage value applied between the connection terminals. Since the off-hook detection level can be changed by this, it is possible to reliably detect the use (off-hook) of the telephone without any malfunction, and It is possible to improve the quality.

[Brief description of drawings]

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

FIG. 2 is a functional block configuration diagram of a terminal network control device according to another embodiment of the present invention.

FIG. 3 is a functional block configuration diagram of a conventional terminal network control device.

[Fig. 4] System configuration diagram of subscriber line

[Explanation of symbols]

 2 Telephone line 3 Data communication terminal 4 Telephone 6 Line termination unit 18 Off-hook detection unit 19 Line voltage measurement unit 20 Line resistance calculation unit 21 Off-hook detection condition change unit 22 Central control unit

 ─────────────────────────────────────────────────── ─── 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 terminal network control device which is applied to a system for calling a data communication terminal and collecting data by a ringing method using a subscriber telephone line from a center, and switching and connecting the telephone line to the data communication terminal and a telephone or the like. At
An off-hook detector that detects off-hook of a telephone or the like,
A line termination unit that terminates a telephone line with a prescribed resistance value during no-ringing communication, and a line voltage measurement unit that measures the line voltage when the line is captured by the line termination unit,
A line resistance calculation unit that calculates a subscriber line resistance from the measurement value of the line voltage measurement unit, an off-hook detection condition change unit that changes the detection condition of the off-hook detection unit from the calculated value of the line resistance calculation diagram, and each unit. A terminal network control device comprising a central control unit for controlling the terminal network.