JPH06105010A - Isdn terminal equipment - Google Patents

Abstract

PURPOSE:To automatically match the polarity of interface in use with the one of another terminal equipment or transmission line terminating equipment by detecting the polarity of a connected line. CONSTITUTION:The polarity of a signal received from the transmission line terminating equipment 12 is detected by a reception polarity detecting part 20, and also, the polarity of a signal transmitted by another terminal equipment connected to the same line with a bus is detected by a transmission polarity detecting part 19. The signal polarity of transmission/reception line in use is automatically matched with the one of the transmission line terminating equipment 12 by a polarity switching part 21 which switches the polarity of the transmission line and reception line of an interface based on such detection when no signal is transmitted from another terminal equipment, and also, when another terminal equipment is transmitting the signal, the signal polarity of the transmission/reception line in use is automatically matched with the signal polarity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN terminal device which is bus-connected to a line of an ISDN basic interface network for communication.

[0002]

2. Description of the Related Art FIG. 2 shows the configuration of a conventional ISDN terminal device. In FIG. 2, 1 is an ISDN network, 2 is a DS
U (transmission path terminating device), 3 is a signal line from the DSU 2 to the TE (terminal device) direction, and 4 is a signal line from the TE to the DSU 2 direction. 5 is the ISDN terminal device itself.
In the SDN terminal device 5, 6 is a line interface unit connected to the signal lines 3 and 4, 7 is a communication unit for transmitting and receiving voice signals or data, and 8 is control for controlling the entire device such as call control. It is a department.

Next, the operation of this conventional configuration will be described. In FIG. 2, the received signal from the ISDN network 1 is input to the ISDN terminal device 5 through the DSU 2 and the signal line 3 from the DSU 2 in the TE direction. The input received signal is passed to the line interface unit 6, and the information channel in the received signal is input to the communication unit 7. The signal of the information channel transmitted from the communication unit 7 is framed by the line interface unit 6 and is transmitted from the TE to the DSU 2
Is output to the signal line 4 in the direction of ISD through DSU2.
It is transmitted to the N network 1.

At this time, if the polarities of the transmission signals of the plurality of terminals connected to the bus are not uniform, the DSU 2 cannot be synchronized and normal communication cannot be performed.

As described above, even in the conventional ISDN terminal device, if the polarities of the terminals connected to the same line by the bus are all the same, normal communication can be performed.

[0006]

However, since the interface polarity is fixed in the ISDN terminal device of the above-mentioned conventional example, when the polarity is not aligned with other terminal devices connected to the bus, and in the wiring in the house. There is a problem that normal communication cannot be performed when there is a connection error, and further communication of other terminal devices is disturbed, and improvement thereof has been a problem.

The present invention solves such a conventional problem, and detects the polarity of the connected line and automatically determines the polarity of another terminal device or transmission line terminating device to its own interface. Excellent I that can match polarities
It is intended to provide an SDN terminal device.

[0008]

In order to achieve the above object, the present invention is an ISDN terminal device for performing communication by being bus-connected to an ISDN basic interface network, in which the polarity of a signal received from a transmission line terminating device is controlled. Reception polarity detection means for detecting, transmission polarity detection means for detecting the polarity of a signal transmitted by another terminal device connected to the same line by a bus, and polarity for switching the polarity of the transmission line and the reception line of the interface It is equipped with a switching means and at least a control means for discriminating the polarity detected by the reception polarity detecting means and controlling the switching of the polarity, and when the other terminal device is not transmitting a signal, the signal polarity of the transmission line terminating device is automatically set. In addition, when another terminal device is transmitting a signal, the signal polarity of its own transmission / reception line is automatically adjusted to the signal polarity.

[0009]

With such a configuration, the ISDN terminal device of the present invention automatically adjusts to the polarity of the terminal device when no other terminal device is communicating. When another terminal device is transmitting a signal, the polarity of its own transmission / reception line is automatically adjusted to that polarity. Therefore, it is possible to perform normal communication even when the signal polarities are not matched with those of other terminal devices connected to the bus or when there is a connection error in the wiring in the house.

[0010]

Embodiments of the ISDN terminal device of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the configuration of the embodiment. In FIG. 1, 11 is an ISDN network, 12 is a DSU (transmission path terminating device), 13 is a signal line from the DSU 12 to the TE (terminal device) direction, and 14 is a signal line from the TE to the DSU 12 direction.

Reference numeral 15 is an ISDN terminal device itself,
In the DN terminal device 15, 16 is a line interface unit connected to a line, 17 is a communication unit for transmitting and receiving voice and data, and 18 is a control unit for controlling the entire device such as call control. . Reference numeral 19 is a transmission polarity detection unit that detects the polarity of the transmission signal of another terminal device that is bus-connected to the same line, and is connected to the signal line on the transmission side of the terminal. Reference numeral 20 denotes a reception polarity detection unit that detects the polarity of the reception signal from the DSU 12, and is connected to the signal line on the reception side of the terminal. Reference numeral 21 is a polarity switching unit that switches the polarities of the transmission line and the reception line, and is controlled by the control unit 18.

Next, the operation of the configuration of this embodiment will be described. The received signal from the ISDN network 11 is DSU
12 and a signal line 13 from the DSU 12 in the TE direction to the ISDN terminal device 15. The input reception signal is sent to the line interface unit 16, and
The information channel in the received signal is input to the communication unit 17.
Further, the signal of the information channel transmitted from the communication unit 17 is framed by the line interface unit 16 and transmitted from TE to D.
The signal is output to the signal line 14 in the SU12 direction and transmitted to the ISDN network 11 through the DSU12.

When another terminal device is transmitting a signal, the transmission polarity detection unit 19 detects the polarity of the transmission line and the control unit 1
Notify 8. The control unit 18 controls the polarity switching unit 21 to match the polarities of the transmission line and the reception line with the detected polarities. Further, when the other terminal device is not transmitting a signal, the reception polarity detection unit 20 detects the polarity of the reception line from the DSU 12 and notifies the control unit 18. The control unit 18 controls the polarity switching unit 21 to match the polarities of the transmission line and the reception line with the detected polarities.

As described above, according to the above-described embodiment, when the other terminal device is not communicating, the signal polarity of the DSU 12 is automatically adjusted to match the polarity of its own transmission / reception line. When sending a message, the polarity of its own transmission / reception line is automatically adjusted to the signal polarity, so if the polarity is not aligned with other terminal devices connected to the bus on the same line, or if it is connected to in-home wiring Even if there is an error, normal communication can be performed.

[0016]

As is apparent from the above description, the ISDN terminal device of the present invention automatically adjusts to the polarity of the terminal device when no other terminal device is communicating, and
When another terminal is transmitting a signal, the polarity of its own transmission / reception line is automatically adjusted to that polarity, so the signal polarity is not aligned with the other terminal connected to the bus. This has the effect that normal communication can be performed even in the case where there is a connection error in the wiring in the house.

[0017]

【Example】 [Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an ISDN terminal device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional ISDN terminal device.

[Explanation of symbols]

 11 ISDN network 12 DSU 15 ISDN terminal device 16 line interface unit 17 communication unit 18 control unit 19 transmission polarity detection unit 20 reception polarity detection unit 21 polarity switching unit

Claims (1)

[Claims] 1. An ISDN terminal device which is connected to an ISDN basic interface network by a bus to perform communication, and is connected to the same line as a reception polarity detecting means for detecting the polarity of a signal received from a transmission line terminating device. A transmission polarity detecting means for detecting the polarity of the signal transmitted by another terminal device, a polarity switching means for switching the polarity of the transmission line and the reception line of the interface, and a discrimination of the polarity detected by at least the reception polarity detecting means. , And a control means for switching polarity, which automatically adjusts to the signal polarity of the transmission line terminating device when another terminal device is not transmitting a signal, and the other terminal device transmits a signal. If so, the ISDN terminal device is characterized in that the signal polarity of its own transmission / reception line is automatically adjusted to the signal polarity.