JPH0548764A - Isdn terminal device - Google Patents

Abstract

PURPOSE:To display the use state of the control channel of a basic interface on the terminal device without placing any load on the central processing circuit of the terminal device. CONSTITUTION:The line use state display means 7 of the ISDN terminal device monitors whether or not there are signals of two information channels of the basic interface of ISDN and detects the information of the control channel directly to make a display 7 of the use state of the information channels without charging any load on the central processing circuit 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used in ISDN terminal equipment. In particular, the present invention relates to a line busy display means that utilizes the presence or absence of a signal on the information channel of the basic interface.

[0002]

2. Description of the Related Art In a conventional example, an ISDN exchange and a plurality of I
The network control circuit of the ISDN terminal device monitors the call setting message and the call disconnection message transmitted / received to / from the SDN terminal device through the control channel of the basic interface, and centrally processes the use states of the two information channels of the basic interface. It was displayed on the display circuit by the circuit.

[0003]

In such a conventional example, the exchange of the call setup message and the call disconnection message between the ISDN exchange and the ISDN terminal device is monitored, the contents are analyzed, and the information channel is analyzed. Since the usage status of the CPU is determined, an analysis program is required in addition to the normal call control, and the load on the central processing circuit increases.

The present invention eliminates such drawbacks, and provides an ISDN terminal device having means for displaying the use status of the control channel of the basic interface without imposing a burden on the central processing circuit of the device itself. The purpose is to

[0005]

SUMMARY OF THE INVENTION The present invention is an ISD that accommodates a plurality of ISDN terminal devices via a basic interface consisting of two information channels and one control channel.
In an ISDN terminal device equipped with a basic interface circuit connected to an N switch and a display circuit for displaying the use status of the two information channels, the ISDN terminal device is connected to the basic interface circuit via two information channels, and the ISDN is connected. A signal detection circuit is provided for determining an information channel in which a call message or a call disconnect message is exchanged between the exchange and the plurality of ISDN terminal devices, and controlling the display content of the display circuit according to the determination result. It is characterized by

[0006]

The first information channel 1 of the basic interface circuit 4 of the ISDN terminal device 2 receives the signal of the information channel connected by the control information transmitted and received via the basic interface 14 between the ISDN terminal device 3 and the ISDN exchange 1.
1 and signal detection circuit 1 in which the second information channel 12 is connected
Monitor at 0. The signal detection circuit 19 displays a display corresponding to the information channel having the signal on the display circuit 7. The signal detection circuit 1 indicates that communication has ended and the information channel signal has disappeared.
When 0 is detected, the display corresponding to the information channel displayed on the display circuit 7 is erased. Thereby, the ISDN terminal device 2 can know the information channel of the basic interface used by the ISDN terminal device 3.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of this embodiment.
To the ISDN exchange 1 via the basic interface 14
SDN terminal devices 2 and 3 are connected. ISDN
The basic interface circuit 4 of the terminal devices 2 and 3 is a signal detection circuit 10 in which a communication circuit 5 and a display circuit 7 are connected via a first information channel 11 and a second information channel 12.
Connected to and. The central processing circuit 8 exchanges control information with the ISDN exchange 1 via the network control circuit 6 by a program in the storage circuit 9.

In this embodiment, as shown in FIG. 1, a basic interface connected to an ISDN exchange 1 accommodating ISDN terminal devices 2 and 3 via a basic interface 14 consisting of two information channels and one control channel. An interface circuit 4 and a display circuit 7 for displaying the use status of the two information channels are provided. Further, as a feature of the present invention, the basic interface circuit 4 is connected via the two information channels, and ISDN. Switch 1 and ISD
A signal detection circuit 10 is provided for determining the information channel with which the call origination message or the call disconnection message is exchanged with the N terminal devices 2 and 3 and controlling the display content of the display circuit 7 in accordance with the result of the determination.

Next, the operation of this embodiment will be described. When a call is made from the ISDN terminal device 3 to the ISDN exchange 1 for communication, the call message is exchanged, and the ISDN exchange 1 selects a free information channel,
N terminal device 3 is connected to the information channel. The information of the information channel connected at this time is transmitted to the ISDN terminal device 2 via the basic interface 14 as the first information channel 11 and the second information channel 12 of the basic interface circuit 4.
Sent to and. The signal detection circuit 10 determines the presence or absence of signals on the first information channel 11 and the second information channel 12,
The result is displayed on the display circuit 7. For example, when there is a signal in the first information channel 11, the LED corresponding to the first information channel 11 of the display circuit is turned on.

When a call disconnection message is exchanged between the ISDN terminal device 3 and the ISDN exchange 1 in order to terminate the communication, the information channel used is ISDN.
The exchange 1 disconnects. When the signal detection circuit 10 of the ISDN terminal device 2 detects that the signal of the first information channel 11 has disappeared, it turns off the LED corresponding to the first information channel 11 of the display circuit 7. By this procedure, the usage status of the information channel of the basic interface can be displayed on the ISDN terminal devices 2 and 3.

[0011]

As described above, according to the present invention, the presence / absence of the signal of the two information channels of the basic interface is directly detected without using the information of the control channel, so that the information can be processed without imposing a load on the central processing circuit. There is an effect that the usage status of the channel can be displayed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

[Explanation of symbols]

 1 ISDN exchange 2, 3 ISDN terminal device 4 basic interface circuit 5 communication circuit 6 network control circuit 7 display circuit 8 central processing circuit 9 memory circuit 10 signal detection circuit 11 first information channel 12 second information channel 13 control channel 14 basic interface

Claims (1)

[Claims] 1. A plurality of ISDs via a basic interface consisting of two information channels and one control channel.
In an ISDN terminal device equipped with a basic interface circuit connected to an ISDN exchange accommodating an N terminal device and a display circuit for displaying the usage status of the two information channels, the basic interface circuit is provided with two information channels via the two information channels. Connected to each other and connected to the ISDN exchange and the plurality of ISDs.
A signal detecting circuit for judging an information channel for transmitting and receiving a calling message or a call disconnecting message to and from the N terminal device and controlling a display content of the display circuit according to the judgment result. ISDN terminal equipment.