JPH05276231A - Digital telephone system - Google Patents

Abstract

PURPOSE:To inform of the fact that a line is disabled when it occurs. CONSTITUTION:The channel of an ISDN line that can be used is monitored by a B channel use detection circuit 2, and a state where both a B1 channel and a B2 channel are closed is detected by a busy state detection circuit 2e, and it is displayed on a busy display part 2f. Thereby, it can be recognized before the telephone set is used that all the channels are busy, which eliminates a wasteful operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ISDN line
The present invention relates to a digital telephone device that notifies the user when all call channels are busy.

[0002]

2. Description of the Related Art As is well known, up to eight ISDN terminals can be connected to one station line by bus connection, and two of them can be used at the same time.

[0003]

When a plurality of such devices are installed in the same room, it is immediately known which one is in use. There is no problem that it cannot be used, but when the terminal devices are installed in different places, it is found that the terminal device cannot be used for the first time after making a transmission process, which is very inconvenient.

The present invention has been made in view of such a situation, and is to notify the user when the line is not available.

[0005]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention is to use line detecting means for detecting the use state for each communication channel, and use all the channels in the use line detecting means. And a busy state informing means for informing the busy state when is detected.

[0006]

The usable channel of the ISDN line is monitored by the used line detecting means, and when all the channels are blocked, the busy state notifying means notifies the busy state.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the present invention, in which this device and the network of ISDN lines are connected via a transformer 1, and B1 and B2 channels of ISDN lines use B channels. Detection circuit (used line detection means)
It is detected by.

Generally, in the ISDN line, the B channel to be used is designated by the network for both the outgoing call and the incoming call. Since the contents are sent as protocol data from the network, if the terminal device in the idle state constantly monitors the received signal from the network and stores the B channel used,
When another terminal is using a certain channel, it can be known even in an idle state, that is, a terminal device not in use.

In this way, the B-channel use detection circuit 2 constantly monitors the received signal from the network and displays the busy signal when all the channels are in use. The frame separation circuit 2a and the B1 channel detection circuit 2c. , A B2 channel detection circuit 2d, a busy state detection circuit 2e for determining whether or not the two channels are busy, and a busy display section 2f for notifying the busy state.

The call information is transmitted and received to and from the network by the interface section, the codec 4, the analog signal control section 5, the speaker 6, and the handset 7. Further, the control of the transmission operation and the like is performed by the key unit 8, the I / O unit 9, the control unit 10, and the display unit 11. In addition, the AC power supply 12, the AC adapter 13, the power supply unit 14, and the power supply switching unit 15 are used to supply drive power for the apparatus.

The state of the ISDN communication signal defines a frame structure as one format, and the position of the B channel bit used for communication is determined for each of the B1 and B2 channels, and the bit is detected for each frame. Then, it is possible to detect whether or not the predetermined B channel is used.

In order not to interfere with communication to other terminal devices in the bus connection, a binary "1" signal is continuously sent to the B channel during non-communication. Therefore, the bit of each B channel is "1" when other terminals are not using it, and "0" is detected during communication. A circuit for detecting "0" is provided for each of the B1 and B2 channels, and when "0" is detected for both the B1 and B2 channels, the line busy may be notified. B based on the concept of B channel use detection circuit box
The usage status of channels 1 and 2 is detected.

FIG. 1 shows this detection performed by a hard circuit, while FIG. 2 shows it performed by software. This device is also a line interface unit 20, a codec 21, an analog signal control unit 22, a control unit 23, an operation unit 24, a display unit 25, a speaker 26, a handset 27, a power supply switching unit 28, a power supply unit 29, an AC adapter 30, an AC. Power supply 3
It has the same ISDN basic hardware circuit as that of FIG. However, in the case of FIG. 2, the CPU inside the control unit 23 detects the above-mentioned busy state by software.

FIG. 3 is a flowchart showing the detection processing. In step 100, it is judged that the incoming call is not to itself, the release signal is sent in step 101, the release completion signal is received in step 102, and the empty state set in step 103. Processing is performed to detect whether or not the bus communication state shown in step 104 is present.

When the bus communication is in progress, step 1
The received signal is monitored in step 05, and step 106
At, it is detected whether or not the channel used is the B1 channel. If the channel being used is the B1 channel, the B1 flag is turned on as shown in step 107, and if it is the B2 channel, the B2 flag is turned on.

Then, in step 108, B1, B2
If it is determined that both channels are on, step 1
In 09, the busy display is turned on to give the busy notification, but if either one is not turned on, the busy display is turned off as shown in step 110. In this case, even if the busy display is not originally turned on, the busy display off process is performed, but only the state change does not occur and the whole operation is not hindered.

In step 100, if the incoming call is to itself, normal incoming call processing is performed. A B channel detection circuit may be added as shown by the dotted line in FIG. 2, and in this case, the configuration is the same as that in FIG.

FIG. 4 is a diagram showing a sequence of the above operation, and is an example in which when C originates and B arrives, A monitors and detects busy. A turns on the busy display when the B1 flag is turned on and then the B2 flag is turned on. Since the B2 flag is turned off in this example after that, the busy display is turned off at that time.

[0019]

As described above, according to the present invention, the busy display is made when both the B1 channel and the B2 channel are busy. Therefore, even if a plurality of terminal devices are installed at distant places, before the call is made. Therefore, it is possible to know whether or not the line is idle, and at a glance whether or not the terminal device is available.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 3 is a flowchart showing an operation for detecting a busy state.

FIG. 4 is a diagram showing an example of a control sequence.

[Explanation of symbols]

 1 transformer 2 B channel use detection circuit 3 interface section 4 codec 5 analog signal control section 6 speaker 7 handset 8 key section 9 I / O section 10 control section 11 display section

Claims (1)

[Claims] 1. A digital telephone device connected to an ISDN network, wherein a used line detecting means for detecting a use state for each call channel, and the use line detecting means detects that all channels are in use states. A digital telephone device, comprising: a busy state informing means for informing a busy state.