JPH0642694B2 - Automatic selection incoming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial field to which the invention pertains The present invention divides a telephone network line into a plurality of extensions and selects an extension selected by a dial signal or an AC signal from a caller side. The present invention relates to an automatic selection call-receiving device that sends a call signal to a caller to make an incoming call to an extension.

(2) Conventional technology In this type of conventional device, first, an incoming call from the network is detected by the incoming call detection circuit, the relay switch and the loop creation circuit respond to this, the connection with the network is made, and then the outgoing call is made. The call signal is generated by the call signal generation circuit of the device to the extension selected by the selection signal of the operator side or the extension set in advance on the device side to receive the call. In the case of the conventional configuration, the ringing time of the extension is set by a preset timer, and when the ringing extension answers within this timer time, the caller side becomes in a call state and when there is no response until the timer expires, it is automatically The line was open. Further, even if the caller side abandons the line for some reason within the timer time, the extension continues to be called until the timeout, so there is a problem that the line may already be disconnected when the extension is answered.

As described above, conventionally, when an extension call is made, it is not possible to identify the occurrence of the caller's abandonment of the call, and if the extension call answerer goes off-hook, the call is already disabled. There was a disadvantage on the part of the called party.

(3) Object of the Invention The present invention provides an automatic selection call-receiving device having a function of stopping an extension call operation when a caller abandons a call while the line is on hold in order to avoid the drawbacks of the prior art. It is a thing.

(4) Configuration and operation of the invention To achieve this object, the automatic selection call receiving device according to the present invention is
Automatically selected call for connecting from the line connected to the telephone network, once connecting with the telephone network, and transmitting the call signal to the extension selected by the selection signal from the caller side of the line to receive the call. In the device, the ringing tone is a pseudo ring tone obtained by modulating a 700 Hz sine wave with the ringing signal on the calling side of the line while the ringing signal is being sent by the incoming call while the ringing signal is being sent. A ring back tone sending circuit for sending, a 400 Hz signal detection circuit connected to the line in a state where the line is captured by the incoming call, and a detection output when the 400 Hz signal detection circuit detects a 400 Hz busy tone And a control circuit for opening the line by stopping the transmission of the ringing signal to the extension line.

The present invention will be described in detail below.

A device configuration to which the present invention is applied is shown in FIG. Here, 1 is a telephone line, 2 to 4 are extensions, 5 and 6 are telephones, 7 is an automatic facsimile, 8 is a protection circuit, 9 to 11 are loop monitoring circuits, 12
~ 14 is an extension switching relay switch (B), 15 ~ 17 is a call signal sending switch circuit, 18 is an incoming call relay switch (A), 19 is an incoming call detection circuit, 20 is a polarity detection circuit, 21 is Loop creating circuit, 22 is a calling signal generating circuit, 23 is a ring back tone sending circuit, 24 is a multi-frequency signal (PB signal) reception detecting circuit, 25 is a calling signal [Calling Tone: 1100 Hz pure tone (single frequency) ... CNG signal] detection circuit,
26 is a circuit side ringing tone (PB signal) sending circuit, 27 is a facsimile network (1300 Hz) incoming call detection circuit, 28 is a dial tone,
A line call progress tone detection circuit for detecting each 400 Hz signal of a busy tone and a ring back tone, 32 is a voice signal detection circuit, and 100 is a control circuit using a microcomputer.

FIG. 2 is a flow chart showing the general operation of the circuit of FIG.

Next, an example of the general operation of the automatic selection call-receiving device of the present invention will be described with reference to FIGS.

First, when power is applied to the device and the device is activated, the control circuit (C
PU) 100 performs each monitoring process (for example, CNG signal monitoring, PB signal monitoring, facsimile network (F network) ringing signal monitoring, line call progress tone monitoring, etc.) (S ₁ ).

When a call signal arrives from the telephone line 1 in such a state, the call output is sent to the incoming call detection circuit 19 via the contact of the incoming call relay switch (A) 18, and the incoming call detection output is sent to the control circuit (CPU) 100. Is input to (S ₂ ). Then, the ringing signal generating circuit 22 operates under the control of the control circuit (CPU) 100 to generate an original extension ringing signal, and the ringing signal sending switch circuit 15 is preselected and switched to automatically receive an incoming call. The extension call signal is sent to the telephone set 5 via the contact point of to call.

When the telephone 5 raises the handset for the call, [L ₁
→ 12 → 9 → 5 → 12 → L ₂ ], the line is captured, and the telephone line 1 and the telephone 5 are connected (S ₃ ).

When the line is captured, the information is transmitted from the loop monitoring circuit 9 to the control circuit (CPU) 100, so that the relay switch (A) 18 for incoming call is switched by the control (capacitor C ₀ side), and thus the incoming call is received. The incoming call detection output of the detection circuit 19 stops. At the same time, the ringing signal generation circuit 22 also becomes inoperative and the transmission of the extension ringing signal is stopped.

On the other hand, under the control of the control circuit (CPU) 100, each detection circuit, for example, line call progress tone (400Hz) detection circuit 28, PB signal reception detection circuit 24, CNG signal detection circuit 25, F (facsimile) network incoming detection The circuit 27 and the like are activated. (S ₄ ).

It should be noted that the detection status of each detection circuit is constantly checked and classified and detected as follows according to each input signal, and the corresponding functional operation is performed (S ₅ ).

PB signal detection When a PB signal is detected, it is detected as an extension telephone number, the corresponding extension telephone (for example, 6) is called, and the telephone line 1 and the extension telephone (for example, 6) are connected in response. (S _6-1 , S _6-2 , S _6-3 , A).

F network incoming detection (1300Hz detection) When a 1300Hz signal is detected, a facsimile (FA
X) Facsimile (FAX), judging that it is a call from the network
Call the terminal device (for example, 7) and respond to the telephone line 1
And FAX (for example, 7) are connected (S _7-1 , S
_7-2 , S _7-3 , A).

If the line call pro Glenstone detection (400 Hz detection) 400 Hz signal is detected, detects as Bijiton, and open the telephone line 1 (S _8, C).

CNG signal detection (1100Hz pure tone detection) When a 1100Hz pure tone signal is detected, CNG
It is judged as a signal, the FAX terminal device (for example, 7) is called, and the telephone line 1 and the FAX (for example, 7) are connected to each other in response (S _9-1 , S _9-2 , S _9-3 , A).

Other signal detection (voice signal detection) When another signal not included in is detected, it is regarded as a real voice, a predetermined specific telephone (not shown) is called, and the telephone line 1 is identified by a response. To connect to the telephone (S _10-1 , S _10-2 , S _10-3 ,
A).

As described above, in response to the call from the calling side, the relay switch 18 and the incoming call detection circuit 19 detect the incoming call, the loop creation circuit 21 creates a loop, network connection is performed, and the selection signal from the caller side or When a time-out occurs in the device, the calling signal generation circuit 22 sends a calling signal to the extension designated by the switch of the device in advance, for example, 2, and at the same time, a ringback tone is sent to the caller side as described later. Do (S
₁₁ ).

Conventionally, the stoppage of the ringing signal transmitted to the extension lines 2 to 4 has been performed only for the timeout of the ringing signal transmission time set in the device of 30 seconds or 60 seconds. Although the extension terminal has been continuously called until now, in the method of the present invention, a 400 Hz signal detecting circuit for detecting a 400 Hz signal from the station, that is, a line call progress tone detecting circuit 28 is added, and as shown in FIG. detecting a busy tone (busy tone) sent from the station during the line abandoned (S _8), a call stop opening of the line (C) and the extension example 2. More specifically, as shown in FIG. 3, while the call signal is being sent to the extension terminal, in order to inform the caller side of the call state, the ring back tone sending circuit 23 changes the signal as shown in FIG. A ring back tone as shown is transmitted (S ₁₁ ). This ringback tone modulates a 700Hz sine wave signal at 16Hz and sends it out for 1 second.
It is sent at the timing of second stop. The busy tone sent from the station when the caller side gives up is 400Hz as shown in Fig. 4 (b).
Is a timing signal having a cycle of 0.5 seconds, and this signal (b) is detected by the line call progress tone detection circuit 28 (S ₁₂ ) while the ringback tone of FIG. The signal is stopped (S ₁₃ ), the ringback tone to the calling side is stopped (S ₁₄ ), and the line is simultaneously released (S ₁₅ ).

Here, the 700 Hz sine wave signal is modulated at 16 Hz, the output signal of FIG. 4 (a), and the line call progress tone detection circuit 28 detects a 400 Hz timing signal from the 400 Hz detection circuit 28, and it is a busy tone. FIG. 5 shows the operation for identifying the. That is, as shown in FIGS. 4 (a) and 4 (b), the pseudo ringing tone, that is, the ring back tone is set to 700 Hz to reduce the influence on the line call progress tone detection circuit 28, and in general, 1 second transmission, 2 A ringback tone with a stop period of 1 second is sent for 1 second, a stop period of 2.5 seconds is set, and the stop time is extended (a) to detect at least 4 busy sounds (b), and other noise It prevented the malfunction to.

Explaining the 400 Hz busy tone detection flowchart of FIG. 5, first, the busy tone is 400 Hz as shown in FIG.
If the busy tone is input during the sense enable period (2.5 seconds) of the ring back tone (700 Hz is modulated at 16 Hz) for 0.5 second period (300 ms period) of Hz, the line call progress tone detection circuit 28 outputs this signal. Is detected by sampling at 4 ms cycle (S ₂₁ ), first it is detected whether or not the ringback tone (RBT) is transmitted (S ₂₂ ), and if the ringback tone is not included, the busy tone 400 Hz is read. (S _23), compared to the busy tone is stored in advance in the memory (S _24),
If the signal form is the same, the 400 Hz sampling counter is incremented (S ₂₆ ), and if it is confirmed that the signal continues for 300 ms (S ₂₇ ), the 400 Hz sampling counter is cleared again, the toggle counter is activated, and the toggle is inverted after adding "1" to the memory (S _29), enters the counting of the inverted signal subsequently arrives. Similarly, the subsequent signals are counted, and when the toggle counter counts the fourth time (S ₃₀ ), it is determined that a busy tone has occurred (S ₃₁ ), and the state returns to the standby state. If the signal does not continue for 300 ms or if the toggle counter cannot count the fourth time, it will not be judged as a busy tone and will be in a standby state. Note ringback tone (RBT) is the case is being sent to clear (S _22), the toggle counter memory 400Hz with (S ₃₂₎
The sampling counter is not activated ( _S33 ). In this way, ring back tone (700Hz /
16Hz modulation) and busy tone 400Hz are discriminated, and the extension side is considered to be abandoned by the caller and the extension call is stopped.

(5) Effects of the Invention As described above, the present invention adds the line call progress tone detection circuit and detects the busy tone from the station, and thus the line abandonment on the caller side is abandoned. Since the extension can be stopped in synchronism, there is an advantage that the extension response after the call is abandoned is eliminated.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an apparatus to which the present invention is applied,
2 is a flow chart showing the operation of the configuration of FIG. 1, FIG. 3 is a flow chart for explaining the operation of the present invention, and FIG.
(a), (b) and FIG. 5 are a time chart and a flow chart for explaining the operation of the present invention in which a 400 Hz component is detected while transmitting a ringback tone to the other party and is regarded as a busy tone. 1 ... telephone line, 2, 3, 4 ... extension, 5, 6 ... telephone, 7
... automatic facsimile, 8 ... protection circuit, 9, 10, 11 ... loop monitoring circuit, 12, 13, 14 ... extension switch relay switch (B), 15, 16, 17 ... call signal sending switch circuit,
18 ... Incoming relay switch (A), 19 ... Incoming call detecting circuit, 20 ... Polarity detecting circuit, 21 ... Loop creating circuit, 22 ... Ringing signal generating circuit, 23 ... Ring back tone sending circuit, 24 ...
Multi-frequency signal (PB signal) reception detection circuit, 25 ... CNG signal detection circuit, 26 ... PB signal transmission circuit, 27 ... Facsimile (F) network incoming detection circuit, 28 ... Line call progress tone detection circuit, 32 ... Voice signal detection Circuit, 100 ... Control circuit (CPU).

Claims (1)

[Claims] 1. A call from a line connected to a telephone network is temporarily connected to the telephone network, and a call signal is transmitted to an extension selected by a selection signal from a caller side of the line. An automatic selection receiving device for receiving an incoming call, wherein a pseudo call is obtained by modulating a 700 Hz sine wave on the calling side of the line with the calling signal while the calling signal is being sent while the line is captured by the incoming call. A ringback tone sending circuit that sends sound as a ringback tone, a 400 Hz signal detection circuit connected to the line in a state where the line is captured by the incoming call, and a detection that the 400 Hz signal detection circuit detects a 400 Hz busy tone A control circuit for stopping the transmission of the ringing signal to the selected extension by the output and opening the line, the automatic selection receiving apparatus.