JPH0243865A - Call transfer device - Google Patents

Abstract

PURPOSE:To use a call transfer function even at a district where a station exchange accepting only a pulse dial signal is installed by storing a data in a received DTMF signal and sending a pulse dial signal based on the stored data. CONSTITUTION:A multi-frequency selection signal (DTMF signal) coming from an incoming trunk line is received by a DTMF signal reception section 323 provided in the device, a received signal code is converted into a transmission pulse dial signal according to a signal conversion table TB in a storage section 324 and the result is sent as a pulse dial signal to a caller trunk line. Thus, the call transfer function can be used even in a district where a station exchange accepting only a pulse dial signal is installed as a selection signal.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to the case where an incoming call is received from one central office line connected to a device, the incoming call is captured on that central office line, and the incoming call is captured on the other central office line connected to the device in the same way. The present invention relates to a call transfer device that captures a call and selects the other party to the central office exchange on the call capture side.

2. Description of the Related Art A conventional call transfer device is shown in FIG. Reference numeral 100 is a block diagram of a call transfer device, which is composed of the parts described below.

Reference numeral 103 denotes a bell detection section, which detects a bell signal sent from the central office exchange 114 through the central office line 115 and the capacitor 102 for cutting off DC current. The detection output of the bell detection section 103 is input to the control section 101 and used for determining incoming call. Reference numeral 104 denotes a relay for capturing the central office line 114, which is controlled by the control unit 101, forms/opens a DC loop for the central office exchange 114, and indicates an intention to make a call, answer, or end a call. 105 is the central office line 1 from the central office exchange 114.
A momentary interruption of the DC loop current which means the end signal is sent out through 15 (hereinafter, this instantaneous interruption of the DC loop current is referred to as a CPC signal). This is a CPC signal detection unit that detects the above and notifies the control unit 101. The capacitor 106 is used to cut off direct current from the office line 115 and transmit only the voice band signal to the internal communication path 120. On the other hand, a capacitor 107, a bell detection section 108, a relay 109, a CPC signal detection section 110, and a capacitor 111 are connected to the office line 116.
are a capacitor 102, a bell detection section 103, a relay 104, a CPC signal detection section 105, and a capacitor 10, respectively.
Performs the same function as 6.

Internal communication path 120 connects capacitor 106 and capacitor 1.
11, and performs signal connection in the speech voice band between the office line 115 and the office line 116.

The telephone 112 is a telephone under the control of the central office exchange 114 and is connected to the central office exchange 114 via a central office line 113. The functions of the telephone 119, central office line 118, and exchange 117 are as follows:
12, central office line 113, and switching center 114.

FIG. 6 is a flowchart illustrating the operation of the conventional call transfer device 100 shown in FIG.

The operation will be explained below using the flowchart shown in FIG. In step 201, the bell detection unit 103 determines whether or not there is an incoming bell call on the central office line 115. If there is no incoming call, the next step 202 is executed; if there is, step 2 is executed.
Execute 03. In step 202, the bell detection unit 108
It is determined whether or not there is an incoming bell call on the office line 116, and if there is no incoming call, the process returns to the first step 201 and returns to the office line 11.
5 and repeats the monitoring of incoming bell calls on the central office line 116. Further, when an incoming call is detected in step 202, the next step 204 is executed. However, if an incoming call is detected on the office line 115 in step 201 and the process moves to step 203, in order to capture the call on the office line 116 side,
It is determined whether there is an incoming call on the side. If there is a bell incoming call on station line 116, if both station lines are captured, a collision will occur, so the process returns to step 201 without capturing both station lines and station line 11
5 and central office line 116.

If there is no incoming bell call on the central office line 116, the call can be captured, so the process moves to the next step 205, and the relay 104.109
ONL, incoming calls are captured on the office line 115, and outgoing calls are captured on the office line 116. In this state, the caller calls the central office line 1 from the telephone 112.
13, means that a new call can be made to the central office line 116 via the central office exchange 114 and central office line 115. A call operation to the central office exchange 117 is performed by a multi-frequency selection signal sent from the telephone 112.
This is done via 6. Here, the central office exchange 117 analyzes the multi-frequency selection signal (hereinafter referred to as DTMF signal) transmitted from the telephone 112, and selects the telephone 11 that the caller desires.
9 (a bell signal is sent to the central office line 118 to which telephone 119 is connected.
The call is confirmed when the called party No. 9 picks up the receiver. The end of the call is confirmed when the caller on telephone 112 or the called party on telephone 119 puts the receiver back on, and the call transfer device 1 is sent from the central office exchange (114 or 117) on the side that put the receiver back on.
A CPC signal is sent to both station lines (115 or 116) connected to 00. Steps 206 and 207 are the CP of each central office line (115 or 116).
This is a process in which a C signal is detected by a CPC signal detection unit (105 or 110), and steps 206 and 207 are repeated until a CPC signal is detected. If a CPC signal is detected in either of these steps, step 208
, relay 104.109 to 0FFL, station line 11
5 and the central office line 116 to end the call. Then step 2
01 and restarts monitoring of incoming bell calls on both station lines (156 and 116).

By the way, the monitoring of incoming bell calls on the office line 115 in step 204 is the same as the process in step 203, and if there is an incoming bell call on the office line 115, collision of incoming calls should be prevented (return to step 201 to continue monitoring incoming bell calls). .Furthermore, if no incoming bell call is detected on the central office line 115, the process moves to step 205 and relays 104 and 109 are turned on.
L, the incoming call is captured on the office line 116, and the outgoing call is captured on the office line 115. The subsequent operations can be explained in the same manner as in the case where the incoming call is captured on the office line 115 and the outgoing call is captured on the office line 116 from the opposite standpoint.

As explained above, conventional call transfer devices employ a method in which the DTMF signal transmitted from the caller's telephone is directly transmitted to the originating central office exchange via the receiving central office exchange and the call transfer device. was.

Problems to be Solved by the Invention However, in such a call transfer device, if the central office exchange on the side that captures the call accepts a pulse dial signal as a selection signal, the DTM sent by the caller is
In order to solve the above-mentioned problems, the present invention uses a signal receiving means to receive a DTMF signal transmitted from a telephone on a receiving side office line, and stores data contained in the received DTMF signal. The device is configured to send out a pulse dial signal based on the stored data.

Effect With the above configuration, even if the central office exchange at the place where the call transfer device is installed is an exchange that only accepts pulse dial signals, if there is a means to send the DTM Fir: number to the calling party's telephone, It is now possible to send a selection signal to the originating central office exchange of the device using a pulse dial signal.
This call transfer device can be installed even in areas where central office exchanges that only accept pulse dial signals are installed.

Embodiments Hereinafter, embodiments of the call transfer device according to the present invention will be described with reference to FIGS. 1, 2, 3, and 4.

FIG. 1 is a block diagram of a call transfer device according to the present invention.
is the main body of the call transfer device.

Reference numeral 303 denotes a bell detection section, which detects a bell signal sent from the central office exchange 314 through the central office line 315 and the capacitor 302 for cutting off DC current. The detection output of this bell detection section 303 is input to the control section 301 and used for determining incoming call. 304 is a relay for capturing the central office line 315, which is controlled by the control unit 301, forms/opens a DC loop with the central office exchange 314, indicates an intention to respond to a call or end a call, and transmits a central office line. During capture, the DC loop is interrupted and a pulse dial signal is sent out. 305
is the C signal sent from the central office exchange 314 through the central office line 315.
This is a CPC signal detection unit that detects a PC signal and notifies the control unit 301. Capacitor 306 blocks direct current from central line 315, and connects contact C of relay 320 between central line 315 and contact a of relay 322 and resistor 321, which functions to attenuate voice band signals, to transmit only voice band signals. It is for the purpose of communication. On the other hand, a capacitor 307 and a bell detection unit 3 are connected to a central office exchange 317 through a central office line 316.
08, relay 309, and CPC signal detection section 310 are respectively capacitor 302, bell detection section 303, and relay 30.
4. Performs the same function as the CPC signal detection section 305. In addition, the capacitor 311 blocks the direct current of the central line 316, and
16 and relay 320 contact d1 resistor 321 and relay 3
This is for transmitting only voice band signals for communication between the contact points 22 and 22. A relay 320 is connected to both ends of a resistor 321, and when a call is in progress between both office lines (315 and 316), both ends of the resistor 321 are short-circuited to prevent attenuation of the call voice band signal level. Also, while pulse dialing is being sent to the calling side office line, the function of the resistor 321 causes the calling side office line (if the calling side office line 315 is the receiving side office line, the calling side office line becomes the office line 316, (The opposite is also true.) This reduces the intermittent sound of the pulse dial signal that leaks to the receiving side's office line. DTMF signal receiving section 323 is relay 3
22, and is switched to contact a or contact S under the control of the control unit 301. When connected to contact a, it receives the DTMF signal coming from the central office line 315, and when connected to contact S, A DTMF signal arriving from the central office line 316 is received, and the received data is input to the control section 301.

Also, while receiving a DTMF signal from the terminating capture side office line, the frame 320 is turned off, and the DTMF signal coming from the terminating capture side office line is turned off.
To protect an MF signal from the interference of DC loop current intermittent sounds of a pulse dial signal sent to a calling/capturing station line. 32
Reference numeral 4 denotes a storage unit connected to the control unit 301, and includes a buffer BF for storing DTMF signal data received by the DTMF signal receiving unit 323, and a program area PA1 in which a control program according to the flowchart of FIG. 2 is stored.
It also has a table area in which the conversion table shown in FIG. 3 is stored. The necessity of the buffer BF in the storage unit 324 is such that when converting the received DTMF signal 500 to the transmitted pulse dial signal 501 as shown in FIG.
This is to ensure consistency between the signal reception speed and the pulse dial signal transmission speed (for example, in the case of a pulse transmission speed of 10 PPS, it takes 1 second to transmit 10 pulses). That is, the received fast-speed DTMF signal data is buffered one after another in the buffer BF in the storage unit 324, and is sequentially converted into a slow-transmission pulse dial signal according to the conversion table TB shown in FIG. sent out on the line. The conversion rule for the received DTMF signal 500 into the transmitted pulse dial signal is as shown in Figure 3.
The DTMF signals meaning ``*'' and ``#'' are converted into pulse dial signals of 10 pulses, and the DTMF signals meaning * and # are discarded without being buffered in the buffer BF in the storage unit 324 as no pulses are sent.

The telephone 312 is a telephone under the control of the central office exchange 314 and is connected to the central office exchange 314 via a central office line 313. The functions of the telephone 319, the office 1318, and the exchange 317 are as follows:
12, central office line 313, and switching center 314.

FIG. 2 is a flowchart showing the operation of the call transfer device of the present invention. In step 401, it is determined whether or not there is an incoming bell call on the central office line 315 based on the input of the bell detection section 303.
If there is no incoming call, the next step 402 is executed, and if there is, step 403 is executed. In step 402, it is determined whether or not there is an incoming bell call on the central office line 316 based on the input from the bell detection unit 308. If there is no incoming call, the first step 401 is performed.
Returning to step 3, the system repeats the monitoring of incoming bell calls on the central office line 315 and central office line 316. Further, if an incoming call is detected in step 402, the next step 404 is executed. Then, in the previous step 401, an incoming bell call on the central office line 3151m is detected, and in step 403, in order to capture the outgoing call on the central office line 316 side, it is determined whether or not there is an incoming bell call on the central office line 316 side. conduct. If there is an incoming bell call on the office line 316, if it is captured as is, a collision will occur between the incoming calls on the office line 315 and 316, so the process returns to step 401 and monitors the incoming bell call on the office line 315 and 316. If there is no incoming bell call on the station line 316, the station line 316 can be captured as a call, so proceed to the next step 406, connect the relay 322 to the contact a side, and connect the DTMF receiver 323 to the incoming station line 315. Connect to. Next step 4
At 07, the relay 304 is ONL, the office line 315 is set to receive an incoming call, the JC 309 is set to ONL, and the office line 316 is set to receive an outgoing call.

In step 408, the relay 320 is turned on, and the resistor 32 is turned on.
1 is short-circuited, and the dial tone sent from the central office exchange 317 through the central office line 316 is set to be audible on the caller's telephone 312. In step 409, the DTM
It is determined whether or not the DTMF signal is being received by the F signal receiving section 323, and if the DTMF signal is not being received, the process moves to step 418. In step 418 and step 419, the sixth
As already explained in steps 206 and 207 in the figure, the CPC signals of both office lines (315 and 316) are monitored. If a CPC signal is not received in both steps (418 and 419), the process returns to step 409 and continues until a DTMF signal is received or a CPC signal is received from either station line (315 or 316). 418, repeat the process of step 419. If a CPC signal is detected in step 418 or step 419, the process moves to step 420, where both relays 304 and 309 are turned off, and both office lines (315 or 316) are disconnected to end the call. Thereafter, the process returns to step 401 and the incoming call detection on the office line 315 and office line 316 is resumed.

Then, when the DTMF signal is received in step 409,
Proceeding to the next step 410, the relay 320 is turned off, and the receiving side office line 315 is muted in order to send a pulse dial signal to the calling side office line 316. Next, in step 411, it is determined whether or not the DTMF signal reception has been completed, and if the reception has been completed, the next step 412 is performed.
Then, the received one-digit DTMF signal dial data is buffered in the storage unit 324. In the next step 413, it is determined whether the pulse dial transmission sequence for one digit has been completed. If it has been completed, the process moves to step 414, and the transmission dial data is stored from the storage unit 324 in order to transmit the pulse dial signal. Perform reading. Further, if the pulse dial sending sequence is currently being executed, the process directly moves from step 413 to step 415, and a sequence subsequent to the currently executing pulse dial sending sequence is executed. In step 415, the office line 316 is turned on by the relay 309 as shown in the office line 316 output waveform 620 (
623) and OFF (624), and a dial pulse sending sequence 622 and an interdigit Bose sending sequence 625 are executed. After executing some of these sequences, step 416 is skipped and the process returns to step 411. If the DTMF signal is still being received in step 411, the process moves to step 416, where it is determined whether reading of all dial data in the storage section 324 has been completed.
If dial data still exists in the storage unit 324, the process moves to step 413, and it is determined whether the pulse dial sending sequence for one digit has already been completed. By the way, in step 416, if reading out all the dial data in the storage section 324 has been completed, step 4
17, it is determined whether or not the pulse dial sending sequence for one digit has been completed. If the pulse dial sending sequence is still being executed, the process moves to step 415, and the pulse dial sending sequence is continued. If the pulse dial sending sequence has been completed in step 417, the process returns to step 408 and the relay 32 is activated again.
0 is turned on, and the subsequent steps 409, 418, and 419 are repeated to monitor DTMF signal reception and detect CPC of both office lines (315 and 316).

If the incoming call on the office line 316 is detected in step 402, the process moves to step 404, and the incoming call on the office line 315 is monitored. If an incoming bell call is detected, the process returns to step 401 to continue monitoring the bells of both office lines in order to prevent a collision of incoming calls on both office lines. However, if no incoming call is detected at station 1315, the process moves to step 405;
The relay 322 is connected to the contact side, the DTMF signal receiving section 323 is connected to the receiving side office line 316, and the DTMF signal is set in a state capable of receiving the DTMF signal. After the next step 407,
The office line 315 explained earlier is the receiving side office line, and the office line 316 is the receiving side office line.
This can be explained from the opposite perspective when is the originating station line.

Here, the timing chart for converting the sending pulse dial signal of the received DTMF signal in FIG. 4 will be explained, assuming that the incoming call capturing side office line is the office line 315 and the originating capturing side office line is the office line 316.

a) is a signal waveform on the central office line 315, which is a DT sent from the telephone 312 via the central office line 313 and central office exchange 314.
MF signal is shown. Note that the internal numbers indicate dial data. b) is a diagram showing the buffering data of the buffer BF in the storage unit 324, in which the dial data is not yet buffered, the DTMF signal is buffered in step 411, and all the buffered data are Indicates that transmission has ended. C)
indicates the operation of the relay 320, which is turned on at step 408, and when the DTMF signal is received, the relay 320 is turned off at step 410. Thereafter, all the buffering data stored in the buffer BF in the storage unit 324 is sent out, and at the timing when the pulse dial signal sending sequence is completed, the process moves from step 417 to step 408, and the relay 320 is ONL, and then, in step 409, DTM is sent out.
It remains ON until the F signal is received. d) is the output waveform to the office line 316, in step 414 one digit worth of dial data is read out from the storage unit 324, in step 415 a sequential dial pulse transmission sequence is executed, and then interdigital Bose transmission is performed. Sequence I
Execute. Subsequently, reading of dial data from the storage unit 324 and transmission of a pulse dial signal meaning dial "1" are started. When the entire transmission sequence for dial "1" is completed, the dial data is read out from the storage section 324 again, and the transmission sequence of the pulse dial signal meaning dial "2" is started.

Effects of the Invention The present invention receives a DTMF signal arriving from the receiving side's office line by a DTMF signal receiving section provided in the device, converts the received signal code into an outgoing pulse dial signal according to a signal conversion table, and transmits the DTMF signal to the calling side. Since it is sent as a pulse dial signal to the central office line, the call transfer function can be used even in areas where central office exchanges that can only accept pulse dial signals as selection signals are installed, which is an unprecedented function. A highly practical call transfer device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a call transfer device according to an embodiment of the present invention, FIG. 2 is a flowchart showing a control procedure in the call transfer device according to the present invention, and FIG. 3 is a diagram of converting a received DTMF signal into an outgoing pulse dial signal. FIG. 4 is a diagram showing a conversion table, and FIG.
Timing chart of TMF signal sending pulse dial signal conversion, Figure 5 is a configuration diagram of a conventional call transfer device, Figure 6
The figure is a flowchart showing processing in a conventional call transfer device. 112.31 113.31 115.31 116.31 118.31 119.31

Claims (1)

[Scope of Claims] Signal receiving means for receiving a multi-frequency selection signal arriving from a first terminal; storage means for storing data included in the multi-frequency selection signal received by the signal receiving means; and the storage means. 1. A call transfer device comprising: pulse generating means for generating a pulse signal based on data stored in the pulse generating means; and means for transmitting the pulse generated by the pulse generating means to a second terminal.