JPS6258581B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a line switching device, and more particularly to a switching device between a dedicated line and a subscriber telephone line in data communications.

Data communications, including facsimile communications, include dedicated communications between specific subscribers using dedicated lines set up by business entities and companies, and communications between unspecified subscribers using subscriber telephone lines (public communication lines). There is a subscription communication that takes place between.

When using a subscriber telephone line, various technical standards have been established to prevent interference with telephone calls and other communications. When using switching and installing data terminals on your own, you are required to connect a line protection device (PD).

To connect a facsimile device to a subscriber telephone line and transmit facsimile signals, the facsimile control unit is usually connected to a communications control unit (CCU), modem (MODEM), and network control unit (NCU).
Connect to subscriber telephone line.

Conventionally, when using the same facsimile device by switching between a subscriber telephone line and a leased line, it was not possible to use the network control unit (NCU) for the subscriber telephone line as is for the leased line, so it was necessary to select the one for the leased line. It was necessary to separately connect a line control unit (LCU) with functions such as signal transmission, ring signal detection, switching to a data communication path, and switching with a telephone attached to a leased line. Furthermore, in order to switch between the subscriber telephone line and the leased line, it is necessary to provide other special equipment, resulting in high costs. Furthermore, since line switching is not performed automatically when receiving,
This is extremely inconvenient.

Therefore, when switching and connecting the subscriber telephone line and the leased line, the present inventor shared the network control device for the subscriber telephone line when connecting the leased line, and the data terminal device (for example, a facsimile machine) for the subscriber telephone line was used. We have previously proposed a line switching device that can be used without modification (see specification of Japanese Patent Application No. 114585/1983). That is, as shown in FIG. 1, the above-mentioned line switching device 1 is added to the facsimile device 3, and
By providing a switching contact y in the DC circuit on the line side of the network control device 31 built into the network control device 31 to switch and connect the subscriber telephone line LN and the dedicated line PL, no matter which one is connected, the connection can be made via the network control device 31. I'm trying to do facsimile communication. Under normal circumstances, switching contact y is connected to the subscriber telephone line LN side, but when a call is received on the leased line PL and the facsimile machine is not communicating, the control circuit 6 controls the switch contact y to connect to the leased line PL side. Switch to
The facsimile device 3 is connected to the private line PL, and the contact x is switched to the main telephone 2 side, so that incoming calls from the subscriber telephone line PL are answered with voice.

However, in the line switching device 1 shown in FIG. 1, the facsimile device 3 is always connected to the subscriber telephone line LN, so when sending a facsimile to the subscriber telephone line LN, the selection switch must be pressed. However, when sending a facsimile to the dedicated line PL, the control circuit 6 is activated by operating the selection switch 7 and the contact y is switched before sending, which saves time and effort. And it takes time. In addition, dedicated line
If multiple data terminals similar to those shown in Figure 1 are connected to the PL, there will be competition among them, so it will be difficult to obtain the right to transmit even if you try to make a call, and if the dedicated line PL is not available, you will not be able to send. Sometimes. Furthermore, when a telephone connected to the leased telephone line LN hangs up, the public telephone exchange sends a howler tone to the telephone, but when a telephone connected to the leased line PL hangs up, When this occurs, all data terminals connected to the leased line PL will be unable to make or receive calls because there is no countermeasure against it.

The purpose of the present invention is to eliminate these conventional drawbacks by making it possible to fully automatically switch the line both when making a call and when receiving a call, and also to enable manual switching, so that communication with subscriber telephone lines and dedicated lines can be used. An object of the present invention is to provide a line switching device capable of performing communication using a common facsimile device and improving the efficiency of communication information processing.

The line switching device of the present invention is added to a facsimile device having a network control device, is connected to a subscriber telephone line and a dedicated line, and is used when making a call in a line switching device connected to a telephone corresponding to each line. The present invention is characterized by having means for connecting the facsimile device to the line by off-hooking the telephone set corresponding to the line, and for connecting the facsimile device to the line selected by the transmitting side at the time of reception.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a connection system diagram of a dedicated line system using the line switching device of the present invention.

The line switching device 10 of the present invention has a function of connecting the subscriber telephone line facsimile device 3 and the leased line PL, and thereby performs leased line facsimile communication using the subscriber telephone line facsimile device 3. Can be done. In addition, the line switching device 10
has a switching function between the subscriber telephone line LN and the leased line PL, and by automatically switching when receiving, and selectively switching by off-hook of the telephone when sending, it is possible to switch between facsimile communication using the subscriber telephone line network, and
The aforementioned dedicated line facsimile communication is possible.

The connection form of the private line PL is, for example, a bidirectional branch line as shown in FIG. 2, and a four-wire private line can be used. Phone 2 in each terminal
is a facsimile destination selection telephone (this telephone), telephone 5 is a conversation telephone, and telephone 4 is a conversation telephone.
is a telephone attached to a leased line.

The basic mode of line connection of the line switching device 10 is as follows:
It is in the subscriber telephone line mode, and becomes the leased line mode by receiving a call from the leased line PL or by performing an off-hook operation on the attached line telephone 4.

Telephones 4 and 5 of each terminal connected to the dedicated line PL
By dialing a preset dial number using the pushphone, it is connected to the facsimile device 3 or conversation telephone 5 of any other terminal, and facsimile communication and telephone calls can be performed.

FIG. 3 is a block diagram of a line switching device showing an embodiment of the present invention.

(1) First, telephone calls and facsimile communications using subscriber telephone line LN will be explained.

In a normal state, facsimile device 3 is connected to subscriber telephone line LN, and relays CN1 and CN2 are not operating at this time. Telephone calls and facsimile communications on subscriber telephone line LN are monitored by relay TA and relay TT.

In other words, if both relays TA and TT are operating, the phone 2 is communicating via facsimile device 3, and if only relay TA is operating, it is controlled to indicate that facsimile communication is in progress. Circuit 11 identifies. Of course, TA,
It is also possible to replace TT with a photocoupler, semiconductor, etc. instead of a relay. Now, when this telephone 2 is taken off-hook for transmission, the following information is connected: telephone 2 - switch SW1 - relay TT - TL terminal of the facsimile machine - LN terminal - relay TA -
A DC loop is formed between switch SW1 and line LN, and relays TT and TA operate. This closes the contacts tt and t _a , but the control circuit 11
Now, since switches SW3 to SW5 are off,
Relays CN1 and CN2 do not operate.

After calling the other subscriber from the telephone 2 and notifying the subscriber of facsimile transmission, the subscriber telephone line LN is reconnected to the facsimile device 3 by on-hooking the telephone 2. That is,
Subscriber telephone line LN - switch SW1 contact cn1 - relay TA - facsimile device LN terminal - PD terminal - contact cn2 - PD (line protection device) - contact cn1
- PD terminal - network control device 31 - modem device 32
- Facsimile transmission is performed through the route of the facsimile control unit 33.

Next, when a call arrives on the subscriber telephone line LN, the facsimile device 3 performs ring detection through the above route, and the DC loop is maintained, so the relay
TA works. The operation of relay TA closes contact t _a to start control circuit 11, and relay CN
1 to switch contact cn1 and call this telephone 2. After the operator answers using the telephone 2, the operator switches to the facsimile device 3 and receives the facsimile.

(2) Next, manual line switching will be explained.

The line switching device 10 of the present invention is provided with manual changeover switches SW1 to SW4. SW
1 is switching between this telephone and line switching device, SW2
is a leased line reservation switch, SW3 is a leased line switch, and SW4 is a subscriber telephone line switch.

When subscriber telephone line LN is in use by telephone 2 but no facsimile communication is being performed, if you wish to connect facsimile device 3 to dedicated line PL, off-hook telephone 4 attached to the dedicated line, and Dedicated line switch SW3
Turn on. The control circuit 11 first includes a relay
By operating CN1 and switching contact cn1, facsimile device 3 is completely disconnected from subscriber telephone line LN, and relay CN2 is operated with a slight (250 mS) delay time.
As a result, facsimile device 3 - contact cn2
- Photocoupler TB1 - Contact rg ₁ - Contact ll ₁ - Transformer - Attenuator ATT - Connected to the dedicated line PL through the path...

Next, when the leased line PL is being used by the attached telephone 4 but no facsimile communication is being performed, if you wish to connect the facsimile device 3 to the subscriber telephone line LN, you must off-hook this telephone 2 and , subscriber telephone line switch
Turn on SW4. As a result, the control circuit 11
First, restore relay CN2, and the
After the delay time of S), relay CN1 is restored. The attached telephone 4 is connected to the dedicated line PL via contact cn2, while the facsimile device 3 is connected to relay TA - contact cn1 - switch SW1 -
It is connected to subscriber telephone line LN through the route of line LN.

(3) A call from the dedicated line attached telephone 4 will be explained.

When attached telephone 4 is off-hook when both lines are not in use, telephone 4 - Photocoupler TF - Contact cn2 - Photocoupler TB1 -
The photo couplers TF and TB1 are turned on by the direct current path of the power supply voltage (+24V) connected to the contact rg ₁ -contact ll ₁ -transformer, the terminals a and b become ground potential, and the control circuit 11 is activated.

The control circuit 11 operates the relay CN2,
By switching contact cn2, attached telephone 4 - photo coupler TF - contact cn2 - TL terminal - LN terminal - contact cn2 - photo coupler TB1
-... is formed, and the attached telephone 4 is connected to the dedicated line PL via the facsimile device 3.

Next, the relay LR is operated for a short time, the contact _lr is switched, and the oscillator 14 sends out a lock signal of two frequencies (for example, 1027.5 Hz and 592.5 Hz) to the dedicated line PL. This prevents calls from other terminals. Next, the oscillator 13 sends a dial tone to the attached telephone 4, but when the push button of the telephone 4 is pressed, the dial tone stops.

If the dedicated line PL is in use, a lock signal is input, so the detector 12 detects this and operates the relay LL, which connects the oscillator 13 - amplifier AMP - (A) - contact ll ₁ −
A visit tone is sent out along the route of contact rg ₁ - photocoupler TB1 - contact cn2 - photocoupler TF - telephone 4.

At the time of facsimile transmission, the photocoupler TF is turned off by the on-hook of the telephone set 4, and only the photocoupler TB1 remains on.

When a call or facsimile communication ends,
The photo couplers TF and TB1 are turned off, the control circuit 11 operates the relay LL, and the oscillator 14 transmits two frequencies (for example, 1027.5Hz,
502.5Hz) reset signal. In addition,
Relays and other semiconductors can also be used in place of the photocouplers TF and TB1.

(4) The case of making a call using the conversation telephone 5 will be explained.

When the telephone 5 is off-hooked, the photocoupler TB2 is turned on and the terminal c becomes the ground potential, so the control circuit 11 is activated, and after sending a lock signal to the dedicated line PL as described above, the lock signal is sent to the telephone 5. Sends a dial tone. In this case, the operation is the same as that of the telephone 4 except that it is not connected to the facsimile device 3.

(5) The case where the attached telephone 4 receives a call will be explained.

A selection signal for telephone 4 from another terminal (e.g. 2
When the digit) is sent out, the detector 12 detects it, operates the relay RG ₁ , and the ringing tone generator 15 transmits the signal to the telephone 4 via the contact RG ₁ .
Sends a call signal to. While the calling signal is being sent, the oscillator 14 sends a ring back tone to the calling party.

When you take off the attached telephone 4, the relay
When RG ₁ is restored, it stops sending out ringback tones and a communication path is established, allowing telephone or facsimile communication.

It should be noted that even when a call is received from another terminal to the conversation telephones 5, 5', it is exactly the same as receiving a call to the attached telephone 4, except that the facsimile device 3 is not connected.

Other unnecessary incoming calls are disconnected from the DC supply transformer by operating relay LL and opening contacts _ll1 to _ll3 .

(6) Explain what happens when the dedicated line reservation switch is turned on.

Reservation switch SW when dedicated line PL is in use
When 2 is turned on, the control circuit 11 immediately sounds the buzzer for a predetermined period of time (for example, 30 seconds), flashes the lamp 17, and turns on the relay LR for that period. When activated, the oscillator 14 sends a lock signal to the dedicated line PL. This makes it possible to prohibit other terminals from making calls and to give priority to making calls during the prohibition period.

In addition, reservation switch SW2 can be used on multiple terminals.
In order to avoid conflicts when the terminal is turned on, priorities are set for all terminals, and the lock signal is sent after waiting for a different amount of time depending on the priority.

For example, the terminal with the highest priority sends a lock signal for 30 seconds 0 seconds after the end of the free communication, the terminal with the next priority sends a lock signal 3 seconds after the end, and the terminal with the third priority Then, a lock signal is sent out 6 seconds after the end point.
As a result, among the terminals that have turned on the reservation switch SW2, the terminal with the highest priority obtains the next right to make a call.

(7) Explain the case of disconnecting the handset.

If one of the telephones 4, 5, 5' of each terminal goes off the hook, the lock signal sent from that terminal makes the other terminals unusable. Therefore, the control circuit of each terminal counts a certain amount of time (for example, 32 seconds) with a counter when the telephone 4, 5, 5' goes off-hook.
If the push button is pressed twice within this time, it is assumed that the transmission is normal and the howler sound transmission is stopped. However, if the push button is not pressed at all or is pressed only once within this time, the oscillator 13 Sends a reset signal to the dedicated line PL to cancel the prohibition of calls from other terminals.
In other terminals that received the reset signal, detector 1
By detecting this in 2, relay LL1
-Restore LL3, switch contacts _ll1 to _ll3 , and stop sending out the busy tone.

The terminal that sent the reset signal to the dedicated line PL operates one of the relays LL1 to LL3 and connects the oscillator 13 - amplifier AMP - (A) - contacts ll _{3 to 3} .
- Contacts rg _{1 to 3} - Photo couplers TB1 to 3 - Telephones 4, 5, and 5' are used to send out howler sounds. In this case, the howler sound is amplified to a considerably high level by the amplifier AMP.

Note that the push button presses within a certain period of time (32 seconds) are determined by detecting the leakage (low level signal) on the receiving terminal side of the hybrid 16 using the detector 12.

Further, when the telephones 4, 5, 5' are in an off-hook state and the reservation switch SW2 is turned on (buzzer on), the howler sound sending circuit does not operate.

In addition, manual operation (button operation) allows data communication on one line while a call is in progress on the other line, and a dedicated line reservation switch allows priority for the next call to be made when the current communication ends. It goes without saying that the functions that can be applied to the line switching device shown in FIG. The invention first proposed a line switching device (patent application 1984-
114585)).

Note that each line of the present invention can be equipped with an automatic facsimile answering device, and by using a well-known device, it is possible to automatically answer incoming calls.

As explained above, according to the present invention, the same facsimile device can be connected to either the subscriber telephone line or the dedicated line by simply off-hooking the corresponding telephone, so there is no need for manual operations such as switches. This allows immediate transmission. In addition, since the facsimile device is automatically connected to the incoming line, you can receive calls on one line even if you are talking on the other line.
Free communication is possible using a dedicated line via a PBX extension, etc., and communication processing can be streamlined.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the previously proposed line switching device, Fig. 2 is a connection system diagram of a dedicated line system using the line switching device of the present invention, and Fig. 3 is a line switching diagram showing an embodiment of the present invention. FIG. 2 is a block diagram of the device. 1, 10: Line switching device, 2: This telephone, 3:
Facsimile device, 4: Telephone with dedicated line, 5,
5': conversation telephone, 6, 11...control circuit,
7: Selection switch, 12: Signal detector, 13,1
4: Oscillator, 15: Ringing tone generator, 1
6: Hybrid coil, 17: Lamp, 3
1: Network control device, 32: Modulation/demodulation device, 33: Facsimile control unit.

Claims (1)

[Scope of Claims] 1. A line switching device which is added to a facsimile device having a network control device, which is connected to a subscriber telephone line and a dedicated line, and which connects telephones corresponding to each line; A relay, photocoupler, or semiconductor switch means connected between the dedicated line, the facsimile device, and the telephone set, and a connection control means activated by the operation of the switch means are provided to correspond to one of the lines to be used when making a call. By off-hooking the telephone, a switch means connected between the telephone, the facsimile device, and the line in use is operated to connect the facsimile device to the line in use, and when receiving, the facsimile device is connected to the line selected by the sending party. A line switching device characterized in that the facsimile device is connected to the facsimile device by operating a switch means to temporarily connect the line to a corresponding telephone, and then on-hook the telephone. 2. The connection control means changes the connection of the facsimile device by manual operation of a button switch even when both telephones corresponding to the subscriber telephone line and the dedicated line are in use. The line switching device according to item 1. 3. The line switching device according to claim 1, wherein automatic response means is arbitrarily set in a facsimile device for the subscriber telephone line and the dedicated line. 4. The connection control means sends a bell signal to the facsimile device when an automatic answering means is set at the time of an incoming call, and sends a bell signal to the corresponding telephone when the automatic answering means is not set. A line switching device according to claim 1. 5. When both the subscriber telephone line and the dedicated line are not in use, when both telephones corresponding to both lines are off-hook, the connection control means turns on the switch corresponding to either the subscriber telephone line or the exclusive line. 2. The line switching device according to claim 1, wherein the facsimile device is connected to a subscriber telephone line or a dedicated line corresponding to a telephone set that is later taken off-hook by operating the facsimile device. 6. When both the subscriber telephone line and the dedicated line are not in use, when both telephones corresponding to both lines are taken off-hook, the connection control means connects the facsimile device to the line corresponding to the off-hook telephone. 6. The line switching device according to claim 1, wherein the line to which the facsimile device is connected is changed by selecting a switch to be pressed. 7 The connection control means is a PD for subscriber telephone line.
(line protection device) and a PD for the dedicated line, and the corresponding PD for the line connected to the facsimile device.
The first claim characterized in that
The line switching device described in section.