JPH0756533Y2 - ISDN terminal device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ISDN terminal device.

[Prior Art] In recent years, ISDN (Service Integrated Digital Communication Network) is being developed, and data terminal devices for exchanging data using this ISDN are gradually being put into practical use.

In the future, this ISDN will replace the conventional PSTN (Public Telephone Network) and will provide various digital data transmission services by integrating them, but until the construction is completed, ISDN and Both PSTNs will be used.

Also, in the ISDN basic interface, two information channels (channel B) and one signal channel (channel D) are multiplexed on one subscriber line, and when the subscriber line is configured in a passive bus format. Can connect up to eight terminal devices.

Thus, a plurality of terminal devices connected to one subscriber line can simultaneously communicate.

In the PSTN, the telephone used as a terminal is supplied with station power, and even if there is a power outage in the area where the telephone is installed, it will be possible to make calls using the telephone. ing.

On the other hand, in ISDN, many options are set in the recommendation regarding station power supply, and the mode of station power supply is not unique.

For example, in some ISDN, 420 per subscriber line
It supplies a current of (mA), and in another ISDN, it does not feed the station, but is left to the self-sufficiency of the terminal.

Further, as described above, up to eight ISDN terminal devices can be connected to one subscriber line. For example, an ISDN terminal device that can operate even if a current of 420 mA is supplied by station power supply is at most a digital telephone. One, other ISDN
Power cannot be supplied to the terminal device. For that, IS
When a power failure occurs in the area where the DN terminal equipment is installed, only one digital telephone can operate and the other ISDN terminal equipment cannot be used.

Therefore, when a power failure or the like occurs in the area where the ISDN terminal device is installed, the ISDN terminal device cannot be used.

By the way, in the PSTN, the station power is not supplied to the data terminal device using this as a transmission path. Therefore, regarding this point, although the conditions concerning station power supply are the same as those for terminal devices other than digital telephones in ISDN, PS
In the TN, the telephone connected to the data terminal device is locally fed.

Therefore, compared with the PSTN, in the ISDN terminal device, a compound terminal having a combination of a telephone function and other data transmission functions has a disadvantage that the telephone cannot be used during a power failure.

[Purpose] The present invention has been made in order to solve the problems of the prior art, and an object thereof is to provide an ISDN terminal device that can use a telephone function even during a power failure.

[Configuration] The present invention includes an ISDN network control means having an ISDN line control function, a public telephone line network control means having a public telephone line control function, and a telephone for communicating with the other party. ,
Selection means for selecting one of ISDN and public telephone line, connection means for switching the telephone to one of the ISDN network control means and the public telephone line network control means, and when power is supplied Switches the telephone to the ISDN network control means or the public telephone line network control means in accordance with the selection made by the selection means, and when the power is not supplied, regardless of the selection made by the selection means. A control means for switching and connecting the telephone to the public telephone line network control means is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a data terminal device according to an embodiment of the present invention. This data terminal device has a facsimile function and a telephone function.
Group 4 facsimile communication function using ISDN (Integrated Services Digital Communication Network) as a transmission path, and PSTN
Group 3 using (public telephone network) as a transmission line
It has a facsimile communication function.

In the figure, the system control unit 1 executes the overall control processing of this data terminal device, and the scanner 2
Is for reading a transmission document at a predetermined resolution, and the plotter 3 is for recording and outputting an image at a predetermined resolution.

The operation display unit 4 is for operating this data terminal device, and has an operation unit equipped with various operation keys for operating the facsimile function and the telephone function and switching the line to be used to ISDN or PSTN. , A display unit for displaying input data, a guidance message for the operator, and the like.

The encoding / decoding unit 5 encodes and compresses the transmission image signal and also decodes the reception image information into the original image signal. The image storage device 6 converts the image information in the encoded and compressed state. It is for accumulating.

Group 4 facsimile communication unit 7
The group 3 facsimile communication unit 8 is for realizing the facsimile communication function, and the group 3 facsimile communication unit 8 is for realizing the group 3 facsimile communication function.

The ISDN-NCU (network control unit) 9 realizes the line control function (basic interface function) of ISDN.
The DEC 10 is a PCM (pulse-code) of A-law (or μ-law) for analog signals in the voice band so that the group 3 facsimile communication unit 8 and the push-button type analog telephone 11 can use ISDN as a transmission path. It is for encoding / decoding a (modulation) signal.

The PSTN-NCU (network control unit) 12 is for allowing the group 3 facsimile communication unit 8 and the analog telephone 11 to use the PSTN as a transmission line.
It has a line control function and an automatic call origination / termination function.

The connection switching unit 13 is for switching and connecting the transmission data input / output terminal of the group 3 facsimile communication unit 8 to one input terminal of the selector 14 or the PSTN-NCU 12.

The telephone switching control unit 15 selects the analog telephone 11 from the selector 14
It is for switching connection to either the other input terminal or PSTN-NCU 12.

The selector 14 CODEs either the group 3 facsimile communication unit 8 or the analog telephone 11.
It is for connecting to C10.

Data is exchanged between the system controller 1 and the group 4 facsimile communication unit 7 and the group 3 facsimile communication unit 8 via the internal bus 16. The group 4 facsimile communication unit 7 and the group 3 facsimile communication unit 8 are detachably attached to the internal bus 16 by a connector connection (not shown).
It is connected to the.

Also, in this case, since one data terminal device has a combined group 4 facsimile communication function, group 3 facsimile communication function, and telephone function, ISDN
A sub-address is set for each function so that each function called from can be identified.

With the above configuration, when the operator inputs from the operation display unit 4 to use the group 4 facsimile communication function, the system control unit 1 notifies the group 4 facsimile communication unit 7 of that fact and starts the operation. .

When the operator inputs from the operation display unit 4 that the group 3 facsimile communication function is used, the system control unit 1 notifies the group 3 facsimile communication unit 8 of that fact and starts the operation.

At this time, when the operator designates to use ISDN, the system control unit 1 notifies the ISDN-NCUU9 of the destination number and the like designated at that time to start the access to the ISDN network and the call. By the time the connection is completed, the group 3
The facsimile communication unit 8 is connected to the CODEC 10.

When an operator inputs a call from the analog telephone 11 using ISDN from the operation display unit 4, the system control unit 1 causes the telephone switching control unit 15 to connect the analog telephone 11 to the selector 14, and
14 to select the telephone switching control unit 15
To CODEC10. Then, at that time, the destination number designated by the telephone switching control unit 15 is notified to the ISDN-NCU 9 to start access to the ISDN network.

When the operator inputs from the operation display section 4 that the analog telephone 11 is used to make a call using the PSTN, the system control section 1 notifies the telephone switch control section 15 of that fact.
To notify the PSTN-NCU 12 of the analog telephone 11.

When an incoming call is received from ISDN, if the sub-address designated at that time has a group 4 facsimile communication function, the system control unit 1 selects the ISDN-NCU 9 as the group 4 facsimile communication unit 7. At the same time, the operation of the group 4 facsimile communication unit 7 is started.

Also, when an incoming call is received from ISDN, if the sub-address specified at that time is for the group 3 facsimile communication function, the system control unit 1 sets the ISDN-NCU 9
The CODEC 10 is selected, the group 3 facsimile communication unit 8 is connected to the CODEC 10 by the connection switching unit 13 and the selector 14, and the operation of the group 3 facsimile communication unit 8 is started.

When an incoming call is received from ISDN, if the sub-address specified at that time has a telephone function, the system control unit 1 causes the ISDN-NCU 9 to select CODEC 10 and the selector 14 to switch the telephone. Select the control unit 15,
The telephone switching control unit 15 connects the analog telephone 11 to the selector 14, thereby enabling the telephone call of the analog telephone 11 using ISDN.

When receiving an incoming call from the PSTN, the system control unit 1 performs the same operation as in the case of a normal group 3 facsimile machine.

In this way, the call-out operation and the call-in operation to the ISDN and PSTN are performed.

Since the details of the incoming and outgoing call operation are not directly related to the present invention, the description thereof will be omitted.

FIG. 2 shows an example of the telephone switching control unit 15.

In the figure, the relay 20 is provided with two switching circuits 21 and 22, and the analog telephone 11 is connected to the common input terminals 21c and 22c of the switching circuits 21 and 22, respectively.
The normally closed contacts 21b and 22b are connected to the PSTN-NCU 12 side.

Further, the normally-open contacts 21a, 22a of the switching circuits 21, 22 have a DC power supply 23 for supplying driving power to the analog telephone 11, an off-hook detector 24 for detecting an off-hook of the analog telephone 11, and an analog telephone 11. 16 Hz AC oscillator 25 for generating the ringing signal of the switch, a switch 26 for giving the signal of the AC oscillator 25 to the analog telephone 11, and a combination of the analog telephone 11 and the selector 4 in the state where the direct current is cut off. The primary side of the transformer 27 is connected.

The push button signal decoder 28 connected to the secondary side of the transformer 27 detects the push button signal output from the analog telephone 11 and outputs the corresponding dial information.

The control unit 29 controls the operation of the telephone switching control unit 15, inputs the detection signal of the off-hook detection unit 24 and the dial information of the push button signal decoder 28, turns on / off the switch 26 and turns on / off the relay 20. ON / OFF of the switch 30 is controlled. Also, the control unit
Reference numeral 29 exchanges various control information with the system control unit 1.

When the system control unit 1 instructs the analog telephone 11 to connect to the PSTN, the control unit 29 turns off the switch 30 and turns off the relay 20.

As a result, the switching circuits 21 and 22 select the normally closed contacts 21b and 22b, so that the analog telephone 11 is connected to the PSTN-NCU 12,
As a result, the analog telephone 11 is supplied with power from the PSTN, operates with the power, and the PSTN is used as a speech path.

Also, when the system control unit 1 issues an instruction to connect the analog telephone 11 to the ISDN, the control unit 29 turns on the switch 30 and turns on the relay 20.

As a result, the switching circuits 21 and 22 select the normally open contacts 21a and 22a, so that the analog telephone 11 is driven by being supplied with power from the DC power supply 23.

In this state, the operator has an analog telephone for calling.
When the analog telephone 11 is taken off-hook when the handset 11 is picked up, the off-hook detector 24 performs a detection operation, whereby the control unit 29 causes the system control unit 1 to operate.
Notifies you that you have gone off-hook.

Next, when the operator of the analog telephone 11 operates and inputs the destination number from the push dial, the push button signals generated in the order of operation are the push button signal decoder 28.
Then, the corresponding dial information is output to the control unit 29, and the control unit 29 sequentially outputs the numerical information of each digit of the destination number to the system control unit 1.

Further, when the control unit 29 is notified by the system control unit 1 that there is an incoming call to the analog telephone 11, the control unit 29 turns on the switch 26 and sends a call signal output from the AC oscillator 25 to the analog telephone 11. It outputs and makes the ringer of the analog telephone 11 ring.

When the operator hears it and picks up the handset, the off-hook detector 24 notifies the off-hook detection.
At that point, the control unit 29 turns off the switch 26 to stop the ringer ringing of the analog telephone 11.

In this way, the switching control operation of the telephone switching control unit 15 is performed.

Further, in the state where the relay 20 is off, the analog telephone 11 is connected to the PSTN-NCU 12, so, for example, when a power failure occurs and power is not supplied to this data terminal device, the relay 20 is turned off. Analog telephone 11 is PSTN-NC
Automatically connected to U12.

Therefore, at the time of the power failure, the setting display is input from the operation display unit 4 so as to connect the analog telephone 11 to the ISDN,
Even if the telephone switching control unit 15 connects the analog telephone 11 to the selector 14, the analog telephone 11 is switched to PSTN and the telephone call becomes possible.

In the embodiment described above, the PSTN-NCU is connected to the normally closed contact side of the relay that switches the connection destination of the analog telephone, and the analog telephone is connected to the PSTN at the time of power failure, but the power failure is detected. It is also possible to provide a power-off detector and forcibly switch the analog telephone to the PSTN when the power-off detector detects a power-off.

In addition, in the above-described embodiment, the push dial operation of the analog telephone is enabled when ISDN is used.
At the time of use, the push dial operation of the analog telephone may be invalidated, and the destination number may be operated and input from the operation display unit.

Further, in the above-described embodiment, the data terminal device (ISDN terminal device) having the telephone function and the facsimile communication function has been described, but in addition to this, the ISDN having the data transmission function is also provided.
The present invention can also be applied to a terminal device.

[Effect] As described above, according to the present invention, an ISDN network control means having an ISDN line control function, a public telephone line network control means having a public telephone line control function, and a partner A telephone for making a call with, a selecting means for selecting one of ISDN and a public telephone line, and a connecting means for switching and connecting the telephone to one of the ISDN network control means or the public telephone line network control means. If the power is supplied, the telephone is switched to the ISDN network control means or the public telephone line network control means according to the selection made by the selection means, while if the power is not supplied, Despite the selection by the selecting means, since the control means for switching and connecting the telephone to the public telephone line network control means is provided, the effect that the telephone function can be used even during a power failure Get.

[Brief description of drawings]

FIG. 1 is a block diagram showing a data terminal device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of a telephone switching control unit. 1 ... System control unit, 7 ... Group 4 facsimile communication unit, 8 ... Group 3 facsimile communication unit, 9 ... ISDN-NCU (service integrated digital communication network-network control unit), 10 ... CODEC, 11 ... … Analog telephone, 12 …… PSTN-NCU (public telephone network-network control unit), 13 …… Connection switching unit, 14 …… Selector, 15 …… Telephone switching control unit, 20 …… Relay, 21,22… ... Switching circuit.

Claims (1)

[Scope of utility model registration request] 1. An ISDN network control means having an ISDN line control function, a public telephone line network control means having a public telephone line control function, a telephone for communicating with the other party, and an ISDN. Alternatively, a selecting means for selecting one of the public telephone lines, a connecting means for switching and connecting the telephone to one of the ISDN network control means or the public telephone line network control means, and when power is supplied, , While switching the telephone to the ISDN network control means or the public telephone line network control means according to the selection by the selection means,
An ISDN terminal device comprising control means for switching and connecting the telephone to the public telephone line network control means regardless of selection by the selection means when power is not supplied.