JPS62207057A - Network control unit - Google Patents

Abstract

PURPOSE:To attain sure automatic incoming processing by providing a line switch disconnecting a telephone set from a telephone line in a short time before the operation of an incoming display ring circuit when a line polarity detector detects the polarity inversion so as to prevent erroneous off-hook of a telephone set. CONSTITUTION:When a call comes from the caller side when a network control unit is set to the automatic incoming mode, the polarity of a telephone line 1 is inverted and the inversion is detected by the line polarity detector 5. When the polarity of line is inverted, a line switch 7 disconnects the telephone set from the telephone line 1 by the switch control of the detector 5 before ringing within 0.3sec Although the telephone set does not ring by the disconnection from the line 1, an incoming display ring circuit 6 informs the presence of an incoming call to a person. After the detection of incoming for 3sec by the detector 5, the switch of the line switch 2 is switched by the control of the detector 5 to connect the line 1 to a MODEM 3 for the automatic incoming processing and a data communication terminal equipment 4 applied data communication.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a network control device used for data communications, and particularly to a network control device in which an automatic call processing mode is set.

〔overview〕

When a network control device installed in a telephone network terminal that performs data communication detects an incoming call on the data communication side, it disconnects the phone from the line before the phone starts ringing and processes the incoming call automatically. This prevents people from accidentally taking their phones off-hook and preventing automatic call processing from occurring.

[Conventional technology]

When data communication is performed via a telephone network, a network control device is provided at a terminal of the telephone network to perform data communication.

Conventionally, the network control device used in this communication system does not have a function to disable the hook operation of a telephone, allowing a person to turn off the telephone when an incoming call rings.

[Problem that the invention seeks to solve]

However, in conventional network control devices, when a person goes off-hook when a call rings when the automatic call receiving mode is set, confusion occurs because the calling party is usually a data processing device such as a computer. For example, the line may be disconnected by a person and the incoming call is abandoned, or the call must be switched to manual incoming, so there is a risk that the automatic incoming call may not be performed effectively.

SUMMARY OF THE INVENTION An object of the present invention is to provide a network control device that prevents a person from accidentally disconnecting a telephone and preventing automatic call processing from being performed when the automatic call reception mode is set.

Means for Solving Problem C] The present invention provides a line switching device that switches a telephone line between a data transmission/reception modem and a telephone set, a line polarity detector that detects an incoming call by reversing the line polarity, and a line polarity detector. In a network control device equipped with an incoming call display ringing circuit that indicates the presence of an incoming call based on the detection result of the device, when the line polarity detector detects a polarity reversal, within a short time before the incoming call display ringing circuit is activated. It is characterized by being equipped with a line switch that disconnects the telephone from the telephone line.

Preferably, the short time is before 0.3 seconds have elapsed after the line polarity is reversed.

[Effect]

When the automatic incoming call mode is set and a reversal of line polarity is detected, the telephone is disconnected from the telephone line before the telephone starts ringing, and automatic incoming processing is performed after a certain period of time has elapsed.

This prevents a person from erroneously taking the telephone off-hook during the automatic call reception mode and preventing automatic call reception processing from being performed.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

The figure is a block diagram of a network control device according to an embodiment of the present invention. In the drawing, 1 is a telephone line, 2 is a line switch, and 3 is a telephone line.
is a modem, 4 is a data communication terminal equipment (DTE), and 5 is a modem.
1 is a line polarity detector, 6 is an incoming call display ringing circuit, 7 is a line switch, 8 is a hook switch, and 9 is a handset.

The line switch 2 switches the telephone line 1 between the modem 3 side and the telephone side, and the telephone line is connected to the data communication terminal device 4 by this switching.

In the automatic call reception mode, the line switch 2 automatically switches the telephone line to the modem 3 side. The switching is controlled by the line polarity detector 5, and the line opening/closing of the line switch 7 is also controlled by the line polarity detector 5.

Next, the operation of the embodiment of the present invention will be explained.

Assume that a call is received from a calling party while this network control device is set to automatic call receiving mode. At this time, first, the polarity of the telephone line 1 is reversed. This reversal of line polarity is detected by line polarity detector 5.

When the polarity of the line is reversed, the line switch 7 is activated by opening/closing control of the line polarity detector 5 before the ringing occurs within 0.3 seconds.
disconnects the telephone from telephone line 1.

Although the telephone does not ring due to this disconnection from the telephone line 1, the incoming call display ringing circuit 6 can notify a person that there is an incoming call.

After the line polarity detector 5 detects an incoming call for 3 seconds, the line switching device 2 is switched under the control of the line polarity detector 5 to connect the telephone line 1 to the modem 3 and perform automatic incoming call processing for data communication. The terminal device 4 performs data communication.

When performing telephone communication, the line switch 7 can be restored. Since the line switching device 2 has already operated and connected the telephone line L to the modem 3, the telephone is connected to the telephone line 1.
The phone never connects (and the phone never moves).

After the communication is completed, the switch of the line switching device 2 is restored to open the telephone line. At this time, if the line switch 7 is restored and the telephone is off-hook, it is possible to proceed to the call without opening the telephone line.

〔Effect of the invention〕

As explained above, the present invention detects the polarity reversal of the line when receiving an automatic call and disconnects the telephone from the telephone line before the telephone rings, thereby preventing a person from accidentally taking the telephone off the hook and ensuring reliable automatic call processing. It can be performed.

[Brief explanation of drawings]

The figure is a configuration block diagram of an embodiment of the present invention. ■...Telephone line, 2...Line switch, 3...Modulator/demodulator, 4...Data communication terminal equipment (DTE), 5...
・・Line polarity detector, 6・Incoming call display ringing circuit, 7・
... Line switch, 8... Hook switch, 9... Handset. Patent Applicant: NEC Corporation, − Agent: Patent Attorney Nao Takashi Ide

Claims (2)

[Claims] (1) A line switching device that switches the telephone line between a data transmitting/receiving modem and a telephone, a line polarity detector that detects incoming calls by reversing the line polarity, and an incoming call based on the detection result of the line polarity detector. In a network control device equipped with an incoming call display ringing circuit that displays an incoming call, when the line polarity detector detects a polarity reversal, a line switch is provided that disconnects the telephone from the telephone line within a short time before the incoming call display and ringing circuit is activated. A network control device comprising: (2) The network control device according to claim (1), wherein the short time is before 0.3 seconds have passed after the line polarity is reversed.