JPS628652A - Network controller - Google Patents

Abstract

PURPOSE:To prevent the occurrence of erroneous action of an incoming-call receiving party and forgetting of the change-over for recovering by executing the calling supervising at the connecting equipment side at a manual incoming-call receiving time and when a pass word is received from the opponent station in the prescribed time from calling start, changing over automatically the line through an NCU. CONSTITUTION:By the response of the incoming-call receiving party by the hooking-off of a telephone set 02, the telephone set 02 is connected to the line. At an NCU 01, the line is known to be in the connecting condition by an electric current detecting device 12, a relay contact 3 is turned ON, and a connecting equipment 03 is inserted in parallel through a transformer 9 between lines by a high impedance shape (loose coupling). Continuously, the pass word to the connecting equipment is transmitted in the prescribed time, and the connecting equipment 30 generates the line change-over command to the NCU 01 through a control signal 04. After the NCU 01 turns ON a relay contact 2 and connects the line to the connecting equipment 03 side, a relay contact 5 is turned ON and the telephone set 02 is connected through the transformer 9 and the amplifier 10. At such a stage, the indication to return the handset from the transmitting side to the incoming-call receiving party by the sound is sent and the incoming-call receiving party returns the handset.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a telephone line network control unit (also abbreviated as NCU).

[Prior art and its problems]

Conventionally, in manual call receiving type NCUs, the subscriber telephone line (
When a call is received to a connected device (for example, a computer) that should be switched from the telephone side to a connected device (such as a computer), the line is artificially switched at the callee's discretion. However, there are problems in that the called party is likely to make operational errors or forget to switch back after communication is completed.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a network control device that can prevent the above-mentioned problems such as malfunction of the called party and forgetting to switch back, etc., in a manual receiving type NCU.

[Key points of the invention]

The main point of the present invention is that when a call is received in a manual call receiving type NCU, the telephone and the connected device are connected in parallel, and the connected device receives a specific signal (password) from the other station within a certain period of time to monitor the communication. When this happens, the NCU detects this and issues a line switching command to the NCU, which causes the NCU to switch the line from the telephone to the connected device, and communication begins. At the end of this communication, the command from the connected device The line is returned to the telephone side, or furthermore, the calling side sends a voice message alternately with the password, and even after the line is switched to the connected device side, the telephone set and line are coupled with high impedance. The main feature of this system is that the telephone device can send messages to facilitate line switching, such as asking the called party to hang up. In other words, the gist of the present invention is to switch the subscriber telephone line from the telephone to a connected device attached to the telephone based on a call to the telephone from the subscriber telephone line side, and to switch the subscriber telephone line from the telephone to the connected device attached to the telephone. In a device (NCU, etc.) configured to communicate with the subscriber telephone line side, means (current detector, etc.) for detecting the communication current of the telephone on the subscriber telephone line, and means for detecting the communication current of the telephone on the subscriber telephone line, and When the connection between the line and the connected device is turned off, the connection between the line and the connected device is such that the impedance seen from the line side to the connected device side is mainly high impedance, and the transmission signal from the line side is not transmitted by the connected device. Means (capacitors, transformers, amplifiers, etc.) to maintain coupling that allows reception (hereinafter referred to as loose coupling)
and after starting the detection of the communication current of the telephone based on the call of the telephone, a predetermined signal ((
a password, etc.), and a line switching means (control unit, relay, , a transformer, etc.), or the line switching means further includes, when the connection between the line and the telephone is turned off in the switching, the connection between the line and the telephone is The impedance seen from the line side to the telephone set is high impedance, and the system is equipped with means (such as an amplifier) to maintain the coupling so that the telephone set can receive the transmission signal from the line side.

[Embodiments of the invention]

The present invention will be explained in detail below based on FIG. FIG. 1 is a circuit diagram showing a configuration as an embodiment of the present invention. In the same figure, Ll and L2 are subscriber telephone lines, 01 is NC
U, 02 is a telephone, and o3 is a connected device. Also 1-5
is a relay contact that switches the circuit within the NCUOl, and is turned on and off by a control output signal from the control section 13. 6 is a load resistor, and 7 is a spark killer that protects the relay contact 1. A capacitor 8 is used to loosely couple the line and the transformer 9, that is, to couple the transformer 9 with high impedance. 9 is a transformer and connected device 0
3 to the subscriber telephone lines Ll and L2. Reference numeral 10 denotes an amplifier for coupling the load of the amplifier 10 to the transformer 9 at high impedance. 11 is a diode for determining the polarity of the call, 12 is a current detector,
Detects call status, polarity, etc. on the line. Next, we will explain the operation in Figure 1. 0 Normal relay contacts 1 to 5
is OFF, that is, in the state shown in FIG. 1, and the line L1. L2 is a current detector 12. It is connected to telephone 02 through relay contact 5 (51°52), and calls from telephone 02 to the network can be made as usual. To make a call from NCUOl to the network side, after confirming that telephone o2 is not in use by checking that no current is flowing through current detector 12,
Relay contact 5 is turned on to disconnect telephone 02, and then relay 1 is turned on and off to perform dialing. At this point, when the other party on the network side appears, the current detector 12. Resistance 6.
Since the direction of the current circulating between lines Ll and L2 via relay contact 1 changes, relay contact 2 (21, 22
), turn on contact 3 (31, 32) and connect device 03.
is tightly connected to the transformer 9, and at the same time, the relay contact 1 is set to 0FFL to disconnect the load resistor 6 from the line side, and then a call is made from the connected device 03 to the network side. After this call, a control signal 0 is given from the connected device 03 to the control unit 13.
4, the relay contact 2°3.5 is turned off and the first
Automatically return to the close reading state of the diagram. Next, the operation when receiving a call from the network side will be explained. In the connection state shown in FIG. 1, first, in response to the ringing of the telephone 02 by a calling signal, the telephone 02 is connected to the line in response to the callee's response by hooking off the telephone 02. At this time, NC
The UOI knows that the line is connected by the current flowing through the current detector 12, and connects the relay contact 3 to ONL and connects the connected device 03 to the high impedance form (
(loosely coupled) between lines L1 and L2 in parallel and enters a call monitoring state. In other words, in this state, the line signal is transmitted to the connected device 03 through the capacitor 8° transformer 9 and the amplifier 10, but because the input impedance of the amplifier 10 is high and the capacitor 8 blocks direct current, this route is The influence on lines Ll and L2 is reduced. In this state, the calling party sends a voice instruction to the called party to wait for a while, and then a password for the connected device is sent within a predetermined time after the telephone set 02 is hooked off. When the connected device 03 receives the password, it issues a line switching command to the NCUOI via the control signal 04. As a result, NCUOI tightly connects relay contact 2 to ONL connection device 03 side, and then connects relay contact 5 to ONL connection device 03 side.
, the telephone 02 is disconnected from the line, however, the telephone 02 is then connected to the transformer 9. Communication on the line can be monitored through the amplifier 10. At this stage, the calling party sends a voice instruction to the called party to return the handset, and the called party receives this instruction from telephone 02 and returns the handset. From then on, the connected device 03 enters the communication state. . If a call is received only for a phone call, the password will not be entered in the call monitoring state, so after a certain monitoring period or when the call is disconnected, relay contact 3 should be set to 0FFL and the call state (state shown in Figure 1). return. Further, after the communication is completed, the relay contact 2°3.5 returns to the 0FFL normal state. Relay contact 4 is connected to line L to prevent collision between incoming and outgoing calls.
1. This is used to determine the polarity of the voltage between L2, and the polarity is determined using the diode 11 and current detector 12.

【Effect of the invention】

As is clear from the above description, the present invention has been achieved. For example, when a call is received manually, the connected device monitors the call, and if a password is received from the other party within a predetermined time from the start of the call, the connected device responds to the NCU.
Since the line is automatically switched via the NCU, even if the called party does not know how to operate the NCU, the line can be switched, and even after the line is switched, communication can be monitored using the telephone. After the line has been switched, the other party can give a voice command to return the handset, allowing the called party to return the handset at the correct time without hesitation (apparently hanging up the phone). This prevents the called party from forgetting to pick up the handset.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a configuration as an embodiment of the present invention. t, t, Lz: Subscriber telephone line, 01: NCU, Q2: Telephone, 03: Connected equipment, 04: Control signal, 1 to 5: Relay contact, 6: Load resistance, 8: Capacitor, 9 Nidorance, 10: Amplifier, 11: diode, 12: current detector, 13: control section.

Claims (1)

[Claims] 1) Based on a telephone call from the subscriber telephone line side,
In a device that switches the subscriber telephone line from the telephone to a connecting device attached to the telephone, and allows communication between the connected device and the subscriber telephone line side, the telephone on the subscriber telephone line When the connection between the line and the connected device is turned off in the above switching, the connection between the line and the connected device is determined so that the impedance when looking from the line side to the connected device side is high impedance. and a means for maintaining the coupling (hereinafter referred to as loose coupling) such that the transmitted signal from the line side can be received by the connected equipment; and after starting the detection of the talking current of the telephone based on the telephone calling, means for determining a predetermined signal received from the line side in a state of loose coupling of the connected equipment within a predetermined time; and after the determination, turning on the connection between the line and the connected equipment by the switching; A network control device comprising: a line switching means. 2) In the device according to claim 1, when the line switching means turns off the connection between the line and the telephone in the switching, the line switching means disconnects the connection between the line and the telephone. What is claimed is: 1. A network control device characterized in that the impedance seen from the line side to the telephone side is high, and the network control device is equipped with means for maintaining a connection such that the telephone set can receive transmission signals from the line side.