JPH0646755B2 - Network controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone line terminal device such as a facsimile machine, and more particularly to a network control device for a telephone line terminal device having an automatic transmission / reception function.

2. Description of the Related Art Conventionally, as shown in FIG. 5, an apparatus of this type conventionally has an incoming detection circuit 51 for automatic reception and a collision detection circuit 52 for avoiding a collision with a call from the other party when starting automatic transmission. , The other party's response detection circuit for detecting the other party's response after making an automatic call 5
3 and an off-hook detection circuit 54 for detecting off-hook of the attached telephone, respectively, and the detection output signals of these circuits connect the telephone line to the telephone and the main portion of the telephone line and the telephone terminal equipment. I was switching the connection with 56. Reference numeral 55 is a dial pulse generation circuit.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, there are problems that equipping each of these circuits with each other results in a high cost and a burden for downsizing the device.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a network control device capable of satisfying each function with a simple configuration without disposing each circuit for each function. .

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides first and second terminals connected to a telephone line and a third terminal connected to a telephone.
And 4th terminal, 5th and 6th terminals connected to the main body of the terminal device, and 1st and 2nd terminals are interlocked with the 3rd and 4th terminals or 5th and 6th terminals, respectively, and switch-connected. First and second switching means, dial pulse creating means provided between the first switching means and the fifth terminal, and a high resistance having one end connected to the first switching means side of the dial pulse creating means. Value of the first resistor, the second terminal of low resistance value one end of which is connected to the fifth terminal, the third switch for switching the connection between the other end of the first or second resistor and the sixth terminal Means and two electric-optical conversion means provided in parallel and opposite in polarity between the means and the first terminal and the first switching means or between the second terminal and the second switching means, and two. Two opto-electric conversion means and the two opto-electric conversion means provided so as to face each of the electro-optic conversion means First to third on the basis of the output signal
And control means for controlling the switching of the switching means.

Action The present invention enables incoming call detection, collision detection, partner response detection, and off-hook detection only with the above-described configuration, which enables cost reduction and device miniaturization.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a circuit diagram showing an outline of a network control device according to an embodiment of the present invention, 1 and 2 are terminals connected to a telephone line, 3 and 4 are terminals connected to an attached telephone, 5
And 6 are terminals connected to the main body of the telephone terminal device.
Reference numeral 7 is a main body of the telephone terminal device, 8 is a relay for creating a dial pulse, 9 is a resistor having a high resistance value, 10
Is a resistor having a low resistance value, and 11 is a relay for switching between the resistors 9 and 10. Further, 12 and 13 are relays for switching the connection between the telephone line and the main body of the telephone or telephone terminal equipment, 14 and 15 are light emitting diodes provided in parallel with opposite polarities, and 16 is a frequency characteristic. It is a capacitor for improvement. Furthermore, 17 and 18 are light emitting diodes 14,
Reference numeral 15 is a light receiving transistor provided so as to face each other, 19 is a diode, 20 and 21 are resistors, 22 is a control circuit, and 23 and 24 are input signals of the control circuit 22. A constant voltage is applied to both ends of the light emitting diodes 17 and 18. Therefore, when light is incident on the light receiving diode 17, the input signal 24 changes from low level to high level, and when light is incident on any of the light receiving diodes 17 and 18, the input signal 23 changes from low level to high level. become. Also, in relays 11, 12 and 13,
Symbols a and b indicate respective contact points.

The operation of the network control device having the above configuration will be described with reference to FIGS.
It will be described with reference to the drawings. FIG. 2 is a timing chart for explaining the off-hook detection operation of the network control device of this embodiment, FIG. 3 is a timing chart for explaining the incoming call detection operation, and FIG. 4 is the same collision detection operation. 6 is a timing chart for explaining an operation and a partner response detection operation. In FIG. 2, (a) shows the signal 24, and (b) shows the signal 23. The arrow 26 in the figure shows the time when the attached telephone (not shown) is changed from the on-hook state to the off-hook state. Also, in FIG.
(A) shows a ringing signal generated at terminals 1 and 2, (B) shows a signal 24, and (C) shows a signal 23. Furthermore, in FIG. 4, (a) shows the selection status of the contacts of the relays 12 and 13, (b) shows the selection status of the contacts of the relay 11, (c) shows the signal 24, and (d) shows the Signal 23 is shown.

First, the off-hook detection operation will be described with reference to FIG. Off-hook detection is necessary to prevent the telephone terminal equipment from operating during a call and interfering with the call. When the attached telephone goes off-hook, the terminals 3 and 4 are short-circuited via a predetermined impedance, whereby a line loop is formed and a line DC current flows in the direction of arrow 25 in Fig. 1 or in the opposite direction. A current flows through one of the light emitting diodes 14 and 15 to emit light. Then, a current flows through either of the light emitting transistors 17 and 18, and the signal 23 changes to a high level as shown in FIG. When a current flows through the light receiving transistor 17, the signal 24 becomes high level as shown by the solid line in FIG. 2 (a), but when a current flows through the light receiving transistor 18, it does not change as shown by the broken line in FIG. 2 (a). . Therefore, the control circuit 22 determines that the signal is off-hook when the signal 23 is high level for a predetermined time and the signal 24 is high level or low level for a predetermined time.

Next, the incoming call detection operation will be described with reference to FIG.
In the state of FIG. 1, when a ringing signal as shown in FIG. 3 (a) is input between the terminals 1 and 2, a current flows through the light emitting diodes 14 and 15 alternately and light is emitted alternately. As a result, a current flows through the light receiving transistors 17 and 18 alternately. Therefore, as shown in FIG.
High level and low level appear alternately, and signal 23 is the third
As shown in the figure (c), it becomes high level. in this way,
When the signal 23 is at the high level for a predetermined time and the signal 24 is in the alternating state of the high level and the low level, the control circuit 22 judges that it is an incoming call, and the contacts of the relays 12 and 13 are turned on.
Switch to.

Next, the collision detection operation will be described with reference to FIG. This collision detection is for preventing a collision with an input ringing signal when an automatic call is made from a telephone terminal device. First, the control circuit 22 opens the relay 8 for dial pulse preparation from the state shown in FIG.
Let b be the contact point. As a result, a line loop is formed, but since the resistance value of the resistor 9 is large, only a small current flows,
An exchange (not shown) does not judge that a loop is formed. Control circuit
22 stores the state of the signal 24 at this time. next,
Before actually making an automatic call, the control circuit 22 again performs the above operation to check whether the state of the signal 24 is the same as that stored, and when it is the same, make an automatic call, When different, automatic calling is prohibited. That is, this utilizes the characteristic that the direct current polarity of the line is reversed by the exchange when the ringing signal is input. In the example of FIG. 4, the state of the signal 24 stored in advance is set to the high level.

Finally, the partner response detection operation will be described with reference to FIG. During dialing, the relays 11, 12 and 13 are switched to the contact b, and the opening / closing operation of the relay 8 creates a dial pulse. When the dial is finished, the relay 8 is closed and the control circuit 22 monitors the inversion of the signal 24. That is, when the other party responds, the exchange (not shown) has the terminal 1
Since the polarity of the direct current supplied to 2 and 2 is reversed, the direction in which the current flows changes, so the other party's response can be detected by checking the reversal of the signal 24. When the response from the other party is detected, the relay 11 is switched to the contact a, and the telephone terminal device shifts to the communication operation.

As described above, according to this embodiment, off-hook detection, incoming call detection, collision detection, and partner response detection can be performed with a simple configuration. It should be noted that the present invention is not limited to the above-described embodiments, and it is easy for those skilled in the art to make simple changes and additions without violating the spirit of the present invention.

As described above, according to the network control device of the present invention, the operations of off-hook detection, incoming call detection, collision detection, and partner response detection can be made common without performing separate circuits. This has an excellent effect that downsizing and downsizing of the device are possible.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of a network control device according to an embodiment of the present invention, FIGS. 2, 3, and 4 are timing charts of the same embodiment, and FIG. 5 is a schematic view of a conventional network control device. It is a block diagram shown. 1 to 6 ... Terminals, 7 ... Main body of telephone terminal equipment, 8, 11, 1
2, 13 ... Relays, 9, 10 ... Resistors, 14, 15 ... Light emitting diodes, 17, 18 ... Light receiving transistors, 22 ... Control circuits.

Claims (1)

[Claims] 1. A first terminal connected to a telephone, a second terminal connected to a telephone line, a third terminal connected to a telephone terminal device, the first and the second terminals. First switching means for connecting and disconnecting terminals and for connecting and disconnecting the second and third terminals; a light-emitting diode connected to the telephone line and having a light-emitting state changed by a change in current value;
Load means for applying a load to the current flowing in the line loop formed by the terminal and the third terminal, a line loop formed via this load means, and a line loop formed without the load means. And a second switching means for switching between and, when the first terminal and the second terminal are connected, when the light emitting diode continuously emits light, off-hook is detected, or when blinking, an incoming call is detected, and When the second terminal and the third terminal are connected and a load is applied by the load means, a comparison between the light emitting state of the light emitting diode at the time of switching of the second switching means and the light emitting state before making a call To detect the collision, and when the second terminal and the third terminal are connected and the load of the load means is not applied, the light emitting diode is turned on or off Network control apparatus characterized by comprising a control means for polarity inversion detection by the change.