JP3478455B2 - Terminal network controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal network controller, and more particularly to a terminal network controller capable of multiple connection.

[0002]

2. Description of the Related Art FIG. 2 shows a schematic block diagram of a conventional terminal network control device. The terminal network control device 50 is roughly divided into a 16 Hz detection circuit 51 that detects a ringing signal (frequency 16 Hz) input from the telephone line L and outputs a 16 Hz detection signal S16, and a polarity reversal of the telephone line during no ringing communication. Polarity inversion detection circuit 52 which detects the polarity and outputs a polarity inversion detection signal SRV, and a first input terminal TIN1 and a second input terminal TIN2.
, A diode bridge circuit 53 having a first output terminal TOUT1 and a second output terminal TOUT2 and switching a current flow path based on a voltage relationship between the first input terminal TIN1 and the second input terminal TIN2, and a first input terminal TIN1. -Second input terminal TIN2
Connected between the dial pulse generating circuit 54 for generating a dial pulse signal and outputting the dial pulse signal via the telephone line L, and the first input terminal TIN1 and the second input terminal TIN2.
A no-ringing transmission / reception circuit 55 for receiving a no-ringing communication and a no-ringing selection signal (hereinafter referred to as an NRS signal) in a predetermined AC impedance state.
And a first primary coil C11 and a second primary coil C12
And a secondary coil C20, and a first primary coil C1
1 and one end of the second primary side coil C12 has a first output terminal T
A transformer 56 having an AC impedance of 600 [Ω] commonly connected to OUT1, a hybrid circuit 57 connected to the secondary coil C2 of the transformer 56 for performing 2-wire to 4-wire conversion, and a hybrid circuit 57. Is
A modem 58 for modulating / demodulating data and a controller 59 for controlling the entire terminal network control device 50 are provided.

The dial pulse generating circuit 54 includes a first transistor switch TSW11 having an emitter terminal connected to a second output terminal TOUT2 and a first transistor switch TS.
One end is connected to the collector terminal of W11, the other end is connected to the first primary side coil, and the collector terminal is connected via a resistor to the base terminal of the transistor switch TSW11. The first phototransistor PC1 has a first phototransistor PT1 connected to the output terminal TOUT1 and is turned on / off based on a first control signal CPC10 from the controller 59.

The no-ringing transmission / reception circuit 55 includes a second transistor switch TSW12 having an emitter terminal connected to the second output terminal TOUT2 and a transistor switch SW12.
Switch SW11 with one end connected to the collector terminal of
And a second resistor R connected to the other end of the first switch SW11
12 and a second resistor R12 connected in series, one end of which is connected to the second primary coil of the transformer CC, and one end of which is connected to the collector terminal of the second transistor switch TSW12 and the other end of which is the second resistor R12. A second switch SW12 connected to an intermediate connection point between R12 and the capacitor CC and a base terminal of the second transistor switch TSW12 having a collector terminal connected via a resistor and an emitter terminal connected to the first output terminal TOUT1. It has two phototransistors PT2 and is turned on / off based on the second control signal of the controller.
And a second photocoupler PC2 which is F.

Next, the operation will be described. At the time of calling a terminal At the time of calling a terminal, if the telephone line L is a dial line, the controller sends the first signal by the first control signal CPC10.
The photocoupler PC1 is controlled, the first phototransistor PT1 is turned on, and the first transistor switch TSW11
The DC loop is closed by turning on.

Similarly, the first control signal CPC10 controls ON / OFF of the first transistor switch TSW11 to generate a dial pulse, which is output to the telephone line L via the diode bridge 53. If the telephone line L is a push button line, the first transistor switch TSW11 is held in the ON state and the modem 58
To generate a push button signal (PB signal) in an AC impedance state of 600 [Ω], and the hybrid circuit 5
The PB signal is transmitted through the transformer 56 of 7,600 [Ω].

After that, the modem 58 transmits / receives a signal via the hybrid circuit 57 and the transformer 56 of 600 [Ω]. During no ringing communication When the polarity inversion detection circuit 52 detects the polarity inversion of the telephone line, it outputs a polarity inversion detection signal SRV to the controller 59.

As a result, the controller 59 determines that the no-ringing communication has started, and determines the second control signal CPC.
The second photocoupler PC2 is controlled by 20, the second phototransistor PT2 is turned on, the second transistor switch TSW12 is turned on, and the control signal SS
The first switch SW11 is turned on by W11 to half-close the DC loop and wait for reception of the NRS signal (no-ringing selection signal).

When the NRS signal is received, the controller 59 sends the control signal SSW11 to the first switch SW.
11 is turned off, and the second switch SW12 is turned on by the control signal SSW12 so that the AC impedance is 600 [Ω].

As a result, the modem 58 and the hybrid circuit 57 are connected to the AC impedance 60 via the transformer 56.
No ringing communication is performed in the state of 0 [Ω].

[0011]

In the above-mentioned conventional terminal network control device, the discharge path of the capacitor is only via the diode bridge 53 and the second transistor switch TSW12. Therefore, the capacitor does not discharge the charge to the telephone line L side, and the capacitor and the resistor R (= R 11 + R 12 ) have the time constant τ = C × R, so the resistance value of the second resistor R 12 is Must be set to a value at which the AC signal is not distorted, and cannot be set to a high resistance value.

Therefore, in order to perform multiple connections, etc., 1
There is a problem in that the 6 Hz detection circuit 51 needs to have a function of detecting a calling signal and opening the telephone line L. Therefore, an object of the present invention is to provide a terminal network control device capable of ensuring a high impedance state of a DC closed circuit without providing a call signal detection circuit (16 Hz detection circuit) and capable of multiple connection.

[0013]

In order to solve the above-mentioned problems, the invention according to claim 1 is a terminal network control device having a no-ringing communication function, which detects polarity reversal of a telephone line during no-ringing communication to detect polarity reversal. A polarity reversal detection circuit that outputs a detection signal and a first connection control signal are connected to the telephone line via a diode bridge to close the DC loop circuit at the time of calling the terminal and at the time of no ringing communication. , A DC loop closure circuit for semi-closing the DC loop circuit in a high impedance state of a predetermined value or more, and a parallel connection to the diode bridge and the DC loop closure circuit based on a second connection control signal. AC transmission and reception with a predetermined AC impedance, transmission and reception of an AC signal through a capacitor And road, based on the polarity inversion detection signal, or constitute comprises a control means for detecting a terminal calling state for outputting said first connection control signal and the second connection control signal.

According to the first aspect of the present invention, the polarity inversion detection circuit detects the polarity inversion of the telephone line during the no ringing communication and controls the polarity inversion detection signal in the terminal network control device having the no ringing communication function. Output to. On the other hand, the control means outputs the first connection control signal to the DC loop closing circuit and outputs the second connection control signal to the AC transmission / reception circuit based on the polarity inversion detection signal or by detecting the terminal calling state. .

[0015] These results, at the time of terminal call, the DC loop closure circuit, based on the first connection control signal, da
The terminal network control device is connected to the telephone line via the iodine bridge to close the DC loop circuit, and the terminal network control device makes a call from the terminal. Further, at the time of non-ringing communication, the DC loop closure circuit is semi閉結in a high impedance state of the predetermined value or more direct current loop circuit, the AC transmission and reception circuit, based on the second connection control signal da
It is connected in parallel with the ion bridge and the DC loop closure circuit.

As a result, the AC transmission / reception circuit transmits / receives AC signals (no ringing communication) in a predetermined AC impedance state. According to a second aspect of the present invention, in the terminal network control device according to the first aspect, the DC loop closure circuit has a DC loop resistance connected in parallel to the telephone line, and a resistance value of the DC loop resistance. Is configured to have a resistance value for holding a predetermined high impedance state required when receiving the no-ringing selection signal.

According to the second aspect of the invention, in addition to the operation of the first aspect of the invention, the resistance value of the DC loop resistance of the DC loop closure circuit is a predetermined high impedance required when receiving the no-ringing selection signal. Since the resistance value is used to hold the state, it is not necessary to open the line when receiving a ringing signal (16 Hz).

[0018] According to a third aspect of the invention, in the terminal network controller according to claim 1 or claim 2, wherein said alternating current transmission and reception circuit, based on the third connection control signals constituting the front Stories second connection control signal The first connection means for connecting the capacitor to the telephone line through the resistor at the time of calling the terminal and receiving the no-ringing selection signal, and the no-ringing communication based on the fourth connection control signal constituting the second connection control signal. Second connection means for connecting a capacitor to the telephone line.

According to the invention of claim 3, in addition to the operation of the invention of claim 1 or 2, the first connecting means of the AC transmitter / receiver circuit selects no ringing based on the third connection control signal. A capacitor is connected to the telephone line through a resistor when receiving a signal. The second connecting means connects the capacitor to the telephone line during no ringing communication based on the fourth connection control signal.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of the terminal network control device. The terminal network control device 10 is roughly divided into a polarity reversal detection circuit 11 that detects a polarity reversal of the telephone line L during no ringing communication and outputs a polarity reversal detection signal SRV, and an AC transmission / reception circuit 12 that transmits / receives an AC signal. ,
A hybrid circuit 13 connected to the AC transmission / reception circuit 12 for performing 2-wire to 4-wire conversion, a modem 14 connected to the hybrid circuit 13 for modulating / demodulating data, and a DC for closing or semi-closing a DC loop. The loop closing circuit 15 and a controller 16 for controlling the entire terminal network control device 10 are provided.

The AC transmission / reception circuit 12 has a first relay circuit 17 whose one end is connected to a telephone line L1 constituting a telephone line L.
And a resistor R1 (for example, 2 [kΩ] or more) connected in series to the other end of the first relay circuit 17, and the first relay circuit 1
7 and a second relay circuit 18 connected in parallel with the resistor R1
And a capacitor C having one end connected to a common connection point of the resistor R1 and the second relay circuit 18, and the other end of the capacitor C is connected to one end and the other end constitutes a telephone line L.
The transformer 21 has an AC impedance of 600 [Ω] and has a primary side coil C1 connected to 2 and a secondary side coil C2 having both ends connected to the hybrid circuit 13.

The DC loop closure circuit 15 has a first input terminal TIN1, a second input terminal TIN2, a first output terminal TOUT1 and a second output terminal TOUT2, and the first input terminal TIN1-second
A diode bridge circuit 19 for switching the current flow path based on the voltage relationship between the input terminals TIN2 and the second output terminal TOU
Transistor switch T whose emitter terminal is connected to T2
SW, a constant current supply circuit 20 having an input terminal connected to the collector terminal of the transistor switch TSW and supplying a constant current, a first switch SW1 having an output terminal of the constant current supply circuit 20 connected to one end, A resistor RL1 (for example, 50 to 300 [Ω]) connected in series to the switch SW1 and the other end of which is connected to the first output terminal TOUT1, and a common connection of the output terminal of the quiescent current supply circuit 20 and the first switch SW1. A second switch SW2, one end of which is connected to the
A resistor RL2 connected in series with the switch SW2 and having the other end connected to the first output terminal TOUT1 (for example, at least 1 [M
Ω]. More specifically, 10 [MΩ]) and a phototransistor PT whose collector terminal is connected to the base terminal of the transistor switch TSW via a resistor and whose emitter terminal is connected to the first output terminal TOUT1. And a photocoupler PC which is turned on / off based on the control signal CPC.

In this case, the resistance R1 is not affected by the resistances RL1 and RL2, which are the DC loop resistances of the DC loop closing circuit 15, so that it is possible to set a high resistance value. is there. Also, the resistance RL2
Since it is not affected by the AC transmission / reception circuit 12, it is possible to set a higher resistance value as compared with the conventional example.

Next, the operation will be described. At the time of calling a terminal At the time of calling a terminal, when the telephone line L is a dial line, the controller 16 controls the photocoupler PC by the control signal CPC to turn on the phototransistor PT and turn on the transistor switch TSW. At the same time, the first control signal CSW1 causes the first switch SW1
The DC loop is closed by turning on.

As a result, the telephone lines L1 and L2 are
Diode bridge circuit 19 → Transistor switch T
SW → constant current circuit 20 → first switch SW1 → first resistor R1 → diode bridge circuit 19 is connected via a path. After that, the controller 16 controls the control signal CPC.
The ON / OFF of the transistor switch TSW is controlled to generate a dial pulse, and the dial pulse is output to the telephone line L via the diode bridge circuit 19.

Further, when the telephone line L is a push button line, it holds the transistor switch TSW to the ON state, the second relay circuit 1 8 by the controller 16 to further output a first relay control signal CRL1 as the on-state, are connected in series to capacitor C on the primary side coil C1 of the transformer 21, the modem 13 600
The push button signal (PB signal) is generated in the AC impedance state of [Ω], and the hybrid circuit 12, 60 is generated.
The PB signal is transmitted via the transformer 21 of 0 [Ω].

After that, the modem 58 transmits / receives a signal via the hybrid circuit 12 and the transformer 21 of 600 [Ω]. As a result, the discharge current of the capacitor C flows to the telephone line L (telephone lines L1 and L2) side and is not affected by the state of the DC loop closing circuit 15. During no ringing communication When the polarity reversal detection circuit 11 detects the polarity reversal of the telephone line L, it outputs a polarity reversal detection signal SRV to the controller 16.

Accordingly, the controller 16 determines that the no-ringing communication has started, turns on the transistor switch TSW by the control signal CPC, turns on the first switch SW2 by the second control signal CSW2, and sets the high resistance value (eg, The DC loop is semi-closed by using the second resistor R2 having 4 [kΩ] or more).

Then, the first relay control signal CRL1 turns the first relay circuit 17 into an ON state to bring it into a high impedance state of 2 [kΩ] (resistance value of the resistor R1) or more to N state.
Wait for reception of RS signal. After that, the controller 16
When the RS signal is detected, the first relay control signal CRL1 turns off the first relay circuit 17, the second relay control signal CRL2 turns on the second relay circuit 18, and the modem 14 with the AC impedance of 600 [Ω] is detected.
To perform no ringing communication.

According to the present embodiment as described above,
Since the discharge current of the capacitor C flows to the telephone line L side,
Since it is not affected by the DC loop closing circuit 15 (DC loop circuit), even if the DC loop resistance RL2 is set to a high resistance, it is N
Distortion does not occur in the AC signal when the RS signal is received.

Therefore, it is not necessary to open the line even when the 16 Hz signal which is the calling signal is detected, and the high impedance state can be maintained only in the detection state (monitoring state) of the NRS signal. Is possible. Further, it is not necessary to provide a 16 Hz detection circuit for opening the line, and the circuit configuration can be simplified.

[0032]

According to the first aspect of the present invention, the polarity inversion detection circuit detects the polarity inversion of the telephone line during the no ringing communication in the terminal network control device having the no ringing communication function and outputs the polarity inversion detection signal. The control means outputs the first connection control signal to the DC loop closing circuit based on the polarity reversal detection signal or detects the terminal calling state and outputs the second connection control signal by AC transmission / reception. Output to the circuit.

[0033] These results, at the time of terminal call, the DC loop closure circuit, based on the first connection control signal, da
The DC network is connected to the telephone line via the Iodo Bridge to close the DC loop circuit, and the terminal network control device makes a call from the terminal. Further, during no-ringing communication, the DC loop closing circuit semi-closes the DC loop circuit in a high impedance state of a predetermined value or more, and the AC transmitting / receiving circuit uses the diode bridge and the DC loop based on the second connection control signal. It is connected in parallel to a closed circuit and transmits / receives an AC signal (no ringing communication) in a predetermined AC impedance state.

Since the AC transmission / reception circuit and the DC loop closing circuit are provided in parallel in this way, the AC transmission / reception circuit and the DC loop closing circuit are less likely to be affected by each other, and the AC signal is received when the no-ringing selection signal is received. The resistance value of the DC loop circuit can be made high without causing distortion, and multiple connections can be performed.

According to the invention of claim 2, in addition to the operation of the invention of claim 1, the resistance value of the DC loop resistance of the DC loop closing circuit is the same as that of the ringing signal inputted through the telephone line. Since it has a resistance value for maintaining a predetermined high impedance state without opening the line at the time of reception, it is not necessary to open the line when receiving a ringing signal (16 Hz), so there is no need to provide a line opening function. Since the high impedance state can be maintained only when the no-ringing selection signal is detected (during monitoring), multiple connections can be performed.

According to the invention of claim 3, in addition to the operation of the invention of claim 1 or 2, the first connecting means of the AC transmitter / receiver circuit selects no ringing based on the third connection control signal. When the signal is received, the capacitor is connected to the telephone line via the resistor, and the second connecting means connects the capacitor to the telephone line during the no ringing communication based on the fourth connection control signal, so that the discharge current of the capacitor flows to the telephone line side. Therefore, the resistance value of the DC loop circuit can be made higher without being affected by the DC loop circuit.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a terminal network control device.

FIG. 2 is a schematic configuration diagram of a conventional terminal network control device.

[Explanation of symbols]

10 terminal network control device 11 Polarity inversion detection circuit 12 AC transmitter / receiver circuit 13 Hybrid circuit 14 modem 15 DC loop closed circuit 16 controller 17 First relay circuit 18 Second relay circuit 19 Diode bridge circuit 20 constant current supply circuit 21 transformer C capacitor C1 primary coil C2 secondary coil CPC control signal L1 telephone line L2 telephone line L telephone line PT phototransistor PC photo coupler R1 resistance RL1 resistance RL2 resistance SRV Polarity inversion detection signal SW1 first switch SW2 Second switch TIN1 1st input terminal TIN2 2nd input terminal TOUT1 Output 1 terminal TOUT2 2nd output terminal TSW transistor switch

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04M 11/00-11/10 H04M 1/00 H04M 1/24-1/253 H04M 1/58-1 / 62 H04M 1/66-1/82

Claims (3)

(57) [Claims] 1. A terminal network control device having a no-ringing communication function, which detects polarity inversion of a telephone line during no-ringing communication and outputs a polarity inversion detection signal, and based on a first connection control signal. Through the diode bridge
And a DC loop closing circuit that is connected to the telephone line and closes the DC loop circuit at the time of calling the terminal and semi-closes the DC loop circuit at a high impedance state of a predetermined value or more during no ringing communication. And a diode bridge based on the second connection control signal
And has a predetermined AC impedance and is connected in parallel to the DC loop closed circuit, and via a capacitor
An AC transmitter / receiver circuit for transmitting and receiving an AC signal, and a control means for outputting the first connection control signal and the second connection control signal based on the polarity inversion detection signal or detecting a terminal calling state, A terminal network control device comprising: 2. The terminal network control device according to claim 1, wherein the DC loop closure circuit has a DC loop resistance connected in parallel to the telephone line, and the resistance value of the DC loop resistance is a no ringing selection. A terminal network control device having a resistance value for maintaining a predetermined high impedance state required when a signal is received. 3. A terminal network controller according to claim 1 or claim 2, wherein said alternating current transmission and reception circuit, terminal call time and non-ringing based on a third connection control signals constituting the front Stories second connection control signal First connection means for connecting the capacitor to the telephone line via a resistor when receiving a selection signal, and the fourth connection control signal forming the second connection control signal to connect the capacitor to the telephone line during no ringing communication. A terminal network control device comprising: a second connecting unit for connecting.