KR910003300B1 - Interface circuit for both of tie line and trunk line - Google Patents

Abstract

The circuit is for transmitting the voice signal and signalling through the different typed lines; the trunk and the tie line trunk. The switches of the interfacing circuit are operated to adapt to the transmission line type. The circuit interfaces a station using the positive power as B/W loop power and a station using the negative power. The circuit includes a first switch which common terminal, a first and a second terminal are connected to a first relay, a transformer, and M line respectively to switching the common terminal input, a second switch which first terminal and second terminal are connected to the transformer (T1) and the earth line respectively, a ring signal attenuator (50) for limiting the level of pulse input through the second terminal of the first switch and a third switch which common terminal is connected to the transformer (T1).

Description

Common interface circuit for trunk line and leased line

1 is a circuit diagram according to the present invention.

2 is a switchable table map according to the present invention.

3 is the B / W all-wire connection circuit of the circuit of FIG.

* Explanation of symbols for main parts of the drawings

10: M line 11: E line

20: TIP wire 21: Ring wire

50: ring signal attenuator 60: B / dedicated detector

71: transformer SW1 -SW3: 1st-7th switch

RL1a, RL1b, RL2, RL3a, RL3b: first, second, third relay

U1, U2: first and second photo couplers

The present invention relates to a signaling interface circuit with a counterpart exchange in a switching system, and in particular, a circuit that enables interfacing of dedicated line signaling of trunk trunk, E / M, R / D, and B / W as one circuit.

In general, a switching device such as a private switch or a key telephone system includes a trunk line trunk (TRUNK) capable of interfacing signaling and voice between a station subscriber and a trunk line, and a dedicated line circuit (Tie) capable of direct communication between the private switching devices. Line Trunk) is installed. Signaling and spoofing transmission methods of the omni-circuit circuit are widely used in E-M (Ear-Mouth), R / D (Ring-Down), and B / W (Both Way), and signaling is occupied by the other station. It is a signal (Seisure Signal), an occupancy response signal (Seisure Acknowledge), a dialing signal.

In the E / M system, there are two signal lines for transmitting and receiving signals and two lines for voice transmission. The E / M system performs a call on a voice line after signaling on the signal line. In the dedicated line circuits of R / D and B / W systems, signaling and voice transmission are performed on two lines. In the conventional exchanger, the above-described dedicated trunk line interface circuits of the trunk line trunk are manufactured and managed for each type of function, resulting in an increase in system manufacturing cost, and despite the fact that the circuits perform almost the same functions, they can be used in common. There was no. In the conventional dedicated line B / W circuit, a loop is formed using a power supply of -48W and GND so that the same B / W is developed when a system using both power sources (eg + 22V, GND) is developed. There has been a problem in that even W-type leased lines cannot be interfaced.

Accordingly, an object of the present invention is to provide a trunk line trunk and a leased line common interface circuit that allows a circuit for signaling and voice interface with a counterpart station to operate as an interface circuit suitable for a plurality of leased line schemes as a simple switching operation.

It is still another object of the present invention to provide a circuit capable of interfacing a negative power supply with a B / W while using a positive power supply as a loop power supply for a B / W.

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

1 is a circuit diagram according to the present invention, M line 10, E line 11, TIP line 20, ring line 21 and the signal detection 30, and the first and second winding 31 on the primary side ), (32) and a pair of transformer contacts having a third winding 33 on the secondary side connected to the switching network, and a switch contact having a common terminal, a first terminal, and a second terminal. Each of the common terminals is connected to the TIP line 20 and the ring line 21, and the output terminal of each ring generator is connected to the first terminal so that the common terminal is switched to the first terminal and the second terminal by a predetermined control. The common terminal is connected to the relays RL1a and RL1b and the second terminal of the first relay RL1a, and the second terminal is connected to the M line, and the first winding 31 of the transformer T1 is connected. A first switch SW1 connected to an external end thereof to switch input of a common terminal by selection, a second terminal grounded, and a first terminal 31 of the first winding 31 of the transformer T1. It is connected to one end and the second switch (SW2) for selectively switching in the first and second input terminals to the common terminal. The second relay RL2 and the second connected between the second terminal of the first switch SW1 and the common terminal of the second switch SW2 and switched by a predetermined control to generate a pulse or form a communication path. Ring consisting of resistor R1, capacitor C1, diode D1, and D2 connected in series between both ends of relay RL2 to limit the pulse input level from the second terminal of first switch SW1. A capacitor C3 connected between the signal attenuator 50, the other end of the first winding 31 of the transformer T1, and one end of the second winding 32 to pass an audio signal, and the transformer ( The common terminal is connected to the other end of the first winding 31 of T1 to have a third switch SW3 switched to the first and second terminals by selection, a common terminal, a first terminal, and a second terminal. The switch contacts are paired, the common terminal of the pair of switch contacts is connected to the second terminal of the third switch (SW3) and another switch A third relay RL3a in which the common terminal of the position contact is connected to one end of the second winding 32 of the transformer T1 and the common terminal is switched to each of the first and second terminals by a predetermined control, A photo coupler comprising a resistor R3 and a phototransistor Q1 light-emitting diode LED1 connected between the first terminal of the two switch contacts RL3b and the third relays RL3a and RL3b. A B / W dedicated detection unit 60 and a third switch SW3 comprising a one-way series connection diode D3 and a resistor R2 between an ENode terminal of U1 and a second terminal of the switch contact. A fourth switch (SW4) connected to a first terminal of the second terminal and a second terminal, and switching input of the first or second terminal by inputting a predetermined positive power source to the first terminal, and switching and outputting to a common terminal; The light emitting diodes (LED) and (LED3), which input the output of the common terminal of the switch (SW4), are bidirectionally coupled and the phototransistor (Q2) The common terminal is connected to one side of the bidirectional photocoupler U2 and the light emitting diodes LED2 and LED3, and the first terminal is a second terminal of one switch contact of the third relays RL3a and RL3b. A fifth switch SW5 connected to and connected to an E-line 11 to be connected to the fifth switch SW5 and a capacitor for removing impulsive noise in series between the collector and emitter of the phototransistor Q2 ( C2) and the control switch SW7, the output of the photocoupler U1 and the output of the bidirectional photocoupler U2 are input to the second terminal and the first terminal, and the input of the two terminals is selectively selected by selective switching. The sixth switch SW6 outputs to the common terminal.

FIG. 2 is a switching enable table diagram of the switches SW1 to SW7 of FIG. 1, and the circuit of FIG. 1 operates as Trunk E / M, B / W, and R / D interface circuits according to each switching state. It is shown.

3 is an embodiment for explaining the operation of the B / W during the operation of the circuit of FIG. 1, the operation example of FIG. 1 will be described with reference to the table and FIG.

In order to use the circuit of FIG. 1 as an interface of the trunk trunk trunk, the first to seventh switches SW1 to SW7 should be switched to the same state as in FIG. 2a. In the table of FIG. 2, the switching "0" is a state where each switch is switched "on" the common terminal (a) and the second terminal (c), and the switching state "1" is the common terminal (a) and the first terminal. (b) refers to the switched "on" state.

As described above, if all relays are switched to the second terminal NC (normal close point) in the state where each switch is switched, it operates as a trunk trunk interface circuit. At this time, the first, second, third relays (RL1a), (RL1b), (RL2), (RL3a), and (RL3b) are driven by a drive signal output from a relay driver under control of a microprocessor of the system. (The microprocessor and the relay driver are omitted.)

Therefore, in a situation where the circuit of FIG. 1 has a switching state as shown in FIG. 2A, when a ring signal is input to the tip line 20, the ring signal attenuator 50 is transmitted through the first relay RL1a and the first switch SW1. Is entered. Therefore, the ring signal (80vrms ± 20Hz) input from the tip line 20, that is, the ring signal current from the trunk line, is clamped to a predetermined level by the resistor R1, the capacitor C1, the zener diodes Dl, and D2. The first terminal 31 of the transformer T1 flows to the common terminal a and the first terminal b of the third switch SW3.

At this time, the first terminal (b) of the third switch (SW3) is the light emitting diode (LED2) of the bidirectional photocoupler (U2), the anode or the cathode of the LED3 and the fifth switch through the fourth switch (SW4) The ring signal path is formed by being input to one end of the second winding 32 of the transformer T1 through the SW5, the resistor R4, and the third relay RL3b.

When the ring signal is input and the ring signal path is formed as described above, the light emitting diodes LED2 and LED3 of the bidirectional photocoupler U2 are "turned on" so that the phototransistor Q1 is also "turned on".

Therefore, the logic of the common terminal a of the sixth switch SW6 is changed, and the microprocessor (controlling the overall operation of the system) that detects the signal of the output line 30 detects it. The microprocessor detecting the inflow state other than the ring signal in the operation other than the bidirectional photo coupler U2 responds to the relay driver with a control signal for occupying the trunk line, that is, data for turning on the second relay RL2 to the relay driver. When writing, the second relay RL2 is driven so that the common terminal COM and the first terminal Normal open are switched on. Thus, a trunk line path is formed.

Meanwhile, when the second relay RL2 is “on” when the transmission is performed in the same state as in FIG. 2a, a loop is formed between the local exchanger connected to the tip line 20 and the ring line 21 to receive a dial tone. At this time, when the second relay RL2 is driven "on"-"off", it is possible to execute dial transmission to the trunk line side.

If the switching state of the first to seventh switches SW1 to SW7 connected to the respective parts of FIG. 1 is switched to the same state as that of FIG. 2b, it may be used as an R / D dedicated line interface circuit. The dedicated line circuit of the R / D method should be capable of transmitting a ring signal in a manner that can directly call an operator or a specific extension subscriber between the private switching devices of the private switching device, and should be able to detect an incoming ring signal. The R / D ring is detected when the first off-circuit circuit is now switched to the switching mode as shown in FIG. 2d, and the second relay RL2 is in the "ON" state of the common terminal COM and the first terminal NO. Will operate in mode. When the ring signal transmitted from the opposite side to the tip wire 20 and the ring wire 21 is caused, the loop of the ring signal current is the first relay RL1a and the first switch SW1. Second relay RL2, second switch SW2, first winding 31 of transformer T1, third switch SW3, fourth switch SW4, bidirectional connection light emitting diode LED2, ( LED3), fifth switch SW5, resistor R4, third relay RL3b, second winding 32 and first relay RL1b of transformer T1. Therefore, regardless of the polarity of the ring signal input to the tip wire 20 and the ring wire 21, the diode of one of the bidirectional light emitting diodes LED2 and LED3 is "on" so that the phototransistor Q2 is "turned on". do.

At this time, the common terminal a of the sixth switch SW6 outputting the output of the phototransistor Q2 to the output line 30 shows “low”. Therefore, the microprocessor that inputs the logic change of the detection line 30 recognizes that the R / D interface is SEIZURE, and when the input detection signal is interrupted, a ring is given to the operator or a specific subscriber to connect the call path. Let's do it. At this time, the negative current is routed through the first winding 31, the capacitor C3, and the second winding 32 of the transformer T1 to the third winding 33 connected to the switching network. The outgoing state of giving the ring to the other side is as follows.

When R / D is selected by the subscriber or operator, the microprocessor writes data to the relay driver to drive the first relays RL1a and RL1b.

At this time, the first relays RL1a and RLlb are switched from the second terminal NC to the first terminal NO, so that the output of the ring generator (not shown) passes through the tip line 20 and the ring line 21. It is sent to the opposite R / D circuit.

On the other hand, if each switch SW1-SW7 in FIG. 1 is switched as shown in FIG. 2B, and the second relay RL2 is open, the E / M dedicated line interface is used. As described above, the E / M tie line is divided into a voice path and a signaling path, so that a call is formed through a sound line and a signal is formed through a signal path. The voice path is always connected.

First, let's look into the incoming call. When the M-line of the other side is switched and the Seizre signal GND is input to the E-line 11, it is connected to the second terminal C and the common terminal a of the resistor R5 and the fifth switch SW5. It will be input to the bidirectional diodes (LED2) and (LED3) other than the bidirectional photocoupler (U2) through the positive power supply VDD (+) through the fourth switch (SW4) as the other input of the bidirectional light emitting diodes (LED2) and (LED3). The phototransistor 02 is " turned on "

The output of the collector of the phototransistor Q is output to the detection line 30 through the sixth switch SW6, so that the microprocessor controlling the operation of the system detects the scissor signal from the other side. After detecting the scissor signal as described above, the second relay RL2 is driven to connect and switch the common terminal COM and the first terminal NO. At this time, a signal of GND (ground) is transmitted as a Sessure Acknowledge signal with respect to the scissor signal. Subsequently, when the pulse dial is transmitted using the M line from the other side, the light emitting diodes LED2 and LED3 of the bidirectional photocoupler U2 are "on" and "off", thereby detecting a pulse signal from the detection line 36. Therefore, the microprocessor that controls the operation of the system detects the dial pulse and controls the user to make a call with the subscriber. The call path is the first winding 31 of the transformer T1, the capacitor C3, and the second. Winding 32. Outgoing Call is made by the second relay RL2 being " on " driven.

When the second relay RL2 is " on " driven, a GND signal is transmitted to the opposing E line. This becomes effective as a scissor signal of the other station. When the other party detects this and sends a scissor response (GND) to the M line, it is input to the E line 11 and thus detected through the bidirectional port coupler U2 as described above.

After detecting the scissor response as described above, the second relay RL2 can be switched to send a dial pulse to execute a call with the requesting caller. On the other hand, if each of the switches SW1-SW7 in FIG. 1 is set to the connected switching mode as in FIG. 2C, the circuit is configured as in FIG. 3 in AS. In Fig. 3, the BS side is a B / W interface circuit on the other side that uses a negative power supply (-48V) as the loop current, and T2 is a transformer.

The operation of an incoming call and an outgoing call in the state where the circuit of FIG. 1 is configured as the AS side of FIG. 3 by switching will be described. When the other subscriber drives the relays (RI) and (RII) and the common terminal (COM) and the first terminal (NO) are connected, both power sources VDD of the AS axis are resistors (R4), third relays (RL3b), and transformers. The first winding 35 on the AS side, the third relay RL3a, the diode D3, and the resistor (2) through the second winding 32, the transformer T2 and the resistor RL of the other subscriber. R2), is input to the photocoupler U1.

Therefore, it is possible to detect whether or not the counterpart constitutes the call route by the resistor R4, the transformer T1, the diode D3, the resistor R2 and the photocoupler U1. Therefore, it can be seen that the dial pulse transmitted by the relays (RI) and (RII) on the opposite BS side is detected by the photocoupler U1. The communication path is formed of a transformer T1 and a capacitor C3 on the AS side, and a transformer T2 and a capacitor CV on the BS side. When the microprocessor writes the relay drive data for driving the third relays RL3a and RL3b to the relay driver, the AS side calls the BS side. That is, when the third relays RL3a and RL3b are switched to the first terminal NO and connected to both ends of the resistor R3, the GND on the BS side forms a DC loop of the transformer T1 and the resistor R3. As a result, the detector on the BS side detects the DC loop state.

As described above, if the desired subscriber of the BS can be called by switching the third relays RL3a and RL3b after the loop is formed, and also sending out the dial pulse.

As described above, the present invention can change the circuit of the trunk, E / M, R / D, B / W by a plurality of switch operation to eliminate the inconvenience of designing and manufacturing according to each interface mode, B / Since W interfacing can be performed, there is an advantage that the negative power supply circuit can be eliminated when configuring a dedicated line circuit.

Claims (1)

In common interface circuit of trunk line and leased line. M line 10, E line 11, TIP line 20. The transformer 21 having the ring wire 21, the signal detection output line 30, and the first, second windings 31, 32 on the primary side and the third winding 33 on the secondary side are connected to the switching network ( T1) and a pair of switch contacts having a common terminal, a first terminal, and a second terminal, each of which is connected to the TIP line 20 and the ring line 21 and each of the output terminals of the ring generator to the first terminal. The common terminal is connected to the first relays RL1a and RL1b in which the common terminal is switched to the first terminal and the second terminal by predetermined control, and the common terminal is connected to the second terminal of the first relay RL1a. A first switch SW1 for connecting a second terminal to an M line, a first terminal connected to one end of the first winding 31 of the transformer T1, and switching input of a common terminal by selection; Two terminals are grounded and a first terminal is connected to one end of the first winding 31 of the transformer T1 to selectively input the common terminal. A second switch SW2 for switching to a second terminal for switching to a terminal, and a second terminal of the first switch SW1 and a common terminal of the second switch SW2 and are connected by a predetermined control and pulsed. Is connected in series between both ends of the second relay RL2 and the second relay RL2 to generate a signal path or to form a communication path, thereby limiting a pulse input level from the second terminal of the first switch SW1. A ring signal attenuator 50 composed of R1, capacitor C1, diode D1, and D2, the other end of the first winding 31 of the transformer T1, and one end of the second winding 32; A capacitor C3 connected between the capacitor C3 and the other end of the first winding 31 of the transformer T1 connected to the common terminal and switched to the first and second terminals by selection; A pair of switch contacts having three switches (SW3), a common terminal, a first terminal, and a second terminal; The common terminal is connected to the second terminal of the third switch SW3, the common terminal of another switch contact is connected to one end of the second winding 32 of the transformer T1, and the respective common terminals are controlled by a predetermined control. Is connected between the first relays of the third relays RL3a and RL3b and the third relays RL3a and RL3b, each of which is switched to the first and second terminals, respectively. And a one-way series connection diode (D3) and a resistor (R2) between the anode (EMode) terminal of the photo coupler (U1) and the second terminal of the switch contact made of the phototransistor (Q1) light emitting diode (LED1). The B / W dedicated detection unit 60, and the first terminal and the second terminal of the third SWID (SW3) are connected, and the predetermined positive power is input to the first terminal to input the first or second terminal. Switch for switching the output to the common terminal and the output terminal of the fourth switch (SW4) and the common terminal other than the fourth switch (SW4) The photodiode (LED) and (LED3) are bidirectionally coupled, the bidirectional photocoupler (U2) having a phototransistor (Q2) and a common terminal is connected to one side of the light emitting diodes (LED2), (LED3) and the first terminal is A fifth switch SW5 connected to the second terminal of one switch contact of the third relays RL3a and RL3b, the second terminal connected to an E-line 11, and switched, and the phototransistor Q2; Is connected in series between the collector and the emitter of the capacitor (C2) and control switch (SW7) for removing impulsive noise, the output of the photocoupler (U1) and the output of the bidirectional photocoupler (U2) second terminal And a sixth switch (SW6) for inputting the first terminal and selectively outputting the input of the two terminals to the common terminal by selective switching.

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