JPS62278890A - Incoming call and polarity inversion detection system - Google Patents

Abstract

PURPOSE:To discriminate and detect an incomming call and a polarity inversion by inserting the light emitting side elements of two photocouplers in one line of a channel in parallel connection each in opposite polarity, and making use of the logic of the output of the light receiving side elements of side two photocouplers. CONSTITUTION:When a call arrives, call signal is transmitted from a trunk, and an A.C. voltage is generated between the A.C. signals (-) and (-) of a bridge BR1. By such a voltage, the light emitting side elements PC1(A) and PC1(B) of the two photocouplers emit light alternately in accordance with the frequency of the call signal. In case of a trunk call from a telephone set TEL, a D.C. voltage to make a resistor R1 side come positive is generated between the A.C. terminals (-) and (-) of the bridge BR1. By such a voltage, the light emitting side element PC2(A) of one the photocouplers emits light. If the callee answers for the trunk call from the telephoneset TEL, the firection of the current reverses, the light emitting side element PC1(A) emits light, and that PC2(A) of the photocoupler stops the light-emitting. As a result, both the detection of a call-arrival and that of polarity invertion can be executed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention detects an incoming call in a call trunk of a telephone exchange and detects separation reversal of a call path by the same circuit means. The present invention relates to an incoming call and polarity reversal detection method.

(Prior art) In telephone exchange equipment, for example, the detection of a shield signal from the central office line and the detection of polarity reversal of the communication path on the central office line are performed in the central office line trunk, especially in telephone exchange equipment that is fully computerized. In many cases, a photocoupler is used as a means of detecting a crime and detecting polarity reversal.

In conventional central office line trunks, incoming calls are detected using a photocoupler with a light-emitting element connected between both lines of the communication path, and polarity reversal detection is performed using a photocoupler with a light-emitting II element inserted and connected to one line of the communication path. I have to.

(Problems to be Solved by the Invention) According to the above-mentioned conventional central office line trunk, an incoming call detection circuit and a polarity reversal detection circuit are required separately, and the incoming call detection circuit is usually installed on both lines of the communication path. Therefore, after detecting an incoming call, a means for separating the incoming call detection circuit from the communication path (for example, a B position relay) and its control are required.
The configuration and control of central office line trunks are complex.

The present invention is proposed to solve the above problems.
It is an object of the present invention to provide a call arrival and polarity reversal detection method that can perform N detection and polarity reversal detection of a communication path by the same means.

(Means for determining the problem) For the above purpose, the present invention provides i! The light-emitting side elements of a 21-pin photocoupler are inserted and connected in parallel to one leg of the 1st block with opposite polarities, and incoming calls and polarity reversal are distinguished from the logic of the light-receiving side element outputs of the two photocouplers. It is designed to be detected.

(Configuration of Embodiment) FIG. 1 is a circuit diagram showing an example in which the present invention is implemented for a central office line trunk.

In the embodiment shown in FIG. 1, a central office line unit is composed of four central office line trunks. That is, the office line unit COU includes an individual circuit ECT provided for each office line trunk, and a common circuit CM provided in common for the four office line trunks.
One of the communication path terminals T and R of the individual circuit ECT accommodates the office line, and the other communication path terminal A and H
A horizontal telephone is connected to the central telephone via a switch network or the like, and the common circuit CMT is coupled to the microprocessor MPU of the central control unit CCU.

The individual circuit ECT i is configured as follows.

That is, two 7-oto coupler light emitting side elements PCI (A
), PC, and (A) are connected in parallel so that they have opposite polarities, and a circuit in which a resistor Rs t is connected in series forms the communication path (
The AC terminal (~) of the diode bridge BR, which is inserted and connected to one wire of the circuit configured between terminals T, R and terminals A, B, and the DC terminals (→←) are short-circuited, is connected to the above circuit. (This diode bridge BR1 is connected in parallel with the output side elements PCl(A) and PC2(A) of the two photocouplers.
), but it is used in a way that is different from the original function of the diode. ), and the outputs of the light-receiving side elements PCI (B) and PC2 (B) of the above two photocouplers are connected to two terminals of an OR circuit OR, and the output of this OR circuit OR is connected to the lead tl via an inverter INV. Furthermore, the output of the light-receiving side element PCI (B) of one photocoupler is connected to the lead t1. Note that resistors R, , R are connected between the outputs of the photo-receiving side elements P CI (B) and P Cz (B) of the photo coupler and the positive electrode of the power supply.

is to set the input of the OR circuit OR to a high level (hereinafter referred to as 'H') when the light-receiving side elements PCI(B) and pc2(B) are off (not receiving light). The circuit consisting of the resistor RSeR6 and capacitor C1 inserted between the output of the OR circuit OR and the input of the inverter INV is a waveform shaping circuit provided to stabilize the output of the OR circuit OR. It is a means.Also,
The above two 7-otocouplers have a light emitting side element Pct (A), a light receiving side element PCI (B), and a light emitting side element PC, (A
) and the light-receiving side element PC, (B) are each enclosed in the same case.

In addition to the above-mentioned, the communication path includes a loop circuit L that forms a DC loop for the voice relay transformer TX office line.
P, Diode Pritsuno BR2 that makes the direction of the current flowing through the loop circuit LPK constant regardless of the polarity of the office line, closes the call loop to the office line, and (when the dialing system of the office line is a DC pulse system) b) Relay contact a1 that relays the dial pulse; capacitor C2 and resistor R2 connected in parallel to relay contact a to form a bypass for the calling signal (AC signal) sent from the central office line when a call arrives; A series circuit of , a capacitor C3r04 to prevent a DC loop from being formed, etc. are connected via the transformer Ti, but these are the same configuration as in a conventional central office line trunk.

The common circuit CMT also receives a control input (?ff1j from the lead ah from the central processing unit CCU) to the terminal CT.
Switch circuit CH that switches and connects terminals IA to 4A and terminals IB to 4B to terminals IY to 4Y according to control signals, switch circuit C) I terminals IY to 4Y and central processing unit CCU
The output is connected to the control input of the gates Gl to G4, which are connected between the gates rW1 and rW4, and the control signals from the central processing unit CCU and the gates rd and co. The AND circuit that controls the opening/closing of the above f-G, ~G4 is AND4, central line unit)
Each lead 41*L2 of the four individual circuits ECT configured in the COU is connected to a switch circuit CH.
are connected to terminals IA-4A and terminals IB-4B.

In addition, information lines between the central control unit CCU and the office line unit COU (read channels, rw 1 to rW4+rd,
The information that can be transmitted in the ``co'' is shown in Table 1 below.

Note that the leads 1w1 to 7W4 correspond to each of the four individual circuits ECT that can be configured in the central line unit (COU).

Also, information on leads ywl to fW4 is from the central office line unit C0U.
(common circuit CMT) to the central control unit CCU (microprocessor MP) leads rd, c
.

and Ch information is transmitted from the central control unit CCU (microprocessor MP) to the office line unit COU (common circuit (JT)).

(Operation of the embodiment) FIG. 2 is a flowchart showing the operation of the embodiment shown in FIG. The operation of the embodiment will be explained below with reference to FIG.

In normal times (when there are no outgoing 1 incoming calls, 9 calls, etc.), the polarity of the office line is on the terminal T side (→, and on the terminal R side ←). At this time, since the first current is not flowing through the communication path, none of the light-emitting side elements PC, (A), PC, (A) of the photocoupler is emitting light, and the light-receiving side element PC1 (B),
Both PC and (B) are off, so the OR circuit O
The two inputs of R are connected to (
+) is applied and becomes "H", its output is low level (hereinafter referred to as "L"), and this 11 is inverted by the inverter ■, and lead t1 becomes "H". Furthermore, since the output of the photocoupler light-receiving side element pcl(B) is directly applied to the lead t2, it becomes H'.

When there is an incoming call, a ringing signal (usually a 16Hz or 20Hz AC signal that is repeated for 1 second and 2 seconds off) is sent from the central office line, and this ringing signal is sent to the terminal T → bridge BR, → bridge BR, - loop circuit. LP-Bridge BR2 → Capacitor C! ← Resistor R2 → Terminal R'' (the arrow indicates the current direction), and the AC terminal of bridge BR1 (~) (~
) occurs between diode 2 (about 1.5 V in forward voltage for l!l1).

This voltage causes the light emitting side element PC of the two photocouplers to
1 (A), PCI (B) is the frequency of the calling signal (16Hz
or 20Hz). Therefore, the light receiving side elements Pct(B) and PCI(B) are turned on alternately.

OFF is repeated, and the two inputs of the OR circuit OR are alternately “
II" and 'L" (one becomes "Hl" and the other becomes "L", and they are not at the same level at the same time), and the output is "
It becomes H#. This "H" is inverted by the inverter INV, and I La is output to the lead t. Furthermore, 'H' and 'L' are alternately output to lead t2.

In addition, when a telephone station makes a central line call, the relay contact a of the individual circuit ECT selected by the central line unit (COU) closes under known control, and the DC loop changes from terminal T to
Bridge BR, → Bridge BR, → Loog circuit LP → Bridge BR1 → Relay contact a → Terminal 3 (arrow indicates the current direction), and there is a resistance between the AC terminals (~) (~) of bridge BR1. A DC voltage (about 1.5 V, which is a forward voltage of two diodes) with the R side being (+) is generated. This voltage causes the light-emitting side element PC2 (A) of one of the 7 OTOCADERAs to emit light, thereby turning on the light-receiving side element PC2 (B). Note that the light-emitting element PCI (A) of the other photocoupler does not emit light, and therefore its light-receiving ti11 element PCI (B) remains off.

Photocoupler light-receiving side elements Pct (B) and PC2 (B
) are off and off, respectively, so the OR circuit O
One of the inputs of R is H'' and the other is L', and its output is H''. This 'Hm is inverted by the inverter ■■, and L'' is output to the lead t1.
Since the level of the output of the light-receiving side element PC, (B) of the photocoupler is ``H'', ``H'' is output.

When the called party answers a telephone call made to the central office line, the polarity of the central office line is reversed and terminal T becomes (-) and terminal R becomes (+).
becomes. Therefore, the direction of the current flowing through the DC loop is opposite to that at the time of transmitting the station line 9, the light-emitting side element PC, (A) of the photocoupler emits light, and the light-emitting side element PC, (A) dims. do. Therefore, the light-receiving side element Pct(B) changes from off to on, and the light-receiving side element Pct,(B) changes from on to off. As a result, the output of the OR circuit OR is 'H1
'1 remains unchanged, so lead L1 remains at "L" and does not change, but lead t! changes from "H" to "L".

In each of the above-described states, the level 1 & of the board 11 ml-2 is summarized as shown in Table 2 below.

Table 2 Lead t1. The level of t2 is input to terminals IA-4A and terminals IB-4B of switch circuit CH of common circuit CMT for each individual circuit ECT. In the switch circuit CH, the microprocessor MP of the central control unit) CCU
Terminal I until switching information is not sent from lead ah to lead ah.
A~4 people are each connected to terminals IY~4Y, and each individual circuit ECT is first connected to the corresponding terminals IY~4Y.
The level of lead 1x is output.

In the above state, when it is time to read data from the central processing unit (CCU) and the central processing unit (CCU),
The microprocessor MP is the station unit in the lead eo)
COU selection information (“L” signal 1t and read mode information (“L-signal)” are sent to 'J-rd'. As a result, the output of the AND circuit AND of the common circuit CMT becomes 1.
This is input to the control terminals of G1-G4, which opens Gl-G4, and the switch circuit CH
The level of lead t1 of each individual circuit ECT, which is output to terminals IY to 4Y, is output to leads fW1 to rW4, and read into microprocessor MP.

Next, when the microprocessor MP sends switching information to the lead channel, the connections between the terminals IA to 4A and the terminals IY to 4Y of the switch circuit C)I are connected to the terminals IB to 4B.

Switching is made to the connection between IY to 4Y, and the level of lead t of each individual circuit ECT is output to terminals IY to 4Y.

The level of lead t2 outputted to terminals lY to 4Y of switch circuit CH in this manner is outputted to leads fW1 to rW4 in the same manner as in the case of lead tI, and read into microprocessor MP.

As described above, when the level of the lead t1zt of the individual circuit ECT is read into the microprocessor MP of the central control unit (CCU), the level of the lead t1zt of the individual circuit ECT is
The terminal determines whether there is an incoming call or polarity reversal according to the flow shown in FIG.

That is, when entering the incoming call/polarity reversal detection process, the microprocessor MP first determines the level of the read read t1. When the level of lead t1 is "H#", as is clear from Table 2, the station line is in a normal state, so the incoming call/polarity reversal detection process in the microprocessor MP is completed.
Return to the starting point including other processing. lead t1
When the level of is L#, as shown in Table 2, the station line is either incoming or outgoing (including when the polarity is reversed). The microprocessor MP determines whether or not it is time to make a call based on data obtained through other control (not shown), and when it is not time to make a call, it determines that there is an incoming call and performs incoming call processing.

Further, when making a call, it is determined from data obtained by other controls (not shown) whether or not the digits of the dial sent from the telephone device have finished. Since the DC loop is intermittent while the dial pulse is being sent out, and the level of lead t1 changes repeatedly, this judgment will result in an error of +111% due to this level change.
This is necessary to prevent fr. If it is determined in this judgment that the dial digits have not been completed, the control is returned to the starting point, and if the dial digits have been completed, the level of the microprocessor MP reading t2 is determined.

When the level of lead t2 is L# (lead 1 first
As shown in Table 2, the microprocessor MP determines that the polarity can be reversed. It is determined that there is one, and the corresponding processing is performed.Furthermore, when the level of lead t! falls to n Hml, control returns to the starting point.

The judgment process in the microprocessor MP explained above is performed after reading the levels of both leads t1 and t2.
When determining the level of lead t2, the level may be read and determined, and then when determining the level of lead t2, the level may be read and determined.

(Effects of the Invention) As described above in detail, according to the present invention, both incoming call detection and polarity reversal detection can be performed by the same means, so the device can be simplified and, for example, the detection means can be connected to the communication path. This has the effect that control can be simplified, such as eliminating the need for separate control.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a flow chart showing control of the embodiment shown in FIG. (Main symbols) COU... Central control unit Pc1 (A), PC, (A)... Photocoupler light emitting side element pc1 (B), PC, (B)... ...Photocoupler light receiving side element MP...Microprocessor

Claims (1)

[Claims] The light-emitting side elements of two photocouplers are inserted and connected in parallel with each other on one line of the communication path, and incoming calls and polarity reversal are detected by distinguishing from the logic of the light-receiving side element outputs of the two photocouplers. Incoming call and polarity reversal detection method.