JPH0373653A - Control line interface system - Google Patents

Abstract

PURPOSE:To automatically set up switching corresponding to an E & M type (interface type of control lines E, M) by monitoring the on-hook potential of a connected control line and its continuous time to identify its interface type and outputting a corresponding switching signal. CONSTITUTION:The potential of a control line M whose potential level is turned to the low level when a trunk circuit corresponding to the E & M type I is detected as the output of a photocoupler 21 and its continuous time is monitored by a counter 27 and an RS type flip flop circuit 28. When the trunk circuit belongs to the E & M type I, an interface type identification part 25 sends a high level switching signal B to an exclusive OR circuit 30 to invert the logic of an output signal A, so that a signaling circuit of an E & M type V is allowed to correspond similarly to the circuit of the E & M type I. When the trunk circuit corresponding to the E & M type V is connected, the switching signal B is turned to the low level to allow the signaling circuit of the E & M type V to correspond to the E & M type as it is.

Description

[Detailed Description of the Invention] [Summary] Regarding the control line interface system that connects the trunk circuit of a private branch exchange and a digital multiplexer or other signaling circuit, any of the control line E, M interface types ■ and V The trunk circuit has an input/output interface means corresponding to the interface type ■ of control lines E and M, and an input/output interface means corresponding to the same interface type V. In the control line interface method of a signaling circuit that is connected to a trunk circuit having an interface means and has an input/output interface means corresponding to the interface type V, the on-hook potential and its duration of the connected control line M are monitored. The interface type identification means identifies the interface type by using the switching signal and outputs a corresponding switching signal, and the output control means controls whether or not the output logic of the input interface means is inverted or non-inverted using the switching signal.

[Industrial application field]

The present invention is an interface system for a control line that connects the trunk circuit of a private branch exchange (PBX) and a digital multiplexer or other signaling circuit [prior art] The interface type of control lines E and M currently used ( (hereinafter referred to as "rE&M type") include ■, ■,
There are five types: ■, ■, and ■, and the trunk circuit and signaling circuit are configured to correspond to this E&M type.

FIG. 3 and FIG. 4 are block diagrams showing configuration examples of trunk circuits and signaling circuits corresponding to E&M types I and II.

In FIG. 3, the E&M type I control line M is connected to ground (GND) or battery voltage (-48V) by a switch 41 that breaks or makes in response to on-hook or off-hook of the trunk circuit 40. Note that a Zener diode 42 and a capacitor 43 are connected between the control line M and the ground in order to hold the potential of the control line M when the switch 41 is turned on. Reference number 44 is a protection circuit for overcurrent prevention.

In the signaling circuit 47, a relay circuit 48 operates according to the potential of the control line M (current flows through the relay circuit 48 when the trunk circuit 40 is off-hook (meter)).
Therefore, an output corresponding to on-hook or off-hook of the trunk circuit 4o can be obtained.

Further, the control line E is connected to the switch 4 of the signaling circuit 47.
A break or make of 9 results in an open (OPN)
) or ground (GND).

In the trunk circuit 40, the relay circuit 45 connected to the battery I (-48V) is activated according to the potential of the control line E, so that an output corresponding to the operation of the switch 49 of the signaling circuit 47 can be obtained. Reference number 46 is a surge prevention protection circuit.

In FIG. 4, the control line M of the E&M type V is opened (OPN) or grounded (GND) by a switch 51 that breaks or meters in response to the on-hook or off-footer of the trunk circuit 50.

In the signaling circuit 57, a relay circuit 58 connected to the battery (-48V) is activated according to the potential of the control line M (current flows through the relay circuit 58 when the trunk circuit 50 is off-hook (meter)). , an output corresponding to on-hook or off-hook of the trunk circuit 50 can be obtained. Reference number 60 is a surge prevention protection circuit.

In addition, in the control line, E&M type I shown in Figure 3
Similarly, the relay circuit 55 of the trunk circuit 50 operates in response to the break or meter of the switch 59 of the signaling circuit 57, and can obtain an output corresponding to the on-hook or off-footer on the opposing trunk circuit side. Reference number 56 is a surge prevention protection circuit.

Table 1 shows the states of control lines E and M corresponding to each E&M type described above.

Table 1 [Problems to be Solved by the Invention] As described above, since the potential of the control line M differs depending on the E&M type, trunk circuits and signaling circuits are prepared corresponding to each E&M type. therefore,
When connecting the control line M between the private branch exchange and the digital multiplexer, it was necessary to connect a circuit suitable for the E&M type.

By the way, the signaling circuit 57 corresponding to E&M type V has a trunk circuit 40 corresponding to E&M type I.
When connected, the output logic of the signaling circuit 57 to the trunk circuit 40 is inverted. That is, the relay circuit 58 of the signaling circuit 57 is connected to the trunk circuit 4.
When 0 is on-hook (break), the potential of the control line M is grounded (GND), and a current flows to operate. When the trunk circuit 40 is off-hook (make), the control line M is connected to the battery (-48V), and no current flows through the relay circuit 58, so it does not operate.

Therefore, the signaling circuit 57 corresponding to E&M type V and the trunk circuit 40 corresponding to E&M type I
When connecting the two, it is necessary to invert the output logic on the control line M side. In other words, when the E&M type V signaling circuit is shared with the E&M type I and V trunk circuits, when used in the E&M type ■, a means for inverting the output logic is provided.
Switching between M types has become possible, and a patent application has already been filed for such a control line interface system (Japanese Patent Application No. 1-68116).

In addition, in the configuration disclosed in the prior application, it is necessary to manually perform switching according to each E&M type in advance when connecting the control line M, which may lead to forgetting to switch or erroneous operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control line interface system that can support both E&M types (1) and (2) and that can automatically perform switching settings.

[Means to solve the problem]

FIG. 1 is a block diagram of the principle of the present invention.

In the figure, the trunk circuit 12 has an input/output interface means 1O111 corresponding to E&M type (2).

The trunk circuit 15 has input/output interface means 13.14 corresponding to E&M type V.

The signaling circuit 18 has input/output interface means 16, 17 corresponding to E&M type ①.

The interface type identification means 19 of the signaling circuit 18 monitors the on-hook potential of the connected control line M and its duration, identifies the interface type, and outputs a corresponding switching signal.

The output control means 20 controls whether the output logic of the input interface means 16 is inverted or non-inverted using the switching signal.

[For production]

Input/output interface means 1 compatible with E&M type V
When the trunk circuits 12.15 corresponding to E&M types I and V are connected to the signaling circuit 18 having the E&M type 6.17, there is no problem because the control line E is common to each E&M type. However, for the control line M, the output logic of the input interface means 16 is inverted depending on the E&M type of the trunk circuit to which it is connected.

In the present invention, the interface type identifying means 19 of the signaling circuit 18 detects the on-hook (
The electric potential at break) and its duration are monitored, and if it continues to be low level for more than a predetermined time depending on the make rate of the dial pulse, it is classified as E&M type I, and if it continues to be high level, it is classified as E&M type. V, and outputs a corresponding switching signal. Output control means 2
0 can connect to both types of trunk circuits by controlling inversion or non-inversion of the output logic of the input interface means 16 using a switching signal according to the E&M type of the identified trunk circuit. can.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.

The present invention enables the connection of trunk circuits corresponding to E&M types ■ and ■ with the same signaling circuit, and in this embodiment, since the control line E side is common to both types, the control line M Only the side configuration example is shown.

In FIG. 2, a battery (-48V) is connected to the control line M via a photocoupler 21 and a resistor 22 as input interface means (16 in FIG. 1).

A Zener diode 23 is connected in parallel to the photodiode of the photocoupler 21, and the output of the photocoupler 21 is taken out via an inverting circuit 24 (hereinafter, this inverting circuit 2
The output of No. 4 is referred to as "output signal AJ".The configuration of the photocoupler 21 and the inverting circuit 24 corresponds to the relay circuit 5 of the signaling circuit 57 shown in FIG.

The interface type identification section 25 corresponding to the interface type identification means (19 in FIG.
ARA pulse) and an R3 type flip-flop circuit which outputs a predetermined switching signal B in response to the output signal A, and an R3 type flip-flop circuit which is set by the output of the count-up signal and sends the d output to the enable terminal EN of the counter 27. It is composed of a flip-flop circuit 29.

An exclusive OR circuit (EOR) 30 corresponding to the output control means (20 in FIG. 1) receives a switching signal B (E&M type I
, V), the logic of the output signal A is inverted or non-inverted. That is, the output signal A is connected to one input of the exclusive OR circuit 30, the switching signal B that identifies the E&M type ■ or V of the signaling circuit is connected to the other input, and the output is connected to the digital circuit (transmission circuit). ).

Note that in this embodiment, the output signal to the digital circuit is
A case will be explained in which the level is low when the trunk circuit side is on-hook (break) and the level is high when it is off-hook (make).

(i) When the E&M type ■ identification trunk circuit side is on-hook (break), the control line M is connected to ground (GND), so current flows through the photocoupler 21 and its output becomes low level. Therefore, the output signal A becomes high level, the counter 27 starts counting, and outputs a count-up signal when the time exceeding the dial pulse make rate has elapsed. The time to exceed the dial pulse make rate is the dial pulse speed (10 ± 0.8 pps or 20 ± 1.6 pps for domestic specifications, 10 ± 0 for AT&T specifications).
．． 2pps) and dial pulse make rate (33±3% for domestic specifications, break rate 6.0± for AT&T specifications)
2%).

Furthermore, the R3 type flip-flop circuit 29 is set by this count-up signal, and the subsequent counter 27
Stops the counting operation.

The R3 type flip-flop circuit 28 is set by the high-level output signal A when the count-up signal is input, and sets the switching signal B to the noise level. In other words, the high level switching signal B is "■" for the E&M type.
The output signal A input to the exclusive OR circuit 30 is logically inverted, becomes low level, and an on-hook (break) signal is sent to the digital circuit.

Furthermore, when the trunk circuit side is off-footer (make), the control line M is connected to battery I (-48V), so no current flows through the photocoupler 21, and its output becomes high level, and the output signal A becomes low level. Become. On the other hand, the switching signal B input to the exclusive OR circuit 30 is
Since the counter 27 does not perform a counting operation, the high level is maintained, and the signal A is output from the exclusive OR circuit 30.
The inverted logic of is taken out and becomes a high level, and an off footer (make) is sent to the digital circuit.

In this way, the potential of the control line M that becomes low level when the trunk circuit corresponding to E&M type I is connected is:
It can be detected as the output of the photocoupler 21, and its duration can be monitored by the counter 27 and the R3 type flip-flop circuit 28 to identify it. That is, when the trunk circuit is of the E&M type (■), the interface type identifying section 25 sends a high-level switching signal B to the exclusive OR circuit 30, and by inverting the logic of the output signal A, the signaling of the E&M type V is performed. It becomes possible to adapt the circuit in the same manner as in the case of EaM type (2).

(ii) When the identification trunk circuit side of E&M type ■ is on-hook (break), the control line M becomes oven (OPN), so no current flows through the photocoupler 21, and its output becomes high level, and the output signal A becomes becomes low level. On the other hand, the switching signal B input to the exclusive OR circuit 30 is maintained at the initial low level since the counter 27 does not perform the counting operation. In other words, the low level switching signal B is E
The output signal A, which indicates that the &M type is "V" and is input to the exclusive OR circuit 30, is taken out at a low level, and an on-hook (break) signal is sent to the digital circuit.

Also, when the trunk circuit side is off-hook (meter), the control line M is connected to ground (GND), so
A current flows through the photocoupler 21 and its output becomes low level. Therefore, the output signal A becomes high level and the counter 27 starts counting, but the time during which the output signal A is high level does not exceed the dial pulse make rate, and the output signal A reaches the high level before the count-up signal is output. A becomes low level. That is, since the low level of the switching signal B is maintained, the high level output signal A is taken out as is, and the off footer (make) is sent to the digital circuit.

In this manner, when a trunk circuit corresponding to E&M type (2) is connected, by setting the switching signal B to a low level, the signaling circuit of E&M type V can be made to correspond as is.

Here, the logic of each part shown in this embodiment is summarized in Table 2. M is the control line M, PC is the output of the photocoupler 21,
A is the output signal A, B is the switching signal B, and EOR is the high level H10-level L of each logic output from the exclusive OR circuit 30.

Table 2 [Effects of the Invention] As described above, according to the present invention, one signaling circuit can be connected to each trunk circuit corresponding to E&M types I and The versatility of multiplexing devices and the like can be increased.

Also, depending on each E&M type, it is possible to automatically perform inversion control of the output logic of the signaling circuit corresponding to on-hook (break) and off-footer (make) on the trunk circuit side, that is, switching settings depending on the E&M type. Therefore, the burden during installation can be reduced.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram showing the configuration of an embodiment of the present invention, Fig. 3 is a block diagram showing an example of the configuration of a trunk circuit and a signaling circuit corresponding to E&M type ■, FIG. 4 is a block diagram showing a configuration example of a trunk circuit and a signaling circuit corresponding to E&M type V. In the figure, 0.13.16 is an input interface means, 1.14.
17 is an output interface means, 2.15 is a trunk circuit, 8 is a signaling circuit, 9 is an interface type identification means, 0 is an output control means, 1 is a photocoupler, 2 is a resistor, 3 is a Zener diode, 4 is an inverting circuit, 5 is an interface type identification section, 6 is an oscillator, 7 is a counter, 8.29 is an R3 type flip-flop circuit, and O is an exclusive OR circuit (EOR). +5v Fig. 2 A block diagram showing the configuration of an embodiment of the present invention Fig. 1 A block diagram showing the principle of the present invention Fig. 3 An example of a configuration corresponding to E&M type I Fig. 3 An example of tiFfi corresponding to E&M type ■ Fig. 4

Claims (1)

[Claims] (1) A trunk circuit (12) having input/output interface means (10, 11) corresponding to interface type I of control lines E, M, and input/output interface means (13, 14) corresponding to interface type V. input/output interface means (1) connected to the trunk circuit (15) and corresponding to said interface type V;
In the control line interface system of the signaling circuit (18) having 6, 17), the on-hook potential of the connected control line M and its duration are monitored to identify the interface type and output a corresponding switching signal. interface type identification means (19);
6) A control line interface system characterized by comprising an output control means (20) for controlling inversion or non-inversion of output logic.