JPS6367855A - Trunk for fire fighting and police - Google Patents

Abstract

PURPOSE:To economize circuits and to save the labor at the time of the setting of the opposite equipment by providing a signal supply circuit for a speaking current and a trunk control circuit which controls the operation of a signal reception detecting circuit according to the kind of the opposite equipment. CONSTITUTION:When a police command board is set by an opposite equipment kind condition input circuit 13, the trunk control circuit 14 inputs a gate control signal CS to a signal supply and signal reception detecting circuit 21 and the signal supply circuit which supplies the output voltage of a battery 25 to the police command board is connected to supply a call signal to the police command board. When the police command board answers, both wires are grounded, but that is detected with the output signals CSS and HDS of signal reception detecting circuits of signal supply and signal reception detecting circuits 21 and 22 and gate driving with the signal CS is held in this state, so that a talk is enabled. For other opposite equipments, a control gate is controlled according to a setting and a monitor output signal to the opposite equipment kind condition input circuit 13 so that the signal supply circuit and signal reception detecting circuits 11 and 12 are connected selectively to an A line 9 or B line 10 similarly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a fire and police trunk connected to a telephone exchange and used for connection to a fire command center, a police command center, a telephone terminal, etc. be.

[Conventional technology]

There are various usage forms for call communication using a telephone network. One of these is trunks for fire and police departments, which are connected to important lines that require a particularly urgent need.

Figure 4 shows the connection form of this fire/police trunk.

In FIG. 4, 1 is a subscriber terminal, 2 is an exchange, and 3 is a trunk for fire and police use. As is well known, the fire/police trunk is a trunk connected to a fire command center, a police command center, or a telephone terminal, and is different from the -S trunk in terms of control system, direction number 8, etc.

Regarding track signals, the correspondence between opposing models and track signal conditions is shown in the table.

In the conventional circuit, when connecting with the opposing model shown in the table, cutting points and connecting points corresponding to the opposing model are provided for the A line and B line of the communication path, and by changing the hardware wiring and logic, I fixed it by changing the settings.

As an example of the conventional circuit, the circuit shown in FIG. 5 will be described, focusing only on the function of supplying communication current to the line. In Fig. 5, 4 is a capacitor that stops the direct current in the communication path and relays the communication signal, 5, 6.7 is a relay for supplying communication current with a DC resistance of 440Ω and an AC high impedance function, and 8
A, 8B are batteries with an output voltage of 148V, 9 is the A line, 10
is B line, JAO~JA2. JBO-JB2 is a wiring change terminal, and TO and Tl are communication path terminals.

Fig. 5 shows the case where the station is facing the fire department or police station shown in the table, and the output voltage of the battery 8A is -48V by relays 5.6 and 440Ω DC resistance for each A line 9 and B line 10. is supplied.

When facing a telephone terminal, mark * (JAO-JA2.J
Delete the wiring of BO-JB2) and add the dotted line (JAO-JAI
, JBO-JBI), the A wire 9 is set to the output voltage of the battery 8B -48V, and the B wire 10 is set to the ground voltage.

[Problem that the invention seeks to solve]

As shown above, traditional fire and police trunks are
Depending on the opposing model, it was necessary to perform predetermined disconnection or connection each time the device was installed. The example shown in Figure 5 only shows an example of changing a part of the fire/police trunk function; if other functions are included, the disconnection and connection changes would be enormous, and the time and effort required. There was a problem that the amount of work required was large, and labor savings could not be achieved.

[Means for solving problems]

In order to solve these problems, the present invention provides a signal supply circuit that supplies a communication current by connecting a two-wire communication line with a battery or the earth at a certain DC impedance or AC high impedance, and the opposite a signal supply detection means having a signal reception detection circuit that detects a response signal of the model to be connected to/disconnects from the communication line; an opposing model condition input circuit for setting opposing model conditions; and the opposing model condition input circuit. A trunk control circuit for driving/controlling the signal supply detection means based on the settings is provided in a fire/police trunk.

[Effect]

In the present invention, the operation control of the signal supply circuit for communication current and the signal reception detection circuit according to the type of opposing device can be easily performed without the need for wiring changes or logic changes.

〔Example〕

A first embodiment of a fire/police trunk according to the present invention will be described below.
This will be explained using FIGS. FIG. 1 is a block system diagram of this embodiment. In FIG. 1, 11 is a signal supply/detection means for supplying communication current on the A line 9 side.
A signal reception detection circuit, 12 is a signal supply/signal reception detection circuit as a signal supply detection means for supplying communication current on the B line 10 side, 13 is an opposite model condition input circuit, and 14 is a setting for the opposite model condition input circuit 13. This is a trunk control circuit that drives/controls the signal supply/signal reception detection circuits 11 and 12 based on the signal supply/signal reception detection circuits 11 and 12.

FIG. 2 is a block system diagram for explaining the operating principle of the block system shown in FIG. 1, and the opposing model condition input circuit and trunk control circuit are not shown. In FIG. 2, 21 is a signal supply/signal reception detection circuit for supplying the output voltage of the battery 25 to the A line 9, and 22 is a signal supply/signal reception circuit for supplying the output voltage of the battery 25 to the B line 10. 23 is a signal supply/signal reception detection circuit for supplying ground air to the B line; 24 is a signal supply/signal reception detection circuit for supplying a CR or IR double signal; 26 is a signal supply/signal reception detection circuit 24 A battery with an output voltage of -48V is connected to the battery, and 27.28 is a contact point.

The signals C3, HD, and HDA input to the signal supply/signal reception detection circuits 21, 22, and 23 are transmitted through the relays 5. Connect a signal supply circuit equivalent to '6.7 to the communication path/
A signal supply circuit indicating a gate control signal for disconnection and in which the gate control signal is in a significant signal state is connected to the communication path.

The output signals css, HDs, and HDAS from the signal supply/signal reception detection circuits 21, 22.23 are status monitoring signals of the opposing model by the signal reception detection circuit, and are determined by the operating status of the relay 5.6.7 in Fig. 5. Corresponds to relay contact output signal. The signal CR input to the signal supply/signal reception detection circuit 24 is a gate control signal like the signal CS etc., and the output signal RG from the signal supply/signal reception detection circuit 24
T is a status monitoring output signal, which detects a loop on the opposite model side.

Contacts 27 and 28 are controlled by the trunk control circuit only when the opposite model is a telephone terminal, and operate until sending out a calling signal and detecting a response signal, and then resume operation. The figure shows the restored state.

As can be seen from the above description, the signal supply/signal reception detection circuits 21 and 22 respectively correspond to the relays 5 and 6 in FIG. 5, and A'! Output voltage of battery 25 -48V for rfA and BvA
The signal supply/signal reception detection circuit 23 is a circuit that supplies ground air and detects signal reception. Regarding the correspondence between FIG. 1 and FIG. 2, the signal supply/signal reception detection circuit 11 is the signal supply/signal reception detection circuit 21.24, and the signal supply/signal reception detection circuit 12 is the signal supply/signal reception detection circuit 22. 2
Corresponds to 3.

Next, the principle of operation when the police command center is set by the opposing model condition input circuit 13 will be explained. When activated from the front side shown in FIG. By the trunk control circuit 14,
The gate control signal CS is supplied to the signal supply/signal reception detection circuit 21
When the signal is input to the A line 9, a signal supply circuit for supplying the output voltage of the battery 25 is connected to the A line 9, and a call signal is supplied to the police headquarters.

When the police command center responds to this, as shown in the table, the line image is returned, which is used as a signal supply and
It is detected by the output signals C3S and HDS of the signal reception detection circuits 21 and 22, and the gate drive by the signal CS maintains this state and starts a call.

When the police command station ends the call, the signals C3S and HDS are not output, and the gate drive shifts to the initial state.

The operating principle of the police command console has been explained above, but for the other opposing models shown in the table, the signal supply circuit and signal reception detection circuit can be selectively connected to the A line 9 or the B line 10 in the same way. , setting to the opposing dual-type condition input circuit 13,
This can be dealt with by controlling the control gate according to the monitoring output signal.

Next, an embodiment of a signal supply circuit for supplying communication current will be described with reference to FIG. In Figure 3, A, B-2
is A line 9. A signal supply circuit that supplies the output voltage of the battery 25 -48V to the B line 10, B-1 a signal supply circuit that supplies earth to the B line 10, and C a signal cs from a trunk control circuit (not shown), 1 (Input DA and signal supply circuit A
, B-1, B-2.

The signal supply circuit A includes resistors A1 to A4. Photocabra APO
-API light receiving side element, capacitor A5, input terminal T
Operational amplifier A6.AO.- has an input terminal TAI. The signal supply circuit B-2 is composed of a transistor A7 and resistors B1 to B3 . Photocoupler BPI light receiving side, element, capacitor B4. 10 input terminal TBO・- input terminal TBI
operational amplifier B5. It is composed of a transistor B6.

The signal supply circuit B-1 includes resistors B7 to B9. Photocoupler B
PO light receiving side element, capacitor BIO, + input terminal TB
2.- operational amplifier Bll, l- with input terminal TB3;
It is composed of transistor B12.

Drive circuit C includes resistors RO, R1, and photocoupler APO-A.
It is composed of PI, BPO, and BPI light emitting side elements.

Next, functions etc. will be explained. The signal supply circuit A divides the voltage between the A line 9 and the battery 25 using resistors A1 to A3,
The voltage applied to the input terminal TAO of the operational amplifier A6 is connected to the reference resistor A4 connected to the emitter of the transistor A7.
It constitutes a constant current circuit determined by the value divided by , and the AC high impedance and the DC impedance are set to 440Ω or 220Ω by the capacitor A5 connected to the input terminal TAO of the operational amplifier A6.

The signal supply circuit B-2 connects the voltage between the B line l〇 and the battery 25 to the resistor B7. B8 constitutes a constant current circuit determined by the voltage divided by the voltage applied to the input terminal TB2 of the operational amplifier Bll divided by the reference resistor B9 connected to the emitter of the transistor B12. By the capacitor BIO connected to the input terminal TB2 of
AC high impedance and DC impedance are set to 440Ω.

The signal supply circuit B-1 divides the voltage between the B line l〇 and the ground using resistors Bl and B2, and converts the voltage applied to the ten input terminal TBO of the operational amplifier B5 into a reference connected to the emitter of the transistor B6. It constitutes a constant current circuit determined by the value divided by the resistor B3, and the input terminal T of the operational amplifier B6
AC high impedance due to capacitor B4 connected to BO.

The DC impedance is set to 220Ω.

The DC impedance is determined by the voltage dividing resistors A1 to A3, Bl,
B2. B7. B8 and the reference resistance A4°B3. This can be achieved by selecting the constant of B9, and the AC impedance can be achieved by selecting the above two sets of resistors and capacitor A5. B4. It is well known that this can be achieved by selecting BIO constants, so the explanation will be omitted.

Next, the operation of the signal supply circuit shown in FIG. 3 will be explained. When the low level C8 signal from the trunk control circuit is input to the drive circuit C, current flows through the light emitting side elements of the photocouplers APO and BPO, and these light emitting side elements emit light.

This light emission turns on between the collector and emitter of each light-receiving side element. As a result, the DC voltage obtained by the resistors A2 and A3 as detection voltage dividing resistors is smoothed by the capacitor A5, and is applied to the input terminal TAO of the operational amplifier A6. Transistor A7 and resistor A
Equivalent DC impedance 440Ω with 4 constant current circuits
The output voltage of the battery 25 is supplied to the A line 9 via the A line 9.

On the other hand, resistor B7. as a detection voltage dividing resistor. The DC voltage obtained at B8 is smoothed by a capacitor BIO and applied to the input terminal TB2 of the operational amplifier Bll.
ll, battery 2 through an equivalent DC impedance of 440Ω by a constant current circuit of transistor B12 and resistor B9.
The output voltage of 5 is Bv! 10, and constitutes a circuit that can send out a police command center call signal.

Next, the C8 signal from the trunk control circuit is high-reherte.
A case where the HDA signal is at a low level will be explained. When a high-level C8 signal is input to the drive circuit C, currents in the light-emitting elements of the photocouplers APO and BPO stop flowing, and these light-emitting elements cease to emit light. In addition, when low level I (DA double signal drive circuit C is input, current flows to the light emitting side elements of photocouplers API and BPI,
These light-emitting elements emit light.

In this state, the light receiving side element of the photocoupler BPO is cut off, and the + input terminal TB of the operational amplifier Bll is cut off.
2 becomes a potential of -48V by the battery 25 via the resistor B8, and the output of the operational amplifier Bll follows and becomes -48V, and the transistor B12 is cut off. As a result, the signal supply circuit B that supplies -48V to the B line 10
2 is disconnected from the B line 10.

On the other hand, by turning on the emitter-collector of the light-receiving side element of the photocoupler BPI, the voltage between the B line 10 and the earth is divided by the resistors B1 and B2 as detection voltage dividing resistors, and is smoothed by the capacitor B4. and is supplied to the input terminal TBO of the operational amplifier B5. As mentioned above, operational amplifier B5. The signal supply circuit including the transistor B6 and the resistor B3 also constitutes a constant current circuit, and earth air is supplied to the B line 10 through a circuit with a DC equivalent impedance of 220Ω and an AC high impedance.

Regarding the A-line 9, the emitter-collector of the light-receiving side element of the photocoupler APO is cut off, and the A-line 9 is cut off.
The emitter-collector of the light-receiving side element of the photocoupler API is turned on instead, and the connection is changed to resistors A1 and A3 as detection voltage dividing resistors, and the operational amplifier A
It is supplied to the input terminal TAO of No. 6. By changing the connection of the detection voltage dividing resistors, a signal supply circuit with a DC equivalent impedance of 220Ω and an AC high impedance is constructed, similar to B'fIIA10, and -48V is supplied to the A line 9.

As explained above, in the trunk control circuit, by inputting the CS signal or HDA signal of a predetermined level to the drive circuit C, the DC resistance can be switched from 440Ω to 220Ω, and the power supply to the B line 10 can be switched. Moichi 48V to earth.

Mutual switching from earth to -48V can be selectively and easily realized.

In the above embodiment, the power supply switching on the B line 10 side was explained, but similarly, only the A line 9 or the A line 9. It is easy to understand that simultaneous power switching of the B lines 10 can be achieved by providing a plurality of signal supply circuits and selectively connecting them through predetermined driving/control.

〔Effect of the invention〕

As explained above, the present invention provides a signal supply detection means having a signal supply circuit that supplies a communication current, a signal reception detection circuit that detects a response signal of an opposing model and connects/disconnects the communication line to the communication line; By providing an opposing model condition input circuit that sets opposing model conditions and a trunk control circuit that drives/controls the signal supply detection means based on the settings of the opposing model condition input circuit, it is possible to control the communication current according to the opposing model. The operation side of the signal supply circuit and signal reception detection circuit can be easily changed without changing the wiring or logic, and the DC equivalent impedance to the line can also be changed.
This has the effect of making the circuit more economical and saving labor when setting the opposing model.

[Brief explanation of drawings]

Fig. 1 is a block system diagram showing an embodiment of a fire/police trunk according to the present invention, Fig. 2 is a block system diagram for explaining its principle, and Fig. 3 is a configuration of the device shown in Fig. 1. A circuit diagram showing a signal supply circuit, Fig. 4 is a block system diagram showing the state of use of a fire/police trunk, and Fig. 5 is a circuit diagram showing an example of a conventional signal supply circuit for communication current in a fire/police trunk. It is. 9...A line, 10...B line, 11, 12.21
, 22, 23, 24...signal supply/signal reception detection circuit, 13...opposite model condition input circuit, 14...
Trunk control circuit, 25°26...Battery, A, B-
1, B-2... Signal supply circuit, C... Drive circuit, APO, API, BPO, BPI... Photo coupler, RO. R1, Al-A4. B1-B5. B7-B9...Resistance, Go, C1, A5. B4. BIO... Capacitor, A6. B5. Bl 1... operational amplifier, A7.
B6. B12...Transistor, To, Tl, TA
O, TAL, TBO, TBL, TB2. TB3...
terminal. Patent applicant: NEC Corporation Nippon Telegraph and Telephone Corporation

Claims (3)

[Claims] (1) In a two-wire fire/police trunk facing multiple models with different control and signaling systems, the two-wire communication line is connected to a battery or earth with a certain DC impedance or AC high impedance. a signal supply detection means having a signal supply circuit for supplying a communication current and a signal reception detection circuit for detecting a response signal of the opposing model and connecting/disconnecting the communication line; and setting conditions for the opposing model. A fire department system characterized by comprising an opposing model condition input circuit and a trunk control circuit that drives/controls the signal supply detection means based on the settings of the opposing model condition input circuit.
Police trunk. (2) The signal supply circuit includes a drive circuit that inputs a signal from a trunk control circuit and outputs a signal that drives the signal supply circuit. trunk. (3) The signal supply circuit includes one or more circuits that switch the DC impedance between the communication line and the battery according to the output signal of the drive circuit. Fire and police trunk.