JPH02262750A - Tester for off-talk communication customer connection device - Google Patents

Abstract

PURPOSE:To perform a normal operation even when no ground is prepared at a tester side by connecting an incoming detection circuit, an outgoing detection circuit, and a channel switching signal detection circuit, etc., to telephone line via a photocoupler. CONSTITUTION:No current flows on a first photocoupler PC1 for detecting an AC signal in the incoming detection circuit 43 when the telephone line 13 is used. The outgoing detection circuit 44 is separated electrically from a customer's private connection device 32 side, therefore, no current flows on a second photocoupler PC2 for detecting the AC signal. Thereby, two input of an AND gate AND go to high levels, and a relay RL1 is operated, and a signal input part 41 is connected to the customer's private connection device 32 and the telephone line 13. When the information of voice, etc., is issued from either the channels of the signal input part 41, it is outputted to output equipment 31 via the customer connection device 32, thereby, an off-talk communication function can be confirmed.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention realizes operations between an information providing center, an in-office connection device, and an in-home connection device that constitute off-talk communication, and improves the characteristics of the in-home connection device. The present invention relates to a device for testing off-talk communication functions.

(Prior Art) Off-talk communication refers to a telecommunications service that uses free time on telephone lines to transmit voice information from an information provider center to subscriber's homes in a simultaneous broadcast manner.

An off-talk communication system is shown in FIG. Inside the telephone office 10, an in-office connection device 1 is connected between the telephone line 13 and the exchange 11.
2 is inserted, and this intra-office connection device 12 and the center device 21 of the information providing center 20 are connected via a center line 22. On the other hand, at the user's home 30, a telephone line 13 and an output device 31 such as a speaker are connected via an in-home connection device 32. Normally, when the user's telephone 33 is not in use, that is, when the telephone line 13 is idle, information such as music played from the center device 21 is transmitted to the telephone line 13 via the in-office connection device 12, and the user It is output from the output device 31 at the home 30 via the home connection device 32 . When the telephone 33 makes a call or receives a call, the in-office connection device 12 disconnects the telephone line 13 and the center line 22, giving priority to the telephone call 33. When the call ends, the intra-office connection device 12 reconnects the center line 22 and the telephone line 13. Similarly, the in-home connection device 32 has a call priority function, and disconnects the telephone line 13 and the output device 31 during a call to prevent the call voice from being output from the output device 31.

The information provided from the center device 21 to the user's home 30 is
It's not just one channel, but multiple channels. The selection is made by a channel switching signal sent from the home connection device 32 to the center device 21, and when the local connection device 12 detects this signal, it switches the center line 22 and connects it to another channel.

[Problem to be solved by the invention]

In such conventional devices, in order to check the call priority function and channel switching signal detection function of the home connection device 32, it is necessary to use an off-talk home connection device tester (hereinafter simply a tester) as shown in FIG. ) 40 is inserted between the home connection device 32 and the telephone line 13. The signal used as the channel switching signal is created by short-circuiting the telephone line 13 to 16 with a high resistance of Ω for a certain period of time inside the home connection device 32. The conventional tester 40 confirms the transmission of the channel switching signal by detecting the voltage change caused by this short circuit, and supplies voltages of -48V and 0■, similarly to the telephone line 13, and sets the reference potential point to the telephone line. In order to make it equal to line 13, there was a drawback that the detection operation would not occur unless it was grounded to the ground.

This invention was made to solve the above problems, and an object of the invention is to provide a tester that does not require earth grounding.

[Means to solve the problem]

The off-talk communication home connection device tester according to the present invention includes a signal input section for manually inputting information corresponding to a plurality of channels, and a first signal switching section connected to the signal input section for selecting the plurality of channels of the signal input section. means, a second switching means for connecting and disconnecting between the in-home connection device and the telephone line, and the first signal switching means;
an incoming call detection circuit that is connected to the telephone line via the photo coupler and detects an incoming signal sent from the exchange to the telephone line and puts the second signal switching means in a disconnected state; a call detection circuit that detects an outgoing signal transmitted from the telephone to the telephone line via the home connection device and puts the second signal switching means in a disconnected state; the first signal switching means; and the second signal switching means. and a channel switching signal detection circuit that is connected to the first signal switching means via a third photocoupler, detects a channel switching signal from the in-home connection device, and switches the selected channel of the first signal switching means.

[Effect]

In this invention, the incoming call detection circuit 1, the outgoing call detection circuit, the channel switching signal detection circuit, etc. are all connected to the telephone line. Second. Since it is connected via the third photocoupler, normal operation can be performed even if there is no earth ground on the tester side.

〔Example〕 Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

40A is an off-talk communication home connection device tester (hereinafter simply referred to as a tester) of the present invention; 41 is a signal input section;
2 is a polarity switching circuit for the telephone line 13, 43 is an incoming call detection circuit, 44 is an outgoing call detection circuit, 45 is a cut relay serving as a second signal switching means, 46 is a channel switching signal detection circuit, and 47 is a first signal detection circuit. A channel switching circuit serving as a switching means, 48 an emergency call circuit, 49 a termination signal circuit, and the rest are the same as in FIGS. 2 and 3. Further, PC1 to PC3 are first to third photocouplers, D is a diode, R is a resistor, C is a capacitor,
RLI is the relay rl, rl is the contact of this relay RL,
RL2 is a relay, rl is its contact, AND is an AND gate, COM is a comparator, and DEL is a delay circuit. Subscripts are added to those necessary for explanation.

The tester 40A has a telephone line 13 and a home connection device 32.
is connected, and signals such as audio are input manually to the signal input section 41.

When the telephone 33 is in a talking state, that is, when the telephone line 13 is in use, a voltage of -48V1 is applied to line L1 of the telephone line 13.
A potential of OV is applied to the line L2. In the incoming call detection circuit 43, the DC component is cut by the capacitor C1, so no current flows through the first photocoupler PC1 for detecting an AC signal in the incoming call detection circuit 43. Therefore, the photocoupler PCI does not operate, and the voltage 1 applied to the resistor R3 is divided by the resistor Ft'3 and then input to one input terminal of the AND gate AND. In addition, in the transmission detection circuit 44, the in-home connection device 32 side is in an electrically open state, and no current flows through the second photocoupler PC2 for detecting an AC signal, so the photocoupler PC2
2 does not operate, and the voltage v2 applied to the resistor R4 is divided by the resistor R4 and inputted to the other input terminal of the AND gate AND. Therefore, and gate AN
Since the surface input of D is at a high level, the output is also at a high level, operating the relay RLI, and the cut relay 45 becomes connected, and the signal input section 41, the home connection device 32, and the telephone line 13 are connected. In this state, the signal input section 4
When information such as audio is transmitted from any channel of 1, it is output to an output device 31 such as a speaker via an in-home connection device 32, and the off-talk communication function can be confirmed.

When there is an incoming call, a 16 Hz signal is sent from the exchange 11 to the telephone line 13. Capacitor C1 of incoming call detection circuit 43
Now, since it is an AC signal, let this 16H2 signal pass,
Photocoupler PCI operates. Therefore, the voltage 1 applied to the resistor R3 flows to the ground via the resistor R3 and the photocoupler Pct, so the AND gate A
The input to ND becomes low level, and the input to ND becomes low level.
The output of D also becomes low level. Therefore, relay RL
The operation of I is restored and the cut relay 45 becomes disconnected. Furthermore, when a call is made from the telephone 33, the telephone line 13 becomes short-circuited, so current flows into the photocoupler PC2 of the call detection circuit 44, operating the photocoupler PC2, and the voltage 2 applied to the resistor R4 increases. resistor R4,
Since a current flows into the ground via the photocoupler PC2, the input to the AND gate AND becomes a low level, and the output of the AND gate AND also becomes a low level. Therefore, the operation of relay RLI is restored and cut relay 45
is in a disconnected state. In this manner, when the telephone line 13 becomes in a call state, the signal input section 41 is disconnected from the home connection device 32 and the telephone line 13. In this state, the signal input section 41
Even if information such as audio is transmitted from any of the channels, it will not be output to the output device 31 such as a speaker.

The channel switching signal from the home connection device 32 is generated by short-circuiting the telephone line 13 to 16 with a high resistance of Ω for about 250 milliseconds. The third photocoupler PC3 of the channel switching signal detection circuit 46 is set in advance to be off at normal voltage depending on the value of the resistor R7, and to operate when a 16Ω resistor is connected in parallel in the circuit. I'll keep it. Therefore, when the channel switching signal is detected, the photocoupler PCB operates and resistor R6
Since the applied voltage (3) causes a current to flow into the ground via the resistor R6, a low level is input to the comparator circuit COM. The low level to the comparator circuit COM is divided into two, one input to the positive terminal of the oP amplifier, and the other input to the negative terminal capacitor C4 via the backflow prevention diode D2 to the positive terminal. Capacitor C4 discharges the electric charge stored in advance by low-level manual input to the negative terminal of the OP amplifier, so the op amplifier compares the magnitude with the signal input to the positive terminal and outputs a high-level signal from its output terminal. Send. The high level sent out from the OP amplifier is passed through a delay circuit to relay RL2 of channel switching circuit 47.
make it work. Thereby, by manually inputting different information to the two inputs CHI and CH2 of the signal input section 41, it is possible to confirm channel switching on the output device 31. Telephone 33
During the period from when the signal is transmitted until the cutter relay 45 operates,
The potential drops for a short period of time, approximately several tens of m5ec, and there is a risk that the photocoupler PCB may malfunction. The delay circuit DEL is designed to remove this signal and pass the channel switching signal, and is an integrating circuit combining a resistor and a capacitor, thereby preventing malfunctions.

The emergency call circuit 48 is for operating the emergency call circuit inside the in-home connection device 32, and is configured to receive, for example, "#°" among the push button dial signals of the telephone 33.

and signals corresponding to "*" are alternately repeated at a cycle of 4 Hz. Similarly, in order to cancel the emergency call circuit 48, signals corresponding to, for example, "C" and "D" are sent out alternately at a 4Hz cycle. The communication end detection circuit of the home connection device 32 is operated by transmitting the signal at the level of 1, and the speaker output ON/OFF circuit inside the home connection device 32 is accordingly activated.

(Effects of the Invention) As explained above, the present invention includes a signal input section into which information corresponding to a plurality of channels is input, and a first signal connected to the signal input section and which selects the plurality of channels of the signal input section. a switching means; a second switching means for connecting and disconnecting between the in-home connection device and the telephone line and the first signal switching means; an incoming call detection circuit that detects an incoming call signal sent to the second signal switching means and puts the second signal switching means in a disconnected state; A transmission detection circuit that detects the transmitted transmission signal and turns the second signal switching means into a disconnected state, and is connected to the first signal switching means and the second signal switching means via a third photocoupler. , and a channel switching signal detection circuit that detects a channel switching signal from the home connection device and switches the selected channel of the first signal switching means, so in the conventional device, grounding was indispensable, but in the present invention, grounding is essential. Since a coupler is used, there is no need for a coupler, and there are no restrictions on use.Also, since the tester of this invention is equipped with all the functions of the center equipment, this unit can be used to connect off-talk communication home connection equipment. It has the advantage of being able to test each function it has.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a tester according to the present invention and its connection with a telephone line and an in-home connection device, and FIGS. 2 and 3 are configuration diagrams of a conventional off-talk communication system. In the figure, 10 is a telephone office, 13 is a telephone line, 30 is a user name, 31 is an output device, 32 is a home connection device, 33 is a telephone, 4OA is a tester, 41 is a signal input section, and 42 is a polarity switching circuit. , 43 is an incoming call detection circuit, 44 is an outgoing call detection circuit,
45 is a cut relay 46 is a channel switching signal detection circuit, 47 is a channel switching circuit, 48 is an emergency call circuit,
49 is a termination signal circuit, Pct is a first photocoupler,
PO2 is a second photocoupler, and PO2 is a third photocoupler. Figure Figure

Claims (1)

[Claims] An off-talk communications home that is inserted between the telephone line and an off-talk home connection device that sends information sent to the telephone line to an output device when the telephone line is not in use, and tests the function of the home connection device. A connection device tester includes a signal input section for inputting information corresponding to a plurality of channels, a first signal switching means connected to the signal input section for selecting a plurality of channels of the signal input section, and the in-home connection device. and a second signal switching means for connecting and disconnecting between the telephone line and the first signal switching means, and a second signal switching means connected to the telephone line via the first photocoupler and sent from the exchange to the telephone line. an incoming call detection circuit that detects an incoming call signal and turns the second signal switching means into a disconnected state; a transmission detection circuit that detects a transmission signal sent to the second signal switching means and disconnects the second signal switching means;
a channel connected to the signal switching means and the second signal switching means via a third photocoupler, detecting a channel switching signal from the in-home connection device and switching the selected channel of the first signal switching means. An off-talk communication home connection device tester characterized by comprising a switching signal detection circuit.