JPH01114250A - Dial pulse receiver - Google Patents

Abstract

PURPOSE:To receive and reproduce a dial pulse via a relay exchange network by detecting a change in the AC impedance of a telephone set and a click sound pulse and deciding the dial pulse. CONSTITUTION:The output signal of the telephone set which generates the dial pulse and the signal of a specified frequency, which has been reflected on the telephone set are inputted to a receiver 7 and a click sound detector 8 through a two-wire/four-wire converter. The receiver decides that the signal strength with the specified frequency, which has been reflected is more than a prescribed value, and the click sound detector 8 detects the click sound pulse which occurs at the rise and fall time of the dial pulse. Next, a decision logic circuit 9 reproduces the dial pulse outputted from the telephone set based on the decided result of the receiver 7 and the detected result of the clock sound pulse detector 8. Thus, the pulse via the relay exchange network can be received and reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is applied to a dial pulse receiver that receives dial pulses from a telephone. In particular, the present invention relates to an end-to-end dial pulse reception system that is used by connecting to trunk lines and subscriber lines via a relay switching network.

〔overview〕

The present invention is applied to a dial pulse receiver, and determines the dial pulse by detecting the change in AC impedance of the telephone when the telephone that generates the dial pulse sends out the dial pulse, and the click sound pulse included in the change point of the dial pulse. By doing so, it was possible to receive and reproduce dial pulses that passed through the relay switching network.

[Conventional technology]

Conventionally, dial pulse receivers are capable of receiving signals only through the subscriber line exchange to which the telephone is directly connected;
It was not possible to receive it via the relay switching network of z.

[Problem that the invention seeks to solve]

However, in such a conventional dial pulse receiver,
In the case of a connection via a relay switching network, a disadvantage that even if the telephone that generates the dial pulse sends information such as its own telephone number as a dial pulse to the other party's terminal, the other party's terminal cannot receive it. was there.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks and aims to provide a dial pulse receiver capable of receiving and reproducing dial pulses transmitted through a relay switching network.

[Means for solving problems]

The present invention provides a dial pulse receiver connected to a telephone that generates dial pulses via a relay switching network.
a transmitter that generates a signal at a specific frequency within the communication band;
The output of this transmitter is connected to the four-wire human power, and the two-wire four-wire converter is connected to the two-wire input/output to the above-mentioned relay exchange network. a receiver that determines that the signal strength of the frequency is greater than or equal to a predetermined value;
A click sound detector that detects click sound pulses generated at the rising and falling edges of dial pulses by manually inputting the four-wire output of the two-wire four-wire converter, and the judgment results of the receiver and the click sound detector. and a determination logic circuit that reproduces a dial pulse output from the telephone based on the detection output of the telephone.

[Effect]

A transmitter generates a signal at a specific frequency in the communication band and outputs it to the relay switching network via a two-wire/four-wire converter.

The output signal of the telephone that generates the dial pulse and the signal of a particular frequency reflected by the telephone are input to the receiver and the click detector through a two-wire and four-wire converter. It is determined that the signal strength of a specific frequency reflected by the receiver is greater than or equal to a predetermined value, and the click sound detector detects the click sound pulses generated at the rise and fall of the dial pulse. The determination logic circuit reproduces the dial pulse output from the telephone based on the determination result of the receiver and the detection result of the click sound pulse detector. Through the above operations, dial pulses via the relay switching network can be received and reproduced.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram of a dial pulse receiver according to an embodiment of the present invention. FIG. 2 is a block diagram of a telephone communication network including the dial pulse receiver of the present invention. In FIG. 2, the output of the rotary dial telephone 14 is the subscriber line 15.
, subscriber exchange 10° trunk exchange 11.1 trunk exchange 1
1□ is connected to the input of the computer 13 via the subscriber exchange 102, the subscriber line answering machine 12 and the dial pulse receiver 3.

In FIG. 1, a dial pulse receiver 3 has an input terminal 1 connected to the output of a rotary dial type telephone 14 via a relay switching network, and a specific frequency f within a communication band of 300 Hz to 3400 Hz. A sine wave transmitter 6 that generates a sine wave signal of a constant level, and the output of the sine wave transmitter 6 are connected to a four-wire human power source, and a relay switching network is connected to the two-wire input/output via the input terminal 1. A hybrid transformer 4 that is a two-wire/four-wire converter, a termination circuit 5 connected to the hybrid transformer 4 to realize a termination impedance, and a four-wire output of the hybrid transformer 4 as human power at a specific frequency f.

A sine wave receiver 7 that determines that the signal strength of the dial pulse is equal to or higher than a predetermined value, and a click sound that detects click sound pulses generated at the rise and fall of dial pulses by manually inputting the four-wire output of the hybrid transformer 4. Detector 8 , a determination logic circuit 9 that reproduces dial pulses output from the telephone based on the determination result of the sine wave receiver 7 and the detection output of the click sound detector 8 , and a computer 13 that outputs the output of the determination logic circuit 9 . The output terminal 2 is provided with an output terminal 2 to provide a signal to the output terminal.

The operation of the dial pulse receiver having such a configuration will be explained. FIG. 3 is an explanatory diagram of the operation of the dial pulse receiver of the present invention.

In FIG. 2, it is assumed that a call path has now been established via the telephone communication network, and when the dial is further turned, dial pulses flow from left to right in FIG. That is, dial pulses emitted from the telephone set 14 are transmitted via the subscriber line 15 to the subscriber line exchange 10. ．． 102 and
The signal is input to the subscriber line transponder 12 via a relay switching network consisting of relay exchanges 111 and 112. The subscriber line answering device 12 detects a calling signal sent from the subscriber line exchange 102 in the process of establishing a call path, and forms a DC loop.
During a call, the DC component of the signal is removed and only the AC component is output to the dial pulse receiver 3. Of the paths from the telephone set 14 to the dial pulse receiver 3, the dial pulse is generally transmitted in the form of impulses from the telephone set 14 to the subscriber line exchange 10□ to which the subscriber line 15 is connected. It is between. The subsequent relay switching network transmits only the damped oscillation type AC component, that is, the click sound pulse, generated at the change point of the dial pulse, and inputs it as it is to the dial pulse receiver 3.

On the other hand, the dial pulse repeats a short circuit state when the dial pulse contact is made and an open state when the dial pulse contact breaks according to the dialing operation of the telephone 14. In addition, in the short-circuit state and the open state, the AC impedance of the telephone set 14 seen from the subscriber line 15 side is significantly different from 200Ω to 2Ω, respectively, and the signal input from the subscriber line 15 to the telephone set 14 is returned to the subscriber line line 15. I'll be back at 15. The reflection coefficients of so-called AC signals also differ greatly. This reflection is small in a short circuit state and large in an open state.

Next, the operation will be explained with reference to FIGS. 1 and 3. FIG. 3(a) shows the state of the telephone 14 when sending a dial pulse, FIG. 3(b) shows the change in AC impedance of the telephone 14 when sending a dial pulse, and FIG. 3(C)
is the frequency f reflected by the telephone 14, corresponding to FIG. 3(b). FIG. 3(b) shows a change in the waveform of the click sound pulse input to the dial pulse receiver 3 corresponding to FIG. 3(a).

At time T in FIG. 3, the telephone 14 is in an open state and the frequency f is output from the sine wave transmitter 6. The sine wave passes through the hybrid transformer 4 and reaches the telephone 14 from the input terminal 1, is reflected there, returns to the input terminal 1 again, passes through the hybrid transformer 4, and is input to the sine wave receiver 7. The sine wave receiver 7 receives the reflected frequency f.

Since the amplitude of the sine wave is large, it is determined that there is "reflection".

On the other hand, the click sound detector 8 determines that there is "no click".

At the next time T2, as the dial pulse rises, the telephone 14 changes to a short circuit state, the reflection of the sine wave becomes small, and the sine wave receiver 7 determines that there is no reflection, and the click sound detector 8, it is determined that "click sound is present". Judgment logic circuit 9 based on two pieces of information: “no reflection” and “click sound present”
can recognize the rising edge of the dial pulse.

At time T3, the telephone 14 changes to the open state as the dial pulse falls, the sine wave receiver 7 determines that there is a "reflection," and the click sound detector 8 determines that there is a "click sound."
Judgment is made again. 2: “With reflection” and “With click sound”
From the information, the decision logic circuit 9 can recognize the falling edge of the dial pulse. In this way, the rising and falling edges of the dial pulse are detected from two states: "no reflection" and "click sound" and "reflection" and "click sound", and in other states, it is determined that there is no change in the dial pulse. By making this determination, the dial pulse sent from the telephone 14 can be reproduced and output to the output terminal 2.

Furthermore, since it does not have timer logic, it can receive data from either 10 pps or 20 pps telephones.

〔Effect of the invention〕

As explained above, the present invention has the excellent effect of being able to receive and reproduce dial pulses via a relay switching network.

This has the advantage that conversations with computers, which were conventionally allowed only through voice signal dialing, can also be done with rotary dial telephones.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a dial pulse receiver according to an embodiment of the present invention. FIG. 2 is a block diagram of a telephone communication network including the dial pulse receiver of the present invention. FIG. 3 is an explanatory diagram of the operation of the dial pulse receiver of the present invention. 1... Input terminal, 2... Output terminal, 3... Dial pulse receiver, 4... Hybrid transformer, 5...
... Termination circuit, 6... Sine wave transmitter, 7... Sine wave receiver, 8... Click sound detector, 9... Judgment logic circuit, 101.102... Subscriber line exchange , 111.
112... Trunk exchange, 12... Subscriber line response device,
13...Computer, 14...Rotary dial telephone, 15...Subscriber line.

Claims (1)

[Claims] (1) In a dial pulse receiver connected to a telephone that generates dial pulses via a relay switching network, there is a transmitter that generates a signal at a specific frequency within the speech band, and the output of this transmitter is a four-wire input. and a two-wire/four-wire converter connected to the two-wire input/output to which the above-mentioned relay switching network is connected; a click sound detector that receives the four-wire output of the two-wire four-wire converter and detects click sound pulses generated at the rising and falling edges of the dial pulse; 1. A dial pulse receiver comprising: a determination logic circuit that reproduces a dial pulse output from the telephone based on the determination result of the click sound detector and the detection output of the click sound detector.