JPH0486093A - Dial pulse reception equipment - Google Patents

Abstract

PURPOSE:To perform detection and reception with high accuracy by deciding whether or not two waveforms are set line symmetrically, and identifying the reception of a dial pulse with a dial pulse discrimination circuit. CONSTITUTION:When the dial pulse is sent from a terminal on one side to the one on the other side after the speech state of the terminals is set via an exchange, a transmission waveform is inverted at the break start/end point of the dial pulse at the terminal on the other side at a reception side, and line symmetric data is inputted to the dial pulse discrimination circuit 11. The dial pulse discrimination circuit 11 confirms the reception of the dial pulse after receiving the two output of a break timer 7 and a comparator 10, and performs the count operation of a counter 4. Thereby, it is possible to reduce erroneous recognition to the extent that the dial pulse can be handled as communication information.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a dial pulse receiving device that performs communication of dial pulses as selection signals in addition to telephone calls and modem signals in voice band communication of a communication network. be.

[Conventional technology]

FIG. 3 shows a conventional dial pulse receiving device. In the figure, 1 is a threshold detection circuit that distinguishes between a normal audio signal and an excessive signal, and 2 has the same function as the threshold detection circuit 1. A threshold detection circuit with a smaller threshold than this,
3 is a dial pulse which is determined to be a dial pulse by measuring the time interval between the threshold detection signals from the threshold detection circuits 1 and 2 and the time interval until the signals from each threshold detection circuit 1 and 2 arrive. A timer 4 outputs a reception signal, a counter 4 counts the dial pulse reception signal from the timer 3 and sends out the count data, and a data latch 5 holds the count data from the counter 4.

Next, the operation will be explained. A voice band signal input from a communication network enters threshold detection circuits 1 and 2. When this audio band signal is received by dial pulse, the threshold detection circuits 1 and 2 are first affected by the first pulse-like excessive signal.
both inform timer 3 of the detection of this excessive signal. Next, the next pulse occurs approximately 17m5 after the pulse that is this excessive signal, and if threshold detection circuit 1 does not respond to this pulse and only threshold detection circuit 2 responds, at this point , the timer 3 determines that the dial pulse has been received, and operates the counter 4. Also, the timer 3 measures the time until the next detection signal comes from the threshold detection circuits 1 and 2, and if it is in the range of 40m5 to 60m,
It is determined that a dial pulse has been received, and this is counted by the counter 5. Similarly, when timer 3 determines that a dial pulse has been received, counter 4
count the dial pulses.

On the other hand, if there is no dial pulse for 200 m5 or more, the timer 3 determines that the transmission of dial pulses has ended or that there is an inter-digit pause, and notifies the counter 4 of this fact. When the timer 3 is in the dial pulse receiving state, the counter 4
Clears the count value for , so that it can be counted from the beginning. Further, when the counter 4 receives a signal from the timer 3 indicating the end of the dial pulse, it sends the count data counted up to that point to the data latch 5. The data latch 5 holds the data,
If data is requested from outside, it will be output.

[Problem to be solved by the invention]

Since the conventional dial pulse receiving device is configured as described above, it is necessary to distinguish between a dial pulse signal and a voice signal only by the voltage level of the received signal.
Even if this received signal is not a dial pulse, a loud voice that exceeds the threshold voltage of each threshold detection circuit 1, 2 or the sound of tapping the handset can easily be mistaken as a dial pulse input. There was an issue.

This invention has been made to solve the above-mentioned problems, and in a communication mode in which a 1 selection signal is also treated as communication information, when a dial pulse is treated as communication information,
It is an object of the present invention to obtain a dial pulse receiving device that can reduce the above-mentioned erroneous recognition to the extent that it can withstand actual operation.

[Means to solve the problem]

A dial pulse receiving device according to the present invention includes a threshold detection circuit that detects whether an audio band signal input from a terminal device is a normal audio signal or an excessive signal exceeding a predetermined threshold; A timer that measures the time until the dial pulse reaches the start time and determines whether it is the make time, break time, or pause time of the dial pulse, a memory that stores the above audio band signal, and the waveform of the break start signal stored in this memory and input. a comparator that compares the break end waveform of the audio band signal to determine whether or not these two waveforms are line symmetrical; and a dial pulse discriminator for identifying reception of dial pulses based on the break time of the dial pulse.

The dial pulse identification reception signal outputted from this dial pulse identification device is counted by a counter, corresponding count data is outputted, and the count data from this counter is held in a data latch.

[Effect]

In the dial pulse receiving device of the present invention, a dial pulse (square wave) sent out from a terminal device is connected to a break start waveform and a break start waveform at a break start portion and a break end portion of the dial pulse in a DC separation circuit for input to an exchange, etc. By taking advantage of the line symmetry between the end waveform and the end waveform, dial pulses can be distinguished from other signals, and threshold detection can be performed using the level difference between the normal audio signal and the break start/end waveform. By monitoring the received signal in conjunction with measuring the break/make/pause times, it functions to significantly reduce the rate of misidentification of excessive signals other than dial pulses.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, IA is a threshold detection circuit, 4 is a counter,
5 is data latch, 6 is dial pulse make (connection)
7 is a break timer that measures the dial pulse break time; 8 is a pause timer that measures the pause time between pulse trains; 9 is a memory that stores the input audio band signal; 10 is a make timer that measures time; a comparator that compares the signal once stored in the memory 9 with the input signal;
11 determines the reception of the dial pulse and the end of sending out the dial pulse based on the information from the make timer 6, break timer 7, pause timer 8, and comparison lead timer 0.
This is a dial pulse discriminator that performs counting operations and clears count values.

Next, the operation will be explained.

First, a voice band signal input from a communication line is monitored by a threshold detection circuit IA to see if it exceeds a threshold voltage. When an excessive signal exceeding the threshold voltage of the threshold detection circuit IA is input, the break timer 7 operates and starts measuring the time until the next excessive signal is input. At the same time, the memory 9 stores this input signal until a time (for example, 10 m5) that can accommodate the start of the next break in a time shorter than the make time. after that,
Break timer 7 has a break time of 20 pps (approximately 3
4m5), monitors whether the threshold detection circuit IA reacts, that is, whether there is an input that exceeds the threshold voltage, and ignores the reaction of the threshold detection circuit IA that occurs within the above break time. do. If there is no response during that break time, the break timer 7 automatically switches the monitoring time to a break time of 10 pps (approximately 67 m5).

Also, if there is a reaction during that break time.

This is notified to the dial pulse discriminator 11. Furthermore, the comparator 1 compares the input waveform with the waveform stored in the memory 9 from the time when the threshold detection circuit IA reacts to the break time.
Start comparing by 0. As a result, if these two waveforms are axisymmetric, the comparator 10 notifies the dial pulse discriminator 11 of this fact. In other words, after the terminals enter a conversation state via the exchange, when a dial pulse is sent from one terminal to the other terminal, at the break start/end point of the dial pulse on the other terminal side on the receiving side, Transmission waveform is inverted (line symmetry centered around -7,65V)
This line target data is used by dial pulse discriminator 1.
1 is input. Therefore, the dial pulse discriminator 11 assumes that a dial pulse is received only after receiving the two outputs from the break timer 7 and the comparator 10, and causes the counter 4 to perform a counting operation. On the other hand, when the threshold detection circuit IA reacts to the above-mentioned excessive signal at the break time, it monitors whether there is a response at the make time (17 m5 at 20 pps, 34 m5 at 10 pps), and if so, sends it to the dial pulse discriminator 11. If not notified, the pause timer 8 outputs a signal to the dial pulse discriminator 11. When the dial pulse discriminator 11 receives a signal from the make timer 6, it determines that the end of the dial pulse has not yet been reached, and operates the counter 4 to count each time there is a dial pulse reception sequence, and when it receives a signal from the pause timer 8, the dial pulse discriminator clear counter 4, assuming that it is the break of
Furthermore, the count value at that time is sent to the data latch 5.

In the above embodiment, the threshold detection circuit IA, the make timer 6, the break timer 7, the pause timer 8, and the comparator 1
0, dial pulse discriminator 11, and counter 4 are configured separately, but as shown in FIG. 2, an analog/digital converter (linear encoder P
12 of the CM system, and configured so that the microprocessor 13 receives the signal, and each of the two functions described above may be realized by software, which can reduce the number of parts used. Functionality can be made more flexible.

〔Effect of the invention〕

As described above, according to the present invention, the threshold detection circuit detects whether an audio band signal input from a terminal device is an excessive signal exceeding a predetermined threshold value than a normal audio signal, and receives the excessive signal. The timer circuit determines whether this corresponds to the make time, break time, or pause time of the dial pulse, and the waveform of the break start signal stored in the memory and the break of the input audio band signal are measured. The end waveform is compared with the comparator to determine whether or not these two waveforms are line symmetrical. If the two waveforms are line symmetrical, the dial pulse is set based on the break time from the timer. The dial pulse discriminator is configured to identify the reception of the dial pulse, so it is possible to clearly distinguish between dial pulses and excessive signals generated by dropping the handset, etc., and to detect the desired dial pulses with high precision. There is an effect that what can be received can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a dial pulse receiving device according to one embodiment of the present invention, FIG. 2 is a block diagram of a dial pulse receiving device showing another embodiment of the present invention, and FIG. 3 is a block diagram showing a dial pulse receiving device according to another embodiment of the present invention. FIG. 2 is a block diagram showing the device. IA is a threshold detection circuit, 3 is a timer, 4 is a counter,
5 is a data latch, 6 is a timer (make timer), 7 is a timer (break timer), 8 is a timer (pause timer), 9 is a memory, 10 is a comparator, and 11 is a dial pulse discriminator. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A threshold detection circuit detects whether the audio band signal input from the terminal equipment is a normal audio signal or an excessive signal exceeding a predetermined threshold, and a threshold detection circuit that measures the time until the above excessive signal is received, and this is the dial pulse. a timer for determining one of the make time, break time, and pause time; a memory for storing the audio band signal; a waveform of the break start signal stored in this memory; and a break end waveform of the audio band signal to be input. a comparator that compares the two waveforms and determines whether or not these two waveforms are line symmetrical; and a comparator that determines whether or not these two waveforms are line symmetrical; A dial pulse discriminator for identifying a dial pulse discriminator, a counter for counting a dial pulse discriminating reception signal outputted by this dial pulse discriminator and outputting corresponding count data, and a data latch for holding count data from this counter. Dial pulse receiver.