JPH1141633A - Dial pulse detection method and dial pulse detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dial pulse detection method and dial pulse detector by which an accurate dial pulse digit is recognized even when a dial pulse has chattering. SOLUTION: A rising of a dial pulse is detected and an MPU discriminates a level of the dial pulse at a time when the 1st prescribed time elapses (step 100). When it is discriminated that the dial pulse has a prescribed level, that is, is in a break state, a dial digit detection timer is made start (step 110), and a dial pulse count is incremented by '1' simultaneously. This is repeated for each input of the dial pulse and when the rising of the dial pulse is not detected within the 2nd prescribed time from start of the dial digit detection timer, the dial pulse count at that time is decided as the dial digit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the detection of a signal for identifying a telephone number on a telephone line, and more particularly to the improvement of the reliability and versatility of dial digit detection on a dial pulse type telephone line. The present invention relates to a dial pulse detection method and a dial pulse detection device.

[0002]

2. Description of the Related Art In a telephone line, a pulse signal corresponding to a dial number (dial digit) generated from a telephone is typically used as a conventional method for detecting a dial pulse. The dial pulse is sampled at a predetermined time interval shorter than the cycle of the above, a count is performed each time a signal of a predetermined pulse width is detected, and a timer for a predetermined time for detecting the end of dial pulse transmission is provided. In some cases, the end of transmission of the dial pulse, that is, the end of the dial digit is detected, and the transmitted dial digit is determined based on the count result.

[0003]

However, in the above-mentioned prior art, the detection operation is performed by using a sampling signal having a frequency at least four times as high as the repetition frequency of the dial pulse because of the restriction by the sampling theorem. Must be done. This is a condition when the so-called break / make ratio (in other words, the duty ratio) of the dial pulse is 50%, and when the break / make ratio is smaller than this, the viewpoint of securing the detection accuracy. Therefore, it becomes necessary to further increase the sampling frequency by 8 times and 16 times.

Incidentally, in various processes such as detection of a dial pulse in a telephone line, a so-called M
An element for arithmetic processing represented by a PU (Micro Processor Unit) is used. Usually, such dial pulse detection and other various processing are performed using a common MPU. For this reason, as described above, only the dial pulse detection requires an MPU having a higher processing capability than other processes, which leads to an increase in the price of the device.

As a measure against such a demand for high processing capability, a dedicated MPU for dial pulse detection is provided.
For processing other than dial pulse detection that does not require much processing power, MP processing with relatively low processing power is used.
U has been proposed, and the processing capability has been improved by increasing the operating frequency of the MPU, and has been actually implemented. Because of the increasing demands described above, conventional measures cannot meet the demands, and more efficient and reliable measures have been required.

[0006] As a measure to solve such a problem,
For example, when a dial pulse interrupt occurs, a timer for a predetermined time is provided for counting the interrupt and detecting the end of dial pulse transmission, thereby ending the dial pulse transmission, that is, ending the dial digit. And a method of determining the transmitted dial digit based on the count result at the end of the dial digit has been proposed and put to practical use, but has the following problems.

That is, in this method, the telephone does not cause so-called chattering when a dial pulse is generated, and there is no problem when the dial pulse is directly transmitted from such a telephone. However, for example, when a dial pulse is transmitted via a MODEM (modulator / demodulator), a commonly used MO
DEM is apt to cause chattering in dial pulses,
For this reason, there has been a problem that the counting of the interrupt of the dial pulse is erroneously performed, and as a result, a correct dial digit cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a dial pulse detecting method capable of accurately detecting a dial digit without erroneous counting even if the dial pulse involves chattering. And a dial pulse detection device.

Another object of the present invention is to provide a versatile method capable of reliably detecting a dial digit even with various dial pulses transmitted from various telephones having different dial pulse speeds and break / make ratios. A dial pulse detection method and a dial pulse detection device are provided.

Another object of the present invention is to enable a dial pulse to be detected by changing a relatively small number of parameters even when the dial pulse speed and the break / make ratio are different. A pulse detection method and a dial pulse detection device are provided.

[0011]

According to a first aspect of the present invention, there is provided a dial pulse system in which a number of dial pulses corresponding to a dial digit of a telephone are serially output. A method for detecting a dial pulse in a telephone line, comprising determining a dial pulse level after a first predetermined time has elapsed from a rise of the dial pulse, and increasing the dial pulse count value by 1 when the dial pulse is at a predetermined level. Is repeated each time a dial pulse is input, and when it is determined that the level of the dial pulse is not at the predetermined level after a second predetermined time has elapsed from the rise of the dial pulse, the input of the dial pulse is terminated. As the dial digit using the dial pulse count value at that time. It is made in the.

In such a configuration, the level of the dial pulse is determined after a lapse of a predetermined time from the detection of the rising edge of the dial pulse, and counting is performed when the dial pulse is at the predetermined level. Counting does not occur, and thus, unlike the related art, the dial pulse can be reliably detected.

According to a third aspect of the present invention, there is provided a dial pulse type telephone line in which a number of dial pulses corresponding to a dial digit of a telephone are serially output. A level determining means for determining whether or not the dial pulse is at a predetermined level after a first predetermined time has elapsed from the rise of the dial pulse; and Counting means for counting when it is determined that the dial pulse is at the predetermined level, and unless the dial pulse is again determined to be at the predetermined level by the level determining means within a second predetermined time from the rise of the dial pulse. ,
Operation control means for stopping the operations of the level determining means and the counting means when the second predetermined time is reached.

The dial pulse detecting device having such a configuration is suitable for executing the dial pulse detecting method according to the first aspect of the present invention. For example, the level detecting means, the counting means, and the operation control means are constituted by a so-called MPU. It can be realized by software processing by a computer.

According to a fourth aspect of the present invention, there is provided a dial pulse detecting apparatus according to the third aspect of the present invention, wherein the second level is selected in advance according to a dial pulse speed. A parameter storage means in which the predetermined time is stored, the operation control means, when starting the operation,
A second predetermined time corresponding to the dial pulse speed is read out from the storage means based on data concerning the dial pulse speed input from the outside, and is set internally.

In such a configuration, for example, by providing parameter storage means capable of reading data stored in advance, such as a ROM, it is possible to detect various dial pulse speeds.
The required data can be read, dial pulse detection at various dial pulse speeds can be performed, and versatility is improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that the members, arrangements, and the like described below do not limit the present invention,
Various modifications can be made within the scope of the present invention. First, the configuration of the dial pulse detection device (the present dial pulse detection device) according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a configuration diagram illustrating a configuration example of a dial pulse detection device according to an embodiment of the present invention.

The dial pulse detecting device includes an MPU 1 for controlling the operation of the entire device as described later, and the like.
A pulse rising detection circuit 2 for detecting a rising of a dial pulse, a chatter time monitoring timer 3 having a function as a chattering monitoring timer, a dial digit detection timer 4 for detecting the end of dial digit, R for the parameter in which the parameter is stored
OM5.

Upon detecting the rising of the dial pulse input from the outside, the pulse rising detecting circuit 2
A predetermined detection signal is output to U1. At the same time as the MPU 1 receives the detection signal from the pulse rising detection circuit 2, the reset signal output to the pulse rising detection circuit 2 causes the dial pulse to be output again. Is configured to be in a state where the rise of the signal can be detected.

The chatter time monitoring timer 3 is output from the MPU 1 to the chatter time monitoring timer 3 to start the timer at the same time as the start signal from the MPU 1, that is, the MPU 1 detects the above-mentioned detection signal from the pulse rise detection circuit 2. Timer operation is started by the start signal
After a lapse of a predetermined time, the timer operation is terminated. More specifically, it is configured such that a chatter time monitoring timer signal of a predetermined level is output to the MPU 1 during a first predetermined time from the rising of the dial pulse.

When the MPU 1 determines that a regular rising of a dial pulse has occurred under a predetermined condition as described later, the dial digit detection timer 4
The timer operation is started in response to the start signal from the timer 1 and the timer operation is terminated when the transmission of the dial pulse ends when a second predetermined time has elapsed from the rise of the dial pulse. Before the end of the operation, the rise of the regular dial pulse is detected,
When the start signal is input again by the MPU1, the timer operation is continued, and a dial digit detection timer signal of a predetermined level is output to the MPU1 during the timer operation. I have. still,
It is preferable that the above-mentioned predetermined time for defining the timer operation time is usually set to a time in which a possible deviation is added to the length of one cycle of the dial pulse.

The parameter ROM 5 stores a time defining the timing at which the dial digit detection timer 4 stops outputting the dial digit detection timer signal as a time from the rise of the dial pulse in accordance with various dial pulse speeds. It is stored in advance. Which time is read by the MPU 1 and set in the dial digit detection timer 4 via the MPU 1 is determined beforehand by the dial pulse detecting device before the operation starts.
It is determined by designating the speed of the dial pulse to PU1. The RO used here
M need not be limited to a specific type, and various types such as PROM, EPROM, and EEPROM can be used.

Next, the operation of the above configuration will be described with reference to FIGS. FIG. 2 is a subroutine flowchart showing a procedure of dial pulse detection performed by the dial pulse detection device, and FIG.
FIG. 4 is a timing chart of signals in a main part of the dial pulse detection device. First, as a precondition, the speed of a dial pulse input to the dial pulse detection device is 10
pps and the first in the chatter time monitoring timer 3.
The so-called timer time (in other words, the time during which the chatter time monitoring timer signal is output) as the predetermined time is 4 m
In s, the so-called timer time (in other words, the time when the output of the dial digit detection timer signal ends) as the second predetermined time in the dial digit detection timer 4 is:
It is assumed that each is set in advance to 120 ms.

A telephone or MOD (not shown)
For example, it is assumed that a dial pulse corresponding to “2” is output from the EM as a dial digit and is input to the pulse rise detection circuit 2.

Under such a premise, the pulse rising detection circuit 2
For example, as shown in FIG. 3A, it is assumed that a dial pulse accompanied by so-called chattering is input after the fall of the dial pulse.

The rising of the first dial pulse is detected by the pulse rising detection circuit 2 and the detection signal is MP
When the signal is output to U1, the MPU 1 enters a state of accepting an interrupt, and first outputs a reset signal to the pulse rising detection circuit 2, whereby the pulse rising detection circuit 2 detects the rising of the dial pulse again. State.

At the same time, the MPU 1 outputs an activation signal to the chatter time monitoring timer 3, whereby the timer operation of the chatter time monitoring timer 3 is started. For example, as shown in FIG. As described above, the chatter time monitoring timer signal is output for a predetermined time (for example, 4 ms here) from the rise of the dial pulse.

When the output of the chatter time monitoring timer signal by the chatter time monitoring timer 3 ends after a lapse of a predetermined time, the falling of the chatter time monitoring timer signal causes an interrupt in the MPU 1 and the dial digit detection timer 4 In response, a start signal is output. As a result, when the dial digit detection timer 4 is started, the subroutine processing for dial pulse detection shown in FIG. 2 is started.

When the subroutine processing for dial pulse detection is started, first, the level of the dial pulse is determined (see step 100 in FIG. 2). That is, the dial pulse has a predetermined level state corresponding to the logical value High, in other words, a break state (FIG. 3).
(See FIG. 3A) or a predetermined level state corresponding to the logical value Low, in other words, whether it is in the Make state (see FIG. 3A).
If the dial pulse is the first one at the left end in FIG. 3A, it is determined that the level of the dial pulse is in the break state.

In this case, it is assumed that chattering does not occur at least in the vicinity of the rising edge of the dial pulse and the dial pulse is input at a normal level, and the dial digit detection timer 4 is started by the MPU 1 and the dial digit detection timer 4 is started. (See step 110 in FIG. 2), dial pulse counting is performed (see step 120 in FIG. 2).

That is, the dial digit detection timer 4
, The operation of the dial digit detection timer 4 is started substantially in synchronization with the fall of the chatter time monitoring timer signal, and the dial digit detection timer signal rises (see FIG. 3D).

At the same time, as the dial pulse count value Dc, a value obtained by adding "1" to the previous value of Dc is set as a new count value Dc. Note that Dc is
Since it is set to zero by the initial setting, in the count of the first dial pulse, Dc = 0 + 1 =
It becomes 1. The count value is stored in, for example, a temporary storage area (not shown) of the MPU 1.

The above-described dial pulse counting operation is performed by M
This is performed by so-called software processing by the PU1, and in FIG. 3C, for convenience, every time the dial pulse count is performed as described above,
Although a pulse is shown as generated, the pulse is not actually output to the outside.

After the dial pulse count is performed for the first dial pulse in this way, a series of subroutine processing is terminated, and the process returns to the main routine (not shown). Then, when the rising of the dial pulse is detected again by the pulse rising detection circuit 2, in the same manner as described above, after the elapse of the output period of the chatter time monitoring timer signal from the rising,
The subroutine processing shown in FIG. 2 is repeated again.

For example, as shown in FIG. 3A, it is assumed that the rise of chattering after the first dial pulse (the leftmost dial pulse in FIG. 3) is detected by the pulse rise detection circuit 2. .

Even in such a case, the operation until the subroutine processing shown in FIG. 2 is performed is exactly the same as the case where the normal dial pulse is input as described above. That is, when the rise of chattering is detected, an interrupt to the MPU 1 occurs,
By U1, the chatter time monitoring timer 3 starts the timer operation, and after a lapse of a predetermined time, the subroutine processing shown in FIG. 2 is started.

When the subroutine process is started, the dial pulse level is determined (step 10 in FIG. 2).
0), as shown in FIGS. 3A and 3B, when the length of the dial pulse in the chattering state is shorter than the chatter time monitoring timer signal, Is completed, the dial pulse level is determined to be in the make state. As a result, a series of subroutine processes are immediately terminated without dial pulse counting, and the process returns to the main routine (not shown). Becomes

Thereafter, the same processing is performed every time a rising edge of the dial pulse is detected. In the case of the example shown in FIG. 3, the dial pulse count value Dc is changed to "2" by the second regular dial pulse. 2 ". Thereafter, even if the rising of the dial pulse occurs due to chattering, the count value Dc does not change, and the output of the dial digit detection timer signal ends 120 ms after the rising of the first dial pulse (see FIG. 3D). ,
At this point, the dial pulse count value Dc is determined to be "2", and a series of processes is temporarily terminated assuming that the dial digit "2" is detected.

In the embodiment of the invention described above,
Although the pulse rise detection circuit 2, the chatter time monitoring timer 3, and the dial digit detection timer 4 have been described as being provided as so-called hardware separate from the MPU1, it is not always necessary to use hardware separate from the MPU1. It doesn't have to be, for example, MP
The function of the pulse rise detection circuit 2, the chatter time monitoring timer 3, and the dial digit detection timer 4 may be realized by software processing by U1.

In the embodiment of the invention described above, the MPU 1 executes the pulse rising detection circuit 2, the chatter time monitoring timer 3, and the step 100 by the MPU 1.
, The counting means by the execution of step 120 by the MPU 1, the operation control means by the execution of step 110 by the MPU 1 and the dial digit detection timer 4, and the operation of the parameter RO by the MPU 1.
M5 implements parameter storage means.

[0041]

As described above, according to the present invention,
After a lapse of a predetermined time from the rise of the dial pulse, the dial pulse count is advanced when the dial pulse is at the predetermined level. Therefore, unlike the related art, it is possible to accurately determine the dial digit, and it is possible to improve the reliability.

In particular, in the dial pulse detecting apparatus according to the fourth and fifth aspects of the present invention, in addition to the effects of the above-described invention, a parameter storing means is provided, so that dial dials at various dial pulse speeds are provided. Pulse detection becomes possible, and there is an effect that a highly versatile device can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration example of a dial pulse detection device according to an embodiment of the present invention.

FIG. 2 is a subroutine flowchart showing a procedure of dial pulse detection performed by the dial pulse detection device shown in FIG.

FIG. 3 is a timing chart of signals in a main part of the dial pulse detection device shown in FIG. 1, and FIG.
FIG. 3B is a timing chart showing an input example of a dial pulse corresponding to the dial digit pulse 2, and FIG.
FIG. 3C is a timing chart showing the output timing of the chatter time monitoring timer signal. FIG. 3C is a timing chart showing the dial pulse count timing.
(D) is a timing chart showing the output timing of the dial digit detection timer signal.

[Explanation of symbols]

1: MPU, 2: Pulse rising detection circuit, 3: Chatter time monitoring timer, 4: Dial digit detection timer, 5: Parameter ROM

Claims (5)

[Claims] 1. A method for detecting a dial pulse in a telephone line of a dial pulse system in which a number of dial pulses corresponding to a dial digit of a telephone are serially output, comprising:
After the elapse of a predetermined time, the level of the dial pulse is determined, and when the dial pulse is at the predetermined level, the increment of the dial pulse count value by 1 is repeated every time the dial pulse is input, while the second predetermined time from the rising of the dial pulse. After a lapse of time, if it is determined that the dial pulse level is not at the predetermined level, it is determined that dial pulse input has been completed and the dial pulse is determined using the dial pulse count value at that time as a dial digit. Pulse detection method. 2. The dial pulse according to claim 1, wherein the second predetermined time is longer than the first predetermined time, and is a value obtained by adding a predetermined time deviation to one cycle of the dial pulse. Detection method. 3. A dial pulse detecting device for detecting a dial pulse in a dial pulse type telephone line in which a number of dial pulses corresponding to a dial digit of a telephone are serially output, the dial pulse detecting device comprising: Level determining means for determining whether or not the dial pulse is at a predetermined level after a predetermined time of 1, counting means for counting when the dial pulse is determined to be at a predetermined level by the level determining means, Unless the dial pulse is again determined to be at a predetermined level by the level determining means within a second predetermined time from the rising of the dial pulse, the level determining means and the level determining means when the second predetermined time is reached, Operation control means for stopping the operation of the counting means. Dial pulse detector. 4. A method according to claim 1, further comprising a parameter storing means for storing a second predetermined time selected in advance in accordance with a speed of the dial pulse. 4. A dial pulse detecting apparatus according to claim 3, wherein said second predetermined time corresponding to said dial pulse speed is read out from said storage means based on data relating to the dial pulse speed, and is internally set. 5. The dial pulse according to claim 4, wherein the second predetermined time is longer than the first predetermined time, and is a value obtained by adding a predetermined time deviation to one cycle of the dial pulse. Detection device.