JPS60117860A - Signal tone detecting system of pseudo call system - Google Patents

Abstract

PURPOSE:To attain accurately signal tone detecting processing even in the presence of malfunction of a signal detection circuit or noise from a telephone exchange by discriminating it as the reception of a signal tone when the interval of the signal tone is correct during a prescribed period of the signal tone from the telephone exchange. CONSTITUTION:A signal detecting circuit 9 detects a frequency of a signal tone from a telephone exchange and generates a signal changing in response to the peak and hollow of the signal tone. A sampling circuit 10 samples this signal and a periodic counter 11 counts an output of the circuit 10 corresponding to the peak and hollow of the signal. A divider circuit 12 operates the peak and hollow in an output of the periodic counter 11. A number of times counter 13 counts the number of times of repetition of the signal tone at the same time. A discrimination circuit 14 dicriminates whether or not the result of operation of the division circuit 12 is coincident with a prescribed value and discriminates it as the detection or no detection of the signal depending whether the coincidence of the number of times of repetition of the number of times counter 13 is detected or not within a prescribed number of times.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a signal tone detection method in a pseudo call system for functionally verifying the switching operation of a telephone exchange.

Prior Art and Problems A pseudo call system is connected to a telephone exchange via a channel interface, generates a simulated situation in which a call to the exchange occurs, and detects the signal sent from the telephone exchange based on this simulated situation. By doing so, the functionality of the switching operation of the telephone exchange is verified.

FIG. 1 shows a telephone call generation system in a telephone exchange. In the figure, reference numeral 1 denotes a pseudo call testing device, which is connected to a telephone exchange 4 together with a subscriber telephone 2 via a terminal board 6. The pseudo call test device 1 has a pseudo call generation circuit 5, which generates a pseudo call to the telephone exchange 4 by performing an operation similar to a hook-off in a subscriber telephone. This pseudo call is sent to the control device 7 via the network 6 in the telephone exchange 4, and the call is identified. The control device 7 thereby activates the signal generator 8 via the network 6, and the signal generator 8 generates a predetermined valence tone. This signal tone is sent to the pseudo call test device 1 via the network 6. The pseudo call test device 1 has a signal detection circuit 9, detects a signal tone from the telephone exchange 4, and determines the validity of the switching operation of the telephone exchange 4.

In such a pseudo call system, conventionally, the signal detection circuit 9 detects a signal tone by detecting only one period of the signal tone interval, and based on this, the validity of the switching operation of the telephone exchange is determined. That's what I was doing. Therefore, if a malfunction occurs in the signal detection circuit or noise is generated from the telephone exchange, the signal tone will be treated as an abnormal one even though the telephone exchange is transmitting a normal signal tone. There was a problem.

OBJECT OF THE INVENTION The present invention attempts to solve the problems of the prior art, and its purpose is to accurately detect signals even in cases where there is malfunction of the signal detection circuit or noise from the telephone exchange. An object of the present invention is to provide a signal sound detection method that can perform sound detection processing.

Embodiment of the Invention FIG. 2 shows the configuration of a pseudo call test device according to an embodiment of the invention. In the same figure, the same parts as in FIG. 1 are indicated by the same numbers, and 110 is a sampling circuit,
1 is a cycle counter, 12 is a division circuit, 16 is a number counter, and 14 is a determination circuit.

Further, FIG. 3 is a diagram for explaining the ejection of a signal tone in the apparatus shown in FIG. 2, and FIG. 4 is a flowchart showing an outline of the 4g tone detection process.

The signal tone from the telephone exchange has a certain frequency, and by detecting the frequency, the signal detection circuit 9 detects the peaks (on state) and valleys (off state) of the signal tone. Generate a changing signal. sampling circuit 10
generates an output by sampling this signal at intervals of, for example, several tens of millimeters. The period counter 11 is a sampling circuit 1o
The outputs of are counted in correspondence to the peaks and valleys of the signal, respectively. The division circuit 12 calculates the ratio between the peak portion and the valley portion in the output of the period counter 11. At the same time, the number counter 13 counts the number of times the signal tone from the telephone exchange is repeated. The determination circuit 14 determines whether the calculation result in the division circuit 12 matches a predetermined value, and when a match is detected within the predetermined number of repetitions of the signal tone counted by the number counter 16, It is determined that a signal from the telephone exchange has been detected, and if no match is detected after a predetermined number of repetitions, it is determined that no signal has been detected.

In FIG. 6, when the telephone exchange signal is normal, the peaks correspond to m sampling periods and the valleys correspond to n sampling periods. When the peak part is counted as m-1 and the valley part as n+1 due to malfunction of the signal detection circuit or noise in the telephone exchange, on the other hand, when the counting result becomes -, it is determined that the signal has been detected.

In FIG. 4, the division circuit 12 matches the result of this calculation with a predetermined value, and if a match is found, the detection operation ends; however, if a match is not found, the check is repeated. , if matching is not achieved even after i cycles have elapsed, since no normal signal was detected, an error process is performed and the detection operation is terminated.

As described in detail, according to the signal detection method in the pseudo call system of the present invention, the signal tone from the four-finger switchboard is turned on,
Means for detecting whether the off interval is correct or not, and means for counting the number of times a signal tone is received from the telephone exchange are provided,
When it is detected that the interval of the signal tone is correct within the fixed period of the signal tone, it is determined that the signal tone has been received, so if there is a malfunction of the signal detection circuit,
Even if noise is generated from the telephone exchange, signal tone detection processing can be performed accurately.

[Brief Description of the Drawings] Fig. 1 is a diagram showing a pseudo call generation system, Fig. 2 is a diagram showing the configuration of a pseudo call test device according to an embodiment of the present invention, and Fig. 6 is a diagram showing a pseudo call generation system. FIG. 4 is a flowchart showing an overview of the signal sound detection process. DESCRIPTION OF SYMBOLS 1...Pseudo call test device, 2...Subscriber telephone, 6.
...Terminal board, 4...Telephone exchange, 5...Pseudo call generation circuit, 6...Network, 7...Control device, 8...
...Signal generator, 9...Hakuzuki detection circuit, 10...
Sampling circuit, 11...Period counter, 12.
...Division circuit, 16...Number of calculations/division, 14...Judgment circuit Patent applicant Fujitsu Ltd. Representative Patent Attorney Tamamushi Department (1 other person) Fig. 1 Fig. 2

Claims (1)

[Claims] In a pseudo call system that verifies the normality of the switching operation of the telephone exchange by generating a pseudo call to the telephone exchange and detecting the signal tone sent from the telephone exchange in response to the pseudo call, Means for detecting whether the on/off interval of the signal tone is correct or not, and means for counting the number of times the signal tone is received from the telephone exchange are provided, and it is detected that the interval of the signal tone is correct within a predetermined cycle of the first tone. A signal tone detection method for a pseudo call system, characterized in that a signal tone detection method is characterized in that a signal reception is determined when a signal is received.