JPH0256870B2 - - Google Patents

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 communication path interface, generates a simulated situation in which a call to the exchange occurs, and detects a signal sent from the telephone exchange in response to the situation. By doing so, the functionality of the switching operation of the telephone exchange is verified.

FIG. 1 shows a pseudo call generation system in a telephone exchange. In the figure, reference numeral 1 denotes a pseudo call test device, which is connected to a telephone exchange 4 together with a subscriber telephone 2 via a terminal board 3. 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's 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 transmits a signal to the signal generator 8 via the network 6.
is activated, and the signal generator 8 generates a predetermined signal 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 the signal tone by detecting only one period of the signal tone interval, thereby verifying the validity of the switching operation of the telephone exchange. I was trying to make judgments. 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.

Purpose of the Invention The present invention is intended to solve the problems of the prior art, and its purpose is to accurately detect signals even when 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 present invention. In this figure, the same parts as in FIG. 1 are indicated by the same numbers, 10 is a sampling circuit, 11 is a cycle counter, 12 is a division circuit, 13 is a number counter, and 14 is a determination circuit.

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

The signal tone from the telephone exchange has a certain frequency, and by detecting the frequency, the signal detection circuit 9 corresponds to the peaks (on state) and valleys (off state) of the signal tone. and generate a signal that changes. The sampling circuit 10 samples this signal at intervals of, for example, several tens of milliseconds and produces an output.
The period counter 11 counts the output of the sampling circuit 10 corresponding to the peaks and valleys of the signal. The division circuit 12 is a period counter 11
Calculate the ratio of the peaks and valleys in the output. 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 or not the calculation result in the division circuit 12 matches a predetermined value.
When a match is detected within a predetermined number of repetitions of the signal tone counted in , it is determined that a signal from the telephone exchange has been detected.If a match is not detected even after the predetermined number of repetitions, the signal is determined to have not been detected.

In FIG. 3, when the signal from the telephone exchange 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 a malfunction of the signal detection circuit or noise in the telephone exchange, the calculation result of the division circuit 12 is m-1/n+1, which is a predetermined value. Since it does not match the value m/n, no determination of signal detection is made. On the other hand, when the count result is m/n, it is determined that a signal has been detected.

In FIG. 4, the calculation result in the division circuit 12 is matched with a predetermined value, and if a match is found, the detection operation ends, but if no match is found, the check is repeated and after i cycles have elapsed. If matching is not achieved, a normal signal has not been detected, so an error process is performed and the detection operation is terminated.

Effects of the Invention As explained above, according to the signal detection method in the pseudo call system of the present invention, there is provided a means for detecting whether the on/off interval of the signal tone from the telephone exchange is correct, and a means for detecting the correctness of the on/off interval of the signal tone from the telephone exchange. A means for counting the number of times is provided, and when it is detected that the interval of the signal tone is correct within a predetermined cycle of the signal tone, it is determined that the signal tone has been received.This prevents malfunction of the signal detection circuit. or
Even when noise is generated from the telephone exchange, signal tone detection processing can be performed accurately.

[Brief explanation of the drawing]

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. 3 is a signal tone detection in the device shown in FIG. 2. FIG. 4 is a flowchart showing an overview of the signal tone detection process. 1...Pseudo call test device, 2...Subscriber telephone,
3...Terminal board, 4...Telephone exchange, 5...Pseudo call generation circuit, 6...Network, 7...Control device, 8...Signal generator, 9...Signal detection circuit,
10...Sampling circuit, 11...Period counter, 12...Dividing circuit, 13...Number of times counter,
14...Judgment circuit.

Claims (1)

[Claims] 1. In a pseudo call system that verifies the normality of the switching operation of a telephone exchange by generating a pseudo call to a telephone exchange and detecting a 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 from the telephone exchange is correct and means for counting the number of times the signal tone is received from the telephone exchange are provided, and the interval of the signal tone is correct within a predetermined period of the signal tone. 1. A signal tone detection method for a pseudo call system, characterized in that signal reception is determined when a signal is detected.