KR100273966B1 - Apparatus for testing a status of digital trunk interface card in pabx - Google Patents

Abstract

PURPOSE: A device for testing a digital trunk interface card in a private exchange is provided to improve a call service in the private exchange by realizing the digital trunk interface card for self-testing B channel status. CONSTITUTION: A system tone generating part(240) generates a system tone by a test control signal, converts the received system tone to test data and outputs the test data. A digital trunk interface part(250) encodes the system tone, allots it to a B channel and transmits it to a central office line. The digital trunk interface part(250) detects and decodes the system tone encoded on the B channel, and sends it to the system tone generating part(240). A controlling part(200) is applied particular test data, and processes the applied data and transmits it to a main control board. A direction changing relay part(254) is connected between the digital trunk interface part(250) and the central office line. The direction changing relay part(254) disconnects a communicating path between the digital trunk interface part(250) and the central office line by relay control signal, loop-backs the signal inputted from the above central office line to the central office line, and loop-backs the signal transmitted from the above digital trunk interface part(250) to the digital trunk interface part(250).

Description

Digital trunk interface card test device in a private exchange {APPARATUS FOR TESTING A STATUS OF DIGITAL TRUNK INTERFACE CARD IN PABX}

The present invention relates to a digital trunk interface card provided in a private exchange, and more particularly, to generating a loop back path of a system tone in a digital trunk interface card and using the loop back path to determine a B channel state of a trunk. It relates to the device under test.

A digital trunk interface card of a conventional private exchange is boarded and linked with a subscriber part of a private exchange, which is a board connected to a digital trunk line of a central office line (CO). It is implemented by T1 card and E1 card according to ITU G.703 and ITU G704 standard to perform the call operation of private exchange. Operators operating private exchanges can ensure reliable operation of private exchanges by continually checking the status of channels, or B-channels, through the calls on the digital trunk interface card and taking the necessary measures according to the results of normal private exchanges. Should be available.

Therefore, the operators of the private exchange exchanged the test equipment with a separate call to the digital trunk interface card as shown in FIG. Operation of the exchange was planned.

However, the conventional test method illustrated in FIG. 1 mentioned above has a problem of increasing test cost by separately purchasing expensive test equipment because a separate external test equipment has to be used. Furthermore, in order to test the digital trunk interface through the separate test equipment, the external trunk line applied to the digital trunk interface card must be cut during the test, which requires prior acknowledgment from the telephone company before the test begins. There was a problem. This is to prevent the telephone station not knowing that it is in the test state when the trunk line is cut during the test, and detect the cutting state of the trunk line and determine that an abnormality of the trunk line occurs and take a corresponding action.

As a result, the conventional method of testing a digital trunk interface card performed by connecting a separate test device to the outside has many problems in terms of speed and efficiency of testing.

Accordingly, the present invention solves the problems caused by the channel state test method of the conventional digital trunk interface card, that is, the need for the purchase of a separate test equipment and the problem of an inefficient test method that requires prior understanding and testing at the telephone station. We also solve this problem by implementing a digital trunk interface card that tests the B-channel status on its own.

Accordingly, an object of the present invention is to provide an apparatus for testing a B channel state by generating a loopback path of a system tone in a digital trunk interface card.

In order to achieve the above object, the present invention provides a system tone generating unit for generating a system tone by a test control signal and converting and receiving the received system tone into test data;

The system tone generated by the system tone generator is coded and allocated to the B channel, and then transmitted to the external trunk line. The system tone coded on the B channel of the input signal is detected, decoded, and then transmitted to the system tone generator. With the digital trunk interface part to say,

By receiving predetermined test data generated according to a result of whether or not a system tone identical to the system tone generated in the system tone generator is received in the system tone generator, the predetermined data is processed and the main control board in the private exchange is processed. And a control unit for transmitting to

Connected between the digital trunk interface unit and an external trunk line, disconnecting a communication path between the digital trunk interface unit and the external trunk line by a relay control signal, looping back a signal input from the external trunk line to an external trunk line, and A device for testing a B-channel in a digital trunk interface card of a private exchange having a redirection relay section for looping back a signal transmitted from the digital trunk interface section back to the digital trunk interface section.

1 shows a test apparatus of a digital trunk interface card of a private exchange according to the prior art.

2 is a block diagram of a digital trunk interface card of a private switch having a B-channel state test apparatus according to the present invention;

Figure 3 is a specific circuit diagram of the direction switching relay unit in the B channel state test apparatus of the digital trunk interface card according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted, and a description of components already known or implemented in advance will also be given. Since the gist of the present invention may be obscured, it is omitted.

Hereinafter, the present invention will be described with reference to FIGS. 2 and 3.

First, FIG. 2 is a block diagram of a digital trunk interface card of a private switch having a B-channel state test apparatus according to the present invention, and a schematic hardware block diagram thereof is shown.

Referring to FIG. 2, the controller 200 generally controls the overall operation of the digital trunk interface card and performs an operation according to a control signal of a main controller provided in a pre-registered program or a main controller board. In addition, it performs an operation of inputting and outputting various control signals and data required. The memory 220 is a memory for storing preprogrammed software and processed data, and operating a program corresponding to the digital trunk interface card. The time switch unit 210 may switch a pre-allocated channel and thus perform a connection and switching operation to a call, and may provide a conference function for a plurality of callers to call according to the connection and switching operation to such a call. The synchronizer clock unit 260 extracts a synchronizer clock from an external network such as PSTN or ISDN, and synchronizes the system clock to the synchronizer clock (PLL) to provide a clock to the system. The power supply unit 270 supplies the operating power required for each device of the private exchange.

The system tone generator 240 provides a system with a tone required under the control of the controller 200, and the cadence, frequency, and gain of the tone are programmed for each channel. The system tone generator 240 includes a DTMF generator, a tone generator, an R2 signal generator and processor, and generates a corresponding tone as needed, extracts the received system tone, converts it into predetermined data, and outputs the converted tone. Do this. The system input / output unit (I / O) 230 is a part for connecting a separate device to the outside, and is usually provided to provide an asynchronous RS-232C port.

The digital trunk interface unit 250 performs a connection operation with a call to an external CO line under the control of the controller 200, and codes a system tone generated by the system tone generator 240 to allocate the channel tone B channel. After detecting and decoding the system tone coded on the B channel of the signal transmitted or transmitted to an external trunk line, the system tone generator 240 transmits the system tone to the system tone generator 240. The T1 252 is implemented with a conventional transformer and its peripheral circuits, and performs separation of the external trunk line and system side signals.

The direction switching relay unit 254, which is an important component of the present invention, is located between the external trunk line CO and the digital trunk interface unit 250. Specifically, the direction switching relay unit 254 is located at the AC terminal of the T1 252 and performs a switching operation under the control of the controller 200. It includes a number of relays to perform. The relays connect a call line between the external trunk line (C.O) and the digital trunk interface unit 250 or allow the call line connected to the external trunk line (C.O) or the digital trunk interface unit 250 to loop back.

A detailed circuit diagram of the redirection relay unit 254 according to an embodiment of the present invention is shown in FIG. 3. Referring to FIG. 3, it can be seen that the redirection relay unit 254 is composed of four relays. That is, Figure 3 is a view showing a specific circuit diagram of the direction switching relay unit 254 provided in the digital trunk interface card for testing the B channel state according to the present invention.

The first relay and the third relay shown in FIG. 3 are connected to the call line of the digital trunk interface 250, and the second relay and the fourth relay are connected to the external trunk line. If a control signal related to a separate relay drive is not applied, the relays of the redirection relay unit 254 connect the external trunk line with the call line of the digital trunk interface unit 254. For reference, four relays are required in the present invention because the external trunk line and the call line are composed of two transmission (Tx) lines and two reception (Rx) lines.

The operation according to the present invention in a private exchange having such a configuration will be described below.

First, the PCM (Pulse Code Modulation) data generated in the main board connected with the digital trunk interface card is transferred to the digital trunk interface unit 250 via the time switch unit 210, and the coding for transmission in the digital trunk interface unit 250 ( Coding) and coded for high-speed line (1.544M or 2.048M) delivery to the external trunk line side. The information of the B channel, which is a communication channel, of the signals input from the external trunk line is extracted by the digital trunk interface unit 250 and transferred to the main board through the time switch unit 210. However, the D channel information coded with the control signal is transmitted to the controller 200.

At this time, the direction switching relay unit 254 performs a call line switching operation for receiving a signal transmitted from the digital trunk interface unit 250 again or transmitting a signal input from an external trunk line to an external trunk line under the control of the controller 200. Perform. The system tone generator 240 is looped back according to the operation of the redirection relay unit 254 to extract the coded signal of the B channel received again by the digital trunk interface unit 250.

The system tone generator 240 generates a specific signal such as DTMF or tone at 64 Kbps using a DSP (Digital Signal Processor) Core and delivers it to the time switch unit 210, which is controlled by the controller 200. Is performed according to. In addition, the direction relay unit 254 analyzes the loopback PCM signal and transmits it to the control unit 200, and the control unit 200 determines whether a normal loopback has been made. Normal loopback refers to a case in which the same tone generated by the system tone generator 240 is received by the system tone generator 240, and indicates that the call channel of the digital trunk interface card is operating normally. On the other hand, if the same tone is not received or a tone signal is not detected by the system tone generator 240, this indicates an abnormality in the call channel.

Accordingly, the control unit 200 transmits the looped back result to the main control unit of the main control board, and the main control unit performs an operation corresponding thereto.

In conclusion, when the present invention is summarized and described, in the case where a divert relay unit is additionally configured between the digital trunk interface card and the external trunk line and the call state of the B channel, which is the call channel of the digital trunk interface card, is to be tested, The control unit transmits a predetermined test signal and a relay control signal to the system tone generator and the direction change relay unit. Then, the call line is switched so that the direction switching relay unit performs a switching operation so that the signal applied from the external trunk line is transmitted to the external trunk line again, and the signal line from the digital trunk interface card is also applied to the digital trunk interface card again. Is switched.

The predetermined system tone generated by the system tone generating unit is applied to the redirection relay unit through the digital trunk interface unit, looped back through the switched relay, and applied to the digital trunk interface card again. The system tone generator extracts the tone, converts the tone into predetermined test data, and transmits the tone to the controller. The controller determines whether the tone is the same tone as the previously transmitted tone, and outputs the result of the private exchange main board. It is sent to the main control part. At this time, if it is determined that the tone extracted by the system tone generator is the same tone as the transmitted tone, this indicates that the call channel of the digital trunk interface card is operating normally.

Meanwhile, in the description of FIGS. 2 and 3, descriptions of components already known and used in common have been omitted since they may obscure the gist of the present invention.

As described above, the present invention has an advantage that it is possible to know whether or not there is a call channel abnormality in the digital trunk interface card without using separate test equipment connected to the outside. In addition, it is possible to quickly test the call channel of the digital trunk interface card as needed, which brings the advantage of implementing an improved private exchange call service.

Claims (4)

A digital trunk interface card that creates a loopback path of system tones and tests B channel conditions. A system tone generator for generating a system tone by a predetermined test control signal and converting the received system tone into test data and outputting the test tone; The system tone generated by the system tone generator is coded and coded into a B channel, and then transmitted to an external trunk line. The system tone coded on the B channel of the input signal is detected, decoded, and then transmitted to the system tone generator. With the digital trunk interface part to say, By receiving predetermined test data generated according to a result of whether or not a system tone identical to the system tone generated in the system tone generator is received in the system tone generator, the predetermined data is processed and the main control board in the private exchange is processed. And a control unit for transmitting to Connected between the digital trunk interface unit and an external trunk line, disconnecting a communication path between the digital trunk interface unit and the external trunk line by a relay control signal, looping back a signal input from the external trunk line to an external trunk line, and And a redirection relay unit for looping back the signal transmitted from the digital trunk interface unit back to the digital trunk interface unit. The method of claim 1, wherein the redirection relay unit, Apparatus for testing a digital trunk interface card of a private exchange comprising two relays connected to an external trunk line and two relays connected to a call line connected to the digital trunk interface. The method of claim 1, wherein the control unit, When the same signal as the system tone generated by the system tone generator is received by the system tone generator, transmitting test data corresponding to a normal call channel of the digital trunk interface card to the main board by processing the predetermined test data Device for testing the digital trunk interface card of the private exchange, characterized in that performing. The method of claim 1, wherein the control unit, When the same signal as the system tone generated by the system tone generator is not received by the system tone generator, the test data corresponding to the abnormal communication channel of the digital trunk interface card may be processed and transmitted to the main board. Device for testing the digital trunk interface card of the private exchange, characterized in that to perform the operation.