KR940006516B1 - Remote maintenance method and device in pabx - Google Patents

Abstract

The method and apparatus includes a remote maintenance center connected to a public switched telephone network (PSTN), generating inquiry data and diagnosing a state of a system, a controller for controlling a talking function of the system and generating response data, an office line connecting circuit for implementing an interfacing function of the maintenance center, a switch circuit for forming a maintenance talking path with the office line connecting circuit by the controller, and a remote maintenance connecting circuit for supplying the inquiry data received from the switch circuit to the controller, supplying the response data received from the controller to the switch circuit and supplying the result data received from the switch circuit to the controller, thereby raising the efficiency of the system.

Description

Remote maintenance method and device of private exchange system

1 is a block diagram of a private exchange system.

2 is a block diagram of a private exchange system for carrying out the present invention.

3 is a detailed circuit diagram of a remote connection circuit in FIG.

4A to 4D are memory map configuration diagrams for carrying out the present invention.

5 is a remote maintenance flow chart according to the present invention.

* Explanation of symbols for main parts of the drawings

201: central processing unit 202: memory

203: interface circuit 204: switch circuit

205: extension circuit 206: general trunk line circuit

207: DID trunk line circuit 208: DTMF receiving circuit

209: tone generating circuit 210: remote connection circuit

211: I / O circuit 220: remote maintenance center

The present invention relates to a private exchange system, and more particularly, to a method and apparatus for maintaining a private exchange system by forming a data communication path through a remotely spaced maintenance center and a public switched network.

1 is a block diagram of a general private exchange system. The central processing unit 101 controls the formation of a call path and controls the overall operation of the system so as to process various functional services. The memory 102 stores a program for storing basic calls and various functions of the private exchange system and initial service data, and data generated during program execution under the control of the central processing unit 101. It consists of RAM which temporarily remembers. An interface circuit 103 is connected between the central processing unit 101 and the components of the system and interfaces each data and signals generated during the exchange function.

The switch circuit 104 is assigned a channel under the control of the CPU 01 to exchange various tone signals, dialing data and voice data. The internal circuit 105 is connected between the switch circuit 104 and the telephone 111, and forms an internal telephone call loop under the control of the central processing unit 101, and supplies a telephone current to the telephone 11. At the same time, various status signals and voice signals are interfaced between the switch circuit 104 and the subscribers 111 and 111 '. The general trunk line circuit 106 is connected between the switch circuit 104 and the public telephone network PSTN, and under the control of the central processing unit 101, the trunk line lines are formed to form a trunk line call loop, and various types of incoming from the trunk line. The switch circuit 104 connects a signal and an audio signal, and outputs a signal and an audio signal output from the switch circuit 104 to the trunk line. The DID trunk line circuit 107 is connected between the switch circuit 104 and the public telephone network PSTN, and under the control of the central processing unit 101, a dial for incoming incoming trunks (Direct Imward Dialing trunk) is dialed from the trunk line. By controlling the ring signal to directly call the desired subscriber 111, and interfacing the various signals and voice signals between the incoming dedicated trunk line and the switch circuit 104. A DTMF receiving circuit 108 is connected to the switch circuit 104, converts the received dialing signal into digital data and sends it to the central processing unit 101. The tone generating circuit 109 is connected to the switch circuit 104, and a corresponding tone signal is designated and sent to the switch circuit 104 under the control of the central processing unit 101. The input / output circuit 110 is connected to an external terminal 112, a printer 113, and the like to interface data between the exchange system and the external terminal under the control of the CPU 101.

Such a private exchange system may be a key telephone system or a general private exchange (PABX). Maintenance of the private exchange system as described above is performed using the switch 111 or the terminal 112.

That is, when an abnormality occurs in the private exchange system or when the subscriber's information is to be changed, the state of the abnormality is confirmed by using the telephone 111 or the terminal 112 connected to the private exchange system, or the subscriber information is changed. You can change it. However, the maintenance of the private exchange system as described above is difficult to perform directly by the system operator or user because the operation of the system is complicated and diverse. Therefore, during the maintenance of the system, the staff of the maintenance center had to visit the installation site of the system to check the abnormal condition and add or remove the functions desired by the user. However, in the conventional maintenance method as described above, it is difficult for the maintenance personnel to visit the installation place of the system and to meet the requirements of the user in a short time, and also to maintain the status of the system in the field. This can be very costly and can also render the system inoperable during maintenance, reducing the efficiency of the system. And maintenance centers had to hire a lot of maintenance personnel because they had to satisfy many maintenance requirements from users of each system.

Accordingly, an object of the present invention is to provide a method and apparatus for connecting a private exchange system to a remotely spaced maintenance center and a public telephone network, and for maintaining the system using the connected signal.

Still another object of the present invention is to provide a method for automatically connecting a remote maintenance connection circuit to transmit a status information of a private exchange system to a remote maintenance center when an incoming call is generated from a remote maintenance center in a private exchange system.

It is still another object of the present invention to provide a modem control circuit that mounts a modem in a system without using a separate port in a private switching system and communicates state information of the system through an installed modem with an external device. have.

Hereinafter, the present invention will be described in detail with reference to the drawings.

2 is a block diagram of a private exchange for carrying out the present invention. The general configuration of the private exchange is similar to that of the private exchange system of FIG. 1, and is an external device in the configuration of the private exchange system as shown in FIG. A remote access circuit 210 for communicating the status information of the system with the remote maintenance center 220 and a remote access circuit 210 for communicating the status information of the system are further added.

The remote connection circuit 210 is connected to the switch circuit 204, forms a data communication call under the control of the central processing unit 201, and transmits the state information of the system through the switching path 204.

The remote connection circuit 210 is configured as shown in FIG. 3, and the input / output circuit 301 serially outputs the parallel data received on the data bus under the control of the CPU 201, and converts the received serial data in parallel. Output to the data bus. The modem controller 302 is connected to the input / output circuit 301, analyzes serial data of the input / output circuit 301, adjusts the state of the model 303, and receives a carrier signal received through the modem 303. It detects the start and end of data communication. The modem 203 is connected between the input / output circuit 301 and the interface circuit 304, and digital serial data outputting the input / output circuit 301 under the control of the modem controller 302 as an analog signal. It converts and outputs serial data in analog form and converts it into digital data. The codec 305 is connected between the interface circuit 304 and the switch circuit 204, and digitally converts an analog signal outputting the modem 303 to the switch circuit 204 in synchronization with a corresponding time slot. At the same time, the data of the corresponding timeslot received from the switch circuit 204 is analog-converted and output to the modem 303. The interface circuit 304 is connected between the modem 303 and the codec 305 to adjust gain and external impedance of data. The buffer unit 306 includes buffers B1-B2, buffers a signal output from the carrier detection terminal CD of the modem controller 302, and detects whether a carrier signal is detected by the MDMRD signal of the CPU 201. Is output to the CPU 201.

Referring to the operation of the present invention based on the configuration of FIG. 2 and FIG. 3 described above, when attempting data communication with the private exchange system from the outside, the external exerciser may first use the general trunk line connection circuit 206 of the private exchange system or the like. The telephone line connected to the DIS trunk line connecting circuit 207 is dialed. Then, the trunk line connection circuit 206 or the DID trunk line connection circuit 207 of the private switching system detects the incoming ring signal input from the public telephone network PSTN and outputs it to the central processing unit 201. Then, the CPU 201 receives an incoming ring signal to recognize the incoming line and controls the switch circuit 204 to form a communication path. In this case, when the call is received through the general trunk line connection circuit 206, a communication path is connected to a telephone 212 of a call destination designated subscriber connected to the extension line connection circuit 205, and the DID trunk line connection circuit 207 or DISA (Direct Inward System) When the call is received with the Acces) function, it is connected with the DTMF receiving circuit 208 to receive a dialing signal received.

In this case, when the call is received through the general trunk line connection circuit 206, the central processing unit 201 supplies a ring signal to the designated phone 212. When the phone 212 is hooked off, the incoming signal is coming. The incoming call designated subscriber's telephone 212 is connected to the call of the external subscriber of the trunk line through the switch circuit 204, so that a voice call can be made with the external subscriber. It is assumed here that the external subscriber is the maintenance center 220.

Therefore, once in a call, the external subscriber requests to switch the phone to mode for remote data communication. At this time, when the central processing unit 201 receives the switch key signal from the receiving party subscriber 202 through the extension connection circuit 205, the call received through the trunk line connection circuit 204 to switch circuit 204 Connect with the remote access circuit 210 through. When the DIS main line connection circuit 207 or the DISA function directly requests communication with the remote connection circuit 210, the CPU 201 controls the switch circuit 204 to control the remote connection circuit ( 210) and the trunk line incoming call.

When the remote access circuit 210 and the trunk line incoming call are connected as described above, the modem 221 of the remote maintenance center 220 and the modem 303 in the remote access circuit 210 are connected, so that the modem 303 is connected. When the carrier (carrier: carrier) is detected, the communication connection procedure for data communication is completed. At this time, when data to be communicated through the modem 221 of the remote maintenance center 220 is generated, the modem 221 converts it to an analog signal and loads it on a carrier and outputs it to a public telephone network (PSTN). The private exchange system converts the received analog signal into a digital signal in the trunk line connection circuits 206 and 207 and outputs the digital signal to the switch circuit 204 connected to the remote connection circuit 210 and the call path. The switch circuit 204 then switches the received digital signal to the remote access circuit 210, and the data input to the remote access circuit 210 is output to the CPU 201. At this time, the central processing unit 201 analyzes the data received from the remote access circuit 210 to generate output data, the output data is formed in the opposite direction to the receiving path, the remote maintenance center 220 To the side.

Looking at the operation of the remote connection circuit 210 in detail, first when the switching command of the remote connection circuit 210 is generated, the central processing unit 201 controls the switch circuit 204 to the remote connection circuit 210 And a communication path between the trunk line connection circuits 206 and 207. At this time, the channel of the remote access circuit 210 uses a fixed channel. In addition, the CPU 201 outputs control data for making the modem 303 on-line to the input / output circuit 301. The input / output circuit 301 then converts the parallel data received through the data bus into serial data and outputs the serial data to the output terminal TXD. At this time, the modem controller 302 receives and analyzes the serial data as an input terminal RKD. At this time, if the received data is on-line data of the modem 303, the modem control unit 302 controls the modem 303 in the on-line state through a local control bus (local control bus). At this time, the modem controller 302 performs communication speed control of the on / offline control modem 303 of the model 303. At this time, the presence or absence of a carrier signal is detected from the modem 303. When a carrier signal is detected, a "low" signal is output to the terminal CD. The output of the carrier detection terminal CD of the modem controller 202 is applied to the buffer 306. The buffer 306 is a three-state buffer, and when an enable signal / MDMRD signal is generated in the CPU 201, The output signal of the carrier terminal CD is output to the central processing unit 201. Accordingly, when the CPU 201 receives a carrier detection signal from the buffer 306 after outputting the on-line data, the CPU 201 may recognize that communication has started. The buffer unit 306 includes a buffer B1 connected to the CD terminal of the modem controller 302 and a buffer B2 connected to a ground or power supply terminal. The buffer B1 buffers a presence / absence signal of a carrier signal, B2 buffers the presence or absence of the remote access circuit 210. In this case, the outputs of the buffers B1 and B2 are as shown in Table 1 below.

Table 1

As described above, when the remote access circuit 210 is online and a carrier signal generated from an external subscriber's modem is detected, the CPU 201 performs a process of receiving and analyzing data generated from the external subscriber. .

Looking at the data reception process, the received frame synchronization signal and data from the switch circuit 204 is applied to the terminals FSR and DR of the cortex 305, respectively. Then, the codec 305 receives the data of the corresponding timeslot by using the frame synchronization signal and the clock, converts the data into an analog signal, and outputs the analog signal to the terminal VPO. The received signal outputting the terminal VPO is adjusted to gain and impedance by the resistors R2 and R5 and applied to the terminal RXA1 of the modem 303. The modem 303 then converts the analog signal received at the terminal RXA1 into digital data and outputs it to the terminal TXD. The data outputting the terminal TXD of the modem 303 is applied to the RXD terminal of the input / output circuit 301, converted into parallel data, and then applied to the CPU 201 through the data bus. ) Analyzes the data sourced on the data bus and generates response data. In addition, the modem controller 302 receives and analyzes the output of the D1 / D0 terminal of the modem 302 and applies the RXD terminal of the input / output circuit 301 through the TXD terminal. Then, the input / output circuit 301 converts the serial data received through the RXD terminal into parallel data and applies it to the central processing unit 201. The central processing unit 201 analyzes the received data to determine the state of the modem 302. Will be analyzed.

As described above, the central processing unit 201 receives data from an external subscriber, and then analyzes the received data to generate response data. In this case, the CPU 201 outputs the response data to the data bus, and the input / output circuit 301 converts the received parallel data into serial data and outputs the TXD terminal according to a clock. At this time, the clock determines the transmission speed of the serial data, and the speed is the same as the transmission speed of the modem 303. The TXD terminal output of the input / output circuit 301 is applied to the RXD terminals of the modem controller 302 and the modem 303. At this time, the modem 303 converts the data received through the RXD terminal into an analog signal and outputs the signal through the TXD terminal. The signal is adjusted by the resistors R3 and R4, and then the GSX terminal of the cortec 305 is adjusted. Is applied. The codec 305 converts the received analog signal into digital data and loads the received analog signal into the corresponding time slot and outputs the same through the DX terminal. Then, the data outputting the codec 305 is applied to the switch circuit 204 to switch to the time slot of the external subscriber, and the switch data is output to the external subscriber through the trunk line connection circuits 206 and 207 and applied to the external subscriber. .

Therefore, upon requesting modem communication from an external subscriber, the central processing unit 201 of the private switching system controls the remote access circuit 210 to control the modem 303 on-line, and then a communication path formed from the external subscriber. Receives and analyzes the data received through the remote access circuit 210. And when the response data according to the received data is generated and output to the remote access circuit 210, it is transmitted from the trunk line through the communication call formed through the switch circuit 204 can be received by the external subscriber.

When the external subscriber generates the disconnect request data in the communication state as described above, the CPU 201 recognizes this through the reception path and controls the modem 303 in the off-line state through the modem controller 302. . In addition, if an abnormality of the carrier signal occurs during communication, the modem controller 302 detects the disconnection of the carrier signal and outputs a "high" logic signal to the CD terminal. Then, the CPU 201 recognizes the end of the carrier signal by the buffer B1 and controls the modem 303 in the off-line state through the modem controller 302.

4A to 4D are map configurations of the memory 202 for carrying out the present invention, in which the subscriber table structures of the trunk line and the extension have the same structure. FIG. 4A is a subscriber table structure diagram for N subscribers of the private exchange system, and FIG. 4B is a detailed table structure diagram for one subscriber among all subscriber tables in FIG. 4A. FIG. 4C is a bitmap configuration diagram for the subscriber type (LINE TYPE) in FIG. 2, and the function of each bit is as shown in Table 2 below.

[Table 2]

4D is a bit map configuration diagram of a subscriber's state (LINE-STATUS), and the function of each bit is shown in Table 3 below.

Table 3

In FIG. 4B, the subscriber's number is stored in the LINE-NUMBER area, and the subscriber's number of the other party on the call is stored in the OPPOSITE-NUMBER area. In the NUMBER) area, the number of the extension subscriber to supply the trunk line incoming ring when the trunk line incoming ring is received by the general trunk line circuit 216 is stored.

FIG. 5 illustrates a process of connecting the remote maintenance center and the remote access circuit 210 using FIGS. 4A through 4D. The connection method is composed of three types: when the trunk line incoming ring is received through the general trunk line connection circuit 206, when the trunk line incoming ring is received through the DID trunk line circuit 207, and by the DISA through the general trunk line circuit 206. The case where a trunk line incoming ring is received as a function is shown.

Looking at the process of forming a remote maintenance communication path between the private exchange system and the remote maintenance center 220 based on the above-described configuration.

First, the process of performing the remote maintenance function through the general trunk line connection circuit 206 will be described. When the trunk line incoming ring signal is received by the general trunk line circuit 206, the central processing unit 201 recognizes this in step 503, and in step 504 the incoming subscriber number AN0 of the extension subscriber table as shown in FIG. 4B. It supplies the ringing signal to the stored recipient designated station and resets LSD0 bit in the subscriber status table as shown in FIG. 4D, sets the LSD1 bit and LSD2 bit to set the subscriber to the busy state, and also provides ring signal supply. Thereafter, the central processing unit 201 checks the state change of the corresponding destination designated extension subscriber port of the extension connection circuit 205 in step 505 to confirm the hook-off of the extension subscriber. At this time, when the called subscriber station is hooked-off, the ring signal being supplied in step 506 is disconnected, and in step 507, the switch circuit 204 is controlled to control the switch circuit 204 and the trunk line destination port of the general trunk line connection circuit 206. A port of a designated call extension subscriber of the extension connection circuit 205 is connected to form a call path. Then, the LSD2 bit of the subscriber state LST as shown in FIG. 4D is reset to indicate the ring release state, and the LSD4 bit is set to indicate that the call is in a busy state. The CO line number is stored in the counterpart subscriber number in the called designated extension subscriber table, and the number of the recipient designated extension subscriber is stored in the counterpart subscriber number in the CO line subscriber table.

When in the busy state as described above, the voice communication path is formed between the CO line and the extension. In this case, when the trunk line subscriber is a remote maintenance center 220 connected through a public telephone network PSIN and requests a connection with the remote access circuit 210, the called subscriber station designates an ID number of the switcher and the remote access circuit 210. Dial.

At this time, when the central processing unit 201 receives the switch key data from the extension connection circuit 205, it recognizes this in step 508 and controls the switch circuit 204 in step 509 to control the call line. It supplies a hold tone or music to the remote maintenance center 220 of the remote maintenance center 220, and supplies a switching sound to the called subscriber station. After that, when the switching subscriber number is generated from the extension connection circuit 205, the central processing unit 201 receives it from the DTMF receiving circuit 209 in step 510, and then returns to the relative subscriber number ON0 of FIG. 4B. Save it.

The CPU 201 then checks in step 511 whether the switched subscriber is the subscriber number of the modem 303 for remote maintenance. This is done by accessing the contents of the subscriber table corresponding to the subscriber's subscriber number and checking the LTD4 bit of the subscriber type LTP as shown in FIG. 4B. That is, if the LTD4 bit is set, the subscriber is configured to perform a remote maintenance function. If the switch subscriber number is found to be the subscriber number of the modem 303 for performing the remote maintenance function in step 511, the LSD0 bit state as shown in FIG. 4D of the corresponding switch subscriber table is checked in step 512. . In this case, if the LSD0 bit is in the reset state, the signal is not in the idle state. In step 513, the tone generating circuit 209 and the switch circuit 204 are controlled to supply a busy tone to the called subscriber station. . However, if the LSD0 bit of the switching subscriber is set in step 513, the idle state is set. Therefore, the control proceeds to step 514 to control the tone generator 209 and the switch circuit 204 to ring the ringing subscriber. back tone) and set the LSD3 bit in the subscriber state as shown in FIG. 4D.

The above state is a state in which the designated destination subscriber connected the incoming call to the remote access circuit 210 by a call received from the remote maintenance center 220. Therefore, when the called designated extension subscriber hooks on, the CPU 201 recognizes the hook-on state through the extension connection circuit 206 in step 515 and the called designated extension in step 516. Transitions the subscriber's state to the idle state and cuts off the holding sound supplied to the CO line subscriber side. In the subscriber state of the called subscriber station, the LSD0 bit is set, the LSD1-LSD5 bit is reset, and FF _H is stored and initialized in the state subscriber number.

Thereafter, the central processing unit 201 controls the switch circuit 204 in step 517 to connect the incoming trunk line port with the remote access circuit 210, thereby connecting the remote access circuit 210 through the public telephone network PSTN. And a communication path for maintenance between the remote maintenance center 220. In this case, the LSD5 bit is reset in the subscriber state of the CO line subscriber table, the LSD4 bit is set, and the LSD4 bit is set in the subscriber state of the remote access circuit 210 and is recorded as a busy state. In addition, the number of the remote access circuit 210 is stored in the relative subscriber number of the CO line subscriber table, and the CO line subscriber number is recorded in the relative subscriber number in the subscriber table of the remote access circuit 210.

When the maintenance communication path is formed as described above, the modem setup and the communication path between the modem 221 of the remote maintenance center 220 and the modem 303 of the remote access circuit 210 as described above. Communicate data for formation. In this case, the CPU 201 outputs a 1MDMRD signal in step 518 to enable the buffer B1 to check the state of the carrier detection signal generated from the CD terminal of the modem controller 302. At this time, when the carrier detection signal is received from the modem control unit 302, the central processing unit 201 between the modem 303 of the remote access circuit 210 and the modem 221 of the remote maintenance center 220. Recognizing that a communication path has been formed, the remote maintenance function is performed by performing steps 519 and 520. In the performing of the maintenance process, when the remote maintenance center 220 generates inquiry data for diagnosing the state of the private exchange system, the central processing unit 201 receives this, and the central processing unit 201 When the response data for the received inquiry data is generated, the remote access circuit 210 transmits it to the remote maintenance center 220 through the communication path formed through the switch circuit 204. Then, the maintenance personnel of the remote maintenance center 220 confirms this, and when the maintenance command or the MMC command for changing the system function is generated, the central processing unit 201 returns to the remote access circuit in the same procedure as described above. This is received through 210 to perform maintenance and function change of the private exchange system.

When the maintenance of the above-described maintenance function is completed, the maintenance personnel of the remote maintenance center 220 generates data (“+++”) for terminating data communication through the terminal 223. The processing device 201 can recognize this through the remote access circuit 210 in step 521. Then, the CPU 201 controls the switch circuit 204 in step 523 to cut the connection with the trunk line port in communication with the remote access circuit 210, and in step 524, the CO line subscriber and the remote connection. Resets the LSD0 bit of the subscriber of the modem 303 of the circuit 210. In this case, all call information recorded in the trunk line subscriber table and the subscriber table of the modem 303 are cleared, and the remote maintenance process is terminated. In addition, if the data is not received from the remote maintenance center 220 within a predetermined time in step 522, the remote maintenance process is terminated by performing steps 523 and 524.

Secondly, the process of performing the remote maintenance function through the DID trunk line connection circuit 207 will be described. The DID trunk line connection circuit 207 is a call-only trunk line circuit. In this case, the state subscriber connected through the public telephone network PSTN must dial an extension number of the station to be called along with the trunk line number of the private switching system. At this time, the subscriber type of the subscriber table capable of talking to the DID trunk line should be set with the LTD1 bit as shown in FIG. 4C.

When the incoming signal to the DID trunk line connection circuit 207 is generated, the CPU 201 checks the state of the LTD1 bit in the subscriber type as shown in FIG. 4C of the corresponding trunk subscriber table in step 501. Recognize that the CO line is a DID CO line. That is, when the LTD1 bit is set, the CPU 201 controls the switch circuit 204 to supply a dial tone to the trunk line receiving side RX. In the subscriber state, the LSD0 bit is reset to release the son from the state, and the LSD1 bit is set to indicate the busy state. In step 526, the switch circuit 204 is controlled to connect the trunk line transmitting side TX to the DTMF receiving circuit 208 to receive a dialing digit received through the DID trunk line circuit.

The CPU 201 then checks whether the dialing digit received in step 527 is the modem 303 number of the remote access circuit 210 for remote maintenance. This is determined as a subscriber for remote maintenance if the LTD4 bit of the subscriber type as shown in FIG. 4C is set in the subscriber table corresponding to the dialing digit. Therefore, if it is determined in step 527 that the remote maintenance subscriber, and in step 528 it is checked whether the modem 303 of the remote access circuit 210 for performing the remote maintenance. This is done by checking the LSD0 bit of the subscriber state as shown in FIG. 4D in the subscriber table of the modem 303. If it is busy in step 528, the process proceeds to step 529, where the LSD1 bit is set in the subscriber state as shown in FIG. However, if it is determined that the idle state in step 529, to proceed to step (517) described above to form a remote maintenance communication path to perform the following procedure.

Thirdly, a process of performing a remote maintenance function using the DISA function through the general trunk line connection circuit 206 will be described. In order to perform the DISA function, the specific trunk line of the general trunk line connection circuit 206 must have the DISA function set. The DISA function may be set by performing MMC through the phone 212 or the terminal 213. At this time, the CPU 201 registers that the CO line is a DISA trunk line port by setting the LTD2 bit in the subscriber state as shown in FIG. 4C of the CO line subscriber table determined by the MMC. At this time, if the remote maintenance center 220 accesses the DISA trunk line of the general trunk line connection circuit 206 through the public telephone network PSTN, the central processing unit 201 of the general trunk line connection circuit 206 in step (502). Recognize the state of the CO line. At this time, when detecting the incoming signal to the DISA trunk line port, the CPU 201 performs steps 525 to 529 in the same manner as the process of the DID trunk line.

As described above, in the private exchange system, the system can quickly and easily respond to the user's demands by using the telephone to remotely identify the system status and to quickly process the system, and the place where the private exchange system is installed. Maintenance can be carried out without visiting, which reduces maintenance costs. In addition, when the modem is connected to the private switching system, the modem can be mounted in the system, saving the extension port, and since the call is formed after the extension call or the DISA function is connected to the modem, there is no need to use the ring detection unit for the modem. When the modem requires remote communication from the maintenance center, the system can be automatically transmitted to the state of the system, thereby maximizing the efficiency of the system.

Claims (5)

A remote maintenance device of a private switching system, which is connected to a public telephone network PSTN, outputs an inquiry data and diagnoses the state of the system by the response data received, and outputs a result data for function setting and maintenance. A control unit for controlling the call function of the maintenance center, the private switching system, outputting response data of the system state by the inquiry data, and setting maintenance and functions according to the result data; and by the control unit, the public telephone network A trunk line connection circuit that performs an interfacing function of the remote maintenance center through a switch, a switch circuit that forms a remote maintenance communication path with the trunk line connection circuit by the controller, and is connected between the switch circuit and the controller, Output the inquiry data received from the switch circuit to the controller And a remote maintenance connection circuit configured to output the response data received from the controller to the switch circuit, and output the result data received from the switch circuit to the controller. Remote maintenance unit. The input / output circuit according to claim 1, wherein the remote maintenance connection circuit serially converts the transmission parallel data of the data bus by the control unit, converts the reception serial data in parallel, and outputs the data to the data bus. Receives data and converts the analog signal to digital data; converts the received analog signal into digital data and outputs the data to the input / output circuit; and receives the multiplication serial data of the input / output circuit, adjusts the state of the modem, and simultaneously outputs the data of the modem. Analyzes and outputs the signal to the input / output circuit, the modem controller detects and outputs the state of the carrier signal of the modem, receives the analog signal transmitted from the modem, converts it into digital data, and outputs the signal to a switch circuit at a specified time slot position. From the switch circuit, Receiving and converting the signal into an analog signal and outputting the signal to the modem; and a buffer unit for buffering the carrier output terminal signal of the modem control unit and outputting the central processing unit under the control of the central processing unit. Remote maintenance unit of the private exchange system. The remote maintenance apparatus of the private exchange system according to claim 2, further comprising an interface circuit for adjusting the gain of the modem and the impedance of the outside of the system between the modem and the codec. A remote maintenance method of a private switching system for transmitting and receiving data to and from a remote maintenance center through a public telephone network having a remote maintenance connection circuit connected between a switching control unit and a switch circuit, the incoming call received through a trunk line connection circuit. Analyzing the information, and controlling a switch circuit to form a data communication path between the remote maintenance connection circuit and the corresponding trunk line receiving port; and in response to the inquiry data received from the remote maintenance center after the data communication path is formed. Transmitting system status data and performing maintenance function based on the received result data, and controlling the switch circuit when receiving communication termination data in the maintenance process, between the remote maintenance connection circuit and the trunk line receiving port. Cut the data communication path and disconnect the remote access circuit. Remote maintenance method of the PBX system, characterized by constituted by any process of evaporation. 5. The method of claim 4, wherein the process of forming a data communication path for remote maintenance comprises forming a trunk line with a designated extension subscriber when detecting a trunk line incoming ring with a general trunk line connection circuit, and maintaining the remote from the designated station subscriber. Analyze the process of forming a data communication path between the incoming trunk line and the remote maintenance connection circuit when receiving the switching data for the maintenance connection circuit, and the dialing digits that are continuously received during ring detection with the DISA trunk line port of the general trunk line connection. Forming a data communication path between the incoming DISA trunk line port and the remote maintenance connection circuit, and analyzing the dialing digital received continuously when the incoming signal is detected by the DID trunk line connection circuit. A private exchange system comprising a process of forming a data communication path between circuits. Other maintenance methods.