JP2531826B2 - Fault isolation method for communication system and fault detector used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is intended to confirm the functional operation of a terminal device and a network and a terminal when a failure occurs during construction / maintenance work in a communication system such as an ISDN system and a standard home bus system. The present invention also relates to a fault isolation method of a communication system used for fault isolation between terminals and the like, and a fault detector used therefor.

[Conventional technology]

Conventionally, there is no maintenance tester dedicated to the terminal equipment in the communication system, so to confirm its function operation, use the actual equipment for testing, or use the development equipment that can simulate the protocol monitor function and the terminal equipment function. Was. Also,
For failure monitoring such as data communication, failure detection using a line (hereinafter referred to as a dedicated line) different from the protocol monitor and the user line has been performed.

[Problems to be Solved by the Invention]

When performing a test using an actual machine, if an abnormality is detected, it is necessary to replace it with a substitute and repeat the test.In the case of a large communication system, not only a large amount of operation is required for replacement, but also a spare machine is required. There was a drawback of dealing with invalid inventory. Further, when a device such as a protocol monitor is used, since it is originally for development, there is a problem that specialized knowledge for operating the device is required.

On the other hand, when there is a failure in the communication system, there is no dedicated maintenance tester, so a general-purpose measuring instrument such as an impedance measuring device or spectrum analyzer is used to isolate the failure between the network and the terminal or between the terminal and the terminal. It was

For this reason, there is a problem in that a general-purpose measuring instrument must be procured by purchasing or renting it, transported to a large number of customers' homes, and an engineer with advanced skills must go to use it.

Furthermore, there is a problem in that a failure that occurs from time to time has to wait at the customer's house until the phenomenon occurs. Further, in the fault diagnosis using the protocol monitor device and the dedicated line, there is a problem that a modem, a dedicated line and the like have to be installed and operated, which requires a great deal of operation.

The purpose of the present invention is not to be an expert who is familiar with protocol specifications, who must install a large number of measuring instruments equipped with the functions necessary for fault isolation, etc., which presume what is the cause of the failure and clarify the failure location. It is not possible to analyze the monitoring results with the protocol monitor device, which must be operated in the place where the protocol monitor device is installed, which may cause malfunction or noise of the communication device. The electromagnetic interference wave is detected by EMI (E
lectro Magnetic Interference). ) And breakdown,
It solves the conventional problems such as being unable to grasp the relationship of malfunctions, having to install and operate a modem or dedicated line for information transfer to perform remote diagnosis, and anyone who is not familiar with protocol specifications can use it in the field. Another object of the present invention is to provide a fault isolation method for a communication system and a fault detector used for the fault isolation method and the basic operation confirmation of the terminal device by remote diagnosis.

[Means for solving the problem]

According to a failure isolation method of a communication system according to the present invention, a failure detector is configured to analyze a communication protocol used by the terminal device when the terminal device communicates with the digital communication network and detect presence or absence of electromagnetic interference. The communication protocol analysis result and the electromagnetic interference presence / absence detection result are compared with a predetermined reference value to determine the presence / absence of a failure, and when a failure is detected, the determination result is the communication protocol analysis result and the electromagnetic interference. A process of transmitting the presence / absence detection result to the failure diagnosis device, and the failure diagnosis device having received the determination result of the communication protocol analysis result and the electromagnetic interference presence / absence detection result, and a coping method corresponding to the received content. And a step of extracting the operation guidance and returning it to the failure detector that is the transmission source.

Further, the failure detector according to the present invention, when the terminal device communicates with the digital communication network, a layer processing unit that analyzes the communication protocol used by the terminal device from the data flowing through the communication line, An electromagnetic interference detection unit that detects the presence or absence of an electromagnetic interference voltage or an electromagnetic interference current on the communication line, a pulse monitoring unit that compares the level and pulse width of a pulse signal on the communication line with a standard value, and a polarity on the communication line. A power supply monitoring unit that monitors the received voltage and compares the received voltage with a standard value, a failure estimation unit that determines whether there is a failure from the processing results of the layer processing unit, the electromagnetic interference detection unit, the pulse monitoring unit, and the power supply monitoring unit, and It has a display section for displaying the estimation result by the failure estimation section. Moreover, it is equipped with a simulator section.

[Action]

In the present invention, not only the protocol monitor analysis result but also the EMI detection result is used for estimating the cause of the failure, so that the relationship between noise and failure can be clarified.

In addition, it is possible to remotely control from a failure diagnostic device at a remote place using a communication line.

〔Example〕

An example of fault isolation in the ISDN system will be described below.

FIG. 1 shows an example of an apparatus for carrying out the present invention and is a block diagram showing a connection configuration of a failure diagnostic device and a failure detector. In FIG. 1, reference numeral 1 is a failure diagnostic device, which is installed at a business office, for example. 2 (2 _{1 to} 2 _n are collectively referred to as 2; other symbols are also the same) is a network terminal installation (hereinafter abbreviated as DSU), 3 is a communication connector, 4 is a DSU, and 4a is a demarcation between the network and terminal equipment. Points (T points), 5 is a failure detector connection terminal, and 6 is a failure detector, which is installed, for example, in a user's house. Reference numeral 7 is a terminal equipment (TE).

The fault diagnosing device 1 is connected to a plurality of DSUs 2 to handle a large number of outgoing and incoming calls. The failure detector 6 is connected via the failure detector connection terminal 5 to the T point 4a below the DSU 4 of the user / network interface where the failure has occurred. The terminal device 7 communicates with the network as shown in FIG.
When receiving a call, protocol information, power supply information,
When a pulse waveform is monitored and EMI is detected and a failure is detected from the monitor result and the detected result, B at T point 4a is detected.
The channel is used to communicate with the failure diagnosing device 1 as shown in the figure, and the failure diagnosing device 1 estimates the cause of the failure from the protocol monitor information, the power supply information and the EMI detection information transferred from the failure detector 6. . Further, the fault diagnostic device 1 transfers the estimated fault cause and coping method to the fault detector 6 as shown in the figure and displays the result.

FIG. 2 is a diagram showing a functional block configuration of the failure detector 6. In FIG. 2, I surrounded by a dotted line is a monitor unit, II surrounded by a dotted line is a communication unit, 5c is a switch for switching between the monitor unit I and the communication unit II, 8 is a receiver unit, 9 is an EMI detection unit, and 10 is power supply monitoring. Part, 11 is a pulse waveform monitoring part, 12 is a layer 1 to 3
Processing unit (Layer is ISO7498DAD17498, CCITTX.200, JISX5
003), 13 is a failure estimation unit, 14 is a memory, 15 is an upper layer processing unit, 16 is a voice monitor unit, 17 is a central processing unit, 18 is a display driver unit, 19 is a display unit, 20 is an operation unit interface, 21 is an operation unit, 22 is a driver / receiver unit, 23 is a layer 1 to 3 processing unit, 24 is an upper layer processing unit, 25 is a code error rate measuring unit, and 26 is a simulator function unit. here,
The simulator means a device having only a terminal or a wire connected to the terminal and having a function of facing the terminal and performing communication. It is possible to communicate with the terminal by the function of performing communication in a face-to-face manner and to judge from the communication result whether the operation of the terminal is normal. Further, by connecting the terminal and the wiring, it is possible to compare with the case where there is no wiring, so that the normality of the wiring can also be confirmed.

 Next, the operation of the monitor unit I will be described.

Information for performing EMI detection, power supply start, and pulse waveform monitoring is drawn from the bus wiring side of the transformer that constitutes the receiver unit 8 that receives and receives signals. The EMI detection unit 9 performs EMI detection induced on the bus wiring (burst detection of induced voltage of empty pair line and control signal). The power supply monitoring unit 10 monitors the polarity, measures the received voltage, and compares it with the standard value. The pulse waveform monitoring unit 11 compares the level and pulse width of the pulse signal with the standard value. Layers 1 to 3 processing unit 12 monitor T line (line from terminal device 7 to DSU4) and R line monitored by receiver unit 8
D channel information of the line (the line going from the DSU4 to the terminal device 7) is defined by the protocol specification (for example, JT-14
30, Q921, Q931). The failure estimation unit 13 detects a failure from the detection result and the comparison result of the EMI detection unit 9, the power supply monitoring unit 10, the pulse waveform monitoring unit 11, and the layers 1 to 3 processing unit 12, and when the failure is detected, the monitor information is stored in the memory 14 And the central processing unit 17 is notified that a failure has been detected. Upon receiving the failure detection, the central processing unit 17 switches the switch 5c to the communication unit II side,
The communication unit II is controlled to establish the failure diagnosis device 1 and the B channel. When the communication with the fault diagnostic device 1 is started, the central processing unit 17
Transfers the information stored in the memory 14 when a failure occurs to the failure diagnosis device 1. In addition, the display unit 19 displays the failure cause estimation result, the coping method, the operation guidance, and the like transferred from the failure diagnosis device 1 according to the instruction from the central processing unit 17, so that the failure isolation of the communication system at the T point 4a can be performed. To do.

The cause of failure is estimated by the remote diagnosis function, but in the case of a simple failure such as the presence or absence of power supply, the failure estimation unit 13, memory 14, and central processing unit 17 of the failure detector 6 do not perform remote diagnosis. However, the probable cause / measure can be displayed on the display unit 19.

The operation unit 21 controls the failure detection unit 6, and the audio monitor unit 16 monitors the signal on the B channel as audio to detect audible noise and the like, and EM is detected at the time when the audible noise is detected.
By determining whether or not I is detected, it is determined whether or not the terminal device 7 connected to the lower part of the T point 4a is affected by EMI.

After the B channel is established by the fault detector 6 and the fault diagnosing device 1, the bit error rate measuring unit 25 of the optional function sets a PN pattern (pseudo random code string) or the like to the fault diagnosing device 1 under the control of the central processing unit 17. Time transmission, and PN to the failure diagnostic device 1
The transmission of a pattern or the like is requested, and the failure detector 6 receives it and measures the code error rate. Alternatively, it is also possible to transmit from the failure detector 6 using the B channel, use the subaddress to perform the call back call reception to itself (the failure detector 6), and measure the code error rate in the round trip of the subscriber line. It is possible.

In the remote diagnosis mode, the simulator function unit 26 connects the simulator function unit 26 to the user bus wiring and the terminal device 7 by closing the switch 5e, and performs a functional operation test of the user bus wiring and the terminal device 7. Central processing unit
17 displays the test result on the display unit 19, and further transfers the test result to the remote fault diagnosing device 1.

FIG. 3 is a diagram showing a configuration of a connection point of the failure detector 6. In FIG. 3, 5a is a switch for disconnecting the lower part of the failure detector 6, 5b is a switch for connecting the bus wiring and the failure detector 6 when the outgoing / incoming of the terminal device 7 is monitored, and 5c is the failure detector. A switch for switching between the monitor unit I and the communication unit II in the reference numeral 6, 5d is a user bus wiring connection terminal, and 5e is a switch for connecting the simulator function unit 26 and the user bus wiring.

The connection point of the failure detector 6 to the bus wiring has a structure that can be electrically separated below the connection point of the failure detector as shown in FIG. In FIG. 3, by connecting the switch 5a and the switch 5b to the bus wiring and connecting the switch 5c to the monitor unit I, the communication procedure of the terminal device 7 connected to the bus wiring can be monitored. When communicating with the fault diagnosing device 1, the switch 5a, the switch 5b, and the switch 5c are interlocked to disconnect the bus wiring below the connection point of the fault detector 6, and the communication section II and the DSU 4 of the fault detector 6 are the points. With the to-point connection, the failure detector 6 and the failure diagnostic device 1 can communicate with each other without being affected by the bus wiring and the terminal device 7 connected to the bus wiring.

In the remote diagnosis mode, when the switch 5e is closed, the simulator function unit 26 is connected to the user bus wiring and the terminal equipment 7, and the user bus wiring and the terminal equipment 7 can be simulated by remote control regardless of the network. Become.

The simulation described the embodiment in the remote mode as described above, but the switch 5b is connected to the user bus wiring, the switch 5c is connected to the monitor unit I, and the switch 5e is connected to be used only by the failure detector 6. It is also possible to do so easily. By doing so, the failure detector 6 can be self-checked and a defect in the DSU 4 can be detected.

FIG. 4 is a diagram showing a functional block configuration of the failure diagnostic device 1. In FIG. 4, 3 is a communication connector, 27 is a line section, 28
Is SCSI (Small Computer System Interfece), 29 is a personal computer, 31 is a keyboard, 32 is a hard disk, and 33 is a printer. In FIG. 4, the line unit 27 has the functions of layers 1 to 3 of the ISDN basic interface and is controlled by the personal computer 29 via the SCSI 28. A plurality of line units 27 are provided so that one failure diagnostic unit 1 can simultaneously communicate with a plurality of failure detectors 6. In addition, such multitask processing is
It can be realized by using an operating system (OS) such as OS-2. The failure cause 6 transferred from the failure detector 6 is analyzed by the personal computer 29 for the cause of the failure, the transmission ID is identified along with the countermeasure, and the information is transferred.
Transfer to. In addition, instead of the instruction manual, the function to transfer the operation guidance to the failure detector 6 and the failure information and the failure estimation result that have been transferred are accumulated in the failure information for each sender ID, so that the terminal failure at the customer's house It is possible to build a history database.

In addition, by using a format of package addition or interface connection for optional functions, it is possible to add new functions, delete functions, and combine optional functions corresponding to failure modes as needed.

Here, the relationship between the EMI detection result and the protocol monitor result will be described.

EMI causes audible noise, data errors in data communication, and LS
Abnormal operation of communication device by causing I to malfunction (such as abnormal display of communication disconnection (temporary protocol error))
It may cause damage or destruction. EMI may be constantly generated like a broadcast wave or may be generated irregularly for only a moment like electrostatic discharge.

Whether the communication is normal or not is usually monitored by a device that monitors the communication protocol. But EM
The conventional protocol abnormality monitoring device could only determine a temporary protocol abnormality due to I as a protocol abnormality.

Although it is possible to measure EMI with a dedicated measuring device, the antenna can be replaced or various locations (electric field strength measurement, commercial power line measurement, communication line (specified at the T-point interface) can be used according to the type of EMI. Existing DSU / terminal / wiring to connect this device)) is required and expertise is required for the measurement.
There is no general device that can measure I, and it is very difficult to judge from the result of measuring with individual measuring instruments whether the timing of detecting EMI and the timing of occurrence of protocol anomalies match.

Therefore, the DSU specified by the T point interface
For the wiring that connects the terminal and this device, the EMI detection part and the protocol monitor part that utilize the characteristics of the generated EMI are performed by one device, and the cause of the failure is estimated according to the individual results. It eliminates the need for specialized equipment to measure with specialized knowledge, and anyone can easily and quickly respond to a failure.

In this embodiment, the remote control function, the information transfer function, the failure cause estimation function, and the failure information storage function are optional functions, and the code error rate test function is described as the standard functions of the failure diagnostic device 1. Also, the standard functions of the failure detector 6 are the layer 1 to 3 monitor function, the layer 1 to 3 monitor information analysis function, the EMI detection function, the disassembly result display function, and the information transfer function, and the code error rate measurement function, T As explained in the point simulation function, the failure detector 6 transfers the monitor information to the failure diagnosing device 1 by using the B channel or two B channels in bulk without analyzing any information, and the failure diagnosing device 1 It is easy to share functions such as analyzing all information and estimating the cause of failure.

Further, as shown in FIG. 2, the functional block configuration of the failure detector 6 includes layers 1 to 3 processing units of the monitor unit I and the communication unit II.
Although 12 and 23 are separated, it is easy to communicate with the monitor by one layer 1 to 3 processing section, and the failure diagnosis device 1 has been explained with the example of using the personal computer 29. It is also easy to use a dedicated device equipped with a failure diagnosis function and a remote control function.

Further, although the failure detector 6 has been described with the example of the display,
Connect to the printer with a Centronics interface, etc.
It is easy to print out.

The example of fault isolation in the ISDN system has been described above. However, in the case of fault isolation in a standard home bus system, the subscriber line is analog and the control channel uses an independent pair line. is there. The protocol specifications and user / network interface are changed to home bus system specifications (for example, Radio Technology Association, Japan Electronic Machinery Manufacturers Association Standard ET-2101), and the failure detector 6 is connected to the main bus wiring or sub-bus wiring under the home bus controller. Connecting. In addition, remote control uses a communication line with a failure detector 6 connected to the home bus of the user's home where the failure has occurred and a failure diagnostic device 1 installed at a remote location, using a communication line of 4800 bits /
It can also be applied to a home bus system by performing data communication using a modem such as s or 9600bit / s.

〔The invention's effect〕

As described above, in the communication system failure isolation method of the present invention, the failure detector includes an analysis of a communication protocol used by the terminal device when the terminal device communicates with the digital communication network and an electromagnetic wave. The presence or absence of interference is detected, and the presence or absence of a failure is determined by comparing the analysis result of the communication protocol and the detection result of the presence or absence of electromagnetic interference with a predetermined reference value. When the failure is detected, the determination result is analyzed by the communication protocol. The process of transmitting the result and the detection result of the presence or absence of electromagnetic interference to the failure diagnosis device, and the determination result is received by the failure diagnosis device that has received the analysis result of the communication protocol and the detection result of the presence or absence of electromagnetic interference. It has a process of extracting a corresponding coping method and operation guidance and sending it back to the failure detector of the transmission source. Not only, EMI detection results are also used, the relationship of noise and failure is apparent.

Further, the failure detector of the present invention, when the terminal device communicates with the digital communication network, a layer processing unit for analyzing a communication protocol used by the terminal device from data flowing through the communication line, An electromagnetic interference detection unit that detects the presence or absence of an electromagnetic interference voltage or an electromagnetic interference current on the communication line, a pulse monitoring unit that compares the level and pulse width of the pulse signal on the communication line with a standard value, and the polarity on the communication line. A power supply monitoring unit that monitors and compares the received voltage with a standard value, a failure estimation unit that determines whether there is a failure from the processing results of the layer processing unit, the electromagnetic interference detection unit, the pulse monitoring unit, and the power supply monitoring unit, and the failure. Since it has a display unit that displays the estimation result by the estimation unit, it is an all-in-one device, so it is small and easy to transport to the customer's home where a failure has occurred, and does not require multiple engineers. That.

Furthermore, the remote diagnosis function that uses the line to which the failure detector is connected makes it easier to diagnose the demarcation point between the network and the terminal device without installing or transporting a new leased line. Since there is no need to wait at the customer's house until a failure occurs, there is an advantage that maintenance efficiency is improved.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention, showing a connection configuration of a fault diagnostic device and a fault detector, and FIG. 2 shows a functional block configuration of the fault detector in FIG. FIG. 3 is a diagram showing the configuration of the connection point of the fault detector, and FIG. 4 is a diagram showing the functional block configuration of the fault diagnostic device. In the figure, 1 is a fault diagnosing device, 2 is a network terminating device, 3 is a communication connector, 4 is a network terminating device, 4a is a demarcation point (T) between the network and the terminal equipment.
Point) 5 is a failure detector connection terminal, 5a is a switch that disconnects the lower part of the failure detector, 5b is a switch that connects the bus wiring and the failure detector when monitoring the incoming / outgoing call of the terminal, and 5c is the failure detector Switch for switching between the monitor section and the communication section, 5d is a terminal for connecting the user bus wiring, 5e is a switch for connecting the simulator function section and the user bus wiring, 6 is a failure detector,
7 is a terminal device, 8 is a receiver unit, 9 is an EMI detection unit, 10 is a power supply monitoring unit, 11 is a pulse waveform monitoring unit, and 12 is layers 1 to 3.
Processing unit, 13 is a failure estimation unit, 14 is a memory, 15 is an upper layer processing unit, 16 is a voice monitor unit, 17 is a central processing unit, 18 is a display driver unit, 19 is a display unit, 20 is an operation unit interface,
21 is an operation unit, 22 is a receiver / driver unit, and 23 is a layer 1
3 processing units, 24 is an upper layer processing unit, 25 is a code error rate measuring unit, 26 is a simulator function unit, 27 is a line unit, and 28 is an SCS.
I and 29 are personal computers, 31 is a keyboard, 32 is a hard disk, 33 is a printer, I is a monitor unit, and II is a communication unit.

Claims (3)

(57) [Claims] 1. A device for monitoring a data flowing through a communication line connecting the digital communication network and the terminal device for a failure occurring in a communication system in which the terminal device and the failure diagnosing device are connected via a digital communication network. Using a failure detector,
A failure isolation method for identifying a failure location from a detected failure cause, wherein the failure detector includes a communication protocol used by the terminal device when the terminal device communicates with the digital communication network. Analysis and detection of the presence or absence of electromagnetic interference are performed, and the presence or absence of a failure is determined by comparing the analysis result of the communication protocol and the detection result of the presence or absence of electromagnetic interference with a predetermined reference value. The process of transmitting the analysis result of the protocol and the detection result of the presence or absence of electromagnetic interference to the failure diagnosis device, and the determination result is received by the analysis result of the communication protocol and the detection result of the presence or absence of electromagnetic interference, A method of extracting a coping method and operation guidance corresponding to the received content and returning the operation guidance to the failure detector of the transmission source. Ri divided way. 2. A failure occurring in a communication system in which a terminal device and a failure diagnostic device are connected to a digital communication network,
A failure detector for monitoring data flowing through a communication line connecting the digital communication network and a terminal device to identify a failure point of the communication system, the terminal device communicating with the digital communication network. In, a layer processing unit that analyzes the communication protocol used by the terminal device from the data flowing through the communication line, and an electromagnetic interference detection unit that detects the presence or absence of electromagnetic interference voltage or electromagnetic interference current of the communication line, A pulse monitoring unit that compares the level and pulse width of the pulse signal on the communication line with a standard value, a power supply monitoring unit that monitors the polarity on the communication line and compares the received voltage with a standard value, the layer processing unit and the electromagnetic wave. A failure estimation unit that determines the presence or absence of a failure from the processing results of the interference detection unit, the pulse monitoring unit, and the power supply monitoring unit, and a display unit that displays the estimation result by the failure estimation unit are included. A fault detector characterized by: 3. The failure detector according to claim 2, further comprising a simulator section which is connected to a communication line to communicate with the terminal, display the communication result on the display section and transmit the communication result to the failure diagnosis apparatus. Failure detector characterized by.