JP3355952B2 - Network monitoring system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a network monitoring system, and more particularly to an improvement of a network monitoring system for monitoring a network constituted by a plurality of communication stations.

[0002]

2. Description of the Related Art In a production line of a factory or the like, various signals are mutually transmitted and received for smooth control between a plurality of devices. At this time, a network using a token is constructed in a facility system that requires transmission and reception of a signal with high real-time properties between devices. Here, each device is a robot controller, a programmable controller, an image processing device, a display, an industrial computer, an operation panel, and the like, and each is connected by a communication cable. At this time, each device is called a "communication station", and the token is used to arrange transmission and reception of signals between the communication stations, and this token passes around each communication station in a predetermined order. For the transmission and reception of the token, all stations are associated with each other in a relationship of “own station” and “subsequent station”.

[0003] When the own station transmits data, it waits until the token passes, and when the token arrives at the own station, if there is data to be transmitted to the own station, the data is transmitted first, and after the data transmission is completed, the token is transmitted. To the subsequent station. In other words, when data output is completed in the own station, a token is transmitted from the own station to the succeeding station, and the succeeding station transmits data if there is data to be transmitted thereto, and if there is no data, transmits to the succeeding station. Pass the token. The own station monitors whether this operation is performed normally. If this operation is performed smoothly, the succeeding station becomes the token holding station (own station), and the same operation as described above is repeated for the succeeding station.

On the other hand, when the own station transmits a token to the subsequent station, if the correct data is not returned from the subsequent station within a predetermined period, the own station performs a recovery operation. That is, the token is retransmitted from the own station to the subsequent station. The retransmission of the token is a case in which noise or the like is mixed in the communication cable and a correct token is not transmitted to the subsequent station, or a failure occurs in the subsequent station. If an inconvenience occurs temporarily due to noise or the like and the operation returns to the normal state when the token is retransmitted, the succeeding station can return the correct data and transmit the token to the succeeding station, thereby continuing the token transfer.

If the succeeding station still does not reply to the token retransmission, it is determined that transmission to the succeeding station has become impossible, the succeeding station is disconnected from the network, and the subsequent succeeding station is set as a new succeeding station to chain the token. Modify the relationship and form a new network.

In a network using a token as described above, if a contact failure of a communication cable or the like (temporary disconnection, signal attenuation, signal abnormal state such as reflection, or abnormal state of a communication station, etc.) occurs periodically or repeatedly, An abnormality in one place can cause the entire network to stop for a long time. That is, detachment and return of an arbitrary communication station are repeated, and it becomes difficult to maintain the network. Therefore, when constructing the system, it is necessary to confirm the construction quality and to promptly identify an abnormal location when a communication error occurs during network operation.

[0007] A technique for specifying such an abnormal occurrence location is disclosed in Japanese Patent Application Laid-Open No. Hei 6-14023. According to this technique, the number of times of retransmission of the token and the reversal timing of the communication participation flag are totaled for each station, so that it is possible to easily specify the location where the abnormality has occurred.

Further, as means for specifying noise contamination and signal attenuation in a network, it is possible to measure a change in impedance characteristics inside a communication cable using an oscilloscope, a cable tester, or the like, and estimate a location where an abnormality has occurred. Generally done.

[0009]

However, according to the conventional specific method, contact failure at a specific period (abnormal state of signal communication).
May be difficult to detect. That is, if the trunk line to which each communication station is connected causes a contact failure at a long cycle of a certain time or longer, a new token is generated on both sides of the abnormality occurrence location. When this token collides in the communication cable after the contact failure recovery, which token ring is interrupted is not unique. Therefore, when a plurality of tokens are generated, there is a problem that the tendency of the aggregated data such as retransmission tokens is not stable, and it is difficult to specify a location where an abnormality has occurred.

[0010] Signal attenuation and noise level measurement by an oscilloscope are effective for finding a complete disconnection. However, when a contact failure occurs due to vibration of equipment or the like, the signal level changes. It is small and difficult to measure, and it is not possible to accurately identify from which communication station the measured data is. Therefore, it is necessary to measure at many points, and there is a problem that in a large-scale network, a great deal of time is required to specify the location where an abnormality has occurred.

Further, the disconnection measurement method using a device such as a cable tester generally has a low measurement accuracy (poor position measurement accuracy, making it impossible to easily identify a change in impedance characteristics due to the device and poor contact). Since the measurement cannot be performed unless the equipment is turned off, if the contact failure occurs due to the vibration of the equipment, etc., the failure state is not reproduced, so the monitoring and measurement of the contact failure and the communication stability during the operation of the equipment There is a problem that can not be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and can constantly monitor contact failures and communication stability even in a facility operating state with respect to communication abnormalities caused by various causes. It is an object of the present invention to provide a network monitoring system capable of easily estimating a failure point.

[0013]

In order to achieve the above object, a configuration of the present invention provides a network monitoring system for monitoring the operating state of a network constituted by a plurality of communication stations, wherein the network comprises: Recognition means for recognizing communication participating stations currently participating in communication, list creating means for creating a communication participating station list based on the recognized communication participating stations for each communication station, and communication participating stations created at each communication station List multiple communication participating stations from the list
Monitoring means for monitoring the operating state of the network by selecting and comparing with each other .

According to this configuration, it is possible to easily recognize participation or non-participation in communication between communication stations, and it is easy to grasp the state of arrival of signals between communication stations. Further, by comparing the created communication participant station list, it is easy to specify a contact failure occurrence location (a temporary communication disconnection, signal attenuation, signal communication abnormal state such as reflection, etc.). In addition, communication participation,
Since the estimation is made based on the non-participation, the poor contact can be constantly monitored even in the equipment operating state.

In order to achieve the above object, according to the present invention, in the monitoring system having the above-mentioned configuration, the monitoring means is a monitoring unit representing a network, and the monitoring unit currently participates in communication. A monitoring part recognizing means for recognizing the communication participant station that is performing the communication, and a monitoring part list generating means for preparing a communication participant list based on the recognized communication participant station. The operating state of the network is monitored based on the result of comparison with the communication participating station list created by the communication station .

Here, the monitoring unit may be included in any communication station or may be configured independently of the communication station.

According to this configuration, the monitoring unit creates a reference communication participation list, compares this list with the communication participation station list created by each communication station, and determines whether the signal has not arrived from the reference position. Since it becomes clear, it is possible to more quickly and accurately specify a contact failure occurrence location.

In order to achieve the above object, a configuration of the present invention is a network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, wherein the network includes a token flowing through the network. Holding station detecting means for detecting a communication station which currently holds the communication station, storage means for storing a transition state of the holding station, and an irregularity recognized in the transition based on the transition state.
A unique token or data frame and its transmitting station
Monitoring means for recognizing and monitoring the operating state of the network;
It is characterized by having.

According to this configuration, it is easy for a particular communication station, which has not participated in the transition of a token, to form a transition state different in interruption from the transition state formed by the specific token holding station. Can be recognized,
It is possible to easily recognize which communication station causes the contact failure. Further, since the estimation is performed based on the transition state of the token, the poor contact can be constantly monitored even in the equipment operating state.

In order to achieve the above object, a configuration of the present invention relates to a network monitoring system for monitoring an operation state of a network configured by a plurality of communication stations, wherein the network is configured to transmit data flowing through the network. Frame detection means for detecting a frame, and converting a detected data frame into a shoot frame or data
Frame analysis means for analyzing whether or not an existing frame exists , and monitoring means for monitoring the operation state of the network based on the analysis result of the data frame.

According to this structure, the analysis means since the analysis of such data errors and short frame data, whether inconvenience data between which communication station has occurred it is possible to easily recognize, this occurs It is possible to easily estimate the cause of the contact failure. In addition, since the estimation is performed based on the data frame to be communicated, it is possible to constantly monitor the poor contact even in the equipment operating state.

In order to achieve the above object, a configuration of the present invention provides a network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, wherein the network is configured to reduce noise in a received data frame. State determining means for determining the influence state, state storage means for storing the determined noise influence state of the frame for each communication station, and noise of the frame stored in each communication station.
Monitoring means for monitoring the operating state of the network based on the influence state of the network.

According to this configuration, the communication station that has received the abnormal data frame affected by noise can be recognized, and the communication station that has transmitted the data can be recognized. The location can be easily specified. In addition, since the estimation is performed based on the data frame to be communicated, it is possible to constantly monitor the poor contact even in the equipment operating state.

In order to achieve the above object, according to a configuration of the present invention, in a network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, the network transmits a token request frame. Station detecting means for detecting a communication station, response detecting means for detecting a response state of each communication station to a token request frame, and monitoring means for monitoring an operation state of a network based on detection results of the station detecting means and the response detecting means And the following.

According to this configuration, by comparing the communication station transmitting the token request frame (claim token) with the response state of each communication station to the token request frame, it is possible to easily identify the defective contact point. It can be carried out. In particular, it is possible to easily recognize whether the reception state of the communication station is well performed. In addition, since the estimation is performed based on the transmitted token request frame and its response, it is possible to constantly monitor the poor contact even in the equipment operating state.

In order to achieve the above object, a configuration of the present invention is a network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations. Means for obtaining the number of times, means for obtaining the number of receptions for each communication station, and monitoring means for monitoring the operating state of the network based on a comparison result between the number of transmissions and the number of receptions, I do.

According to this configuration, it is possible to easily recognize the stable state of the network by comparing the number of times of transmission and the number of times of reception of each communication station, and it is also possible to easily identify a poor contact point due to the difference in the number of times of transmission and reception. . In addition, since the estimation is made based on the number of times of data transmission / reception, it is possible to constantly monitor the poor contact even in the equipment operating state.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the embodiments described below, the term “contact failure” simply includes an abnormal signal communication state due to a temporary disconnection, signal attenuation, reflection, device abnormality, or the like.

First embodiment. FIG. 1 is a configuration conceptual diagram of the network monitoring system of the first embodiment. In the present embodiment, a robot controller, a programmable controller, an image processing device, a display, an industrial computer,
Devices such as an operation panel are connected by a communication cable to form a network, and each device forms a communication station. In the present embodiment, a network composed of six stations is taken as an example, but the number of communication stations is arbitrary.
At this time, a token is used to arrange the transmission and reception of signals between the communication stations, and the token repeatedly circulates from the 0th station to the 5th station. This is called token ring or token passing. To send and receive this token,
All stations are associated with each other in a relationship of “own station” and “subsequent station”.

When the own station transmits data, it waits until the token passes, and when the token passes, transfers the data together with the token to a target communication station (subsequent station). In other words, when data output is completed at the own station,
The token is transmitted from the own station to the succeeding station. The succeeding station transmits the data to the succeeding station if there is data to be transmitted thereto, and passes the token to the succeeding station if there is no data. The own station monitors whether this operation is performed normally. If this operation is performed smoothly, the succeeding station becomes the token holding station (own station), and the same operation as described above is repeated for the succeeding station.

In the first embodiment, a network monitoring system for easily recognizing a communication abnormality due to attenuation of a communication waveform and specifying an abnormal point will be described. For example, a signal wave transmitted through the network when a resistance portion is formed due to a terminating resistance or poor contact set in the middle of the trunk of the network, or when the input impedance of the receiving unit of each communication station is mismatched. May decay rapidly. As a result, the signal waveform is attenuated below the receivable level, and normal communication cannot be performed. In such a case, signal attenuation is most likely to occur in communications between communication stations with the longest communication distance.
For example, in FIG. 1, it is when transmitting a signal waveform from the right end station (fifth station) to the left end station (first station).

In the present embodiment, an example will be described in which an arbitrary communication station existing at a physical intermediate position of the network, for example, the 0th station is set as a representative station, and the operating state of the network is monitored based on the 0th station.

A characteristic feature of the present embodiment is that it is verified whether a communication station physically farthest from an arbitrary communication station (for example, the 0th station 10) in the network participates in network communication. By doing so, the communication abnormality is recognized and the abnormality location is specified. Generally, a communication station (own station) hands a token to a predetermined succeeding station,
It monitors whether or not another communication station is transferring the token, that is, monitors whether or not to participate in communication. Utilizing the participation / non-participation status, the communication abnormality is recognized and the abnormal part is specified.

FIG. 2 shows an arbitrary communication station (in FIG. 1,
A configuration block diagram of the monitoring station when the 0th station 10) located substantially in the middle of the physical station is set as a monitoring station is shown. When the 0th station 10 functions as one receiving station in the network, the receiving modem 16 of the 0th station 10 receives data from another communication station shown in FIG. The received data is temporarily stored in the reception data storage area 20, and the cyclic data
The check (CRC) 22 checks the content of the received data (whether or not data is garbled). Then, only the data determined to be normal data is transferred to the CPU 24, and the communication station is controlled based on the data. Thereafter, the CPU 24 sets the transmission data storage area 26
Is transmitted to the succeeding station via the transmission modem 28 and the communication cable 18 together with the token and transmitted to the succeeding station held in the subsequent station. Further, the CPU 24 also monitors whether the subsequent station is operating normally as described above.

The CPU 24 monitors the passing status of the token of another communication station via the receiving modem 16 or the like as described above. That is, the CPU 24 recognizes the communication participating station currently participating in the communication by the not-shown recognition means, and creates the communication participating station list 10a as the communication state data as shown in FIG. , Are stored in the participating station recording unit 30 shown in FIG.

The same exchange of data and tokens is performed in each communication station (first station 11 to fifth station 15), and the first station 11 and the fifth station, which are located farthest from the 0 station 10.
In the station 15, the communication participating station lists 11a and 15a are created and stored in the participating station recording unit of each communication station.

Hereinafter, a network monitoring process by comparing the communication participant list created by the 0th station 10 with the communication participant list created by another station will be described with reference to the flowchart of FIG. First, the CPU 24 of the 0th station 10 transmits the communication participant station list request signal stored in the transmission data storage area 26 via the transmission modem 28 to the communication stations at both ends (the first station).
Station 11 and the fifth station 15) (S100). In response to the communication participant station list request signal, if the reception of the communication participant list from both end stations is not confirmed (S101), the terminal station next to the communication station that did not receive it (communication one closer to the 0th station 10). ), And transmits a communication participation station list request signal (S102). In the case of the present embodiment, when there is no communication participating station list from the first station 11, a communication participating station list request signal is transmitted to the second station 12.

When the reception of the communication participating station list from both the end stations is confirmed, the CPU 24 of the 0th station 10 reads out the communication participating station list 10a created by itself from the participating station recording section 30 (S103). The list comparing unit 24a compares the communication participating station list 10a with the received communication participating station lists 11a and 15a (S104). As a result of the comparison, if there is no difference between the communication participating station lists, it is determined that signal attenuation that causes communication failure in the network has not occurred, and a message such as “No abnormality” is displayed by a display device (not shown) or the like. Perform (S105) and end the monitoring process.

On the other hand, if the communication participant station list 10a differs from the other communication participant station lists 11a and 15a in S104, it is determined whether or not the reception of the communication participant list has been performed for a certain time or a certain number of times. Perform (S10
6). This is to increase the reliability of data by performing sampling at a certain level or more because there is a time difference in the token transfer cycle for each communication station, and the processing from S100 is repeated. On the other hand, if there is a difference in the list despite the fact that sampling has been performed for a certain period of time or a certain number of times, that is, the 0th station 10 is
a, the first station 11 recognizes that the fifth station has not participated in communication, while the first station 11 recognizes that the fifth station has not participated in communication. And
When the fifth station 15 recognizes from the communication participating station list 15a that the first station has not participated in communication, it determines that signal communication has occurred for these communication stations and good communication is not being performed. . Then, the inspection result is determined to be "abnormal" (S107), and the display of the communication station and the list of the communication participating stations are performed as necessary to display the defective portion and the like.

When such a defect is found, measures such as changing the arrangement of communication stations in the network and arranging signal amplifiers are taken.

Second embodiment. FIG. 4 is a configuration conceptual diagram of the network monitoring system according to the second embodiment. In the present embodiment, as in the first embodiment described above, a network composed of six stations is taken as an example. However, the number of communication stations is arbitrary, and token exchange, data transmission, communication participant station list creation, and the like are also possible. This is the same as the first embodiment.

In the second embodiment, a network monitoring system for easily recognizing a communication error due to signal non-arrival due to signal reflection and specifying an abnormal point will be described. For example, when the input impedance of the receiving unit of each communication station is mismatched, or when the balance between the stray capacitance of the communication cable and the distributed capacitance of the receiving unit is not good, reflection of a communication signal occurs. As a result, when the signal waveform is distorted beyond the receivable level, normal communication cannot be performed. In such a case, signal reflection is most likely to occur in a network having a relatively long trunk line, and when the arrangement of communication stations is uneven. When signal reflection occurs, communication may not be possible only between specific communication stations.

A characteristic feature of the present embodiment is that a communication participant list of another communication station is compared with a communication participant list of an arbitrary communication station (for example, the 0th station 10) of the network based on the list. This is where the recognition of a communication error and the identification of the error location are performed.

When the 0th station is a monitor station, the block diagram of the 0th station 10 is the same as that of FIG. 2, and transfers data and tokens, creates a list of communication participating stations, and the like.
The configurations of the other stations (the first station 11 to the fifth station 15) are also the same as those described in the first embodiment.
Each station 15 creates communication participant station lists 11a to 15a and stores them in the participant station recording unit of each communication station.

Hereinafter, the network monitoring by comparing the communication participant list created by the 0th station 10 with the communication participant list created by the other stations will be described with reference to the flowcharts of FIGS. The processing will be described. First, station 0
The CPU 24 of No. 0 transfers the communication participation station list request signal stored in the transmission data storage area 26 to each communication station via the transmission modem 28 (S200). In response to this communication participant station list request signal, if the reception of the communication participant station list from any communication station is not confirmed (S201), it is determined that the network is not operating, and the inspection result "no participation station" is given. The monitor is displayed (S202), and the monitoring process ends.

On the other hand, when the reception of the communication participating station list is confirmed, the CPU 24 of the 0th station 10 reads the communication participating station list 10a created by itself from the participating station recording unit 30 (S
203), the read communication participating station list 10a and the received communication participating station list, for example, the communication participating station lists 11a to 11a.
15a is compared with the list comparing unit 24a (S20).
4). As a result of the comparison, if there is no difference between the communication participating station lists, it is determined that there is no signal reflection that causes communication failure in the network, and a message such as “No abnormal station” is displayed on a display device or the like. (S20
5), end the monitoring process.

In S204, if any or all of the communication participant station list 10a and any or all of the other communication participant station lists 11a to 15a are different, the communication participant station list is received for a certain time or more or for a certain number of times. It is determined whether or not it has occurred (S206). This is to increase the reliability of data by performing sampling over a certain amount because there is a time difference in the token transfer cycle for each communication station, and the processing from S200 is repeated. On the other hand, if there is a difference in the list despite the fact that sampling has been performed for a certain period of time or a certain number of times or more, that is, the 0th station 10 communicates with the 0th to 5th stations according to the communication participating station list 10a. The first station 1
1 recognizes that the fifth station does not participate in the communication by the communication participating station list 11a, and the second station 12 to the fifth station 15 determine that only the first station does not participate in the communication according to the communication participating station list 12a to 15a. If it is recognized that there is, it is determined that good communication is not being performed due to signal reflection in the network.
Then, the inspection result is determined as “abnormal station exists” (S20
7) If necessary, display a communication station or display a list of communication participating stations. In the case of signal reflection, a communication failure is unlikely to occur near the occurrence of reflection, and a communication failure due to reflection is likely to occur at a position separated by n times or 1 / n times the wavelength.

In the first and second embodiments described above,
Although an example is described in which an arbitrary communication station is used as a monitor station and the CPU there compares each communication participant station list, separately from the communication stations, the communication participant list created by each communication station is simply collected. Even if a monitor for comparison is provided, the same processing can be performed, and the same effect can be obtained.

Third Embodiment FIG. 6 is an explanatory diagram for explaining the concept of the network monitoring system according to the third embodiment. In the present embodiment, a description will be given of a network monitoring system capable of easily specifying a contact failure location when a contact failure occurs in a trunk line or a branch line connecting each communication station.

On the other hand, in a network that requires strong real-time characteristics, a token passing protocol is used to guarantee that each communication station can communicate within a predetermined time by transferring a token between devices participating in the communication. Have been. This token passing is
Although excellent in real-time performance assurance, when a contact failure occurs, the characteristics of the protocol may render the entire network system incommunicable.

First, a description will be given of a mechanism by which the communication of the entire network becomes impossible due to the characteristics of the protocol. In FIG. 6, for example, if a contact failure occurs at point A (branch line), the first station 11 cannot receive signals from other stations. Then, after a while, the first station 11 determines that it is not connected to the network, and periodically transmits a claim token (token acquisition request) to another station. If this claim token does not reach the main line due to poor contact at point A, it will not stop the entire network system,
If the poor contact is improved for some reason, the claim token is transmitted to other stations, and as a result, all other stations interrupt all communication once and respond to the request . Similarly, when contact failure occurs in the figure 6 B point (trunk), it is impossible to transmit beyond the contact failure point token. Then, the group to which the communication station that had the token at the time of the occurrence of the contact failure belongs will skip the communication station that has stopped responding (the communication station farther from the contact failure point) among the communication stations that have passed the token, and Perform a recovery operation that starts turning. In addition, the group to which the station that did not have the token at the time of the contact failure belongs issues a complaint token because a valid token is not sent even after waiting for a while. Since the claim token is not transmitted to the communication station holding the token due to poor contact, there is no response to the claim token. As a result, it creates a new token itself and starts passing independent tokens.

However, if the contact failure is improved for some reason, the token is transmitted to other stations beyond the contact failure location. As a result, there are two tokens, and all the communication stations interrupt all the communication once.

As described above, a contact failure at one location makes the entire network system unable to communicate. When the above-mentioned phenomenon occurs, each communication station actively repeats participation and departure from communication, and it may not be possible to sufficiently identify poor contact only with data on which communication station is participating in communication. Come out.

Thus, in the third embodiment, the transition state of the token is monitored by monitoring the sudden occurrence of an irregular token and its transmitting station, and the location of the contact failure of the communication cable is specified.

Hereinafter, a specific transition state of the token will be described. As shown in FIG. 6, when a contact failure occurs on the main line (point B), the monitor 32 at the point A indicates the fourth station → the third station → the second station → the fourth station → the third station → the second station. It can be confirmed that the token changes in the order of. At this time, monitor 34
If there is, station 1 → station 0 → station 1 → station 0 → station 1 →
It can be confirmed that the token changes in the order of the 0th station → the 1st station → the 0th station. Also, if the contact failure is improved for some reason, the monitor 32 at the point A shows the tokens that have been transferred at the first station 11 or the 0th station 10 from the fourth station → the third station → the second station. → It can be observed that the token that flows in the order of the fourth station is suddenly interrupted. At this time,
By continuing the observation for a predetermined time or more, it is possible to determine that there is a poor contact in the trunk between the first station 11 and the second station 12.

On the other hand, if a contact failure occurs at the branch line (point A), as described above, the first station 11 cannot receive signals from other stations, and after a while, issues a claim token. At this time, on the monitor 32, the fourth station → the third station → the second station
It can be confirmed that the token changes in the order of the station, the 0th station, the 4th station, the 3rd station, the 2nd station, and the 0th station. At this time, if the contact failure is improved for some reason, 2
The same phenomenon is observed. One is when the poor contact is improved while the first station 11 is issuing a claim token, the claim token is transmitted to other stations, and all other stations interrupt all communication once. At this time, it is confirmed that the irregular data frame (claim token) suddenly interrupts the normal token flow on the monitor 32 at the point A.

The other is that when the first station 11 is silent, the contact failure is improved and the invitation frame issued by the other station (the communication station number is skipped such as the second station to the 0th station). This is a case where the first station 11 responds to the occasionally skipped communication station (frame data for searching for a communication station). In this case, on the monitor 32 at the point A, an invitation frame from another station and a response frame to the invitation from the first station 11 are observed.

As described above, based on the result observed by the monitor, a contact failure portion is specified.

FIG. 7 shows a schematic configuration of the monitors 32 and 34. Data flowing through each communication station is stored in the reception data storage area 40 via the communication cable 36 and the reception modem 38. Here, similarly to FIG. 2, the content check of the received data (whether or not data is garbled) is determined by the CRC.
42. Checked data is CPU
The data is transferred to the participant station recording section 46, and the data of the necessary participant stations are sequentially transferred to the participant station.
It is stored in. In the case of the present embodiment, since the monitor 32 and the like only monitor each communication station, the CP of the normal data (mainly control data) checked by the CRC 42 is used.
Reading from U44 is not performed. And the CPU 44
Performs a display and the like at a predetermined timing on the basis of the analysis result to identify a contact failure portion.

Hereinafter, in addition to FIG. 7, the flowcharts of FIGS. 8 to 10 and the data of FIGS.
A specific processing flow will be described. Received data storage area 4
When data is transferred from CPU 0 to CPU 44,
No. 4 determines whether or not the transferred data is a MAC (media access control) frame (S300), and determines whether or not the source station number is 63 or less (when the network is composed of the 0th to 63rd stations) (S301), it is determined whether the transferred data is a token frame, a claim token, or a response frame (S302). Here, the MAC frame means a frame including data for the purpose of token maintenance. These determinations are for excluding data that does not contribute to the detection of a contact failure from processing. Then, the source station that has transmitted the data contributing to the detection of the contact failure and the destination station of the data are recorded in a predetermined memory of the participating station recording unit 46 (S303). Then, based on the source station and the destination station, a communication participating station list shown in FIG. 11, a part of the token transition history list shown in FIG. 12, a claim token transmitting station state list shown in FIG. 13, and a state shown in FIG. Communication participation state data such as a response transmission state list is created (S304).
Then, the processing from S300 is repeated (S305) in order to perform the above-described data collection for a predetermined time or a predetermined number of times to construct stable communication participation state data.

When the collection of the sample for the predetermined time or the predetermined number of times is completed, the identification of the actual contact failure is started. First, necessary data is read from the data recorded in the participating station recording unit 46 (S306), and it is determined whether or not an irregular token has occurred on the network (S307). If it has been received, the transmitting station is recorded, an irregular token transmission count list as shown in FIG. 15 is created, and a token transition history list in FIG. 12 is constructed (S308). As described above, irregular tokens are generated when multiple communication stations leave the network, so irregular tokens are generated, and a poor connection occurs on the trunk line due to the formation of a token transfer loop. Can be determined to be. if,
If there are no more than two transmitting stations in spite of the occurrence of an irregular token, it is determined that the number of data is insufficient and the process returns to S300 to collect data again (S309).

Next, when the tokens are exchanged by two or more stations, it is determined whether or not the number of the stations that do not participate in the network and the number of the transmitting stations of the irregular token match (S3).
10). If they match, it is possible to clearly identify the communication station that has left the network due to poor contact and the communication station that has not left the network. Is displayed (S31
1). If they do not match, there is a possibility that there is a communication station that has not participated in the communication, and it is not possible to make a clear distinction as described above. Is displayed (S312), and the process for identifying a poor contact is terminated. When such a contact failure location is specified, maintenance work such as re-pulling of the communication cable is performed.

On the other hand, if no irregular token is received in S307 of the flowchart of FIG. 9, the process proceeds to the flowchart of FIG. First, it is determined whether or not a claim token has been received based on the claim token transmitting station state list created in S304 of FIG. 8 (S313). If the claim token is received, it is confirmed that the poor contact is sometimes recovered. Then, it is determined whether or not there are two or more claim token transmitting stations (S314).
4 indicates that there is a possibility that two or more branch lines
"Check station and station" is displayed (S315). Further, when the number of claim token transmitting stations is one, the CPU 4
No. 4 displays "the poor contact position is the first branch line" (S316), and ends the determination processing.

If it is determined in S313 that no claim token has been received, it is determined whether there is a response frame based on the response transmission status list created in S304 of FIG. 8 (S317). If there is no response frame, it is determined that the network is communicating normally, and the process returns to S300 in FIG. 8 to continue monitoring the network. On the other hand, when a response frame exists, the response frame is, for example, a response frame to the invitation frame. Then, it is determined whether or not the response frame is from a non-participating station (S318). If the communication station does not participate due to the contact failure and the communication station happens to transmit a response frame due to the recovery from the contact failure, it is determined whether or not there are two or more response frame transmission stations (S319). , S31
Similarly to 5, the CPU 44 displays a message such as “There is a possibility that two or more branch lines have a poor contact position, and confirms stations ○ and ○” (S320). When the number of transmitting stations is one, the CPU 4
No. 4 displays "the poor contact position is the first branch line" (S316), and ends the determination processing. If the response frame is from the communication participating station in S318, it is determined that the contact failure has been improved, and the process returns to S300 in FIG. 8 to continue monitoring the network.

As described above, by examining the transition history of the token, it is possible to identify a contact failure portion. In the third embodiment, the example in which the transition of the token is observed by the monitor independent from the network has been described. However, the same function is performed by executing the function performed by the monitor on behalf of an arbitrary communication station. The effect can be obtained.

Fourth Embodiment FIG. 16 is a configuration conceptual diagram of the network monitoring system of the fourth embodiment. In the present embodiment, when a data frame flowing in a communication cable is dropped (short frame data) due to a poor contact, the short frame data is analyzed to easily recognize a communication error and specify an abnormal point. The network monitoring system will be described.

FIG. 17 shows an example of the structure of the data frame 48. The data frame 48 includes a start flag, a frame type, a destination station, a source station, a specified data length L1, an actual data length L2, a checksum (CRC check contents), an end flag, and the like. As shown in FIG. 16, when a contact failure occurs at point B, the 0th station 10
And the data frame 48 transmitted from the first station 11 is cut at the break position 48a or the like, and the data frame becomes short frame data shorter than a specified length.

FIG. 18 shows a schematic configuration of the monitor 50. Similarly to the above-described embodiments, the data flowing through each communication station is transmitted from the communication cable 36 to the monitor 50.
The data is stored in the reception data storage area 40 via the reception modem 38. Here, in the reception data storage area 40, each data is stored at an optimum address according to the data length, and a check request flag “1” for the CRC 42 is set. In FIG. 18, for the sake of explanation, normal data, noise, short-circuit F, etc. are displayed, but in practice there is no distinction until the CRC 42 check is completed.
If the checked data is normal data, a read enable flag “1” is added, otherwise, a read enable flag “0” is added and reading is prohibited. In the case of the present embodiment, since the monitor 50 only monitors each communication station, normal data (mainly control data) is not transferred to the CPU 44, but necessary data of the participating stations, for example, FIG.
The data for the list of communication participating stations as shown in
The stored information is sequentially stored in the participating station recording unit 46 via 44.
Further, the CPU 44 extracts the short frame data from the data to which the read enable flag “0” is added, obtains necessary information from the data, stores the information in the participating station recording unit 46, and Based on the extracted data from the short frame data at the timing, a contact failure location is specified and displayed.

In the following, adding the flowchart of FIG.
A process of specifying a contact failure portion based on data extracted from the short frame data will be described. First, it is determined whether or not short frame data has been received based on the check result of the CRC 42 (S400). If the short frame data has not been received, the network determines that communication is normally performed, and continues monitoring in S400.
The determination of the short frame data is performed when L1> L2 by comparing the specified data length L1 with the actual data length L2. When the short frame data is received, it is determined whether the short frame data can be read from the beginning to the length data (S401). This is the source station or the like that discussed later, it is determined whether data for the contact failure place specifying is obtained that the data can not be obtained is to eliminate as unnecessary data. Subsequently, it is determined whether or not the source station number is 63 or less (when the network is configured by the 0th to 63rd stations) (S40).
Perform 2). Here, too, data that cannot be used as data for specifying a contact failure location is excluded.

Subsequently, the CPU 44 sets the participating station recording section 46
Of the communication participant station list stored in the server (S40).
3). Then, an inquiry is made between the communication station that has transmitted the short frame data and the communication station in the communication participating station list (S404). If there is a difference, it is determined that the communication station cannot be used as data for identifying a poor contact point. Exclude. On the other hand, if the communication station transmitting the short frame data is a communication station participating in the communication, it is determined that contact and separation of the communication station due to poor contact are repeated, and the CP is determined.
U44 records the source station in the participating station recording section 46 (S4).
05).

The processing from S400 to S405 as described above is repeated for a predetermined time or a predetermined number of times (S406).
A short frame transmission count list 52 as shown in FIG. And short frame transmission count list 5
2, the CPU 44 specifies the contact failure location, and displays, for example, "the contact failure location is a station ○" or the like (S40).
7).

In this embodiment, the example in which the transition of the token is observed by the monitor independent of the network communication has been described. However, even if the function performed by the monitor is executed on behalf of an arbitrary communication station, the same applies. The effect of can be obtained.

Fifth embodiment. FIG. 20 is a configuration conceptual diagram of the network monitoring system of the fifth embodiment. In the present embodiment, when data corruption occurs in a data frame flowing through a communication cable due to the incorporation of noise, a network monitoring system for easily recognizing a communication error and specifying an abnormal point by analyzing the data corruption is provided. explain.

The routes through which network noise enters as shown in FIG. 20 are roughly classified into those directly entering from a communication cable and those entering from a communication station (equipment). Intrudes through the ground or power supply of the communication station. In this case, it is known that the garbled rate of specific data increases. The data frame transmitted at this time has the same structure as that shown in FIG.

FIG. 21 shows a schematic configuration of the monitor 50. Similarly to the above-described embodiments, the data flowing through each communication station is transmitted from the communication cable 36 to the monitor 50.
The data is stored in the reception data storage area 40 via the reception modem 38. Here, in the reception data storage area 40, each data is stored at an optimum address according to the data length, and a check request flag “1” for the CRC 42 is set. In FIG. 18, normal data, noise, and the like are displayed for explanation, but there is no distinction until the CRC 42 check is actually completed. If the checked data is normal data, a read enable flag “1” is added, otherwise, a read enable flag “0” is added and reading is prohibited. In the case of the present embodiment, since the monitor 50 only monitors each communication station, normal data (mainly control data) is not transferred to the CPU 44, but necessary data of the participating stations, for example, as shown in FIG. Data for such a communication participating station list is sequentially stored in the participating station recording unit inside the CPU 44. Also, the CPU 44
Extracts a data garbled frame due to noise from the data to which the read enable flag “0” is attached, obtains necessary information from the data, stores it in the participating station recording unit,
The CPU 44 specifies a contact failure location based on the extracted data from the garbled frame at a predetermined timing, and performs display or the like.

Hereinafter, the flowchart of FIG.
A process of specifying a noise-containing portion based on data extracted from a corrupted frame will be described. First, it is determined whether or not a data garbled frame has been received based on the check result of the CRC 42 (S500). If no garbled data frame has been received, the network determines that communication is being performed without being affected by noise, and continues monitoring in S500. In addition, the determination of a garbled data frame is made by the device that has received the data checking whether there is any error in the data. If the check data and the checksum included in the data frame do not match, the determination is made. Will be When the data garbled frame is received, it is determined whether the data garbled frame can be read from the beginning to the source station number data (S501). This is to eliminate data for which only a few bits of noise have been received. Next, the source station number is 63 or less (stations 0 to 63).
It is determined whether or not the station has a network (S502). Also in this case, data that cannot be used as data for specifying a noise intrusion point is excluded.

Subsequently, the CPU 44 extracts the communication participant station list stored in the participant station recording unit (S503).
Then, a query is made between the communication station that has transmitted the garbled data frame and the communication stations in the communication participating station list (S50).
4) If there is a difference, that is, data from a station that does not participate in communication is excluded because it cannot be used as data for identifying a noise intrusion point. On the other hand, if the communication station that has transmitted the data garbled frame is a communication station participating in the communication, it is determined that noise has entered from that station, and the CPU 44 records the source station in the participating station recording unit. (S505).

The processing from S500 to S505 as described above is repeated for a predetermined time or a predetermined number of times (S506).
A list 54 of garbled frame reception counts for each communication station as shown in FIG. Then, based on the data garbled frame reception count list 54, if there is a bias in the occurrence of noise in a specific station, the CPU 44 specifies the location of noise intrusion, and displays, for example, "Noise mixing station is the first station" ( S507). When such a display is performed, for example, a noise intrusion station or a shield process for the periphery thereof is performed.

In this embodiment, the example in which the data corruption is observed by the monitor independent of the network has been described. However, the same effect can be obtained by executing the function performed by the monitor on behalf of an arbitrary communication station. Can be obtained. Although the CPU 44 shown in FIG. 21 has a configuration including a participating station recording unit and the like inside, it may be provided separately as shown in FIG.

Sixth embodiment. FIG. 23 is a configuration conceptual diagram of the network monitoring system of the sixth embodiment. In the present embodiment, similarly to the fifth embodiment, when data corruption occurs in a data frame flowing through a communication cable due to noise contamination, the data corruption is analyzed to recognize a communication abnormality and specify an abnormal part. This is to explain a network monitoring system that is easily performed.

In the fifth embodiment, the monitoring system when noise enters from a communication station (equipment) has been described. In this embodiment, a monitoring system when noise directly enters from a communication cable is used. explain. What penetrates the telecommunication cable is often very high in frequency and attenuates rapidly during transmission through the telecommunication cable. Therefore, a communication station near the noise entry point receives a relatively large amount of noise. On the other hand, the frequency of noise reception is low at a communication station far from the intrusion point. In the present embodiment, an example in which a noise intrusion inspection is performed using this fact will be described. The transmitted data frame has the same structure as that shown in FIG.

FIG. 24 is a block diagram of a monitor station when an arbitrary communication station is used as the monitor station. Basically, the configuration is the same as that shown in FIG. When the fifth station 15 functions as one receiving station in the network, the receiving modem 16 of the fifth station 15 receives data from another communication station shown in FIG. As for the received data, each data is stored in the reception data storage area 20 at an optimum address according to the data length, and the CRC 22
A check request flag "1" is set for the. In FIG. 24, for example, normal data, noise, and the like are displayed, but there is no distinction until the check of the CRC 22 is actually finished. If the checked data is normal data, a read enable flag “1” is added, otherwise, a read enable flag “0” is added and reading is prohibited. Then, only the data determined to be normal data is transferred to the CPU 24, and the communication station is controlled based on the data. Thereafter, the CPU 24 transmits the data to be transmitted to the subsequent station held in the transmission data storage area 26 together with the token to the transmission modem 28 and the communication cable 18.
To the subsequent station via. In addition, as described above, it also monitors whether the subsequent station is operating normally.

The CPU 24 sets the read enable flag “0”
The noise is extracted from the data marked with, and the number of times of noise reception is stored in the participating station recording unit 30 connected to the CPU 24. Similarly, recording of the number of noise receptions 10b to 14b
b is also performed in each communication station (the 0th station to the 4th station 14).

Further, C of the fifth station 15 serving as a monitor station
The PU 24 periodically transmits the data of the noise reception count data transmission request data in the transmission data storage area 26 to each station via the transmission modem 28. The CPU 24 of the fifth station 15 creates an all-station noise reception count list 56 based on the noise reception count data transmitted from each station, and performs a noise contamination inspection based on this list.

Hereinafter, by adding the flowchart of FIG.
The processing of the noise contamination inspection based on the noise data will be described. First, the CPU 24 of the fifth station 15 serving as a monitor station
Requests each station to transmit the number of times of noise reception data (S600). Next, it is determined whether or not there is a response to this request (S601). That is, when the fifth station 15 cannot receive the noise reception count data of each station, it is determined that there is no communication station participating in the communication, and "no participating station" or the like is displayed as the inspection result display (S602). . On the other hand, when the fifth station 15 receives the data on the number of times of noise reception of each station, the fifth station 15 creates a noise reception number list 56 shown in FIG. 23 based on the data (S603). Then, the data collection is repeated for a certain time or a certain number of times (S60).
4), the noise reception count list 56 is constructed.

In the fifth station 15, when the sufficient noise reception count list 56 has been constructed, an actual noise contamination inspection is started. First, it is determined whether the number of times of noise reception of all stations is “0” (S605). If the number of noise receptions of all stations is "0", it is determined that the network is operating normally without noise contamination, and a display such as "no noise intrusion" is displayed as the inspection result display (S606). . On the other hand, if it is not “0”, it is determined whether there is a difference in the number of times of noise reception between the stations (S60).
7). When there is almost no difference, it is a case where the intrusion of noise occurs uniformly, and for example, a display such as "there is noise intrusion in the entire network" is displayed as the inspection result display (S608). If there is a difference, there is a case where noise has entered at or near a specific communication station, and for example, a display such as "noise has entered" or "abnormal station exists" is displayed as an inspection result display (S609). The processing of the noise contamination inspection ends.

In the above-described embodiment, an example has been described in which an arbitrary communication station is used as a monitor station and the CPU of the monitor station processes the data from each communication station as a representative. Even if a monitor for collecting and comparing data created by each communication station is provided, the same processing can be performed, and the same effect can be obtained.

Seventh Embodiment FIG. 26 is a configuration conceptual diagram of the network monitoring system of the seventh embodiment. Similarly to the fifth embodiment, when data is garbled in a data frame flowing through a communication cable due to noise contamination, the data processing unit of the communication station is overloaded due to the garbled data and network operation is maintained. May inhibit.
In the seventh embodiment, the number of times of noise reception (noise occurrence frequency) is obtained in the same manner as in the above-described sixth embodiment, and the operational stability of the network is quantitatively grasped by referring to the use status of the received data storage area. FIG. 1 illustrates a network monitoring system that can be used. The transmitted data frame has the same structure as that shown in FIG. The block diagram of the monitor station when an arbitrary communication station is used as the monitor station is the same as that of FIG. 24, and the generation of the noise reception count list is the same as that of the sixth embodiment.

In the case of this embodiment, the CPU of each communication station
The reception data storage area usage rate is always calculated and transmitted to the fifth station 15 as a monitor station together with the noise reception count data. The CPU of the fifth station 15 creates an all-station noise reception count list 56 and a reception data storage area usage list 58 based on the noise reception count data transmitted from each station and the reception data storage area usage rate. The operation stability of the network is inspected based on.

Hereinafter, in addition to the block diagram of FIG.
With reference to the flowchart of FIG. 7, the processing of the network operation stability inspection will be described. First, the fifth station to be the monitor station
The CPU 24 of the station 15 requests each station to transmit noise reception count data and data storage area usage rate data (S700). Next, it is determined whether or not there is a response to this request (S701). In other words, the 2
If the fifth station 15 cannot receive the type of request data,
It is determined that there is no communication station participating in the communication, and “no participation station” or the like is performed as the inspection result display (S702). On the other hand, when the fifth station 15 receives data from each station, based on the data, the noise reception count list 5 shown in FIG.
6 and the received data storage area usage rate list 58 shown in FIG. 26 is created (S703). Then, the data collection is repeated for a certain time or a certain number of times (S704), and a noise reception number list 56 and a reception data storage area usage rate list 58 are constructed.

After the fifth station 15 has constructed the sufficient noise reception count list 56 and received data storage area usage rate list 58, the actual operation stability test of the network is started. First, it is determined whether or not the number of noise receptions of each station is sufficiently small (for example, about once / one hour) (S705). When the number of times of noise reception is sufficiently small, it is further determined whether or not the data storage area usage rate of each station is sufficiently small (for example, 50% or less) (S706). If the data storage area usage rate is sufficiently low, it is determined that the network is performing communication processing with a margin, and a display such as "network is stable" is displayed as the inspection result display (S707). On the other hand, if the data storage area usage rate is high, it is determined that there is a communication station that is not affected by noise or the like but is slow in processing, and a display such as “there is a device with no noise influence but a slow processing” is displayed. (S
708).

On the other hand, when it is determined in S705 that the number of times of noise reception is large, it is determined whether or not the usage rate of each data storage area is high (S709). Then, when the usage rate is low, each communication station of the network performs data processing with a margin, and there is no problem in operation, but it is determined that there is an influence of noise on the network, and as an inspection result display, for example, A display such as "there is little influence on the network but noise is present" (S710). Also, S709
In the case where the data storage area usage rate is high, it is determined that the data processing of the communication station is overloaded due to the incorporation of noise, and the inspection result is displayed, for example, "there is an influence on the network due to the influence of noise". Is displayed (S711).

[0093] If necessary, the communication station affected by the noise intrusion may be estimated and displayed from the noise reception count list 56 and the reception data storage area usage rate list 58.

In the above-described embodiment, an example has been described in which an arbitrary communication station is used as a monitor station and the CPU of the monitor station performs processing on behalf of data from each communication station. Even if a monitor for collecting and comparing data created by each communication station is provided, the same processing can be performed, and the same effect can be obtained.

Eighth embodiment. FIG. 28 is a conceptual diagram illustrating the configuration of the network monitoring system according to the eighth embodiment. As described above, when a communication station cannot receive a token from another communication station for some reason, it periodically transmits a claim token requesting a token. For example, a communication station having a failure such that it cannot receive a normal token for a predetermined time or longer, such as when the transmission section is normal but the reception section fails and cannot receive, or when the occurrence of contact failure and recovery are repeated and the reception state is unstable, etc. Send the claim token periodically. On the other hand, the communication stations that have normally passed the tokens temporarily stop communication with each other and perform an operation of responding. As described above, a station that cannot receive a normal token for more than a predetermined time periodically transmits a claim token. When only the receiving unit is out of order or when the poor contact is temporarily recovered, the claim token is transmitted to another station. As a result, the network communication is repeatedly stopped, and the network does not function normally. In other words, if the transmitting unit does not function, the network is not stopped, but if the receiving unit does not function, the network is stopped.

In the present embodiment, a network monitoring system for specifying a fault location based on a claim token transmitted in such a case and a response operation to the claim token will be described.

As shown in FIG. 28, the monitor 60 which does not exchange tokens is connected to each communication station (the 0th station to the
The station 14) monitors the state of transmission / reception of token frames, claim token frames, and response frames. The configuration of the monitor 60 is substantially the same as the configuration shown in FIG. 7, and data flowing through each communication station is stored in the reception data storage area 40 via the communication cable 36 and the reception modem 38.
Then, the CRC 42 checks the content of the received data (whether or not data is garbled). The checked data is transferred to the CPU 44, and the above-described failure analysis is performed. At the same time, necessary participating station data is sequentially stored in the participating station recording unit 46. And CPU4
Reference numeral 4 designates a failure position based on the analysis result at a predetermined timing and performs display or the like.

In the case of the present embodiment, the CPU 44 monitors the state of the number of transmissions of the claim token transmitted and received by each communication station and the state of transmission of the response frame, and creates a list. Based on this list, the fault location of the network is specified.

In the following, adding the flowchart of FIG.
A process for inspecting a fault location of a network will be described. First, the CPU 44 of the monitor 60 transmits the MAC from each station.
(Medium access control) data (data for token maintenance and management, including tokens, claim tokens, response frames, etc.) is fetched (S800).
Then, it is determined whether or not the fetched data is a response frame (S801). If the fetched data is a response frame, the response frame transmitting station is recorded in the participating station recording section 46 (S802), and the process returns to S800 to fetch the next data. If it is determined in S801 that the data is not a response frame, it is further determined whether or not the data is a claim token frame (S803). Here, if the received data is not a claim token frame, it is determined that the data cannot be used for specifying the location of a failure in the network, and the process returns to S800 to fetch the next data.

If it is a claim token frame in S803, the CPU 44 records the claim token transmitting station in the participating station recording section 46 (S804), and as shown in FIG. 30 and FIG. Create a list of response replies. Then, the process returns to S800 to collect data for a certain time or a certain number of times and construct a highly reliable list (S805).

After the sufficient list has been constructed, the actual network check is started. First, the claim token transmitting station determines whether a response frame has been transmitted (S806). If a claim token is transmitted and a response frame is transmitted, the transmitting / receiving unit of the communication station functions normally, and transmission / reception to / from another station can be performed normally. It is determined that the communication disabled state sometimes occurs due to the above, and a display such as "branch contact failure" is displayed as a network inspection result display (S807). In this case, the judgment is made based on the list as shown in FIG.

On the other hand, when the claim token is transmitted but the response frame is not transmitted, that is, when only the claim token is transmitted without being able to respond to the call from another station, the receiving unit is abnormal. If it is determined that there is, a display such as "1st station receiving unit error" is displayed as a network inspection result display (S808). In this case, the judgment is made based on the list as shown in FIG.

In this embodiment, an example in which the MAC data (such as a claim token) is observed by a monitor independent of the network communication has been described. However, the function performed by the monitor is executed by an arbitrary communication station as a representative. Even if it does, the same effect can be obtained.

Ninth embodiment. FIG. 32 is a conceptual diagram of the configuration of the network monitoring system according to the ninth embodiment. Some networks in the field of FA perform communication called a data link. In this data link, each communication station provides a common memory for communication, and each communication station writes data to its own write area in the memory. This data link communication employs a communication method generally called broadcast. This simultaneous broadcast is for unilateral communication regardless of whether or not the receiving side has correctly received the broadcast. Therefore, when the cycle time of the equipment system is very short and the time allowed for control is extremely short, it is necessary to check whether or not the transmitted data has been reliably received at the receiving station side in order to maintain the operation of the network. Is important.

In the present embodiment, a network monitoring system capable of quantitatively grasping the operating stability of a network by comparing received data from each station observed by an arbitrary monitor with the number of times each station transmits data. It is to explain. Note that any communication station (FIG. 32)
In the case of the present embodiment shown in FIG. 7, the configuration block diagram of the monitor station when the fifth station 15) is a monitor station is the same as FIG. 2, and the CPU 24 of the fifth station 15 is sent from each station. A transmission / reception count list as shown in FIG. 33 is created based on the transmission / reception counts of the data and its own data, and based on this list, the operation stability of the network is checked.

Hereinafter, the processing for checking the operational stability of the network will be described with reference to the flowcharts shown in FIGS. First, the CPU 24 of the fifth station 15 serving as a monitor station
Requests the respective stations to transmit the number of times of data reception and the number of times of transmission (S900). Next, it is determined whether or not there is a response to this request (S901). In other words, when the fifth station 15 cannot receive the two types of request data from the respective stations, it is determined that there is no communication station participating in the communication, and "no participating station" or the like is displayed as the inspection result display. (S
902). On the other hand, when the fifth station 15 receives the data from each station, the fifth station 15 records the data in the participating station recording unit 30, and creates a transmission / reception count list shown in FIG. 33 based on the data (S903). Then, the data collection is repeated for a fixed time or a fixed number of times (S904), and a transmission / reception count list is constructed.

In the fifth station 15, when a sufficient list of the number of times of transmission / reception has been constructed, an actual operation stability check of the network is started. That is, the reception count data of each station is lower than the actual transmission count data by a certain value or more (eg,
% Or more) (S905). If the number of times of reception and the number of times of transmission substantially match, each communication station determines on the network that data is normally transmitted and received, and
As the inspection result display, for example, a display such as “No abnormal station” is performed (S906). On the other hand, if the number of receptions is lower than the number of transmissions by a certain value or more, it is determined that a potential abnormality has occurred in the network due to some cause, for example, failure, poor contact, noise, reflection, etc. For example, a display such as "abnormal station exists" is performed (S907). Note that, as shown in FIG. 35, if the transmission / reception count list shown in FIG. 33 is calculated and displayed as a ratio of the reception count to the actual transmission count, the network administrator or the like can easily understand.

In the above-described embodiment, an example has been described in which an arbitrary communication station is used as a monitor station and the CPU of the monitor station processes data on behalf of each communication station. Even if a monitor for collecting and comparing data created by each communication station is provided, the same processing can be performed, and the same effect can be obtained.

Note that the format of the list created in each of the above-described embodiments is merely an example, and a list showing similar contents can be used for the same purpose.

[0110]

According to the present invention, by monitoring the status of communication stations participating in the network and the status of data being transmitted and received, the network can be constantly monitored even when the equipment is in operation, and contact failure points can be monitored. It is possible to maintain a network that performs good communication by accurately and quickly comprehending and monitoring the operation stability of the network.

[Brief description of the drawings]

FIG. 1 is a configuration conceptual diagram of a network monitoring system according to a first embodiment of the present invention.

FIG. 2 is a configuration block diagram of a monitor station of the network monitoring system according to the first embodiment of the present invention.

FIG. 3 is a processing flowchart of a monitor station of the network monitoring system according to the first embodiment of the present invention.

FIG. 4 is a configuration conceptual diagram of a network monitoring system according to a second embodiment of the present invention.

FIG. 5 is a process flowchart of a monitor station of the network monitoring system according to the second embodiment of the present invention.

FIG. 6 is a configuration conceptual diagram of a network monitoring system according to a third embodiment of the present invention.

FIG. 7 is a configuration block diagram of a monitor of a network monitoring system according to a third embodiment of the present invention.

FIG. 8 is a part of a flowchart of a monitor process of the network monitoring system according to the third embodiment of the present invention;

FIG. 9 is a part of a flowchart of a monitor process of the network monitoring system according to the third embodiment of the present invention;

FIG. 10 is a part of a processing flowchart of a monitor of the network monitoring system according to the third embodiment of the present invention.

FIG. 11 is a communication participating station list created by a monitor of the network monitoring system according to the third embodiment of the present invention.

FIG. 12 is a token transition history list created by a monitor of the network monitoring system according to the third embodiment of the present invention.

FIG. 13 is a claim token originating station status list created by a monitor of the network monitoring system according to the third embodiment of the present invention.

FIG. 14 is a response transmission state list created by a monitor of the network monitoring system according to the third embodiment of the present invention.

FIG. 15 is an irregular token transmission count list created by a monitor of the network monitoring system according to the third embodiment of the present invention.

FIG. 16 is a configuration conceptual diagram of a network monitoring system according to a fourth embodiment of the present invention.

FIG. 17 is a structural example of a data frame transmitted and received by the network monitoring system according to the fourth embodiment of the present invention.

FIG. 18 is a configuration block diagram of a monitor of a network monitoring system according to a fourth embodiment of the present invention.

FIG. 19 is a flowchart of a monitor process of the network monitoring system according to the fourth embodiment of the present invention.

FIG. 20 is a configuration conceptual diagram of a network monitoring system according to a fifth embodiment of the present invention.

FIG. 21 is a configuration block diagram of a monitor of a network monitoring system according to a fifth embodiment of the present invention.

FIG. 22 is a processing flowchart of a monitor of the network monitoring system according to the fifth embodiment of the present invention.

FIG. 23 is a configuration conceptual diagram of a network monitoring system according to a sixth embodiment of the present invention.

FIG. 24 is a configuration block diagram of a monitor station of the network monitoring system according to the sixth embodiment of the present invention.

FIG. 25 is a processing flowchart of a monitor station of the network monitoring system according to the sixth embodiment of the present invention.

FIG. 26 is a configuration conceptual diagram of a network monitoring system according to a seventh embodiment of the present invention.

FIG. 27 is a process flowchart of a monitor station of the network monitoring system according to the seventh embodiment of the present invention.

FIG. 28 is a configuration conceptual diagram of a network monitoring system according to an eighth embodiment of the present invention.

FIG. 29 is a processing flowchart of monitoring of the network monitoring system according to the eighth embodiment of this invention.

FIG. 30 is an example of a list of the number of times a claim token has been received and the number of times a response has been returned, created by the monitor of the network monitoring system according to the eighth embodiment of the present invention;

FIG. 31 is an example of a list of the number of claim token receptions and the number of response replies created by the monitor of the network monitoring system according to the eighth embodiment of the present invention.

FIG. 32 is a configuration conceptual diagram of a network monitoring system according to a ninth embodiment of the present invention.

FIG. 33 is a transmission / reception count list created by a monitor station of the network monitoring system according to the ninth embodiment of the present invention.

FIG. 34 is a processing flowchart of a monitor station of the network monitoring system according to the ninth embodiment of the present invention.

FIG. 35 is a transmission / reception count rate list created by a monitor station of the network monitoring system according to the ninth embodiment of the present invention.

[Explanation of symbols]

10 No. 0 station, 11 No. 1 station, 12 No. 2 station, 13 No. 3 station, 14 No. 4 station, 15 No. 5 station, 16, 38 Reception modem, 18, 36 Communication cable, 20, 40 Reception data storage area, 22, 42 CRC, 24, 44 C
PU, 26 transmission data storage area, 28 transmission modem,
30, 46 participant station recording unit, 32, 34, 50 monitor, 48 data frames, 52 short frame transmission count list, 54 data garbled frame reception count list, 56 noise reception count list, 58 received data storage area usage rate list.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/28-12/46

Claims (7)

(57) [Claims] 1. A network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, said network comprising: recognition means for recognizing a communication participant station currently participating in communication; a list creation means for creating a communication participant station list based on a station for each communication station, double in the communication participant station list created in each communication station
By selecting a number of participating stations and comparing them with each other.
Network monitoring system, characterized in that it comprises a monitoring means for monitoring the health of a network, the Ri. 2. The system according to claim 1, wherein the monitoring unit is a monitoring unit representing a network, wherein the monitoring unit includes a monitoring-side recognition unit that recognizes a communication participating station that is currently participating in communication. includes a monitor side list creating means for creating a communication participant station list based on the recognized communication participant station, and the comparison result of the communication with the participating stations list communication participant station list and the communication station monitoring unit created created A network monitoring system for monitoring an operation state of a network based on the information. 3. A network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, wherein the network includes: a holding station detection unit that detects a communication station that currently holds a token flowing in the network; Storage means for storing a transition state of the holding station; and an irregisty recognized in the transition based on the transition state
Token or data frame and its transmitting station
And a monitoring means for recognizing and monitoring the operating state of the network. 4. A network monitoring system for monitoring the health of configured network by a plurality of communication stations, the network includes a frame detection means for detecting data frames flowing in the network, shot on the detected data frame Frame or day
A network monitoring system, comprising: frame analysis means for analyzing whether or not there is a garbled frame ; and monitoring means for monitoring the operation state of a network based on the analysis result of the data frame. 5. A network monitoring system for monitoring the health of a network constituted by a plurality of communication stations, the network, thereby determining the noise influence state of the received data frame, the determination frame noise A network monitoring system comprising: state storage means for storing an influence state for each communication station; and monitoring means for monitoring an operation state of a network based on a noise influence state of a frame stored in each communication station. . 6. A network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, said network comprising: station detection means for detecting a communication station transmitting a token request frame; and a token of each communication station. A network monitoring system, comprising: response detection means for detecting a response state to a request frame; and monitoring means for monitoring an operation state of a network based on detection results of the station detection means and the response detection means. 7. A network monitoring system for monitoring an operation state of a network constituted by a plurality of communication stations, wherein the network obtains a transmission count for each communication station, and obtains a reception count for each communication station. A network monitoring system comprising: an obtaining unit; and a monitoring unit that monitors an operation state of a network based on a comparison result between the number of transmissions and the number of receptions.