JPS62169543A - Network extending system - Google Patents

Abstract

PURPOSE:To perform a test job without affecting a normal network by forming a test ring to a network and confirming the normalcy of the communication of a medium access control (MAC) level via said test ring. CONSTITUTION:For a line concentrator 1 which has no rise yet, the communication controllers 8, 9, etc., are bypassed from a transmission line 3 so that the received signals can be directly relayed. While a test ring 31 is formed between a follower communication controller 8 and a line concentrator 1-B which has a new rise for test of nromalcy of the corresponding section for a line concentrator 1-A which has a rise already and contains a local ring 30. The ring 31 is independent of the ring 30 kept under a working state and therefore the controller 8 can test the normalcy of the ring 31 without affecting the communication which is under execution via the ring 30.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an expansion method of a ring-shaped network, and in particular, a method for expanding the network sequentially in response to the establishment of a new station (ST) or recovery from a failure. This invention relates to a network expansion method suitable for.

[Conventional technology]

In a network system in which a plurality of stations are connected by a ring-shaped transmission path, the ring-shaped network failure recovery monitoring method can be applied to network expansion control.

As a conventional failure recovery monitoring method, for example,
50639 or JP-A-58-197940 are known.

In this case, 5T (ST
3A) sends a kind of monitoring signal to the ST (ST#B) adjacent to the other side through the faulty part, and depending on whether ST#B can receive the above monitoring signal, the faulty part is detected. I am trying to detect recovery. However, in these conventional monitoring systems, the transmission path, for example, the active first ring transmission path and the standby second ring transmission path, are not connected between ST#A and ST#B. That is, for example, no consideration is given to ensuring that the token can normally circulate between the two STs, that is, ensuring the normality of MAC level communication.

International standardization machine QISO
nalStandard Organization
) Connection OS I (0p
en System Interconnect-tio
According to the data link layer DLC (Data Lj, n
k Layer) is further media access-ml
Control M A C (Medium Access C
ontrol) and logical link control LLC (Log
ical Link Control). In light of the above model, the conventional method can test and confirm the normality of only the lower first layer, that is, the PHY (Physical layer).

[Problem that the invention seeks to solve]

In the above conventional technology, no consideration is given to confirming the normality of communication at the MAC level, and even if the PHY function is normal, if the MAC function is abnormal, communication cannot be performed normally. There was a problem that it was not sufficient.

An object of the present invention is to provide a network monitoring method that can also confirm the normality of MAC level communication. Another object of the present invention is to provide a function to sequentially expand a network while starting STs irregularly by applying this monitoring method, that is, to provide a control method for sequentially incorporating STs into a network. It's about doing.

[Means for solving problems]

The above objective is achieved by configuring a test ring that includes a newly installed ST in the network or a ST that monitors failure recovery, and confirming the normality of MAC level communication via this test ring. . Note that the upper layer of MAC, that is, the functions of LLC and above do not depend on the form of the transmission path, so there is no need to check the normality using the test ring.

[Effect]

In order to confirm that the faulty part has recovered normally or that there is no abnormality in the circuit part newly incorporated into the network, it is necessary to test the part to be detected in the network's original communication form. desirable. Therefore, when targeting a ring network, a test to confirm the normality of a faulty part or a newly added part is performed on another ring network that includes the above-mentioned test target, independently of the normal ring network that is already in operation. is configured, and test operations can be performed within this test ring without affecting the regular network.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an internal configuration diagram of the ST that best represents the features of the present invention, and FIG. 2 is an overall configuration diagram of the network system.

In FIG. 2, 1 is an ST with a line concentrator function (hereinafter referred to as a line concentrator), 2 is a terminal device connected to the line concentrator,
3 connects a plurality of concentrators to each other. This is a double ring transmission line consisting of a second transmission line. Each concentrator 1 also includes a plurality of terminal connection branch lines 4 for connecting the terminal devices 2 to the ring transmission path.

FIG. 1 shows the internal configuration of two adjacent line concentrators. Reference numerals 1 to 4 correspond to each of the above elements. Reference numeral 5 denotes a dual-system transmission line switch mechanism for, for example, switching from the first transmission line to the second transmission line, or turning back the transmission line in the opposite direction, as a measure against abnormalities in the transmission line, and 6 indicates a dual transmission line switch mechanism connected to the concentrator. 7 is a switch mechanism for configuring a local ring 30 that enables local communication only between terminal devices and connecting the local ring to the network; A branch line bypass switch mechanism 8 for disconnecting communicates with the terminal device 2 and the slave communication control device 8 to check the normality of the part to be added to the new network 1-network, that is, the ring transmission line part to be expanded. The main communication control circuit 1.10 which performs communication control is a start signal detection circuit for detecting, by means of a predetermined current value, that the line concentrator has started up or that a fault has been recovered by turning on the power.

The operation of one embodiment of the present invention will be described based on the above configuration.

First, when only one line concentrator 1 is started up in the network, the main communication control device 9 included in it outputs a signal, for example, a specific data pattern, and this signal goes around the ring transmission path 3 and transmits a predetermined data pattern. Check to see if they return in time. If the return of the signal cannot be detected even after a predetermined period of time has elapsed, it is determined that communication in the ring-shaped network I-network via the transmission line 3 is impossible, and a closed local ring is established within the concentrator. Once the 6 local rings are formed by applying an activation signal to the local ring switch mechanism 6 to form them, communication becomes possible at least between the terminal devices connected to the concentrator. In the line concentrator 1 that has not yet been established, each communication control device 8, 9, etc. is bypassed from the transmission path 3 so that the received signal can be relayed as is.By doing this, the local ring 30 is formed only when there is a fault in the transmission line 3, or when the total length of the transmission line 3 is too long for signal relaying only by the established line concentrator.

The procedure for the line concentrator 1 that has formed the local ring 3o to expand the ring is as follows.

In this state, it is first necessary to detect which side of the line concentrator is activated, for example, which side of the line concentrator is on the input side or the output side of the clockwise first transmission path 3A. This detection can be performed using the activation signal detection circuit 1o. That is, since a newly started line concentrator sends out a signal for confirming the state of the transmission path as described above, this can be detected by the starting signal detection circuit 10.

When this signal is detected, the main communication controller forms a test ring with the new start-up concentrator.

Test the health of this ring part.

FIG. 1 shows a state in which the test ring 31 is formed between the line concentrators 1-A- and 1-B.

The line concentrator 1-A, which started up first and has already formed the local ring 30, checks the normality of the section between the slave communication control device 8 and the newly started line concentrator 1-B. A test ring (Test 1 to ring) 31 for testing is formed. Since this test ring 31 is independent of the local ring 30 that is in operation, the slave communication control device 8 can transfer data to the test 1 without affecting the communication taking place via one local ring 30. The normality of the ring 31 can be tested. This test also uses a ring-shaped test ring 3.
1, the normality of MAC level communication can be confirmed as described above. When the normality of MAC level communication by the test ring is confirmed, the test ring is incorporated into the ring that is in operation.

In this case, for example, in a ring network based on token control, the test can be performed as follows.

In this case, the main and slave communication control devices 9 and 8 are provided with, for example, the document r Token Ring Access Method.
d and Physical Lager 5pec
ification.

IEEE 5 standard 802, 5 198
5 (ISO/DP880215) J. A test operation is performed on the test ring 31 according to the above protocol. If there is no obstacle on the ring,
The protocol is in a normal state, ie, 5tand-by or Active state. On the other hand, if there is a failure on the ring 31, the protocol is in an abnormal state, i.e. 13eacon
state. This makes it possible to confirm the normality of MAC level communication on the test ring.

FIG. 3 summarizes what has been described above into an operational flow of the line concentrator. For example, when the line concentrator starts up when the power is turned on, it first checks whether the transmission line relayed by the square line unit is already in use (step 3).
10). This can be done, for example, by monitoring reception on the transmission path and whether or not tokens are flowing on the transmission path in a state where no transmission is performed (listening state). If the token is flowing, the transmission line is in use and there is a steady connection to the transmission line, i.e., the clockwise first
The transmission path 3A becomes connected to relay the received data to the first transmission path (step 380). If the transmission line is not in use, then

Check whether the data can travel around the ring or whether there are other prefectural line devices that can communicate with each other.

For this check, 1. Second image transmission path 3A, 3
An activation signal is sent to B (step 320). if,
If the destination activation signal is 1, for example, if the square line device returns after going around the first transmission line 3A, it assumes that the data can go around the ring and establishes a steady connection state to the ring (
step 380). If an activation signal sent by another prefectural line device is received, it is assumed that there is another prefectural line device with which one communication can be made, and a test ring 31 is formed between the image collecting devices (step 35o). The health of the ring communication protocol is tested, and once the health is confirmed, the test ring is incorporated into the operational ring (step 360). When a steady connection state is achieved by incorporating the test ring into the working ring, the line concentrator ends the operation for network expansion (step StO>).

If neither the activation signal sent in step 320 nor the activation signal from another prefectural line device can be received, the local ring 3o described above is formed (step 340). In addition, for the above operation, the line concentrator that includes the active ring but is not in a steady connection state should always or periodically connect to the test ring side or form this in order to detect the start-up of other prefectural line devices. Monitor the status of the side transmission path. For this purpose, for example, the activation signal may be sent out all the time, or it may be sent out after detecting the activation signal sent by another prefectural line device.

〔Effect of the invention〕

According to the present invention, it is possible to test the normality of communication at the MAC level in a part where a new ring is to be expanded, so that failure recovery can be monitored and necessary and sufficient confirmation can be performed at the time of system startup. Further, since the above test is performed by forming a local ring separate from the ring transmission line that is already in operation, there is an advantage that the test can be executed without affecting the network system that is in operation.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the internal configuration of a line concentrator and the formation of a test ring, FIG. 2 is an overall configuration diagram of a network system implementing the present invention, and FIG. 3 is an operational flowchart of each line concentrator. DESCRIPTION OF SYMBOLS 1... Line concentrator, 2... Terminal device, 3... Ring transmission path, 8... Slave communication control device, 9... Main communication control device, 10. Starting signal detection circuit, 30... - Local ring, 31... test ring. 2 year old figure

Claims (1)

[Claims] 1. In a ring-shaped network in which a plurality of stations (STs) are connected by dual transmission paths, an ST located at the end of the ring-shaped network that is already in operation and a newly added station to the network Between the ST to be added and the new ST, the end ST and the new ST
forming a test ring path including a test ring path; testing the normal operation of a ring communication protocol on the test ring path; and connecting the test ring path to the operating network in response to the test results. A network expansion method characterized by including the following. 2. In claim 1, each ST is:
It comprises first and second control means that operate according to a ring communication protocol, the first control means controls communication in the operating network, and the second control means performs a normality test of the test ring path. A network expansion method characterized by performing the following.