JPS62117437A - Initialization control system for loop transmission system - Google Patents

Abstract

PURPOSE:To eliminate the necessity of a monitoring station, by initializing a looped transmission system by fixing a logic ring table composed of the addresses of a preceding station, its own station, and succeeding station in accordance with a forward or reverse packet received by a data transmission station. CONSTITUTION:Physical synchronism is taken at the moment when all of A-E stations become operable and synchronous initialization is completed. When a timer started from the synchronous initialization exceeds a set time determined by (office number X basic initialization time), the A-station firstly sends a forward initial packet FIP. At this time, each station knows its own address only and, by the arrival of the FIP, that the preceding station is A-station. The station sending the FIP further sends a free token and gives the next station in the downstream the transmission right. The station which has received the free token fixes the preceding station of a logic rink table LRT and a forward number. The same procedure is performed on the B-E stations and the preceding stations and forward numbers are determined.

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention provides a system in which a plurality of data transmission stations for transmitting and receiving data are connected in a ring through a transmission path, and receive 1-kun circulating on the transmission path. The data transmission station acquired the right to transmit data]--Relates to an initialization control method for initializing a loop transmission system using a Kunpassing method.

<Prior Art> The token passing method, which is one of the access methods used in the loop transmission system, is based on data transmission stations A, B, -, and E, as shown in FIG.
A token circulates around a transmission path connecting stations in a ring, and when a data transmission station requesting transmission receives the token, it acquires the right to transmit data. At this time, the data transmission station with the transmission request converts the reserved fleet tokens into busy tokens and obtains the transmission right.

<Problems to be Solved by the Invention> Network monitoring and management in the conventional token passing system is centrally performed by a fixed monitoring station that performs high-performance processing on the network.

In this case: 1) If the monitoring station fails, the entire network will go down. In other words, it becomes a danger concentration system.

ii) If the monitoring station has a data transmission function like other stations, detection of a network failure may be delayed due to other processing.

There is a drawback.

Therefore, during network initialization, each data transmission stage 9 memorizes the addresses of the preceding station, its own station, and the succeeding station, and when a failure occurs, countermeasures can be quickly taken based on this information, and the network monitoring function can be distributed. A method has been proposed that aims to achieve this.

Traditionally, the initialization method for this network was
A method of constructing a logical ring based on the idea of distributed control has been considered. That is, regarding the construction method of logical rings in path topology, methods such as response windows have already been standardized (TREE 802.4). However, in this method, a claim token is first generated to determine the fleet originating station, and then a logical ring is constructed through a contention process using a response window based on address comparison, which makes the process complicated. There is a drawback that it takes a long time.

[First step to solve the problem] The initialization control method in the loop transmission system of the present invention connects a plurality of data transmission stations that send and receive data in a ring and circulates on a transmission path ζ]
- In the loop transmission iX system using the token passing method in which the data transmission station that receives the message acquires the right to transmit data, the data transmission station mentioned above is the leading station.

The data transmission station Z7 transmits forward packets and reverse packets containing address data of its own station and the connected station, and receives these forward packets and reverse packets. The present invention is characterized in that a logical ring table consisting of the addresses of the preceding station, the own station, and the succeeding station is fixed in accordance with No. 1-.

Embodiment FIG. 1 shows the basic configuration of a loop transmission system according to the present invention, and includes five data transmission stations A, B, 0, and D that transmit and receive data.

The fE stations are connected in a ring by a transmission path RING, and data is transmitted via adjacent data transmission stations. In this loop transmission system, the 1--Kun passing method is used as the access protocol, and the construction of a logical ring at initialization is a necessary condition. l・-kun is the transmission path R
The station orbits on the ING, and when a data transmission station requesting transmission receives a token, it obtains the right to transmit. Station numbers are set in advance for the five data transmission stations A, B, -, and E, with station A being 1 and B being 2, -, and E.
The station is 5.

Figure 2 fat shows the frame structure of the forward direction initial packet transmitted during initialization, the figure 2) also shows the frame structure of the reverse direction initial packet, and figure 2 (fat) shows the frame structure of the reverse direction initial packet.
C1 indicates the frame structure of a free token packet.

In the forward direction initial packet and reverse direction initial packet, p and s are the address of the preceding station, T and S are the address of the own station, and N.

S is the address of the connected station. Also, DBS.

ADD is a destination address, SOU, ADD is a source address, and CRC is a cyclic redundancy check.

FIG. 3 shows the structure of a logical ring table held by each data transmission station, and shows forward direction numbers.

It consists of the preceding station address, own station address, 1&following station address. This logical ring table is used to construct logical rings in order to cope with network failures. That is, each data transmission station records information about the preceding station, its own station, and the succeeding station, and forms a logical ring based on this context. In this case, it can be constructed freely without using a general ring topology or even if the logical ring does not match the sequence in which physical signals flow. In other words, it can be used when a failure occurs in the path topology or ring network.

Below, a procedure for initializing the system by circulating tokens in this loop transmission system will be explained.

FIG. 4 shows a sequence for recognizing a preceding station at each data transmission station.

i) Physical synchronization is achieved when all stations become operational, and the synchronization initialization ends.

+1) Next, when the timer started from the synchronization initial exceeds the set time determined by station number x initial basic time, for example, in this case, since the station number of station A is the smallest, the timer TAt of station A is first set for the set time] △4 timeout, A station forward initial bakeso 1-FI
Send P. At this time, each station knows only its own address, and upon arrival of this forward direction initial packet YLF I P, it learns that the upstream station, that is, the preceding station, is station A. However, in order to perform broadcast l- (simultaneous broadcast), the forward direction numbers of other stations in the logical ring table LRT are all interchanged with those of the preceding station.

The station that sent out the initial packet FIP for requesting further sends out a free token to give the next downstream station the right to transmit.

(2) The station that receives the free token fixes the forward direction number with the preceding station in the logical ring table LR'r.

v) The procedures of ii), 1ii), and iv) are performed for stations 13 to E in the same way as for station A, and the preceding stations and forward direction numbers of all stations are determined.

FIG. 5 shows the sequence of recognition of the successor station following recognition of the preceding station described above.

1) The area number to which I received Fleet Kun again, [, jf
Send direction initial bucket l E I I). As a result, the preceding station l? which could be recognized by the above-mentioned forward direction initial? , informs the station that *・l L II is the next station.

ii) Reverse direction initial packet 1-ET+); 1i: Station A transmits a fleet token, and station E, which receives the reverse direction initial packet EIP, obtains the transmission right.

iii) The E station that obtained the fleet token fixes the subsequent part of the logical ring table LRT.

iv) i>, ii), Repeat the same procedure as 1ii) for stations 1), C, and B in order to complete the initialization.

The flowchart in FIG. 6 shows the above-mentioned processing procedure expanded to the processing of each data transmission station, in which station A executes the processing from step a onwards, and station A executes the processing from step bJ2J.
Executed by a station other than the station. This is determined depending on how the station number is determined, and for any station, step a
Subsequent processing and processing after step b can be executed.

<Effects of the Invention> As explained in Section 2 below, in the present invention, a data transmission station transmits a forward packet and a reverse packet having address data of the leading horse, its own station, and the succeeding station, and transmits the forward packet. And the data transmission station that received the reverse packet is the preceding station according to the forward packet and reverse packet above.

Since the system is initialized by fixing the logical ring table consisting of the addresses of the own station, 1 & subsequent stations, there is no need for a monitoring station, and each data transmission station has a common rough address and no 1-doware. By optimizing the system, system costs can be reduced. In addition, since it is a distributed control, it is possible to spread the risk.
Large initialization failures can be avoided, and initialization processing can be speeded up and carried out in-process. Furthermore, management data related to initialization can be collected at all data transmission stations, and network information can be obtained by comparing the management data of each data transmission station.
Early detection of unstable or dangerous parts of the workpiece is possible.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic configuration of a loop transmission system using the present invention, FIG. 2 is a diagram showing the frame structure of a packet according to an embodiment of the present invention, and FIG. 3 is a diagram showing a logical ring table according to an embodiment of the present invention. 4 and 5 are diagrams showing the sequence of the embodiment of the present invention, FIG. 6 is a flow chart showing the processing procedure of the embodiment of the present invention, and FIG. 7 is a diagram showing the configuration of a conventional loop transmission system. It is. A station, B station, -, E station...data transmission station RING...transmission line

Claims (1)

[Claims] In a loop transmission system using a token passing method in which a data transmission station that receives a token circulating on a transmission path formed by connecting a plurality of data transmission stations that transmit and receive data in a ring acquires the right to transmit data, the above-mentioned data A transmission station transmits a forward packet and a reverse packet containing the address data of the preceding station, its own station, and the succeeding station, and the data transmission station that receives the forward packet and reverse packet transmits the forward packet and reverse packet. An initialization control method in a loop transmission system characterized by fixing a logical ring table consisting of addresses of a preceding station, its own station, and a succeeding station according to the following.