JPH04225642A - Physical address setting method in lan - Google Patents

Abstract

PURPOSE:To prevent the overlap of a physical address by using a temporary address not overlapping the address of a subscriber station, and seceding once from temporary subscription, and subscribing newly and formally for a logical ring by using the formal address. CONSTITUTION:The address of its own station is selected at random from an address table, and the station subscribes temporarily for the ring. The station having temporarily subscribed sends a frame by simultaneous multi-address calling in order to collect the address information of other stations. Every station having received this address request frame returns respectively an answer frame to the requesting station as the address data of a succeeding station. In this case, the station having used the temporary address of the address table at the time of the new subscription sends the address of the succeeding station to a preceding station, and seceds once from the line. Then, it subscribes again formally for the line by the formal address determined previously.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is based on a token bus system in which a plurality of stations are connected by a shared bus having a bus-type structure, frames called tokens are circulated among the stations, and the station that acquires the token has the right to transmit. The present invention relates to a method of setting a physical address for identifying a partner station when each station communicates with each other in a LAN (Local Area Network).

[0002] In the following figures, the same reference numerals indicate the same or corresponding parts.

0003

[Prior Art] In a token bus type LAN, a physical address owned by each station is used to identify the source and destination stations when transferring tokens and data.
It is stored in the header part of the communication frame. There are two types of physical addresses: a local management type in which each station has a unique address within a LAN, and a global management type in which each station has a unique address worldwide. performs communication using either a physical address using the former method, which is arbitrarily set by the user, or a physical address using the latter method, which obtains an address that is globally managed and sets it as a fixed value in advance. Token circulation is performed using a certain algorithm. For example, a station with a large address transfers a token to a station with a small address, and the station with the lowest address transfers the token to the station with the largest address. Note that this ring-shaped chain between stations will hereinafter be referred to as a logical ring. When configuring this logical ring, each station acquires the addresses of its predecessor and successor stations in addition to its own address, and circulates tokens.

[0004] A station that wants to newly join receives a participation request packet (
Recruitment is carried out by frame). A newly joining station whose physical address is between the local station address SA and the destination address DA of this participation request packet returns a response within the response window time. Based on the response, the station that sent the participation request packet recognizes that the station downstream of itself is a new station that is about to join, and thereafter changes the destination of the token to the new station that is about to join. If the physical address of a new station attempting to join overlaps with the address of any station in the logical ring, transmissions from exactly the same address are heard and an abnormality is detected.

[0005]

SUMMARY OF THE INVENTION It is desirable for all stations forming a network to obtain their own address as a unique physical address in the entire world for communication. However, if the number of stations increases and globally managed physical addresses have not been obtained for all stations, or if the physical addresses of all stations are not correctly understood even in a locally managed network, or if temporary temporary addresses are required for testing or debugging. When attempting to join a station under test to a line, there is a problem in that the physical address of the newly joining station is mistakenly duplicated with the address of the station that has already been set. If addresses overlap, not only will a newly joined station be unable to communicate, but there is also the possibility that the problem will spread to the entire network.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for setting physical addresses in a LAN that can solve these problems.

[0007]

[Means for Solving the Problems] In order to solve the above problems, in the physical address setting method of claim 1, "a plurality of stations (such as 1) connected to a common bus (such as 2) This is a method in which tokens are passed around in a ring-like order in a predetermined order, and from the end of this order to the beginning of this order, and the station that receives this token acquires the transmission right. In LAN,

0008
】A new station (such as a new temporary joining station 1X) that attempts to join the ring-shaped order that has already been formed (consisting of stations 1A to 1E, etc.) has an address that overlaps with the address of an already joining station. One or more predetermined temporary addresses (10
a to 10c, etc.), temporarily join the ring order, collect the addresses of the already joined stations (and store them in the other station address table 20, etc.), and Then, find an address that does not overlap with the temporary address and use it as the regular address of the own station, then leave the ring order once and use the regular address (as the last station to join 1Y, etc.) to return to the ring order. to officially join the

In the physical address setting method according to claim 2, in the physical address setting method according to claim 1, ``the temporarily joining station transmits an address read request frame (30, etc.) to the already joining station, Then, the station that has already joined the station transmits a response frame (such as 40) containing the address of the station to the station that has joined temporarily.
,Also

[0010] In the physical address setting method of claim 3, in the physical address setting method of claim 2, ``the response frame includes an address (such as 41) of a subsequent station of the responding station.'' .

[0011]

[Operation] A station that newly attempts to join an existing logical ring is given a predetermined temporary address that is divided in advance so that it does not overlap with the address of an already joining station. ) to temporarily join the logical ring and collect address information from stations that have already joined,
An address that does not overlap with the collected existing joining station addresses and the temporary address is determined as a regular address, and at this point, the user temporarily withdraws from the temporary joining and once again officially joins the logical ring using the regular address. do. When there are multiple stations that wish to newly join, the multiple stations repeat the above procedure one by one in turn.

0012

Embodiments An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG. 1 shows a conceptual diagram of the present invention. In the figure, 2 indicates a common bus, 1 (1A to E, 1X, 1Y) indicates a station, and broken line arrows indicate the flow of tokens. 1A to 1E are already joining stations that have already formed a logical ring for exchanging tokens, and 1X is a new temporary joining station (that is, a station that is newly joining the LAN and has a temporary address that will be used only at the time of new joining). ), 1Y is the final joining station (that is, the station that determined a regular address and joined the LAN). And the same figure (
A) first shows a state in which already joined stations 1A to 1E form a logical ring, and FIG. 2B shows a state in which a station 1X having a temporary address for new joining, which will be described later, temporarily joins. In addition, (C) of the same figure shows that the new temporary joining station 1X does not overlap with the addresses of other stations 1A to 1E or the above-mentioned temporary address based on the address information received from other stations 1A to 1E at the time of temporary joining in (B) of the same figure. The state is shown in which, after determining a regular address and once leaving the logical ring, the station 1Y joins the logical ring as the final joining station 1Y with the finally determined regular address.

[0013] According to the present invention, a station newly joining a LAN can switch between two modes: a mode in which its own address is fixed and a mode in which it is automatically set. FIG. 3 shows an address table 10 prepared for each station for the above-mentioned mode in which the own station address is automatically set. One or more specific addresses (herein referred to as candidate addresses) 10a for temporary joining that are common to each station and that are preselected in advance.
10b... are stored. In this automatic setting mode, if there are multiple stations, a new station that wishes to join will be given its own (temporary) address at random from this address table 10, with the condition that it joins one by one in order. , and tentatively joins the ring using the same procedure as when newly joining as described in the conventional technique. A station that has temporarily joined the station transmits an address request frame 30 having a format shown in FIG. 5 by broadcasting in order to collect address information of other stations. In the figure, PREAMBLE is a synchronization code at the beginning of the frame, SD is a start delimiter as a code indicating the start of data, FC is frame control data as data indicating the type of the frame, and DA is the destination address for this frame. In the case of No. 30, this DA is data equivalent to an address indicating simultaneous broadcasting (that is, all other stations are addressed). SA is the source address and this frame 30
In this case, the candidate address is selected from the above-mentioned new joining address table 10. Further, 31 is an address read request command.

Now, this address read request frame 30
Each station that receives this returns a response frame 40 having a format shown in FIG. 6 to the requesting station, using the address of the subsequent station as data. In addition, in the same figure, the destination address D
A is the new joining address (candidate address) of the station that sent the request frame 30, and is the source address SA.
is the own address of the station that returns this response frame 40. 41 is the address of the subsequent station of the responding station.

[0015] Upon receiving such a response frame 40,
The temporary joining station receives the address information of each other station, that is, the source address SA and the succeeding station address 41 in the response frame 40.
The information is sequentially stored in the other station address table 20 provided in advance within the local station as shown in FIG. Further, the regular address of the own station is determined to be an address other than those registered in the new joining address table 10 and the other station address table 20. Using the (temporary) address in address table 10 when joining as a new member (trying to join as a new member)
The station sends the address of the succeeding station to the preceding station in the same way as when leaving a conventional line, and temporarily leaves the line (logical ring). Then, it (officially) rejoins the line using the previously determined regular address and performs normal data transfer. Thereafter, even if the line is initialized, this newly joined station will operate with the finally determined regular address in its possession.

FIG. 2 shows a frame sequence of the invention corresponding to FIG. In FIG. 2, ■ indicates the flow of tokens of the stations 1A, 1B, and 1C that initially form the logical ring. (2) shows the procedure for the station 1X, which newly wants to join, to join the ring. That is, the station 1A sends a participation request packet (solicit-successor) to the downstream station 1B.
) and has an address between stations 1A and 1B.
is a response frame (set-success) to station 1A.
or) is returned. 3 shows the flow of tokens after the station 1X temporarily joins. In case of (3), station 1X sends an address read request frame 30, and each station 1A to 1C sends a response frame 40.
Indicates the status of returning. (3) shows a state in which the temporarily joined station 1X leaves the logical ring and transitions to the final joined station 1Y. 3 shows the procedure by which the final joining station 1Y joins the logical ring.

[0017]

According to the present invention, a plurality of stations 1 connected to a common bus 2 are arranged in a ring shape between their addresses in a predetermined order, and the last one in this order returns to the first one in this order. A LAN in which tokens are exchanged cyclically in the following order, and the station that receives the token acquires the transmission right.
In,

[0018] Each new temporary joining station 1X, which is a station newly attempting to join into the already formed ring-shaped order consisting of stations 1A to 1E, has an address that does not overlap with an address of an already joining station. One or more predetermined temporary addresses 10a to 1 set in the address table 10 at the time of new joining
0c, temporarily joins the ring order, collects the addresses of the stations that have already joined, and stores them in the other station address table 20, and does not overlap with this collected address or the temporary address. The address is determined and set as the regular address of the own station, and then the station temporarily leaves the ring order and uses the regular address to officially join the ring order as the final joining station 1Y. You can get the following effects.

(1) In a network that uses addresses in a local management format, a newly joining station automatically determines a unique address on the network, so it can connect to the line without being aware of the physical addresses of other stations. can intervene, and no failures such as communication failure will occur.

(2) If the upper address assigned to an organization in a global network is fixed and the method of the present invention is adopted for the lower address (address part that differs for each product) managed by each organization, the lower address There is no need to assign addresses to each product, which prevents duplication of physical addresses due to management errors, and is advantageous in terms of manufacturing and maintenance.

[Brief explanation of the drawing]

[Figure 1] Conceptual diagram of the present invention

[Fig. 2] A diagram showing a frame sequence corresponding to Fig. 1.

[
FIG. 3: A configuration diagram of a new join address table as an embodiment of the present invention

[Figure 4] Similarly, configuration diagram of other station address table

[Figure 5]
Similarly, the configuration diagram of the address read request frame.

[Figure 6] Configuration diagram of response frame as well

[Explanation of symbols]

1 (1A to 1E, 1X, 1Y) Stations 1A to 1E Already joined station 1X New temporary joining station 1Y Last joining station 2 Bus 10 New joining address table 10a to 10
c Candidate address 20 Other station address table 30 Address request frame DA Destination address SA Sender address 31 Address read request command 40
Response frame 41 Subsequent station address

Claims (3)

[Claims] Claim 1: A plurality of stations coupled to a common bus send tokens in a predetermined order among their addresses, and in a ring-like order, with the last of this order returning to the beginning of this order. In a LAN in which cyclic transfer is performed and the station that receives the token acquires the transmission right, each new station that attempts to join the ring-shaped order that has already been formed is assigned to an existing joining station. selects one of a predetermined one or more predetermined temporary addresses that do not overlap with the address of the station, temporarily joins the ring order, collects the addresses of the already joined stations, and selects one of the predetermined one or more temporary addresses that does not overlap with the address of The mobile station finds an address that does not overlap with the address and sets it as the regular address of its own station, then temporarily leaves the ring order, and then uses the regular address to officially join the ring order. How to set a physical address in a LAN. 2. The physical address setting method according to claim 1, wherein the temporarily joining station transmits an address read request frame to the already joining station, and in response, the already joining station reads the address of the station. 1. A physical address setting method in a LAN, characterized in that a response frame including a response frame containing the above is transmitted to the temporary joining station. 3. A physical address setting method in a LAN according to claim 2, wherein said response frame includes an address of a subsequent station of said responding station.