JP3212365B2 - Inviting Multiplexing Stations in Networks - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for soliciting a multiplexing station in a communication system in which a plurality of computers, controllers and the like are connected by a network.

[0002]

2. Description of the Related Art Conventionally, in a network system in which a plurality of computers and controllers are connected, when a computer user communicates with another computer on a network, the station number of a partner computer is designated and the station number is transmitted. And sent to the network. The other computer recognizes the destination station number of the transmission frame flowing on the network, and if it matches its own station number, fetches the transmission frame and performs communication between the computers.

In the case of inviting a new station to a network link, the inviting station similarly sets the station number of the station (invited station) to be invited in a new station solicitation frame as a destination address, and transmits the new station solicitation frame. Send out on the network. The invited station recognizes the destination station number of the new station invitation frame flowing on the network, and if it matches the station number of itself, determines that the own station has been invited to the link, and sends an invitation response frame to the invitation station. To join the link.

In a multiplexed network system, when setting station addresses of computers on a network, for example, the same station number is set in two computers, ie, an active system and a standby system, and these stations are assigned to those computers. A multiplexing identifier may be assigned to configure a station address. In such a case, if a solicitation of a new station is performed with the station number as the destination station number, a plurality of solicited stations will exist at the same time. I have.

[0005]

FIG. 9 is an explanatory diagram of a conventional multiplex station solicitation method. Hereinafter, a case will be described where the 00 station invites the duplicated 01 station a and 01 station b to the link. Now, assuming that 01 station a is the priority station,
The 00 station transmits a new station invitation frame designating the 01 station a as the invited station according to the priority order on the network. At this time, if there is no response from the invited station 01a, the invitation right is passed to another station, or the multiplexing identifier is changed to b and the next
Invite 01 station b.

In the former method, even if the 01 station a does not exist on the network, the solicitation is performed from the 01 station a having a higher priority, and the solicitation of the 01 station b is continued until the solicitation right reaches the 00 station. Since this is not performed, when there are a large number of computers on the network, there is a problem that it takes time until a station having a lower priority can join the link.

[0007] The latter method has a problem in that the solicitation process is extended twice for the solicited station in which the solicited station is multiplexed because the solicited station multiplexes the solicited station twice. is there.

In the above-mentioned solicitation method, the soliciting station 00 has information on whether the invited station 01 is duplexed,
In the case of duplexing, it is necessary to further have information on the invitation priority of each invited station. Therefore, when the network configuration is changed, it is necessary to change the information of the relevant solicitation station, and there is a problem that the system cannot be flexibly changed.

[0009] These problems are not limited to a system in which stations are duplicated, and become more remarkable as the degree of multiplexing and the number of stations connected to the network increase. An object of the present invention is to make it unnecessary to manage information on the degree of multiplexing of solicited stations in a solicited station and the priority order. Also,
The purpose is to reduce the time required for the invited station to join the link.

[0010]

FIGS. 1A and 1B show the first embodiment.
10 is a flowchart showing the principle of the invitation method according to the second invention.

In the first invention, in a network system in which the same station number is set to a plurality of stations on the network and the stations are multiplexed, each inviting station responds to the maximum number of multiplexing identifiers determined by the system. A waiting time frame is set (S1), solicitation is performed simultaneously for invited stations of the same station number, and invited stations that have responded within the response waiting time frame join the link (S2).

In the second invention, each invited station sets a predetermined time shorter than the time required for returning a response frame to the soliciting station as a response start time frame (S3), and the invited stations having the same station number receive the same time. When simultaneously inviting to the inviting station, if the inviting station with a higher priority does not start a response to the inviting station within the response start time frame, the inviting station in the lower invites A response is started to the invitation station within the start time frame (S4).

[0013]

In the invitation system of the first invention, for example, the maximum number of multiplexing identifiers in the entire network system is "2",
That is, assuming that the system has a maximum of two invited stations with the same station number, each soliciting station sets a response waiting time for two stations as a response waiting time frame from the invited station. Then, solicitation is performed simultaneously for the two invited stations having the same station number, and the station that first responds within the response waiting time frame is added to the link.

In this solicitation method, each inviting station knows how many invited stations to which it invites are multiplexed and, when the invited stations are multiplexed, the priority of each station. Since there is no need, there is no need to manage such information at the solicitation office. Thus, even when the system configuration is changed, it is not necessary to notify the contents of the change to the invitation station, and the system configuration can be changed more flexibly.

Since solicitation is performed simultaneously for a plurality of stations having the same station number, if there is no upper station, the lower station can join the link in one invitation process, and the multiplex is performed. The time required for a station to join a link can be reduced.

Further, in the second invention, each invited station includes:
By setting a time shorter than the time required to return the response frame to the solicitation station as the response start time frame, the time until the lower station can join the link when there is no upper station can be further reduced. .

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 4 are diagrams illustrating a configuration of a network system in which invited stations are duplicated. FIG.
FIG. 3 is a station configuration diagram when only 01 station a exists on the network when 01 stations are duplicated, and FIG. 3 is a station configuration diagram when only 01 station b exists on the network. 4 is a station configuration diagram in a case where both the 01 station a and the 01 station b exist.

The priorities of the invited stations are determined in order to join the link. In this embodiment, each station is constituted by a computer, and the 01 station a having the highest priority has the active system and the lower station 01 has the lower priority.
01 station b is the standby system.

Next, a method of inviting a multiplexing station according to the first embodiment of the present invention will be described with reference to FIGS. This embodiment is an example in which the maximum number of multiplexing identifiers determined at the time of constructing the network system is "2", that is, the invited station is duplicated at the maximum.

In this case, each invitation station sets a response waiting time frame for the maximum number of multiplexing identifiers determined by the system as a response waiting time of the invitation process. First, the solicitation operation when the invited station 01 station a exists on the network and the 01 station b does not exist (FIG. 2) will be described with reference to FIG. The following processing is executed by a central processing unit (not shown) in the invitation station or the invited station.

The inviting station 00 sends out an invitation frame with the invited station 01 as the destination station number on the network. When the invited station 01 receives a solicitation frame with its own station as the destination station, it determines that it has been invited to join the link and returns a solicitation response frame, but the invited station 01 station a (a The setting station) returns a response frame with the inviting station 00 as the destination station during the setting station response waiting time frame A assigned to itself.

When the inviting station 00 receives the invitation response frame from the a setting station, the inviting station 00 joins the a setting station to the link.
The solicitation process ends after T1 time when the set station response waiting time frame B elapses.

In this case, the solicitation processing time T1 may be the sum of the time T0 for transmitting the invitation frame, the response waiting time A for the setting station a, and the response waiting time B for the setting station b. Invitation processing time can be reduced as compared with the conventional invitation system in which an invitation frame is transmitted for each of the stations. As a result, the solicitation processing time of the entire network is shortened, so that the time required for the invited station to join the link can be shortened.

Next, a solicitation operation in the case where the invited station 01 exists on the network as shown in FIG. 3 and the 01 station a does not exist will be described with reference to FIG. In this case as well, as described above, the inviting station 01 transmits an invitation frame with the 01 station as the destination station. In this case, since the 01 station a does not exist, the response frame from the 01 station a is not returned, and after the elapse of the response waiting time A for the setting station a, the response frame from the 01 station b to the response waiting time frame B for the b setting station is returned. A response frame is returned.

The inviting station 00 causes the invited station (01 station b in this case) that has returned the response frame first to join the link. The timing at which the 01 station b returns the response frame includes, for example, a storage unit that stores the priority of the multiplexing identifier of its own station in the 01 station b, and a timing unit that counts the elapsed time after receiving the invitation frame. When the timer measures the elapse of the response waiting time of a station having a higher priority than the own station, a response frame is returned.

Next, the solicitation operation when both the invited stations 01a and 01b exist on the network as shown in FIG. 4 will be described with reference to FIG. The solicitation station 00 sends out an invitation frame with the 01 station as the destination station in the same manner as described above. In this case, since both the 01 station a and the 01 station b exist, the response frame is returned from the 01 station a within the response waiting time frame A for the setting station a, and the response frame is returned within the response waiting time frame B for the setting station b. 01
A response frame is returned from the station b.

The soliciting station 01 causes the station which has received the response frame first (in this case, the station 01 having a higher priority) to join the link, and ignores or discards the response frame of the station 01 b after receiving it. After T1 hours, the invitation process is terminated.

If neither the 01 station a nor the 01 station b exists on the network, the inviting station 00 waits for a response from the invited station for a time T1. Terminates the invitation process.

As described above, in the first embodiment, the solicitation station sets a response waiting time frame for the maximum number of multiplexing identifiers determined at the time of system construction (for example, a response waiting time frame for two stations).
Is set, the invited stations multiplexed with the same station number are invited simultaneously, and the invited station that responds first is joined to the link. Compared with the method of transmitting a frame, the waiting time until the invited station can join the link and the time required for the invitation station to process the invitation can be reduced.

Further, in this case, each inviting station has information on whether or not the invited stations are multiplexed, and when the invited stations are multiplexed, the priority in which each invited station joins the link. Since there is no need to have information on (priority of the multiplexing identifier), there is no need to manage such information in the invitation station. Thus, even when the system configuration is changed and the number of multiplexed invited stations changes, it is not necessary to notify the soliciting station of such information, so that the system configuration can be changed more flexibly.

When each inviting station sets a response waiting time frame for the maximum number of multiplexing identifiers as in the above-described embodiment, the total response waiting time in each inviting station is, for example, the response time of the invited station. (Or the response time if the response time at each invited station is equal) by the maximum number of multiple identifiers determined by the network system. Therefore, in this embodiment, the time required for the solicitation process in the entire network system is uniquely determined, so that the time required for the solicitation process in the entire system can be clearly defined.

Even when a response waiting time frame corresponding to the maximum number of multiplexed systems is provided in each solicitation station, if the solicitation processing is terminated when a response frame from the invited station is received, the solicitation can be completed. The processing time can be further reduced.

Next, a second embodiment of the present invention for further shortening the solicitation processing time of the solicitation station will be described with reference to FIG. 7 and FIGS.
A description will be given with reference to FIG. In this embodiment, each invited station sets a time frame in which to return a solicitation response frame based on the priority of the multiplexing identifier of its own station.
For example, assuming that the invited station is duplexed into a 01a setting station and a 01b setting station, the 01a setting station sets a time C shorter than a time required for its own station to return a response frame as a response start time. Set as frame C, the 01b setting station starts the same response start time frame D from the time when the response start time frame C ends.
Set.

On the other hand, the inviting station 00 sets a response waiting time frame T4 corresponding to the response start waiting time frame in the invited station. Now, assuming that the maximum number of multiplexing identifiers determined by the system is "2", the invitation station 00 sets a value obtained by adding the response waiting time of one station to the response start waiting time of one station. This is set as the response waiting time frame T4.

Further, as a non-response monitoring time T3 for terminating the invitation process when there is no response from the invited station, a response start time frame for two stations [for example, C + D, generally C = D].

When the 01b setting station receives the solicitation frame, the 01a setting station having a higher priority order sets the response start time frame C
During the response start time frame C, it is monitored whether or not the response frame is returned to the solicitation station 00. If the 01a setting station starts returning the response frame within the response start time frame C, the 01b setting station returns the response frame. If no frame is returned and the 01a setting station does not start returning a response frame within the response start time frame C, the response frame is returned to the invitation station 00 during the response start time frame D of the own station. To start.

The inviting station waits for a response frame to be returned from the setting station, and first joins the setting station that has returned the response frame to the link. At this time, if there is no response from the setting station, the invitation process is terminated when the non-response monitoring time T3 has elapsed.

Next, the operation of the invited station and the invitation station will be described for the case of the station configuration shown in FIGS. For example, if there is only the b-set station among the 01 invited stations whose station configuration is duplicated as shown in FIG. 3, a solicitation frame from the solicited station 00 to the 01 station is received. Then, the b setting station becomes a
The setting station monitors whether or not to start returning a response frame during the response start time frame C. If no response frame is returned within the response start time frame C, the response time frame D
During this time, transmission of the response frame of the own station is started.

The solicitation station 00 ends the solicitation process when the response time frame T4 in which the reception of the response frame from the b setting station is completed has elapsed. In this case, since the setting station b can return its own response frame when the response starting time frame C of the setting station a has elapsed, it can join the link in a shorter time than in the first embodiment.

When the station configuration includes both the a setting station and the b setting station as shown in FIG. Start sending the response frame. The b setting station monitors the a setting station, and does not return a response frame to the 00 station if the a setting station starts returning a response frame.

The inviting station 00 terminates the inviting process when the response waiting time T4 has elapsed after the reception of the response frame from the a setting station is completed. Further, although not shown, if neither the 01 station a nor the 01 station b exists on the network and a response frame is not returned, the 00 station terminates the invitation process when the non-response monitoring time T3 has elapsed. Let it.

In this case, that is, when both the 01 station a and the 01 station b do not exist on the network, the non-response monitoring time T
Since the invitation process is terminated at the time when 3 has elapsed, the invitation process time when there is no response from the invited station can be shortened.

In the above-described second embodiment, each invited station multiplexed sets a predetermined time shorter than the time required for returning a response frame to the invitation station as a response start time frame, and sets a higher priority order. If the other station does not start a response within the response start time frame, the lower station starts sending back a response frame to the invitation station. If there is no higher priority station, the lower station is shorter than in the first embodiment. Subordinate stations can join the link in time.

Further, in this embodiment, since the response waiting time frame on the inviting station side is substantially superimposed, the inviting processing time T2 of each inviting station is reduced. Further, in the second embodiment, as in the first embodiment, the solicitation station does not need to have information on the degree of multiplexing of the solicitation and the priority between the solicitation stations. While being reduced,
It is possible to change the system configuration more flexibly.

In the above-described embodiment, a case has been described where the maximum value of the multiplexing identifier determined by the system is "2", that is, the invited station is duplicated. The present invention can also be applied to the case where multiplexing, quadrupling, etc. are performed.

The network may be connected in any form, such as a bus, a loop, or the like.

[0047]

According to the present invention, since a solicitation is performed to a plurality of invited stations of the same station number in one invitation process, the time required for the invited station to join the link can be reduced. it can. Further, since there is no need for each soliciting station to manage the degree of multiplexing of the solicited stations and the priorities of the solicited stations, the burden on the soliciting stations can be reduced and the system configuration can be changed more flexibly. Furthermore, by setting the response start time frame in which each invited station starts to return the response frame to a time shorter than the response frame return time, the invitation processing time at the invited station can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the principle of the present invention.

FIG. 2 is a diagram (a) showing an example of a station configuration.

FIG. 3 is a diagram (b) showing an example of a station configuration.

FIG. 4 is a diagram (c) showing an example of a station configuration.

FIG. 5 is an explanatory diagram (a) of a multiplexing station invitation system according to the first embodiment;
It is.

FIG. 6 is an explanatory diagram (b) of a multiplex station invitation method according to the first embodiment;
It is.

FIG. 7 is an explanatory diagram (c) of a multiplex station invitation system according to the first embodiment;
It is.

FIG. 8 is an explanatory diagram of a multiplex station solicitation method according to the second embodiment.

FIG. 9 is an explanatory diagram of a conventional multiplex station invitation method.

[Explanation of symbols]

 T0 Solicitation frame transmission time T1, T2 Solicitation processing time T3 No response monitoring time

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/28 H04L 12/403

Claims (2)

(57) [Claims] In a network system in which the same station number is set to a plurality of stations on a network and the stations are multiplexed, each inviting station has a response waiting time frame corresponding to the maximum number of multiplexing identifiers determined by the system. A solicited station having the same station number is simultaneously invited, and a solicited station that has responded within the response waiting time frame is caused to join the link. . 2. In a network system in which the same station number is set to a plurality of stations on a network and the stations are multiplexed, each invited station has a predetermined time shorter than a time required for returning a response frame to the soliciting station. Is set as the response start time frame, and when the soliciting station simultaneously invites to the invited station of the same station number, the inviting station having a higher priority ranks the solicited station within the response start time frame. A method for soliciting a multiplexing station in a network, wherein when a response is not started, a lower invited station starts a response to the solicited station within its own response start time frame.