JPH03259643A - Network access method - Google Patents

Abstract

PURPOSE:To improve the utilizing efficiency of a network by permitting the circulation of a frame while a transmission frame from other node is linked to the frame and circulating only the linked frame through a local area network twice so long as the frame circulation is a first circulation. CONSTITUTION:When a node 2c recognizes it that a transmission destination address 4b of a frame 4 of linked frames 4, 5, the frame 4 addressed to its own node is received and reception reply information 4d is added to the frame 4. Since the node 2c is a node having no access right, the frame passes by a circulation discrimination control function 7c and a transmission destination address 6a, a transmission destination address 6b, and a transmission data 6c are set based on the production of a transmission request to the node 2b, the resulting frame is connected after the frames 4, 5 linked already as a frame 6 and the resulting frame is sent to a local area network 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a network access method, and particularly when there are multiple nodes that wish to transmit data at the same time in a token passing network. This invention relates to a network access method suitable for communication between networks.

[Prior Art] Figure 4 is an explanatory diagram of the conventional network access method shown in, for example, the document rOsI - Computer Networks for Tomorrow (2nd edition, March 18, 1987, published by the Japanese Standards Association, p. 23B). However, in the figure (1
) is a local area network arranged in a loop, (2a), (2b), (2c) are nodes accommodated in local area network (1), and (3) is which node (2a), (2b), Local area network (1) is also unused in (2c).
), (4) is a frame containing a busy token indicating the usage status of the local area network (1), and is transmitted (has access rights)
Source address (4a) indicating the node, destination address (4b) indicating the other node, and transmission data (4C)
It consists of the sending data (4C) at the other node.
is received, reception response information (4d) is added. Further, in the figure, an arrow indicates movement from a frame format before passing through an arbitrary node to a frame format after passing through an arbitrary node.

Next, the operation of the above configuration will be explained.

Here, node (2a) is the source node and node (2a) is the source node.
C) will be explained as the destination node.

First, as shown in FIG. 4(a), the node (2a) obtains the access right by acquiring a fleet token (3) circulating in the local area network (1), and acquires access to this fleet token. Change (3) to a busy token that indicates its usage status and send it to other nodes (2b) and (2C)
After prohibiting the transmission of , a source address (4a), a destination address (4b), and transmission data (4C) are set and transmitted on the local area network (1) as a frame (4) containing a busy token.

Next, as shown in FIG. 4(b), each node (2b),
(2c) is a frame (4) sent from node (2a).
) is monitoring the destination address (4b) of the node (
When 2c) learns that the destination address (4b) of frame (4) is its own node, it receives the frame (4) addressed to its own node and adds reception response information (
4d) and reconnect the local area network (1
) to send on.

Then, as shown in FIG. 4(C), the frame (4) to which this reception response information (4d) is added goes around the local area network (1) once and is sent to the source node. When returning to a certain node (2a), the busy token is changed to a fleet token (3) again, sent out on the local area network (1), and sent to another node (2b).
).

(2c) communication is enabled.

[Problem to be solved by the invention] Since the conventional network access method is configured as described above, when multiple nodes want to transmit data at the same time, one node acquires a free token and sends the frame to the other party. After the frame is delivered to a node, the other node has to wait for the frame to be sent until the node transfers the free token to another node, which reduces the number of nodes communicating with each other. There was a problem to be solved that it was difficult to perform node communication.

This invention was made to solve the above-mentioned problems, and only when multiple nodes want to transmit data at the same time, it enables frames to be transmitted even by nodes other than those that have acquired fleet tokens. The present invention aims to provide a network access method capable of realizing multi-node communication between multiple nodes and controlling the number of times a frame circulates according to the number of transmitted frames.

[Means for Solving the Problems] In order to achieve the above object, the present invention uses fleet tokens that circulate in a loop-like local area network to which a plurality of nodes are connected as main nodes that have a data transmission request. A process in which the node acquires the main transmission frame as a busy token and sends it to the looped local area network along with the main transmission frame, and a process in which the main transmission frame is sent around the looped local area network and received by the destination in the first round. , a process of connecting a secondary transmission frame based on a transmission request from another node to the main transmission frame in the first round of the main transmission frame, and a second round of the rotation of the main transmission frame and the secondary transmission frame connected thereto.
After the first round, the secondary transmission frame is received by each destination, and the main transmission frame is not concatenated with the secondary transmission frame in the first round, and only the main transmission frame circulates in the looped local area network. In this case, a network access method is provided which consists of a process of aborting frame circulation at the first round, and a process of returning a busy token to a fleet token at the main node upon aborting frame circulation.

[Operation] In the network access method of the present invention, in the above means, the main node having a data transmission request acquires a free token that circulates in a loop-like local area network to which a plurality of nodes are connected, and the main node is used as a busy token. The main transmission frame is sent to the loop local area network together with the transmission frame, and this main transmission frame is received by the destination in the first round of the circuit, and the secondary transmission frame based on the transmission request at other nodes is connected to the main transmission frame. After the second round, the secondary transmission frame is received by each destination, and when only the main transmission frame circulates in the looped local area network, the frame circulation is terminated at the first round, and the frame circulation is stopped. When terminating the service, the main node returns busy tokens to free tokens.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram of a network access method according to an embodiment of the present invention. In the figure, (5), (6
) is a frame containing a busy token indicating the usage status of the local area network (1) together with the frame (4), and the source address (5a), (6a) indicating the node to send (having access rights), and the other node. It consists of the destination address (5b), (6b) indicating the destination address (5b), (6b) and the transmission data (5c), (6c), and when the transmission data (5c), (6c) is received at the other node, the reception response information (5d) is sent. , (6d) is added. Furthermore, (7a), (7b), and (7c) are cycle determination control functions for controlling the number of cycles of frames transmitted in nodes (2a), (2b), and (2c). Further, in the figure, an arrow indicates movement to a frame format after passing through an arbitrary node.

Next, the operation of the above-described configuration will be explained according to the flowchart shown in FIG. By the way, Fig. 3 shows the cyclic judgment control functions (7a) and (7b).

(7c) shows the flow of the cyclic determination sub-control process.

Now, here, node (2a) has access rights, and when sending frame (4) from node (2a) to node (2C), the first cycle of this frame (4) is During the process, a transmission request is generated from node (2b) to node (2a), and a transmission request is generated from node (2C) to node (2a).
The following explanation assumes that a transmission request has occurred for b).

First, as shown in FIG. 1(a), a node (2a) obtains an access right by acquiring a fleet token (3) circulating in a local area network (1), and acquires access to this fleet token. Change (3) to a busy token that indicates that it is in use and on its first cycle, set the source address (4a), destination address (4b), and transmission data (4C), and use the busy token. is transmitted onto the local area network (1) as a frame (4) containing the following information.

Next, as shown in FIG. 1(b), the node (2b) confirms that the frame (4) transmitted from this node (2a) is not addressed to its own node.

Since the own node is a node without access rights, the node (2) is passed through the cyclic determination control function (7b) based on the determination in step (31) in FIG.
Based on the occurrence of a transmission request for a), a source address (5a), a destination address (5b), and transmission data (5c) are set and concatenated as a frame (5) after the first frame (4). and transmit it over the local area network (1).

On the other hand, as shown in FIG. 1(c), the node (2C) is the inner frame (
When it learns that the destination address (4b) of 4) is its own node, it receives the frame (4) addressed to its own node and adds reception response information (4d) to this frame (4). Since the node (2c) does not have access rights, it passes through the cyclic determination control function (7C) based on the determination in step (31) in FIG.
Based on the generation of a transmission request to the node (2b), a source address (6a), a destination address (6b), and transmission data (6C) are set, and the frame (4) is already concatenated as a frame (6). , (5) is further concatenated and transmitted onto the local area network (1).

Frames (4) are connected as described above.

(5), (6) are local area networks (1
) and returns to node (2a), which is the source node, as shown in Figure 1(d).
In a), it learns that the destination address (5b) of frame (5) is addressed to its own node, and receives frame (5) addressed to its own node, and also sends reception response information (5d) to frame (5). Add. Then, the concatenated frames (4), (5), and (6) pass through the cyclic determination control function (7a), but here step (
In step 31), it is determined that the node (2a) has access rights, so in the next step (32) it is determined whether the first round has ended. at this point
Since each frame has completed its first round, the process moves to the next step (33) and the number of frames to be concatenated is determined. Here, the number of frames is determined to be three, so the process moves to step (36) and each frame enters the second round of circulation. At this point, the number of cycles and the number of connections of all frames are set in the cycle determination control function (7a).

Next, as shown in FIG. 1(e), the concatenated frames (4), (5), and (6) come to node (2b) on the local area network (1) for the second time.
The node (2b) sends the destination address (
6b) is addressed to its own node, it receives the frame (6) addressed to its own node, adds reception response information (6d) to the frame (6), and performs step (31) in FIG. ) based on the judgment of the cyclic judgment control function (7
b) Pass through the local area network (1)
Send to.

Then, as shown in FIG. 1(f), the concatenated frames (4), (5), and (6) come to the node (2C) in the second round on the local area network (1), but the In (2c), reception response information (4) of frame (4) indicates that reception from frame (4) has already been completed.
d), so do nothing and go to step (3) in Figure 3.
Based on the determination in step 1), the data is sent to the local area network (1) without passing through the cyclic determination control function (7c).

Finally, as shown in FIG. 1(g), the concatenated frames (4), (5), (6) complete the second round on the local area network (1) and are sent to the node (2a).
When the node returns, the cyclic determination control function (7a) determines that the node (2a) is a node that has access rights based on the determination in step (31) in FIG. Then, in step (32), it is determined whether or not the number of cycles of each frame is the end of the first cycle, but since it is of course the end of the second cycle, the process moves to step (34) and it is determined. , the tour is aborted in step (38). In other words, the cycle determination control function (7a) determines whether the frame is a frame on the condition that the node (2a) is a node that has access rights, the frame cycle ends at the end of the second cycle, and the transmitted frames are concatenated. After the frame (4) is absorbed, the busy token is changed to a fleet token (3) and sent to the local area network (1).

As described above, all nodes (2a), (2b),
The transmission request issued from (2c) is received by the destination node, but during the second round of frame (4), each node (2a).

It is necessary to set the condition that even if a transmission request from (2b) or (2c) occurs, it cannot be connected to frame (4). Furthermore, even after the second round of circulation is completed, some of the concatenated frames (4), (5), and (6) to which reception response information (4d), (5d), and (6d) are not added remain. Even so, it is possible to know during the second round that the node that has already sent the message has not received the message.
At the end of the second round, the concatenated frames may be absorbed and transmitted at another opportunity.

FIG. 2 is an explanatory diagram showing an example of operation when frames are not concatenated, with node (2a) being the source node and node (
2c) is exemplified as the destination node.

Another operation mode of the network access direction of the present invention will be explained based on FIGS. 2 and 3.

As shown in FIG. 2(a), the node (2a) obtains access rights by acquiring Fleet Tokens (3) circulating on the local area network (1), and obtains access rights by acquiring Fleet Tokens (3) circulating on the local area network (1). ) to a busy token indicating that it is in use and is on its first cycle, and sends the source address (4a), destination address (4b), and transmission data (
4C) and contains a busy token (4)
on the local area network (1).

As described above, local area network (1)
When the frame (4) sent from the node (2b) reaches the node (2b), the node (2b) confirms that the frame (4) sent from the node (2a) is not addressed to its own node.

Since the own node does not have access rights and there is no transmission request from the own node, the frame (4) is directly sent to the cyclic judgment control function (based on the judgment in step (31) in FIG. 7b) and then transmitted onto the local area network (1).

Next, when the frame (4) reaches the node (2c) on the local area network (1), the node (2c) sends the frame (4) to the destination address (4b ) is addressed to your node. Then, upon receiving a frame (4) addressed to its own node, it adds reception response information (4d) to this frame (4).

Since the node (2C) does not have access rights, based on the determination in step (31) in FIG.
After passing through the cyclic determination control function (7c), no transmission request is issued to the node (2b), so the frame (4) is transmitted directly onto the local area network (1).

When the frame (4) to which the reception response information (4d) is added at the node (2C) goes around the local area network (1) and returns to the source node (2a), here Since it is determined in step (31) in FIG. 3 that the node (2a) is a node that has access rights, it is determined in the next step (32) whether or not the first round has ended. At this point, each frame has completed its first round, so the process moves to the next step (33) and the number of frames to be concatenated is determined.

Here, the number of frames is determined to be one, so the process moves to step (37) and the frame circulation is discontinued.

In other words, the cycle determination control function (7a) requires that the frame's cycle on the local area network (1) is at the end of the first cycle, and that only one frame is received and other frames are not connected. Then, it stops circulating the frame, absorbs the frame (4), changes the busy token to a free token (3) again, and transmits it on the local area network (1).

Note that even if the reception response information (4d) is not added when the frame (4) returns to the node (2a), the node (2a) can know that the reception has not been received. You can achieve your goal by sending it at the appropriate opportunity.

As in the above embodiment, by controlling the number of rounds on the local area network based on the number of frames transmitted on the looped local area network, nodes that have not acquired free tokens can It is possible to concatenate the frame requested for transmission by the node to the transmission frame from the node that acquired the free token, and transmit this frame to the desired destination node during the tour.

[Effects of the Invention] As described above, according to the present invention, after a frame transmitted from a node that has acquired a free token from a loop local area network, only when this frame is circulating for the first time. , allows transmission frames from other nodes to be circulated while concatenating them, and only the concatenated frames are circulated on the local area network for two weeks, during which time data transmission based on transmission requests from other nodes is not allowed. Since this is done, it is possible to improve the efficiency of network usage, and there are effects such as simultaneous communication between multiple nodes can be performed efficiently, such as in a conference system.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a network access method according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a network access method when frames are not concatenated, and FIG. 3 is an illustration of the configuration of FIGS. 1 and 2. A flowchart for explaining the operation and FIG. 4 are explanatory diagrams of a conventional network access method. In the figure, (1) is a local area network,
(2a), (2b), (2c) are nodes, (3
) is Free Token, (4), (5), (6)
is the frame, (4g), (5a), (6a) is the source address, (4b), (5b), (6b
) is the destination address, (4c), (5c), (
6c) is the transmission data, (4d), (5d), (
6d) is reception response information, (7a), (7b),
(7c) is a cyclic determination control function. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A process in which a main node with a data transmission request acquires a free token that circulates in a loop-shaped local area network to which multiple nodes are connected and sends it as a busy token to the loop-shaped local area network along with a main transmission frame, and a main transmission process. A process in which a frame is received by the destination in the first round of circulation, a process in which a secondary transmission frame based on a transmission request at another node is connected to the main transmission frame in the first round of circulation, and a process in which the frame is connected to the main transmission frame based on a transmission request at another node in the first round of circulation, and A process in which the secondary transmission frame is received by each destination, a process in which the frame circulation is terminated at the first round when only the main transmission frame circulates in a looped local area network, and a process in which the frame circulation is terminated at the main node. A network access method comprising the step of converting a busy token back into a free token.