JPS6077552A - Data transmission control system - Google Patents

Abstract

PURPOSE:To attain the recognition of system constitution in each transmitter and to improve communication efficiency of a network without using a special control instruction by detecting a sender address in reception information and storing it. CONSTITUTION:The transmitter is provided with a means 14 receiving transmission information on a communication medium 1, a means 15 detecting a sender address in the received transmission information and an RAM16 storing the detected sender address. Furthermore, the transmitter constituting a network system is discriminated by the detected sender address.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a data transmission control method for transmitting data by connecting a plurality of transmission devices to a communication medium, and particularly to a data transmission control method for efficiently managing addresses of each transmission device. Regarding.

[Prior Art] In recent years, a plurality of transmission devices such as office equipment have been connected through a low-cost and simple communication network transmission line. So-called local area networks (hereinafter referred to as LANs) are being put into practical use.

When a certain transmission device (hereinafter referred to as a node) in the LAN transmits data to another node, the destination address is added to .nq'. In order to determine the destination address, each node must use some means to recognize the system configuration within the network. That is,
Each node must know which addresses exist in the network.

As a method for each node to recognize the system configuration of the network, there is one method in conventional methods (1) and (2).

(1) One person who provides a monitor node in the network that manages the entire system, and that monitor node notifies other nodes of system configuration information.

(2) Each node issues a status check command to all nodes with valid node addresses other than its own,
A method of storing the node address of the node that received a response.

However, in method (1), since functions are concentrated in the monitor node, alternative means, ie, additional means for increasing system reliability, are indispensable in case the monitor node fails.

Furthermore, method (1) was originally not suitable for a network such as a LAN that is strongly oriented toward distributed control. Also, providing a special monitor notebook in a small-scale system has the disadvantage that the system cannot be constructed at low cost.

Next, method (2) has the disadvantage that the processing time required to recognize the system configuration is long, resulting in a low F of system efficiency. For example, the total number of nodes is N, the number of operational nodes is n, and a status check command is issued.41. Then, assuming that TI is the time from an operational note until an answer is returned, and T2 is the timeout time for waiting 15 answers for an inoperable notebook, the processing time Ts for recognizing the system configuration is calculated by the following formula. % Formula % ) (1) Here, (n l) TI is the processing time for an operable node, and (N-n) T2 is the processing time for an inoperable node.

In other words, as is clear from equation (1), as the number of nodes increases, the time Ts cannot be ignored by method (2), so it is difficult to apply method (2) to large-scale systems. The drawback was that it was extremely difficult.

[1.1] The purpose of the unfinished use is to eliminate the disadvantages mentioned in #, 5, and to make it possible to use a special monitor without having to provide a separate monitor note.

The object of the present invention is to propose a data transmission control method that can efficiently recognize each node in the network or the system configuration in the network without using control commands.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a system configuration diagram of a LAN according to an embodiment of the present invention. In the figure, 1 is a /x type network transmission path, 2 is a node a (1), 3 is a node 1:b (2), and 4 is a node c
(3), 5 is no 1” d(4), 6 is node e(5
), and the number in parentheses for each number indicates the address number assigned to each mate.

FIG. 2 is a diagram showing an example of the block configuration of the notebook shown in FIG. 1. In the figure, reference numeral 1 indicates a network transmission path similar to that in FIG.

Inside the notebook 12, 14 is a transmitting/receiving circuit, 15 is a microprocessor (hereinafter referred to as CPU) that stores firmware therein and controls the entire node using the firmware, and 16 is a random access unit that stores name information. A memory (hereinafter referred to as RAM), 17 is a self-node address setting section for specifying its own node address, and 18 is an interface control section for controlling input/output with various communication devices 13.

FIG. 3 shows a portion of the storage area allocated to the RAM 16.

Here, the area Aa stores the total number of nodes count a that stores the total number of other recognized nodes, which will be described later, and the area Abl-
The address number of the recognized node is stored in Abn. First node address b1, second node address b
2. Third node address b3 to nth node address bn
(Hereinafter, areas Abl to Abn are stored as [
system configuration table (TBL)).

Note that the starting addresses in the RAM 16 for each area are A, Bl to B.
It is n.

FIG. 4 shows an example of the format of communication data used in the LAN of this embodiment. Here 21 is the destination address, 2
2 is a source address, and 23 is a data area in which various communication control commands and data are written.

The fifth diagram schematically represents the function of the node related to tree power & example.
The block diagram will be as shown in the figure.

In the same parts of the figure as in Figure 2, the same numbers are indicated by [f (shita).

Reference numeral 21 indicates a sending section which sends out the sending 4J data in accordance with the format shown in FIG. The receivers 1, 1, and 25 that receive the data are comparison units that check whether the destination address information 30 received by the reception unit 23 and the i address number set in the own node address setting unit 17 match. The output signal 34 from the unit 25 indicates that data addressed to the own node has been sent,
Based on this signal, the control unit 22 knows that a data frame addressed to its own node has been received. Reference numeral 26 denotes a node address comparison unit that checks whether the source address information 31 received by the reception unit 23 matches the address number of the mate in the system configuration table TBL shown in FIG. 3 in the RAM 16; As a result of the comparison, if a source address that is not in the TBL is received, the controller 22
is output to.

The control unit 22 receives this non-coincidence signal 32 manually and stores the source address information in ij format in the TBL in the RAM 1S as a new node address number.At the same time, the node whose address number is stored in the TBL The counting unit 27 that indicates the number of nodes is also counted up. 27 is a counting unit that counts the number of nodes whose address numbers are stored in the TBL in the RAM 16 (as described above).

Next, the operation of this embodiment will be explained with reference to the node address management processing flowchart shown in FIG.

Normally, the control unit 22 receives a data frame addressed to its own node, waits for input of a communication signal 34 addressed to its own node from the comparison unit 25, and receives the data frame when the signal is input. In addition, when there is a request for transmission from the 11v service equipment 13 or the like, the sending section 21 sends out the sending data onto the transmission line l via the sending/receiving circuit 14.

In addition to this, the data frame on the transmission path l is always received by the receiving unit, and the source address and R in the data frame are
A node address comparison unit 26 monitors the node address number stored in the TBL in the AM 16.

The node address management process for this address monitoring will be explained with reference to flowchart 1 in FIG. 6).

The receiving unit 23 in the CPU 15 in the normal node 12 waits to receive a normal frame via the transmission path l. If the reception section 23 receives a normal frame in step S1, the source address (SA) of the frame is sent to the node address comparison section 26 via the signal line 31 in the next step S2, and step S3 The node address comparison unit 26
Then, it is checked whether the source address from the signal line 31 is registered in the system configuration table TBL in the RAM 16.

If not registered, the process advances to step S4, where the node address comparison section 26 outputs a non-coincidence signal 32, and the counting section 27 5D counts up the total number of recorded nodes by one. Upon receiving the non-coincidence signal 32, in step S5, the control unit 22 stores the source address received at this time in the TBL in the RAM 16, and also increments the total number of nodes in the TBL by one in the same way as the counting unit 27. do. Then it waits for the next frame to be received.

Further, if the source address is already registered in step S3, nothing is done and the next frame reception is waited.

Here, the area where the value of SA is stored in TBL in RAMI 6 is the storage area Abl of the first node address bl when the total node count a is 1, and the same applies hereafter when the total node count (a) is n. In the n-th case, it becomes the storage area Abn of the first node address bl.

Note that the counting section 27 and the /-total total number counter 1-a are initialized to zero immediately after the node is powered on.

In this way, the addresses of nodes existing in the network are sequentially stored in the system configuration table TBL, so each node can recognize the address number of the node existing in the network by referring to the system configuration table TBL. Also, by referring to the total number of mates count a, it is possible to recognize how many nodes exist in the network I.

Note that CSMA/CD (Carrier
Sense Multiple Access wit
h Collision Detection method and Token Passing method, and it is clear that the data transmission control method according to the present invention can be applied to either method.

[Effects] As explained above, according to the present invention, each node can recognize the network system configuration without using special communication control commands, and can prevent failures, disconnections, and power supply of connected nodes. Even in the event of a power outage, a system can be constructed extremely quickly, and a data transmission control method that can improve network communication efficiency can be provided.

Furthermore, each node has 4. Since the system configuration of the network can be recognized without using different monitor nodes as ghosts, the network system can be configured at low cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the configuration of a local area network system, and FIG. 2 is a diagram illustrating a configuration 1Δ of a transmission device according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of the configuration of the system configuration table of the transmission device of this embodiment, FIG. 4 is a diagram showing an example of the format of communication data according to the present invention, and FIG. 5 is a functional block diagram of the device of this embodiment. , FIG. 6 is a flowchart showing an example of node address information processing of the apparatus of this embodiment. H middle, l... network transmission line, 2-6, 12...
- Transmission/reception node, 13... Electric equipment, 14... Transmission/reception circuit, 15... CPU, 16... RAM, 17.
...Self-node address setting unit, 18...Interface control unit, 21...Sending unit, 22...Control unit, 2
3... Receiving section, 25... Comparing section, 26... Note address comparing section, 27... Counting section. Figure 1 Figure 2 Figure 3 Figure 6 Figure 4

Claims (2)

[Claims] (1) In a data transmission control method for a network system in which a plurality of transmission devices are connected to a communication medium, a receiving means for receiving transmitted information on the communication medium to the transmission device;
The transmission end received by the receiving means? A source address detecting means for detecting a source address in M, and a storage means for storing a source address detected by the source address detecting means, and a source address detected by the source address detecting means. A data transmission control method characterized by identifying transmission devices that constitute a network system based on addresses. (2) Claim 1, characterized in that the storage means is provided with a counting means for counting the number of stored transmission source addresses, and a second storage means for storing the count value of the counting means.
Data transmission control method described in section 2〇