JPH05336122A - Method for controlling network - Google Patents

Abstract

PURPOSE:To easily detect the connection state of a network by discriminating a repeater through which the communication passes. CONSTITUTION:In a network control method controlling the connection state of each network when data are transmitted among communication terminal equipment stations 11, 12, 18-22 via repeaters 15-17 connected to respective networks, when the data are transmitted from the communication terminal equipment station 21, a control station 14 sends a data frame to each of repeaters 15-17 to forcibly stop the relay function of each of repeaters 15-17 sequentially and a data frame requesting a reply is sent to the communication terminal station 21 to confirm the presence of a reply, thereby discriminating a repeater through which data passes in the network control method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network management method for managing the connection status of networks.

[0002]

2. Description of the Related Art Conventionally, in a bus-type or tree-type network constructed by connecting a plurality of communication terminal stations and repeaters to each transmission line, a destination address, a source address,
There has been a method of using a transmission method for transmitting a packet-type data frame having a header having a data length and the like and a trailer such as a frame check sequence between the communication terminal stations.

[0003]

However, in the above transmission method, when a data frame is transmitted via a repeater, it is not possible to recognize in which network the communication terminal station exists. There is a situation in which it is not possible to determine which relay is used for data transmission, and thus network management cannot be performed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a network management method capable of easily detecting a connection state of a network by discriminating a relay device passing through.

[0005]

According to the present invention, there is provided a network management method for managing a connection state of each network when data is transmitted between communication terminal stations via a repeater connected to each network. Provided is a network management method in which, when data is transmitted from the communication terminal station, the network management means forcibly stops the relay function of the repeater and recognizes in which network the communication terminal station exists. To be done.

[0006]

When the data is transmitted from the communication terminal station, the management station, which is the network management means, transmits a data frame to each repeater, and each repeater receiving the data frame receives the contents of the frame. The relay function is stopped or restored according to the above, and the management station confirms through which relay the response is transmitted from the communication terminal station.

Therefore, the management station can determine the relay station through which the data is transmitted by confirming the response from the communication terminal station.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a diagram showing a connection state of a network used in a network management method according to the present invention. In the figure, the bus 10 includes communication terminal stations 11, 12
However, a management station 14 and a repeater 15 are connected to the bus 13, respectively. A repeater 16 is connected to the buses 10 and 13. The repeater 15 includes a repeater 17,
The communication terminal stations 18 and 19 are connected to the repeater 17 in the tree format via the transmission lines 23 to 28, respectively. As a result, the bus 1
0, the communication terminal stations 11 and 12 and the repeater 16 connect the first network to the bus 13, the management station 14, the repeater 15,
16 is a second network, and the relays 15, 17,
The communication terminal stations 18 to 22 and the transmission paths 23 to 28 are the third
Each network is being built.

The communication terminal stations 11, 12, 18 to 22 transmit and receive packet-type data frames as shown in FIG. The packet format data frame shown in FIG. 2 includes a preamble for synchronizing the frames, a frame start delimiter (SFD) indicating the beginning of the frame, a destination address (DA) indicating the station that should receive the frame, A source address (SA) indicating a station that transmits a frame, a data length indicating a data length of a data portion described later, a data portion storing predetermined data, and a CRC.
It is composed of a frame check sequence (FCS) for detecting a transmission error such as (Cyclic Redundancy Check).

The management station 14 also transmits the data frame shown in FIG. 2 to each of the repeaters 15-17. That is, when the management station 14 does not recognize the positional relationship of the transmission terminal station, which is the communication terminal station that performs data transmission, it transmits the data frame to stop or restore the relay function of the repeater. In addition, by transmitting data to the transmitting terminal station and confirming the response, the relay device through which the data is transmitted is determined. In this case,
Address data of the repeater that should receive the frame is stored in DA of the data frame, and address data of the management station 14 is stored in SA.

Addresses are set in the relays 15 to 17, respectively, and the relays 15 to 17 relay the data frame transmitted between the communication terminal stations and, as described above, When the data frame transmitted from the management station 14 is received and the DA is the address data of the own station, the relay function is stopped or restored according to the data content in the frame.

Next, the management station 1 in the above network
The network management operation of No. 4 will be described. In addition,
In this embodiment, a case where data is transmitted from the communication terminal station 21 will be described. First, the communication terminal station 21 of the transmission source
A data frame having the above-described structure is assembled, a packet is completed, and the packet is transmitted. The transmitted data frame is received by the management station 14 via the relay devices 17 and 15.

In this case, the management station 14 recognizes the transmitting terminal station by the SA of the data frame, but when the positional relationship of the communication terminal station 21 cannot be recognized, the management station 1
In order to investigate the positional relationship of the communication terminal station 21, 4 transmits a data frame instructing the stop of the relay function to one of the relays 15 and 16 directly connected, for example, the relay 16 first. .. When the repeater 16 receives the data frame, it determines whether the DA of the data frame is the address of its own station, and if it is the address of its own station, stops the relay function according to the data content.

Next, the management station 14 transmits a data frame requesting a reply to the communication terminal station 21 via the repeaters 15 and 17. After that, the communication terminal station 21 transmits a response data frame to the management station 14 in response to the return request. The data frame of the above reply is transmitted to the repeaters 15 and 17
Is transmitted to the management station 14 via the frame, and the management station 14 can recognize from the frame that the communication terminal station 21 is not connected to its own station via the repeater 16.

Next, the management station 14 transmits a data frame that restores the relay function of the relay 16 and the relay 16
The relay function is restored and a data frame instructing the relay device 15 to stop the relay function is transmitted. When the repeater 15 receives the data frame, it determines whether the DA of the data frame is the address of its own station, and if it is the address of its own station, stops the relay function according to the data content.

Next, the management station 14 transmits a data frame requesting a reply to the communication terminal station 21. However, in this case, since the relay device 15 does not relay the frame, the frame is not transmitted to the communication terminal station 21, and the management station 14 receives the response data from the communication terminal station 21 within a predetermined time, for example. I can't receive. As a result, the management station 14 uses the repeater 15 for data transmission from the communication terminal station 21.
Can be recognized through.

Next, the management station 14 transmits a data frame that restores the relay function of the repeater 15, and the repeater 15
The relay function is restored and a data frame instructing the relay device 17 to stop the relay function is transmitted. When the repeater 17 receives the data frame via the repeater 15, the repeater 17 determines whether the DA of the data frame is the address of the own station, and if it is the address of the own station, stops the relay function according to the data content. To do.

Next, the management station 14 transmits a data frame requesting a reply to the communication terminal station 21. However, in this case, the relay device 15 relays the frame,
Since the repeater 17 does not relay the frame, the frame is not transmitted to the communication terminal station 21, and the management station 14 cannot receive the reply data from the communication terminal station 21. As a result, the management station 14 can recognize that the data transmission from the communication terminal station 21 is performed via the repeaters 15 and 17.

Therefore, in this embodiment, the relay station, which transmits a data frame from the management station to the relay station and receives the data frame, stops or restores the relay function depending on the contents of the frame. Therefore, the management station can check which relay is used to send a response from the communication terminal station, and this enables active acquisition of network information and the connection status of each network. Can be managed.

[0020]

As described above, according to the present invention, when the data transmission is performed between the communication terminal stations via the repeater connected to each network, the network management for managing the connection state of each network. In the method, when performing data transmission from the communication terminal station, the network management means forcibly stops the relay function of the repeater and recognizes in which network the communication terminal station exists. It is possible to easily detect the connection state of the network by discriminating the relay device that operates.

[Brief description of drawings]

FIG. 1 is a diagram showing a connection state of a network used in a network management method according to the present invention.

FIG. 2 is a diagram showing a structure of a packet-type data frame according to the present invention.

[Explanation of symbols]

 10, 13 Bus 11, 12, 18-22 Communication terminal station 14 Management station 15-17 Repeater 23-28 Transmission path

Claims (1)

[Claims] 1. A network management method for managing the connection state of each network when performing data transmission between the communication terminal stations via a repeater connected to each network. When performing, the network management means forcibly stops the relay function of the relay device and recognizes in which network the communication terminal station exists.