JPH02119341A - Local area network - Google Patents

Abstract

PURPOSE:To eliminate the need of the installation of a main line cable, to prevent a fine spectacle from being impaired, and to save facility expense and extension expense by generating a token to supply a transmission right sequentially to plural stations, and performing transmission to the plural stations with a prescribed token holding limitation time interval via a radio line. CONSTITUTION:A network controller 10, when being started up, refers to an address managing table 11 simultaneously by starting up an access managing means 12, and generates the token addressed to each station in sequence registered on the table, and supplies it to a modulation means 13 sequentially. The delivery interval of the token is decided as the prescribed token holding limitation time interval decided based on the scale of a network and the total number of terminals. The modulation means 13 to which the token is suppled from the access managing means 12 performs the modulation of the token, and supplies it to a transmission means 14, and transmits it via the radio line. Each station 20 starts up a reception means 23 simultaneously with the start-up. The token is demodulated, and a selection means 251 supplies transmission data if it exists to a modulation means 211 when it is judged that the token is the one addressed to its own station. When no transmission data exists, a processing is completed at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is suitable for medium distance data communication. -Used for local area networks. Particularly, the present invention is a control method in which data transmission between each station is performed via a wireless line.% The present invention provides a method for connecting a network control device and each station and between each station via a wireless line in a local area network. The work control device sequentially gives tokens to each station, and each station transmits the token within the token holding time limit after acquiring the token. This eliminates the need to install trunk cables, reduces equipment costs and expansion costs without compromising the aesthetics. In addition, the system allows easy station relocation and improves reliability.

[Conventional technology]

Traditionally, local area networks use physical media such as coaxial cables or fiber optic cables as transmission media, depending on the surrounding environment and transmission speed, and each station connects a transceiver to this trunk cable to transmit data. Ta.

FIG. 4 is a block diagram of a conventional local area network. In FIG. 4, station 2001 is station 20
When data addressed to 0□ is generated, the data is sent to the transceiver 3001 via the relay cable 4001, and the data is sent to the transceiver 300. was being sent to trunk cable 500.

Next, the transceiver 300° received this signal and passed it to the station 2002 via the relay cable 400□.

[Problem that the invention seeks to solve]

However, such conventional local area networks have the following drawbacks.

(a) In order to connect all the stations (electronic computers, terminals, control equipment, etc.), main cables must be stretched around the premises, and there is generally no space to store the main cables and transceivers, which obstructs traffic. This spoils the aesthetic appearance.

b) In order to add a new station, connection work must be carried out and the trunk cable may need to be extended.

(C) When laying trunk cables on the floor, there is a risk of wire breakage, and shocks may cause damage to transmitters and receivers, etc.

(cl) When moving a station, connection work and trunk cable relocation and extension are required.

The present invention solves the above-mentioned drawbacks, and provides a highly reliable local area network that eliminates the need to lay trunk cables, reduces equipment costs and expansion costs without compromising aesthetics, and allows for easy station movement. The purpose is to

[Means for solving problems]

The present invention provides a local area network including a plurality of stations that perform data communication with each other, including a network control device, the network control device including means for creating a token that sequentially grants transmission rights to the plurality of stations. ,
and means for transmitting the output of the generating means to the plurality of stations via a wireless line at predetermined token holding time limit intervals, and each of the plurality of stations includes means for receiving a signal on the wireless line. , means for selecting a token addressed to the own station from the output of the receiving means, and means for transmitting transmission data onto the wireless line within the predetermined token holding control time based on the selection result of the selecting means. It is characterized by containing.

[Effect]

7) The work control device creates tokens that sequentially grant transmission rights to a plurality of stations, and transmits the tokens to the plurality of stations via a wireless line at predetermined token holding time limit intervals. Each of the plurality of stations receives tokens over the wireless line, and when a token addressed to the station is selected, sends transmission data over the wireless line within a predetermined token holding time limit. With the above operations, there is no need to lay trunk cables, and equipment costs and expansion costs can be reduced without impairing the aesthetics, and the station can be moved easily, improving reliability.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram of a local area network according to an embodiment of the present invention. In FIG. 1, a local area network 100 includes a plurality of stations 20..202 that perform mutual data communication.

Here, the present invention is characterized by comprising a network control device 10, which includes a plurality of stations 20. ．． The address management table 11 and the access management means 12 are used as means for creating tokens that sequentially give transmission rights to the stations 20□, and the output of the access management means 12 is transmitted to the plural stations 20 at predetermined token holding limit time intervals via a wireless line. Each of the plurality of stations 20 includes a receiving means 23 and a demodulating means 24 as a means for receiving signals on a wireless line, and a signal from the output of the demodulating means 24 to the own station. A selection means 25 is used as a means for selecting the destination token, and a memory 26 for storing the address of the own station is used, and based on the selection result of the selection means 25, transmission data is sent onto the wireless line within the predetermined token holding control time. The apparatus includes modulation means 21, transmission means 22, and transmission data display means 27 for referring to transmission data.

The operation of a local area network with such a configuration will be explained. In FIG. 1, the network control device 10 starts the access management means 12 at the same time as it is started. The access management means 12 refers to the address management table 11, creates tokens addressed to each station in the order registered therein, and sequentially supplies them to the modulation means 13.

When the access management means 12 refers to the end of the address management table 11, it returns to the beginning again.

Furthermore, the token sending interval is set to a predetermined token holding time limit interval determined from the network scale and the total number of terminals. The modulation means 13, which is given the token from the access management means 12, modulates the token and sends it to the transmission means 14.
and transmits it via wireless link.

Each station 20 activates the receiving means 23 at the same time as it is activated. Now station 20. If the destination token is sent from the network control device 10, the receiving means 23 provides the received token to the demodulating means 241.

Demodulation means 24. demodulates this token and then provides it to selection means 251.

The selection means 251 compares the destination address included in the encoded token with the own station address stored in the memory 261, and if it is determined that the token is addressed to the own station, the selection means 251 determines that the transmission data is stored inside the own station. It is determined whether the data exists by referring to the transmission data display means 27□. If there is transmission data, the selection means 25 modulates the modulation means 21. Give this sending data to . If not, the process ends at that point.

Modulation means 21. transmitting means 22. modulates the transmission data and then transmits the data to the transmitting means 22. give to Transmission means 22. sends this out over the wireless line.

Data transmission is completed within a predetermined token holding time limit to avoid collision with the next token sent to the local station 201 or the other station 202 over the wireless line.

When the receiving means 23□ of the station 20□ receives the token from the wireless line, it supplies it to the demodulating means 24□. Demodulation means 242
demodulates the received transmission data and supplies it to the selection means 25°. The selection means 25° determines whether the received token is addressed to its own station by referring to its own address stored in the memory 26□, and if it is addressed to its own station, it receives the token in the same manner as the station 201. Perform processing.

FIG. 2 is a diagram showing the contents of the address management table of the network control device of the local area network of the present invention. In FIG. 2, the address management table 11 has a registration number of 110, a station address area of 120, and an unused area of 1.
30.

In the station address area 120, station addresses are stored in the order of registration. The unused area 130 is an area that can be newly registered.

FIG. 3 is a diagram showing the flow of tokens in the local network according to the present invention. The token is sent to each station 2 via wireless line.
01-20. are passed in order. Next, the flow of tokens is shown.

1st time 10-20 2nd time lO → 202 3rd time 10 → 20.3 4th time to -20° Furthermore, in this example, transmission rights are passed in the following order.

20, →202-203-20. →201→ [Effects of the Invention] As explained above, the present invention eliminates the need to lay a trunk cable as a transmission medium, so it is possible to reduce the cost of laying cables without impairing the aesthetics, and to add new stations. There is no need for additional construction by simply installing the terminal, etc., as long as the radio wave can be received, and it is also easy to move the station, reducing the risk of cable breakage or damage to the transmitter/receiver due to external impact. This has the excellent effect of improving network reliability.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a local area network according to an embodiment of the present invention. FIG. 2 is a diagram showing an address management table for a local area network according to the present invention. FIG. 3 is a diagram showing the flow of tokens in the local area network of the embodiment. FIG. 4 is a block diagram of a conventional local area network. DESCRIPTION OF SYMBOLS 10... Network control device, 11... Address management table, 12... Access management means, 13...
- Modulation means, 14...transmission means, 20. ~204.2
001-2003...Station, 210.212...Modulation means, 22. ．． 222... Transmission means, 2323□...
- Receiving means, 24. ．． 24. ... demodulation means, 251.
252... selection means, 26. ．． 26□・・・Memory,
274.272...Transmission data display means, 100...
Local area network, 110...Number of registrations, 1
20... Station address area, 130... Unused area,
4001-4003...Relay cable, 3001-3
003... Transmitter/receiver, 500... Trunk cable, 6
001.6002...Terminate.

Claims (1)

[Claims] 1. In a local area network including a plurality of stations that perform data communication with each other, a network control device is provided, and the network control device generates a token that sequentially grants transmission rights to the plurality of stations. and means for transmitting the output of the generating means to the plurality of stations at predetermined token holding limit time intervals via a wireless line, and each of the plurality of stations receives a signal on the wireless line. a means for selecting a token addressed to the own station from the output of the receiving means; and a means for transmitting transmission data onto the wireless line within the predetermined token holding control time based on the selection result of the selecting means. A local area network comprising means for transmitting.