JPS5844843A - Data exchange system for communication network - Google Patents

Abstract

PURPOSE:To decrease the number of interruptions to stations where no data link is established and to improve the processing ability, by making a Baud rate for data link establishment and the Baud rate for actual data transfer to have a different value from each other. CONSTITUTION:When a station 1 transmits data to a station 3, a packet for data link establishment is transmitted to the station 3 in the Baud rate of low speed. After the station 3 returns the response for confirmation to the station 1, the station 3 designates that the succeeding data transfer is executed in the Baud rate of high speed to a network controller 6. On the other hand, a network controller 5 of a station 2 independently of the data link establishment is in the Baud rate mode of low speed, then the data transfer packet executed in the Baud rate of the said high speed is not correctly received, allowing to avoid useless interrupting processing to the station 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data exchange system in a communication network.

In recent years, as data processing technology has improved, information has been effectively distributed and processed by completely exchanging data between multiple stations. Communication networks are formed to effectively achieve this kind of distributed processing, but
Conventionally, in this type of system, stations other than the two stations with which a data link has been established distinguish whether the data belongs to one station or not while the two stations are exchanging data, and determine whether the data belongs to one station or not. Therefore, the disadvantage is that the data is discarded and other processing is delayed.

The present invention was made with the aim of eliminating the drawbacks of the conventional example, and allows stations other than those with which a data link has been established to perform their own processing without being affected by the communication network. We are here to propose a complete data exchange method for a communication network that will enable efficient operation of the communication network.

Hereinafter, the present invention will be explained in detail using the drawings.

The figure is a diagram illustrating a communication network in which the present invention is implemented. 1, 2.3 are stations in the network, 4, 5.6 are network control devices that control the network, and 7, 8.9 are information transmission paths.

Now, when station l sends data to station 3, station 1 first transmits data to the network controller [4] at a low baud rate (a unit pulse that can be sent per second) in order to establish a data link with the other stations. number), and then station 3
packet for calling digit? The network control equipment 4 is transmitted to the transmission paths 7 and 9. The network controllers 5 and 6 receive this packet and forward it to the stations 2 and 3, respectively. station 2
In this case, station 3 determines that the packet is not sent to its own station and does not perform any further data link establishment operations, but station 3 detects the packet as it is sent to its own station, so it checks the stage. After returning the response, the data link establishment operation is performed by instructing the network control device 6 to perform data exchange at the full high speed baud rate from now on. Upon receiving the response from the network control device it4, it specifies the baud rate mode of ^ speed and transmits the data packet onto the network.The network control device 6 immediately changes the mode to the high speed baud rate mode. Since the change has been made, the packet f, which has been sent from station 1, can be received, and the said packet is transferred to station 3.

On the other hand, network controllers M and 5 are in low-speed baud rate mode, so packets (I) cannot be received correctly, resulting in a framing error, and station 2
Do not transfer data to. As a result, station 2 does not need to perform unnecessary interrupt processing (processing to discard data), and can therefore perform other processing. After the data exchange is completed, stations 1 and 3 specify a low-speed baud rate mode to their respective network controllers 4.6, return to the initial state, and have packets from the network or data to be transmitted from their own stations.

In the embodiment described above, the case where the number of stations is three has been explained, but it is clear that the number of stations may be any number as long as it is three or more in order to obtain the effect of the present invention = 5-. Also, establishing a data link between stations does not necessarily have to be one-to-one (,
For example, it is clear that the effects of the present invention can be obtained even when broadcast communication is performed. Furthermore, although the baud rate has been described as being low when all data links are established and the baud rate is high when transferring data packets, it is clear that the same effect can be obtained even in the opposite case.

As explained above, according to the present invention, after the data link is established, all stations other than those for which the data link was established can set a specific baud rate for data transfer.
It provides the effect of improving processing speed because it can perform all of its own processing without being affected by the communication network.

[Brief explanation of drawings]

6- is a diagram showing a communication network. Here, 1, 2.3 are stations, 4, 5.6 are network control devices, and 7, 8.9 are transmission lines. Patent applicant: Canon Co., Ltd. 7-

Claims (1)

[Claims] A data exchange system for a communication network, characterized in that after at least two stations establish a data link, all communication baud rates different from those at the time of establishing the data link are set between the stations with which the data link has been established.