JPS6074832A - Data transmission method - Google Patents

Abstract

PURPOSE:To exclude transmitting stations that have no need to be used as the primary stations and to improve the overall efficiency of transmission for a data transmitting system, by using a primary station rejection answer command and a primary station forcible variation command. CONSTITUTION:Transmitting stations 11-1N are connected to a transmission line 10, and one of these transmitting stations is defined as a primary station with other stations used as the secondary stations for transmission of data. Thus the transmitting stations take charge of a primary station alternately to perform N:N transmission of data in a semidouble system. In this case, a command CND1 is used to reject a change into a primary station and the secondary stations having no need to transmit data deliver the command CND1. Thus the change into a primary station is inhibited for the transmitting stations which delivers the command CND1. In addition, a command CND2 is used to change forcibly a secondary station into a primary station. When a transmitting station 13 delivers a command CND2, a transmitting station 14 which is delivering a command CND1 is changed forcibly into a primary station. Then the station 13 executes another processing as a secondary station.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a data transmission method for mutually transmitting data between a plurality of transmission stations using a half-duplex transmission method.

[Technical background of the invention and its problems]

As shown in FIG. 1, one transmission line 10 has N transmission stations 11, 12 . ..., when an IN is provided and N:N transmission is performed using a half-duplex transmission method, multiple transmission stations cannot simultaneously transmit data to the transmission line 10, so they have the initiative in transmitting data and transmitting data. N transmission stations (hereinafter referred to as "secondary stations") are set as one transmission station, and other transmission stations are designated as transmission stations that only receive data (hereinafter referred to as "secondary stations"). ．． ..., IN become primary angles in order, thereby realizing N2N transmission. That is, for example, at time t'' t+, as shown in FIG.
..., if IN is a quadratic interval, then the primary time t''t!
As shown in FIG. 1(2), the transmission station 12 is changed from a secondary station to a primary station, and the transmission station 11 is changed from a primary station to a secondary station.

Furthermore, at the next time t=ts, as shown in FIG. 1(3), the next transmission station 13 is changed from a secondary station to a primary station, and the transmission station 12 is changed from a primary station to a secondary station. Similarly below,
Transmission stations 11, 12, . ..., N:N transmission is realized by changing the IN to the primary station.

Some transmission stations do not perform data transmission themselves. Furthermore, even at a transmission station that transmits data, it is not possible to transmit data during data processing or the like. Even if these transmission stations change to the next station, they do not actually transmit data, but simply wait for the next transmission station to become the primary station.

However, in the past, all transmission stations were changed into primary stations one after another without being differentiated, resulting in waste and low transmission efficiency.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances.

The purpose is to provide a data transmission method with high transmission efficiency.

[Summary of the invention]

In order to achieve this object, the data transmission system according to the present invention is such that one of a plurality of transmission stations provided on a transmission line is designated as a primary station that transmits data to other transmission stations;
By making the other transmission station a secondary station that only receives data, and changing the plurality of transmission stations to the primary station in turn, data is mutually transmitted between the plurality of transmission stations in a half-duplex transmission method. In the transmission method, a primary station rejection response command that rejects a change to the next station, and a primary station forced change command that forcibly changes the secondary station to the primary station are provided.

When some of the secondary stations have issued the -next station rejection response command, the secondary stations that have not issued the -next station rejection response command are changed into primary stations in turn.

When all the secondary stations have issued the -next station change refusal command, the -next station issues a primary station forced change command to forcibly change the predetermined secondary station to the primary station. It is said that

[Embodiments of the invention]

FIG. 2 (1) shows a data transmission method according to an embodiment of the present invention.
, (2), (3), and (4).

One transmission line 10 has N transmission stations 11, 12 .・
..., IN is provided, and N:N is provided in half-duplex transmission system.
shall be transmitted. Then, one transmission station is designated as the primary station.

N:N transmission power is achieved by transmitting data using other transmission stations as secondary stations and taking turns becoming the primary station, but this embodiment is characterized in that it does not simply change to the primary station in turn. There is. In other words, as a response command for transmission, a command CNDi'& is provided to reject a change to the next station, and this command CND is used between secondary stations where there is no need for data transmission.
Make it emit 1.

The transmission station issuing this command CNDI should not be changed to the primary station. For example, as shown in FIG. 2 (1), at time t1, the transmission station 11 is the primary station, and the other transmission station 1
2,13. ..., IN is between secondary and primary transmission station 12
Trying to change it to the primary station. However, the 12 transmission stations are transmission stations that do not transmit data themselves.

command CMDI due to data processing in progress.
Since it emits, the first time t! Now, as shown in FIG. 2 (2), the transmission station 12 is skipped and the transmission station 13 that has not issued the command CNDI is changed to the primary station. In this way, the command to reject the change to the next station is sent. CNDI
By sequentially converting the secondary stations that are not emitting tt into primary stations, there is no need to waste time, which was the case in the past, and transmission efficiency is greatly increased.

However, as shown in Figure 2 (2), N-
1 transmission station 11.12.14.15. . . . If all INs are issuing the command CNDI, even if the transmission station 13, which is the next station, completes data transmission, it will not be able to change to the second order and no other processing will be possible.

There is a possibility that the transmission efficiency as a whole may be reduced. Therefore, the command CN to forcibly change the secondary station to the primary station
D2 is provided, and as shown in FIG. 2 (3), this command C
When the transmission station 13 issues ND2, the command CND
The transmission station 14 that is emitting I is forcibly changed to the primary station, as shown in FIG. 2 (4).

As a result, the transmission station 13 becomes a secondary station and can perform other processing.

Note that the number of transmission stations may be any number, and the transmission stations may be computers, for example, but any other transmission stations may be used.

〔Effect of the invention〕

As described above, according to the present invention, transmission stations that do not need to become the next station can be skipped, thereby eliminating conventional waste and allowing transmission with high transmission efficiency. Furthermore, since a particular transmission station does not always remain a primary station, other processing performed by the transmission station can be delayed, and the efficiency of the system as a whole can be achieved.

[Brief explanation of the drawing]

Figure 1 (1), (23, (3)) shows the conventional 0 data transmission method, Figure 2 (1), (2), (3)
, (4) is a diagram showing a data transmission method according to an embodiment of the present invention. 10...Transmission line, 11.12. −・・,IN・
...Transmission station, CND1, CND2...Command. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] One of the plurality of transmission stations installed on the transmission line is a primary transmission station that transmits data to other transmission stations, and the other transmission station is a secondary transmission station that only receives data. In the data transmission method, the data transmission method mutually transmits data between the plurality of transmission stations in a half-duplex transmission method by changing the angle of the plurality of transmission stations alternately to a linear angle. a primary station rejection response command that rejects a change to the primary angle;
A primary station forced change command for forcibly changing the two-friend station to the primary angle is provided, and when some of the secondary stations are issuing the -next station rejection response command. The secondary stations that have not issued the above-mentioned -Next station rejection response command are changed to the primary mode in turn, and if all the secondary stations have issued the -Next station change rejection command, the -Next station becomes the primary station. A data transmission method characterized in that a predetermined secondary station is forcibly changed to a primary angle by issuing a forced change command.