JPH02114738A - Communication system for common communication line - Google Patents

Abstract

PURPOSE:To avoid the collision of information from plural slave stations and to realize an efficient operation by sending sequentially information of a prescribed capacity from a master station to each of plural slave stations at the same interval of information transmission and allowing a slave station to finish the reception of information to its own station and to send the information to the master station immediately. CONSTITUTION:Slave stations 2, 3 are connected with a master station 1 by a communication line 4. The communication line 4 has a sharing access point between the master station and the slave station and a transmission section 6 exists between the sharing access point P and the slave stations 2, 3. Let the ratio of the transmission time from the sharing access point P till the slave stations 2, 3 to one information transmission time of the master station 1 is 1, then the master station 1 sends alternately plural bits of information a1, a2, a3 to the slave station 2 and plural bits of information b1, b2, b3 to the slave station 3 at the same interval as the information transmission. The slave stations 2, 3 receive the plural bits of information a1, a2, a3, b1, b2, b3 after the transmission time after the end of information reception to its own station and sends the information to the master station. Thus, the collision of the information among the master station 1 and the slave stations 2, 3 at the sharing access point P of the master station and the slave station is avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to communication between one master station and a plurality of slave stations, and particularly relates to communication between a master station and a plurality of slave stations through a single communication line. This relates to a communication method from a slave station to a master station on a common communication line.

[Conventional technology]

Conventionally, this type of communication system has been associated with collisions because a plurality of slave stations send information to the master station without permission via a common communication line.

[Problem to be solved by the invention]

The conventional common communication line communication method described above is a format in which multiple slave stations send information asynchronously to the same line when necessary, so collisions often occur, and when a collision occurs, it must be retransmitted, so the transmission The disadvantage is that speed and transmission efficiency are reduced.

[Means to solve the problem]

The present invention provides a communication method using a common communication line in which a master station and a plurality of slave stations are connected by a single communication line having a common access point. The master station sequentially transmits information to the plurality of slave stations at the same time interval as the information transmission time, and each of the slave stations receives information from the master station to its own station. It is characterized by transmitting information to the main station immediately after receiving the destination information.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of the configuration of an embodiment of the present invention, in which slave stations 2 and 3 are connected to a master station 1 through a communication line 4. In FIG. The communication line 4 has a shared access point P for a master station and a slave station, and a transmission delay section 6 is provided between the shared access point P and the slave stations 2 and 3.

Let us assume that the ratio of the transmission time from the shared access point P of the master station and slave stations to the slave stations 2 and 3 to the information transmission time of one time of the master station 1 is 1. As shown in FIG. 2, the master station 1 sends information a1. a2. Information for a3 and slave station 3 b1 + b
2 + b3 is sent out alternately for slave station 2 and slave station 3 at the same intervals as the information transmission.

The slave stations 2 and 3 use the information al, a2, a3 in FIG.
b,, b2. b3 is received after the transmission time, and immediately after the own station has finished receiving the information, the main station sends the information.

FIG. 3 shows the procedure by which the slave station 2 sends out information, and FIG. 4 shows the procedure by which the slave station 3 sends out information. Information al ′,
A2' and a3' are information to be sent to the slave station 2 or the master station 1, and information b1', b2', and b3' are information to be sent to the slave station 3 or the master station 1. When communicating as above,
As shown in FIG. 5, information from the master station 1 and the slave stations 23 is transmitted without collision at the shared access point P between the master station and the slave stations, and is received by the master station 1 and the slave stations 2 and 3.

〔Effect of the invention〕

As explained above, in the present invention, a master station sequentially transmits a fixed amount of information to each of a plurality of slave stations at the same intervals as the information transmission, and the slave station immediately sends information to the master station after receiving the information. By sending information to the substation, information from multiple slave stations can be efficiently operated without colliding with each other.

[Brief explanation of the drawing]

FIG. 1 shows a master station 1 and a plurality of slave stations 2 and 3 in an embodiment of the present invention.
2 is a block diagram showing the configuration of the main station 1 and the slave stations 2 and 3.
FIG. 3 is a schematic diagram showing the procedure for transferring information sent from the slave station 2 to the master station 1.
FIG. 4 is a schematic diagram showing the transfer procedure of information sent from slave station 3 to master station 1, and FIG. 5 is a schematic diagram showing the passage of information at shared access point P between master station 1 and slave stations 2 and 3. It is. 1...Main station, 2, 3...Slave station, 4...Communication line,
5... Shared access point P between the master station and the slave station, 6... Transmission delay section.

Claims (1)

[Claims] In a communication system using a common communication line in which a master station and a plurality of slave stations are connected by a single communication line having a common access point, the transmission time from the common access point to the slave stations relative to the information transmission time of the master station once. The master station sequentially transmits information to the plurality of slave stations at the same time interval as the information transmission time, and each of the slave stations receives information addressed to it from the master station. A communication method for a common communication line that is characterized by sending information to the main station immediately after receiving it.