JPH0563751A - Communication system for frame level - Google Patents

Abstract

PURPOSE:To reduce a reply wait time in inter-communication and to attain high speed communication by changing information exchange of a frame level having been made in semi-duplex into data communication in an action in terms of full-duplex. CONSTITUTION:In the case of sending a command, a means sending a command, a discrimination means discriminating whether reception data from an opposite station are response data or command data from the opposite station, a response data processing means implementing the processing when the result of discrimination indicates response data, and a response transmission means sending the response data when the data are command data from the opposite station. Furthermore, in the case of receiving a command, a means receiving a command, a check means checking the presence of a transmission request of the command, a response transmission means sending response data when no command transmission request comes, and a processing means sending a command and receiving the response data from the opposite station or sending the response data to the command from the opposite station when no command transmission request comes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame level communication system, and more particularly to a frame level communication system between a master station and a slave station.

[0002]

2. Description of the Related Art FIG. 9 is a diagram showing a conventional frame transmission / reception procedure, showing a flow when a master station causes a data transmission to a slave station. First, an ENQ (inquiry) is transmitted to request a response from the partner station. The slaves are
ACK (acknowledgement) is transmitted to ENQ, and TEXT (data body to be transmitted) is transmitted after the protocol level link is established. This TEXT is called a "command" from the master station to the slave station. Next, the main station receives ACK and EO
T (transmission end) is transmitted. In STEP 1, the master station shows the flow of command transmission operation to the slave stations. Next, in STEP 2, TEXT is transmitted from the master station to the slave station as a response to the command. This TEXT
Is called a "response" to the command.

The response is the TEX transmitted from the main station.
It is a TEXT having the meaning of an affirmative response, a negative response, and a reception temporary delay by examining T at the frame level. That is, in the conventional method, the protocol at the protocol level and the protocol at the frame level are configured by half-duplex communication.

[0004]

After the command is transmitted, the conventional communication means cannot transmit the next command until the response to the command is returned, and the side receiving the command does not transmit the command. Since the configuration is such that the command cannot be sent to the other side unless the response to the received command is sent to the other side, there is a problem that the transmission time is greatly affected by the response waiting time after sending the command. It was

[0005]

The frame-level communication system of the present invention is a frame-level communication in which a command between two stations is transmitted from one side to the other side and a response corresponding to this command is transmitted from the other side to the one side. In the method, when transmitting a command, means for transmitting the command from an idle state in which the command can be transmitted and received, and receiving from the partner station in a waiting state for a response from the partner station after transmitting the command from the own station Discriminating means for discriminating whether the data is "response data corresponding to the command transmitted previously" or "command data from the partner station", and if the discrimination result is response data, a predetermined process is performed on the response data. And a response data processing means for returning to the idle state, and the determination result is command data from the partner station. And a response transmitting means for transmitting response data corresponding to the command of the partner station and returning to the idle state. When receiving the command from the idle state, the means for receiving this command and, after receiving this command, the own station Means for checking whether or not there is a "command transmission request" from the device, and if there is no "command transmission request" in this checking means, response transmission means for transmitting response data corresponding to the received command and returning to the idle state. Then, when there is a "command transmission request" in the checking means, the command from the own station is transmitted first,
It is provided with processing means for receiving the response data from the partner station after the transmission or transmitting the response data for the command from the partner station and returning to the idle state.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the frame level communication system of the present invention will be described with reference to the drawings. However, the protocol level is not shown in the figure. FIG. 1 shows an embodiment when a command is transmitted from a master station to a slave station. First, the master station sends a command to the slave station. The slave station enables the command to be transmitted during (2) when the information to be transmitted to the master station, that is, the factor for transmitting the command occurs during the process of receiving the command. However, the main station is not allowed to send the next command while it is in the response waiting state after sending the command (1). This is because it cannot be determined whether the transmitted command is a positive response or a negative response. If the response is negative, the previously transmitted command is retransmitted.

Next, FIG. 2 is a diagram when a command is transmitted from a slave station to a master station. At this time, the main station enables command transmission during (3) of transmitting a response to the command. However, the slave station is not allowed to send commands during (4) waiting for a response after sending commands.

Next, in FIG. 3, as in FIG. 1, the slave station receives the command, but when a factor for transmitting the command to the master station occurs, the command is transmitted during (5) and the master station transmits the command. The side is a case where the response to the command from the slave station is transmitted first during the response waiting state (5). This is because the slave station receives the response first after transmitting the command with a delay, and then transmits the response. Also in this case, command transmission is not permitted during the period (5) similar to the period (1) in FIG.

Next, in FIG. 4, as in FIG. 2, the master station receives the command, but when the factor for transmitting the command to the slave station occurs (7), the command is transmitted, and the slave station side
This is the case where the response to the command from the main station was transmitted first during the response waiting state (8). As for the main station side, although the command is transmitted with a delay, the response is received first and then the response is transmitted.

Also in this case, (7) is the same as in (3) of FIG.
During this period, command transmission is not allowed.

FIG. 5 shows a case where the slave station transmits the master station by dividing it into n frames. When the master station receives a command from the slave station, when a factor that sends a command to the slave station occurs, if the master station transmits the command while receiving all n frames, the slave station will receive the command from the master station. As soon as a response to the command is created, it will be sent to the master station. However, the master station is not allowed to send a new command during (9) and the slave station is allowed to send a new command during (10).

Next, the operation will be described. FIG. 6 shows a flow in which a transmission request is issued from the idle state and a command is transmitted. In this flow, the process branches depending on whether it is the response to the previously transmitted command or the received command from the partner station when waiting for a response after transmitting the command.

First, if it is a response, it is checked whether it is an affirmative response or a negative response. If it is a positive response, it goes to an idle state, and if it is a negative response, it retransmits the previously transmitted command and waits for a response after transmitting the command. On the other hand, if it is a command from the partner station, the received command is verified and a response is sent.

FIG. 7 is a flow when a command or response is received from the idle state. In this flow, the process branches depending on whether or not there is a command to be transmitted by itself when receiving a command and receiving a response. First, when there is no command to be transmitted, the received command is verified, a response is created, and the response is transmitted. On the other hand, if there is a command to be transmitted, the command is created and the command transmission sequence for command transmission is started.

FIG. 8 is a time chart showing the relationship of the response to the command. FIG. 8A shows the conventional one, and FIG. 8B shows the present one. T ₁ and T _{1 ′} are response waiting times after command transmission. Also T
₂ , T _{2 ′} is the time required for receiving the command, verifying the received command, and transmitting the response. T ₃ and T _{3 ′} are the total time when two sequences of command transmission and command reception occur at the same time. Here, when T ₁ = T _{1 ′} and T ₂ = T _{2 ′} ,
The result is T ₃ > T _{3 ′} .

[0016]

As described above, the frame-level communication method of the present invention uses the half-duplex method for frame-level information exchange, but the mutual exchange of data is performed in full-duplex operation. In the inter-communication, the response waiting time is shortened and the communication speed is increased.

[Brief description of drawings]

FIG. 1 is a diagram showing a frame-level transmission / reception procedure when a command is transmitted from a master station to a slave station according to an embodiment of a frame-level communication system of the present invention.

FIG. 2 is a diagram showing a frame level transmission / reception procedure when a command is transmitted from a slave station to a master station according to an embodiment of the frame level communication system of the present invention.

FIG. 3 is a diagram showing a frame level transmission / reception procedure in the case where the main station of the embodiment of the frame level communication system of the present invention first transmits a response to a command from a slave station while waiting for a response. ..

FIG. 4 is a diagram showing a frame level transmission / reception procedure in the case where a slave station according to an embodiment of the frame level communication system of the present invention first transmits a response to a command from the slave station while waiting for a response.

FIG. 5 is a diagram showing a frame level transmission / reception procedure in the case where a slave station of an embodiment of a frame level communication system of the present invention divides a command into n frames and transmits a command.

FIG. 6 shows a transmission request from an idle state, which shows an example of the operation in the frame level communication method of the present embodiment
This is a flow for transmitting a command.

FIG. 7 is a flow of command reception or response reception from an idle state showing an example of operation in the frame-level communication method of the present embodiment.

FIG. 8 is a frame-level time chart.

FIG. 9 is a diagram showing a conventional frame transmission / reception procedure.

Claims (1)

[Claims] 1. In a frame level communication method for transmitting a command from one station to another station between two stations and transmitting a response corresponding to the command from the other station to the other station, when the command is transmitted, the transmission / reception of the command is performed. Means for transmitting the command from a possible idle state, and in the state waiting for a response from the partner station after transmitting the command from the own station, the received data from the partner station is "response data corresponding to the previously transmitted command". Or a "command data from the partner station", and if the result of this determination is response data, the response data processing means performs predetermined processing on the response data and returns to the idle state, If the determination result is command data from the partner station, the response data corresponding to the partner station command is sent. Then, when a command is received from the idle state, the response transmission means for returning to the idle state is provided, and the means for receiving this command and the presence / absence of a “command transmission request” from the own station after receiving this command Means to check,
If there is no "command transmission request" with this checking means,
When there is a "command transmission request" from the response transmission means that returns the response data corresponding to the received command and returns to the idle state, and the check means, the command from the own station is transmitted first, and after the transmission. A frame-level communication method comprising: processing means for receiving response data from a partner station or transmitting response data to a command from the partner station and returning to the idle state.