JPS61189050A - Data transferring system - Google Patents

Abstract

PURPOSE:To improve the reliability of a data communication system by changing a response time of a transmittable signal in accordance with a data transfer speed, informing the data transfer speed to the other party side, and making the transfer speed coincide exactly between devices for sending and receiving the information. CONSTITUTION:Before data transfer is executed, a transmission requesting signal is outputted through a transmission requesting signal line 101 to a data terminal equipment 2 from a communication control device 1. In the data terminal equipment 2, with respect to the transmission requesting signal, a response time T1 and T2 of a transmittable signal are changed in accordance with a transfer speed of the own device, and this transmittable signal is answered to the communication control device 1 through a transmittable signal line 102. In the communication control device 1, in accordance with the response time T1 and T2 of the transmittable signal to the transmission requesting signal, the same speed as the transfer speed of the data terminal equipment 2 is set to the own device, and the data transfer is executed at this transfer speed. In case of a short response time T1, the data transfer speed becomes high, and in case of a long response time T2, the data transfer speed becomes low.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a data transfer method in a data communication system.

In particular, it relates to transfer rate control.

〔overview〕

In a data transfer method in which data is transferred at a transfer rate selected from among different transfer speeds, the present invention provides a response of a send permission signal from the other party's device to a transmission request signal sent to the other party's device prior to data transfer. Recognizes the data transfer speed of the other device according to the time, sets the transfer speed of the own device to the transfer speed of the other device, and transfers data by ensuring that the transfer speeds of the own device and the other device match. By doing this, it is possible to prevent data errors from occurring due to mismatched transfer speed settings, and also to prevent the data communication system from going down due to data errors. be.

[Conventional technology]

In the conventional data transfer system, the communication control device, data terminal device, etc. set the speed of each device using a switch or a program before data transfer.

[Problem that the invention seeks to solve]

In conventional methods like this, if there is a difference in speed settings between the two parties sending and receiving data, errors will occur in the data being sent and received.
Furthermore, if there is no means to notify the other party of a data error, the data communication system goes down due to the data error, resulting in lower reliability. In addition, it is necessary to change the speed setting when a data error is detected, which has a drawback in terms of maintenance.

The present invention aims to eliminate this drawback and provides a data transfer method that can recognize the data transfer rate of the other party.

[Means for solving problems]

The present invention is a data transfer method that transfers data between two devices at one of a plurality of different transfer speeds, and as a means to solve the above-mentioned problems, the present invention is a data transfer method that transfers data between two devices at one of a plurality of different transfer speeds. The device that performs the data transfer includes first signal sending means that sends a transmission request signal to the data transfer destination device prior to data transfer, and receives a transmission enable signal from the data transfer destination device from the sending time of the transmission request signal. a first timer for measuring the elapsed time, and a selection means for selecting one of the transfer speeds of the own device based on the time value measured by the timer; The device that performs the data transfer includes a second timer that sends an output when the elapsed time from the time of reception of the transmission request signal from the data transfer source reaches a time corresponding to the transfer speed of the device itself, and an output of this timer. and second signal sending means for sending a transmittable signal to the data transfer source based on the data transfer source.

[For production]

Prior to data transfer, when a send clear signal is returned from the data send destination in response to a send request signal sent from the data send source, the response time of the send clear signal is changed according to the transfer speed of the own device. This transfer rate is notified to the data sending source, and the transfer rate of the data sending destination is set.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block configuration diagram showing the configuration of this embodiment system. FIG. 2 is a waveform diagram showing the operation of this embodiment system.

As shown in FIG. 1, this embodiment system consists of a communication control device 1, a data terminal device 2, a transmission request signal line 1o1 connecting these two devices, a transmission permission signal vAIO2, a transmission data line 103, and a reception and a data line 104. This communication control device 1 is equipped with a means for transmitting a transmission request signal to the transmission request signal %'i 101 prior to data transfer, and the data terminal device 2 is equipped with a means for transmitting a transmission request signal as transmission request signal %'i 101 prior to data transfer, and the data terminal device 2 is equipped with a timer for transmitting an output when the timer reaches a time corresponding to one of the plurality of transfer speeds of the data terminal device 2; and a timer for transmitting a transmission enable signal based on the output of the timer. The communication control device 1 further includes a timer for measuring the elapsed time from the sending time of the transmission request signal to the reception of the transmittable signal, and a timer for measuring the elapsed time from the sending time of the transmission request signal to the reception of the transmission enable signal. means for selecting a transfer rate corresponding to a time value from among a plurality of transfer rates;
The device 1 and the data terminal device 2 are equipped with a transmitting/receiving means for transmitting and receiving data via the transmit data line 103 and the receive data line 104 at the set transfer rate.

Next, the operation of this embodiment system will be explained based on FIGS. 1 and 2.

Before data transfer, the communication control device 1 sends a transmission request signal to the data terminal device 2 as a transmission request signal tj.
101. In the data end device 2,
The response times T1 and T2 of the ready-to-send signal are changed according to the transfer speed of the device itself in response to the request-to-send signal, and the ready-to-send signal v
This transmittable signal is responded to the communication control device 1 via A102. In the communication control device 1, the same speed as the transfer speed of the data terminal device 2 is set in the communication control device 1 according to the response times T1 and T2 of the transmission enable signal to the transmission request signal, and data transfer is performed at this transfer speed.

FIG. 2 shows that for a short response time T, the data transfer rate is high, and for a long response time T2, the data transfer rate is low.

〔Effect of the invention〕

As explained above, the present invention changes the response time of the ready-to-send signal according to the data transfer rate, notifies the other party of the data transfer rate, and ensures that the transfer rates between devices exchanging information match. This has the effect of improving the reliability of data communication systems.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a waveform diagram showing the operation of the system according to the embodiment of the present invention. l... Communication control device, 2... Data terminal device, 10
1... Transmission request signal line, 102... Send enable signal line,
103... Transmission data line, 104... Reception data line.

Claims (1)

[Claims] (1) In a data transfer method in which data is transferred between two devices at one of a plurality of different transfer speeds, the device that transmits data among the above devices transfers data to the data transfer destination prior to data transfer. a first signal sending means for sending a transmission request signal to the device; a first clocking means for measuring the elapsed time from the sending time of the transmission request signal to the reception of the transmission ready signal from the data transfer destination device; , a selection means for selecting one of the transfer speeds of the own device based on the time value measured by the timer, and among the above devices, the device that receives data receives a transmission request signal from the data transfer source. a second timer that sends an output when the elapsed time from the reception time reaches a time corresponding to the transfer speed of its own device; and a second timer that sends a send ready signal to the data transfer source based on the output of this timer. A data transfer method characterized by comprising a second signal sending means for transmitting a signal.