JPS62159547A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To make the time required from the first data transmission to a fault report to a host device nearly constant by starting a timer at the initial data transmission and applying the fault report when the time of the timer is over at the detection of fault of transmission and applying transmission retrial when no time-out takes place. CONSTITUTION:A control section 104 gives a transmission command of the content of a data buffer 102 to a common transmission line to a transmission circuit 103 and starts the timer 12. When the time of the timer 12 is not over at the detection of a transmission fault by a transmission fault detection section 14, a transmission retrial section 15 applies a retrial request to the control section 104 of the transmission section 11 and the control section 104 gives a transmission command of the content of a data buffer 102 to the common transmission line to the transmission circuit 103. When the time of the timer 12 is over at the detection of transmission fault by the section 14, a fault report section 13 is started and the transmission fault is reported to the host device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transmission device in a data transmission system, and particularly relates to transmission retry when transmission fails.

[Conventional technology]

Conventionally, in this type of data transmission device, the time it takes for a failure report to be reported to a higher-level device when a transmission operation fails, including retries, depends on both the number of retries and the cause of the failure. was.

[Problem that the invention seeks to solve]

In the conventional data transmission device described above, the time it takes for a failure report to be reported to a higher-level device depends on the number of retries and the cause of the failure. The disadvantage is that there is variation in the time it takes for reports to be made.

In view of the above-mentioned points, an object of the present invention is to provide a data transmission device in which the time taken until a failure report is reported to a higher-level device in the event of a transmission failure is approximately constant.

Means for Solving Problem C] The data transmission device of the present invention is a data transmission device that is connected to a higher-level device such as a data processing device and sends data from the higher-level device to a common transmission path, etc. a transmitting means for transmitting data from the device to the common transmission path, etc.;
a timer that is started when the first data is sent and stopped when the transmission ends normally; a transmission failure detection means that detects that the transmission by the transmission means has failed; failure reporting means for reporting the fact to the higher-level device if the timer times out; and a transmission retry for starting retransmission if the timer does not time out when a transmission failure is detected by the transmission failure detection means. means.

〔Example〕

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

The figure is a block diagram showing one embodiment of the present invention.

The data transmission device l of this embodiment includes a transmitting section 11, a timer 12, a failure reporting section 13, a transmission failure detecting section 14, -
The transmission retry section 15 is configured to include a transmission retry section 15.

The transmitter 11 further includes a receiver circuit 101, a data buffer 102, a transmitter circuit 103, and a controller 104.

The receiving circuit 101 and failure reporting unit 13 of the transmitting unit 11 are connected to a host device such as a data processing device, and the transmitting circuit 103 and transmission failure detecting unit 14 of the transmitting unit 11 are connected to a common transmission path. Other devices (not shown) are connected to the common transmission path.

Next, the operation of the data transmission apparatus of this embodiment configured as described above will be explained.

When transmission data is sent from the host device to the data transmission device 1, the reception circuit 101 first detects it and sends it to the control unit 1.
Notify on 04. Upon receiving this notification, the control unit 104 instructs the data buffer 102 to store the transmission data, and the data buffer 102 stores the transmission data.

When the transmission data has been stored in the data buffer 102, the control unit 104 instructs the transmission circuit 103 to transmit the contents of the data buffer 102 to the common transmission path, and starts the timer 12. Further, the control unit 104 enables the operation of the transmission failure detection unit 14.

When the transmission operation by the transmission circuit 103 is successful and a normal response is returned from the common transmission path, the transmission failure detection section 14 detects this and stops and resets the timer 12, and also causes the control section 104 of the transmission section 11 to Notify that a normal response has been returned. Upon receiving this notification, the control unit 104 resets the data buffer 102.

If an abnormal response is returned from the common transmission path or the transmission operation fails even after a response is returned, the transmission failure detection unit 14
detects this and sends the failure report unit 13 and transmission retry unit 15
Notification to that effect shall be given to the

When the transmission failure detection unit 14 detects a transmission failure, the timer 12
has not timed out, the transmission retry unit 15
makes a retry request to the control unit 104 of the transmitting unit 11, and the control unit 104 instructs the transmitting circuit 103 to send the contents of the data buffer 102 to the common transmission path.

When the transmission failure detection unit 14 detects a transmission failure, the timer 12
If the transmission failure has timed out, the failure reporting unit 13 is activated and reports the transmission failure to the host device.

〔Effect of the invention〕

As explained above, the present invention starts a timer when transmitting data for the first time, reports a failure if the timer times out when a transmission failure is detected, and retries the transmission if it does not time out. This has the effect of making the time it takes for a failure report to be sent to the host device almost constant.

[Brief explanation of drawings]

The figure is a block diagram showing a data transmission device according to an embodiment of the present invention. In the figure, 1... Data transmission device, 11... Transmission section, 12... Timer, 13... Fault reporting section, 4... Transmission failure detection section, 15... Transmission retry section , 101...reception circuit, 102...data buffer, 103...transmission circuit, 104...control unit.

Claims (1)

[Scope of claims] In a data transmission device that is connected to a host device such as a data processing device and sends data from the host device to a common transmission path, etc., the data transmission device transmits data from the host device to the common transmission path, etc. a timer that is started when the first data is sent and is stopped when the transmission ends normally; a transmission failure detection means that detects a failure in transmission by the transmission means; failure reporting means for reporting the fact to the higher-level device if the timer times out when the timer is detected; and failure reporting means for retransmitting if the timer does not time out when the transmission failure detection means detects the transmission failure. A data transmission device comprising: a transmission retry means for activating;