JPH0219948A - Fault processing system for input/output controller - Google Patents

Abstract

PURPOSE:To continue the input/output actions to a terminal equipment of an electronic computer with no interruption and to improve the operability of the title system by making a buffer memory of an input/output controller substitute for the input/output controller in the case the terminal equipment has a fault. CONSTITUTION:In the case an input/output controller 1 decides the transfer of the state of a terminal equipment 11 is impossible based on a state control table 4, the controller 1 does not carry out the transfer to the equipment 11 and reports the normal end to an electronic computer 2 just with the replacement of a virtual screen buffer memory 9. When the recovering process is through with the equipment 11, the contents of the memory 9 are transferred to a screen buffer memory 12. Thus the computer 2 can output the display data to the memory 9 despite the fault of the equipment 11. As a result, the input/output actions can be continued to the equipment 11 from the computer 2 with no interruption. Then the processing load like the reconnection performed after recovery of the fault can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an input/output control method for a computer, and in particular, an input/output control method for handling faults in a terminal device. As a method of controlling input/output operations to the device, the six-person output control device, which controls the data transfer procedure by the input/output control device, issues a polling signal to the terminal device and receives a response from the terminal device. is monitoring the status of.

When a failure in a terminal device is detected through such monitoring, the input/output control device issues an instruction to force a reset to the terminal device, thereby taking measures to recover the terminal device.

For example, publicly known examples of this type of recovery measure include:
JP-A No. 58-1234 can be mentioned.

[Problem to be solved by the invention]

In the above conventional technology, when a failure occurs in a terminal device, the input/output control device reports the abnormality of the terminal device to the computer, and takes steps such as logically disconnecting it from the terminal device within the computer. When the process is performed and the terminal device is started up again, the logical connection is required again, and a procedure is required before the terminal device can be used again, which poses a problem in operability.

The purpose of the present invention is to: When a failure occurs in the terminal device,
It is an object of the present invention to enable input/output operations of a computer to the terminal device to continue without interruption, thereby improving operability.

[Means to solve the problem]

The above purpose is to update a data buffer memory 1 of a display screen of a terminal device and a data buffer memory 2 in the input/output control device, which is a copy of the data buffer memory 1, in an input/output control device.

A means is provided to switch between updating processing 1 for both data buffer memories or updating processing 2 only for data buffer memory 2, and when a failure of the terminal device is detected, updating from normal updating processing 1 is provided. This is achieved by switching to process 2 and transferring the update processing result by data buffer 2 to data buffer 1 after the terminal device recovers.

[Effect]

The input/output control device transfers data to the buffer memory 1 of the display screen of the terminal device and serves as a copy of the buffer memory 1 for input/output operations from the computer to the terminal device when the terminal device is normal. Update processing is also executed for the buffer memory 2 in the input/output control device. However, when a failure of the terminal device is detected, the data transfer to the terminal device is interrupted and the processing is switched to only updating the buffer memory 2. In this way, with respect to input/output operations from the computer to the terminal device, an abnormality report due to a failure of the terminal device is suppressed, and the input/output operations of the computer are allowed to continue. In parallel with this process, a forced reset of the terminal device is instructed, and when the recovery process of the terminal device is completed, the processing results in the data buffer memory 2 are transferred to the data buffer memory 1 by the update process 2. Then, the subsequent input/output operation is switched to update processing 1.

The above function allows the computer to continue processing to the terminal device without interrupting input/output operations due to a failure of the terminal device.

〔Example〕

An embodiment of the present invention will be described below using a terminal device equipped with a CRT and performing display processing.

FIG. 1 shows a configuration diagram of an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an input/output control device connected to a computer 2, and a terminal device 11 is connected to the input/output control device 1 through a line 10.

The human output control device 1 includes a microprocessor 3.state management table 4. Timer 52 line control circuit 6° processing section 7. Transfer buffer memory8. and a memory (hereinafter referred to as virtual screen buffer memory 9) that serves as a copy of the display screen of the terminal device 1111.

The input/output control device 1 is a terminal device from the electronic computer 2! 11
An instruction for outputting display data to is received through the processing unit 7. It also issues a polling signal to the terminal device 11, updates the state management table 4 based on the response from the terminal device 11, and monitors the state of the terminal device 11. When outputting display data from the computer 2 to the terminal device 11, the input/output control device processes the startup process through the processing unit 7, receives subsequent display data, stores it in the transfer buffer memory, and at the same time, The virtual screen buffer memory 9 corresponding to the screen buffer memory 12 of the terminal device 11 is also subjected to screen update processing using display data.

When the status of the terminal device 11 is determined to be transferable based on the status management table 4, the line control circuit 6 is activated to transfer the display data stored in the transfer buffer memory 8 to the terminal device 11.
and reports normal completion to computer 2. The above is the normal operation, but in the terminal device 11 that performs display processing using the CRT 13, the circuit of the terminal device 11 may become inoperable due to discharge energy noise of the CRT 13, etc. The computer 2 receives a report of abnormal termination from the input/output control device 1. When the computer 2 receives an abnormality report on the terminal device 11, it logically disconnects the terminal device 11, and when the terminal device 11 becomes usable again, performs logical recombination processing, etc. Reusing terminal equipment required complicated processing.

In FIG. 1, when the input/output control device 1 determines that the state of the terminal device 11 is not transferable based on the state management table 4, it does not perform the transfer to the terminal device 11 and only updates the virtual screen buffer memory 9. Report normal completion to computer 2.

On the other hand, when one line 10 is not in use, the input/output control device 1 activates the line control circuit 6 and issues a polling signal to the terminal device 11. When a non-response from the terminal device 11 is detected, a transfer impossible state is set in the state management table 4, and the terminal device 11
A forced reset instruction is issued to the computer, and 1 recovery processing is started. When the recovery process of the terminal device 11 is completed, a transferable state is set in the state management table 4, and the contents of the virtual screen buffer memory 9 are transferred to the screen buffer memory 12 of the terminal device 11.
Transfer to.

According to this embodiment, even if a failure occurs in the terminal device 11, the computer 2 can output display data to the virtual screen buffer memory 4 of the input/output control device 1, and the computer 2 can output display data to the virtual screen buffer memory 4 of the input/output control device 1. There is no interruption in input/output operations.

〔Effect of the invention〕

As explained above, according to the present invention, even if a failure occurs in a terminal device, the computer can detect the failure by switching the input/output operation of the buffer memory in the input/output control device. Input/output operations can be continued without interruption, and the processing load such as recombination after failure recovery can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention. 1... Input/output control device, 2... Electronic computer. 3... Microprocessor, 4... Status management table, 5... Timer, 6... Line control circuit, 7
...Processing device, 8.. Transfer buffer memory, 9.. Virtual screen buffer memory, 10.. Line, 11.. Terminal device, 12..
・Screen buffer memory, 13...CRT. 1st entrance/exit 7711opVk engineering

Claims (1)

[Claims] 1. A data buffer memory that has a procedure for transferring data to a terminal device equipped with a data buffer memory 1 for a display screen as a control of input/output operations from a computer to a terminal device, and serves as a copy of the data buffer memory 1. 2, when the monitoring function of the terminal device determines that data transfer to the terminal device is possible, the input/output control device having the data buffer memory 1 and the data buffer 2 executes updating processing of both the data buffer memories, the data buffer memory 1 and the data buffer 2. , when a failure is detected in the terminal device and data transfer is impossible, the data buffer 2
By providing a function that transfers the update processing results of data buffer 2 to data buffer 1 when the terminal device recovers, even if a failure occurs in the terminal device, input from the computer can be maintained. A failure handling method for an input/output control device characterized by continuing output operation without interruption.