JPH08249277A - Computer system of input/output device sharing type - Google Patents

Abstract

PURPOSE: To automatically and simultaneously switch a pair of input and output devices to one of the necessary computers in response to the generation of a prescribed external phenomenon. CONSTITUTION: This computer system 1 switches and connects a pair of input and output devices 60 to one of the plural computers 10 and 20 through a switching part 51 so as to share the devices 60. In the computer system 1, when a switch requiring phenomenon necessitating the switch of the input/output devices 60, switch requiring signal sending part 14 and 24 respectively provided for the plural computers 10 and 20 send a switch requiring signal SA corresponding to the phenomenon and a switch control part 52 controls the switching part 51 to simultaneously switch a pair of input/output devices 60 in consideration of the priority of the switching request at the time in response to the switch requiring signal SA. The automatic and simultaneous switching of the input/output devices 60 is executed by the generation of the prescribed external phenomenon so that operability can be improved and each computer can, efficiently be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output device sharing type computer system in which a set of input / output devices is shared by a plurality of computer devices.

[0002]

2. Description of the Related Art Conventionally, for the purpose of cost reduction, space saving, etc., a set of input / output devices has been prepared for a plurality of computers, and this set of input / output devices is used as necessary. A computer system having a shared input / output device, which is adapted to be switched and connected to a desired computer, has been adopted. In this type of conventional system, a dedicated switch is provided for each of the input device and the output device, and the operator operates the switch to independently connect the input device and the output device to a desired computer. There is known a configuration capable of performing the above, or a configuration capable of simultaneously switching the input device and the output device to a desired computer by using one switch.

[0003]

As described above, in the conventional input / output device shared computer system, the operator operates the changeover switch or the like provided on the selector to connect the input / output device and the computer. The state is switched appropriately. Therefore, if a high-priority event occurs in one of the computers while multiple computers are operating, the operator checks whether or not an I / O device is connected to the computer, and the result of this check Therefore, the required switching operation of the input / output device has to be performed. The same applies when a function of another computer is selected while data processing is being performed by a certain computer. Therefore, in the conventional computer system of this type, an operator must surely grasp and manage various processes executed by a plurality of computers, and an input / output device due to occurrence of a predetermined external event. There is a problem that simultaneous automatic switching of the above cannot be performed.

The object of the present invention is therefore to overcome the abovementioned disadvantages of the prior art. That is,
The present invention relates to a computer system in which one set of input / output devices is shared by a plurality of computers, when an event of higher priority occurs in a computer device to which no input / output device is connected, or To provide an input / output device shared computer system in which simultaneous switching of input / output devices is automatically executed when a function of another computer device is selected in the computer device to which the device is connected. With the goal.

[0005]

The feature of the present invention for solving the above-mentioned problems is that one set of input / output devices is connected by switching to any one of a plurality of computers via the switching means and shared. In the shared input / output device type computer system, when a switching request event that requires switching of the input / output devices provided in each of the plurality of computers occurs, a switching request signal is transmitted in response to the switching request signal. Means and switching control means for responding to the switching request signal from each switching request signal sending means and controlling the simultaneous switching of the one set of input / output devices by the switching means in consideration of the priority of the switching request at that time. Is equipped with.

As the switching request event, for example, a detection signal is input from an external sensor such as a fire detector to a computer to which an input / output device is not connected, or another external signal that requires emergency processing. Can be mentioned as an example. In addition, the selection of the function of another computer in the computer to which the input / output device is connected can be cited as an example of the switching request event.

In each computer, each event that requires switching of the input / output device can be individually set in advance, and when a predetermined event occurs, a switching request corresponding to the event and its priority are assigned. A switch request signal sending means may send the switch request signal as the content.

The priority of each content of the switching request signal transmitted in this way varies, and the priority of processing for each switching request event can be appropriately determined in each case.

[0009]

When a switching request event occurs in any of the computers, a switching request signal indicating the contents of the switching request is sent from the switching request signal sending means provided in the computer. In response to this, the switching control means controls the switching means so as to connect the set of input / output devices to a more appropriate computer in consideration of the priority, and as a result, the switching control means is turned on in response to the occurrence of a predetermined event. Simultaneous switching of output devices is automatically performed.

[0010]

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

FIG. 1 is a system configuration diagram showing an embodiment of a computer system for sharing input / output devices according to the present invention. The computer system shown by reference numeral 1 includes computers 10 and 20, a keyboard 30 shared as an input device of the computers 10 and 20, and a CRT display device 30 shared as an output device of the computers 10 and 20. .

The computer 10 includes a central processing unit (C
PU) 11 and input / output interface unit (I / O) 1
2 is a computer having a general configuration, and the other computer 20 also has a central processing unit (CP).
U) 21 and input / output interface unit (I / O) 22
It is a computer having a general configuration including. Therefore, a general description of each configuration of the computers 10 and 20 is omitted here.

Since the input / output device 60 consisting of the keyboard 30 and the CRT display device 40 as a set is selectively connected to either the computer 10 or the computer 20 at the same time by switching, the computer system 1 uses the switching device 5.
It has 0. The switching device 50 is an input / output device 60 and each input / output interface unit 1 of the computers 10 and 20.
2, 22 and the switching unit 5 connected as shown in FIG.
1 is provided. A change-over switch having a known structure (not shown) is provided in the change-over unit 51, and the change-over switch allows the input / output device 60 to move the input / output unit 60.
It can be connected to either one of 2, 22.

Reference numeral 52 indicates a switching control unit for controlling the above-mentioned switching connection operation by a changeover switch (not shown) of the switching unit 51. The switching control unit 52 is operated by an operator, and a manual switching signal SM from a switching button 53 and a switching request from the switching request signal receiving unit 54 for instructing whether to switch the input / output device 60 to the computer 10 or 20. The switching unit 5 receives the signal SA and
The switching control signal SC for controlling the switching operation of No. 1 is output to the switching unit 51.

Before describing the switching control unit 52 in detail, the input / output device 60 in each computer 10, 20.
The switching request will be described.

First, a request for switching the input / output device 60 in the computer 10 will be described. The data processing operation of the computer 10 is executed according to a normal processing program stored in advance in a memory (not shown), and a fire sensor 13 is connected to the input / output interface unit 12. When the fire sensor 13 detects the occurrence of a fire, the fire signal F output from the fire sensor 13 is taken into the computer 10 via the input / output interface unit 12, and the fire occurrence notification process is stored in advance in a memory (not shown). The program is executed by the CPU 11 by interrupt processing.

In the computer 10, (1) when an external event having a higher priority than other normal processing such as a fire occurs, (2) another external processing is executed during execution of the normal processing program. When an external event such as a request to use the function of the computer, that is, the computer 20 occurs,
(3) When an external event corresponding to any of the other specified external events occurs, the input / output device 6 is connected to the most appropriate computer according to the external event.
It has a function of outputting a request for switching 0 to the switching device 50. The switching request signal transmission unit 14 executes this function.

FIG. 2 is a flowchart showing a switching request signal transmitting program for realizing the function of the switching request signal transmitting unit 14 in the computer 10. The switching request signal transmission program is repeatedly activated at a predetermined fixed time interval and executed by the CPU 11. When the execution of the switching request signal transmission program starts, first, at step 141, it is judged if a switching request event has occurred. The switching request event here is the external event of (1) to (3) already described. If the determination result of step 141 is YES, the process proceeds to step 142, where the input / output device 60 corresponding to the content of the external event that has occurred.
A switching request signal CM1 is transmitted to request switching (see FIG. 1).

Here, the contents of the switching request signal CM1 generally include a priority level code indicating a priority level of a predetermined process for an external event whose occurrence is determined, and which computer the input / output device 60 is connected to. It consists of a request code indicating whether to connect. An example of each code content for each external event in the case of the present embodiment will be shown. External event Priority level code Request code Fire signal F generation 01 01 Intrusion detection signal W generation 10 10 Function use of computer 20 11 10

Here, the priority level code 01 indicates the highest priority level, and the priority level code 11 indicates the third highest priority level. on the other hand,
The request code 01 indicates a request for switching the input / output device 60 to the computer 10, and the request code 10 is the input / output device 6
A request to switch 0 to the computer 20 is shown.
These codes are sent to the switching request signal receiving unit 54 as the switching request signal CM1 in a predetermined format. This ends the execution of this program.

On the other hand, if the decision result in the step 141 is NO, the execution of the program ends without executing the step 142.

The configuration of the switching request signal transmitting section 14 of the computer 10 has been described above.
Since the configuration of the switching request signal transmission unit 24 is also the same, the description thereof will be omitted. The switching request signal transmission unit 2
The switching request signal CM2 from the computer 4 is also sent to the computer 20.
The switching request signal CM1 has the same format as the above-mentioned switching request signal CM1 and is composed of a priority level code and a request code corresponding to the external event that occurred in (1), and the code used here is the same as the above case. For example, when an external event occurs in which the intrusion signal W from the intrusion detection sensor 23 is input to the computer 20, the priority level code becomes 10, which indicates the second priority, and the request code becomes 10. Further, in the computer 20, the computer 1
If the use of the 0 function is requested, the priority level code will be 11.

The switching request signals CM1 and CM2 thus sent from the computers 10 and 20 are received by the switching request signal receiving section 54 and input to the switching control section 52 as the switching request signal SA. The switching signal SM output by operating the switching button 53 is also composed of a priority level code and a request code, like the switching request signals CM1 and CM2. In this embodiment, the priority level code is 00, which indicates the level with the lowest priority.

The switching control unit 52 is constructed by using a microcomputer, and a control program for performing the priority level switching control function is stored therein in advance.

FIG. 3 is a flow chart showing this control program, which is also repeatedly activated and executed at predetermined fixed time intervals. When the control program is activated, it is first determined in step 521 whether the switching request signal SA or the switching signal SM has been input. If neither signal is input, execution of this control program ends.

If it is determined in step 521 that any one of the signals has been input, step 522 is entered in which the current switching state data stored in the memory of the microcomputer constituting the switching control unit 52 is referred to. Then, the priority level of the current switching state and the priority level of the switching request by the input signal are compared. That is, it is determined based on the priority level code whether the switching request at that time should be prioritized. For example, when the current switching state is the state of the priority level code 01 based on the occurrence of a fire, the priority level code 11 is used for using the computer function of the other party.
If the switching request is generated, the priority of the current switching state is high, so that the process proceeds from step 522 to END, and the switching request at that time is ignored.

On the other hand, if it is determined in step 522 that the priority level of the switching request generated at that time is equal to or higher than the priority level of the current switching state, step 523 is entered, in which the priority level generated at that time is generated. The switching control of the input / output device 60 is executed according to the switching request. In the next step 524, the switching state requested at that time is stored in a predetermined memory as the current switching state, and the execution of the program ends.

Since the computer system 1 is configured as described above, when various external events occur in each computer, the switching request of the appropriate content and the priority level corresponding to the external event are the switching request. The signal SA is sent to the switching control unit 52 of the switching device 50. Further, the switching device 50 is provided with a switching button 53 for manual switching, and the operation of the switching button 53 also outputs the switching request content and its priority level as a switching signal SM,
It is sent to the switching control unit 52.

When a switching request occurs, the switching control unit 52 compares the priority level of the current switching state with the priority level of the switching request at that time, and determines whether the priority level of the switching request is higher than that of the current switching state. Only when they are equal, the switching unit 51 is controlled so that the input / output device 60 is connected to the required computer according to the switching request.

Therefore, the switch button 53 allows the operator to switch the input / output device 60 to a desired computer, and the input / output device 60 responds to an external event occurring in each computer in accordance with a predetermined priority order. It is always automatically set to an appropriate switching state. In this case, the CRT display device 40 and the keyboard 30 can be simultaneously switched to a desired computer.

In the above embodiment, the computer system 1
Although the case where the number of computers is two is described as an example, the present invention can be similarly applied even when the number of computers is three or more, and the same effect can be obtained.

Further, in the above embodiment, the case where one set of the input / output device 60 is composed of the keyboard 30 and the CRT display device 40 is shown. However, since at least one input device and at least one output device are required, the configuration of one set of input / output devices is not limited to the configuration of this embodiment. For example, a printer is added to the keyboard 30 and the CRT display device 40. Alternatively, a bar code reader may be added, and these may be simultaneously switched as one set of input / output devices.

The priority level assigned to each external event described in the embodiments is an example, and what should be prioritized should be determined by the operational purpose of the computer system. Therefore, the notification of the fire sensor is not necessarily the first priority level.

[0034]

According to the present invention, an input / output device can be automatically brought into an appropriate switching state automatically at the same time when a predetermined external event occurs. Therefore, in a computer system sharing an input / output device, it is not necessary to use two switching devices, so that low cost, space saving, and improvement of operability can be achieved, and each computer can be operated efficiently. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a computer system sharing an input / output device according to the present invention.

FIG. 2 is a flowchart showing a switching request signal transmission program for performing the function of a switching request signal transmission unit.

FIG. 3 is a flowchart showing a control program for performing a switching control function in a switching control unit.

[Explanation of symbols]

 1 Computer System 10, 20 Computer 13 Fire Sensor 14, 24 Switching Request Signal Transmission Unit 23 Intrusion Detection Sensor 30 Keyboard 40 CRT Display Device 50 Switching Device 51 Switching Unit 52 Switching Control Unit 60 Input / Output Device CM1, CM2 Switching Request Signal F Fire Signal SA switching request signal SM Manual switching signal W Intrusion signal

Claims (1)

[Claims] 1. A shared input / output device computer system in which a set of input / output devices is switchably connected to any one of a plurality of computers via a switching means and shared. When a switching request event that requires switching of the input / output device occurs, a switching request signal transmitting means for transmitting a switching request signal corresponding to the event and a response to the switching request signal from each switching request signal transmitting means. An input / output device sharing type computer system, comprising: a switching control unit for controlling the simultaneous switching of the one set of input / output devices by the switching unit in consideration of the priority of the switching request at that time.