JPH08314859A - Computer system - Google Patents

Abstract

PURPOSE: To secure the function without preparing a standby machine even at the time of the stoppage of a part of host computers or CRT devices. CONSTITUTION: In this system in which the plural host computers and the plural CRT devices are connected to each other by a network, the respective CRT devices 4 and 9 are provided with display servers 124 and 129 and connection changeover control parts 144 and 149 respective host computers 1 and 3 are provided with display clients 111 and 113 and the control part switches the connection of the CRT device to an optional host computer by the connection changeover request of the host computer. The CRT devices are provided with the display clients 154 and 159 for state display at the time of switching the connection with the host computer. Also, connection changeover is requested by the key operation of keyboards 134 and 139 and the keyboards are provided with the common key of the host computer, keys for respective functions and allowing/denying switch of the connection changeover.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system in which a plurality of host computers and a plurality of CRT devices are connected by a network.

[0002]

2. Description of the Related Art In a computer system for monitoring and controlling a plant or the like, it is necessary to prepare a wide variety of functions.
A plurality of host computers and CRT devices are provided.

FIG. 3 shows an example of the configuration of a computer system for supervisory control, and three host computers 1, 2, 3
Are connected by Ethernet work, and CRT device 4 consisting of CRT controller and CRT is connected to Ethernet work.
~ 9 are combined. A part or all of the host computers 1, 2, and 3 are coupled to a plurality of remote monitoring control device master stations via a LAN.

In this system configuration, a host computer and a CRT device are divided into groups according to the supervisory control target in consideration of the equipment redundancy of the supervisory control unit.

For example, a host computer 1, a group A1 of CRT devices 4 and 5, a host computer 2 and C
The function A is executed by the group A2 of the RT devices 6 and 7, and the function B is executed by the group B of the host computer 3 and the CRT devices 8 and 9.

In this grouping, the connection between the host computer and the CRT device is fixed only within the group. For example, the CRT device 4 cannot be connected to the host computers 2 and 3.

[0007]

The conventional grouped system has the following problems.

(1) When the host computer is stopped due to inspection or failure, the CRT device fixedly connected to it cannot function as a signal input from the equipment to be monitored and cannot output a signal to the equipment to be controlled. Will not do.

Along with this, the number of CRT devices required for operation decreases. For example, in FIG. 3, when the host computer 1 is stopped, CR is required to execute the function A.
Only T-devices 6 and 7 can be used.

(2) When the CRT device stops due to inspection or failure, the number of CRT devices that can be used for the function decreases.

For example, in FIG. 3, when the CRT device 8 is stopped, as the function B, two CRT devices are required, but only one CRT device 9 can be used.

As described above, the host computer or C
When the RT device stops, the CRT device or host computer required for operation runs short, and therefore it is necessary to install these spare devices, which makes the system configuration complicated and expensive.

An object of the present invention is to provide a computer system capable of ensuring functions even when some of the host computers or CRT devices are stopped without preparing a spare device.

[0014]

In order to solve the above problems, the present invention provides a plurality of host computers and a plurality of CRs.
In a computer system in which T devices are connected by a network, a display server and a connection switching control unit are provided in each CRT device, a display client is provided in each host computer, and the control unit of each CRT device is a connection switching of the host computer. It is characterized in that the display server of the CRT device is switched to a display client of an arbitrary host computer in response to a request.

The CRT device is characterized by comprising a display client for displaying a status when switching the connection with the host computer.

The connection switching request is made by operating a key on the keyboard, and the keyboard is provided with a common key of the host computer, a key for each function, and a connection switching enable / disable switch.

[0017]

By providing the display client in the host computer and the display server in the CRT controller, the connection of the CRT device can be switched between the functions, and the standby device is not needed even when the CRT device or the host computer is stopped. Secure the function.

By providing a display client on the CRT device, a status display at the time of connection switching can be displayed on the CRT so that the switching operation can be confirmed on the screen display.

By the function-specific keys and the enable / disable switch on the keyboard, the function-specific switching and function operation are made safe and reliable.

[0020]

FIG. 1 is a block diagram showing an embodiment of the present invention. In the system configuration of Figure 3, each display client 11 ₁ to 11 ₃ each host computer 1, 2, 3 provided in the present embodiment, each displayed on the controller 4 _to 93 ₁ of each CRT devices 4-9 Server 12 ₄ ~
12 ₉ are provided.

By these display client and display server, each CRT device can be combined with a host computer having a different function, and the function as a display device for each function is realized.
The connection switching between the CRT device and the host computer is as follows.

[0022] The keyboard 13 _{4-13 9} to be associated with each CRT controller 4 _to 93 _1, as shown in FIG. 2, the common key K1 and function keys K2, K3 (color coded by function) is provided And then turn on / off with LED display
A function connection designating key K4 for displaying an off state and a connection disconnection key K5 are provided. In addition, a switch K6 for enabling / disabling is provided so that connection switching is not accidentally performed. The keys K4, K5 and the switch K6 enable the keyboard to switch the connection of the CRT device and the keyboard itself.

A connection switching request from the keyboard is sent to the switching control unit 14 ₄ in the controllers 4 _{1 to} 9 ₁ .
To 14 ₉ accepts the connection determination unit 15 ₁ to 1 in the host computer that the control unit 14 _{4-14 9} corresponds
5 ₃ issues a connection request with the path B to. This determination unit 15 ₁ to 1
The number 5 ₃ is preset with the number of CRT devices to which the host computer can be connected in parallel. According to this setting, it is determined that connection is possible, and if connection is determined, the connection state is established.

By this connection switching, for example, a CRT
Host computer 1 for device 4 to perform function A
Connected to. In this case, the display client 11 ₁ for executing the function A issues a CRT display request to the display server 12 ₄ in the controller 4 ₁ via the route A, and the screen of the function A is displayed on the CRT of the CRT device 4. It

Further, by switching the connection, the CRT device 4
If is connected to a host computer 3, by displaying the client 11 ₃ of the host computer 3 to generate the CRT display request, the screen function B is displayed on the CRT device 4.

The operation of the keyboard is notified from the CRT controller to the host computer at the connection destination,
The display client in the host computer issues a CRT screen display request to the display server.

Further, when the host computer is in the dual system operation (DUPLEX or DUAL), the CRT device connected to this host computer is automatically switched in conjunction with the switching of HOT and STANDBY of the host computer.

The display clients 15 ₄ to 15 ₉ in the controllers 4 _{1 to} 9 ₁ are for displaying a screen when the CRT device starts up and for displaying a failure message when switching the CRT device. No display request is made after connecting to the host computer.

Therefore, in this embodiment, the display client is provided in the host computer, and the display server and the switching control unit are provided in the CRT controller, so that the connection of the CRT device can be switched between the functions.

As a result, when one host computer is stopped, the CRT device is switched to a healthy host computer having the same function, and the same number of CRT devices as before the host computer was stopped can be operated.

Further, when one CRT device is stopped, another CRT device can be connected to the host computer which is being connected to secure the CRT device necessary for operating a certain function.

Further, due to these effects, the required number of CRT devices can be minimized in the design of the hardware configuration in consideration of the redundancy for securing the CRT device always required for each function.

Further, the connection switching by the keyboard is
Safely with the changeover switch K6, keys K4, K5
It is surely performed by the LED display of. Further, the operation of each function is simplified by the arrangement and color arrangement of the keys K2 and K3 for each function.

[0034]

As described above, according to the present invention, each CR
A display server and a connection switching control unit are provided in the T device, a display client is provided in each host computer,
Since the control unit of each CRT device switches the connection of the display server of the CRT device to the display client of an arbitrary host computer in response to the connection switching request of the host computer, the connection of the CRT device can be switched between the functions. Even when the CRT device or the host computer is stopped, there is an effect that the spare device is unnecessary and the function can be secured.

Further, according to the present invention, since the CRT device is provided with the display client for displaying the status at the time of switching the connection with the host computer, the status display at the time of switching the connection is displayed on the CRT to confirm the switching operation on the screen display. it can.

Further, according to the present invention, the connection switching request is made by the key operation of the keyboard, and the common key of the host computer, the function-specific key, and the connection switching enable / disable switch are provided on the keyboard. It has the effect of making switching and function operation safe and reliable.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a key configuration diagram of the keyboard according to the embodiment.

FIG. 3 is a configuration example of a computer system.

[Description of Reference Numerals] 1, 2, 3 ... host computer 4, 9 ... CRT device 4 _1, 9 ₁ ... controller 11 _1, 11 ₃ ... display client 12 _4, 12 ₉ ... display server 13 _4, 13 ₉ ... keyboard 14 ₄ , 14 ₉ ... Switching control section 15 ₄ , 15 ₉ ... Display client

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Suzuki 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stock company inside Meidensha (72) Inventor Yoshigo Tokunaga 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stocks Inside the company Meidensha

Claims (3)

[Claims] 1. A plurality of host computers and a plurality of CRs
In a computer system in which T devices are connected via a network, a display server and a connection switching control unit are provided in each CRT device, a display client is provided in each host computer, and the control unit of each CRT device is a connection switching of the host computer. CRT on request
A computer system characterized in that the display server of the device is switched to a display client of an arbitrary host computer. 2. The computer system according to claim 1, wherein the CRT device includes a display client for displaying a status when switching the connection with the host computer. 3. The connection switching request is made by a key operation of a keyboard, and the keyboard is provided with a common key of the host computer, a key for each function, and a connection switching enable / disable switch. The computer system according to 1 or 2.