JPH06242858A - Power source controller of shared i/o device - Google Patents

Abstract

PURPOSE:To eliminate troublesomeness and an error caused by conventional manual opening/closing by opening and closing automatically a power source of the shared I/O device such as a printer, etc., utilized by plural computers (in this example, a personal computer, a work station) through a network, in accordance with a utilization state of the computer. CONSTITUTION:The power source controller 10 for opening and closing automatically a power source of the shared I/O device is provided. This device 10 monitors ON and OFF states of power sources of computers 6, 8 with power source output lines 6b, 8b, respectively, supplies a power source of a printer 31 by connecting a power source input line 10a contained in itself and a power source input line 3a of the shared I/O device, when the power source of the computer is in the ON state even by only one, and disconnects the connection of the power source input lines 10a and 3a, and stops power source supply to the printer 31, when the power sources of both the computers are in the OFF state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shared I / O on a network to which a plurality of computers such as personal computers and workstations and a shared input / output device (hereinafter also referred to as I / O device) such as a printer are connected. Turn the device power on /
The present invention relates to a power supply control device capable of automatically turning off.

In the following figures, the same reference numerals indicate the same or corresponding parts.

[0003]

2. Description of the Related Art FIG. 3 shows a configuration example of a conventional system having this type of network. In the figure, 5 is a network, 1 and 2 are computers connected to this network, and 3 is a computer 1 or 2 via the network 5.
It is a shared I / O device such as a printer that is used together.
Further, 1a, 2a and 3a are power source input lines for the computers 1 and 2 and the shared I / O device 3, respectively.

As shown in FIG. 3, the power input line 3a of the shared I / O device 3 conventionally connected to the network 5 is used.
Are independent, and the power of the shared I / O device 3 is turned on / of
The control of f was performed manually regardless of the power on / off of the computers 1 and 2 connected to the network 5.

[0005]

Since the shared I / O device 3 connected to the network 5 is used by an unspecified number of people, the power of the shared I / O device should be turned off without special attention. I won't. However, it is not easy to turn the power off because it is not easy to know who is using the network when the network configuration becomes large and complicated.

Computers 1 and 2 on the network
When trying to use the shared I / O device due to such reasons, it is necessary to confirm the on state of the power source of the shared I / O device, and the mistake is made when the shared I / O device is powered off. There are problems such as. In any case, in order to turn on / off the power of the shared I / O device, it must be done manually, and there is always a risk of human error.

Therefore, in the present invention, in order to solve the above problem, the power supply of the shared I / O device connected to the network can be automatically turned on / off.
It is an object to provide a power supply control device for an O device.

[0008]

In order to solve the above-mentioned problems, in the power supply control device of the present invention, a plurality of computers (personal computers 6, workstations 8 etc.) are connected in common via a network (5 etc.). Output device (printer 3
In a system using a shared I / O device, such as 1 below, the on / off state of each power supply (power supply input lines 6a, 8a, etc.) of the computer (power supply output lines 6b, 8b, voltage detection circuit). 13), and if there is a computer powered on, the shared I
Means for closing the power supply path for the I / O device (between the power input lines 10a and 3a, etc.) and opening the power supply path for the shared I / O device if there is no computer in the power-on state (logic circuit 15, power supply voltage output circuit) 16 etc.).

[0009]

Function: means for detecting the on / off state of the power supply of each computer connected to the network,
Depending on the combination of the states, the power of the shared I / O device is turned on /
A means for controlling off is provided. Power on / off of each computer connected to the network
The means for detecting the state takes the output of the power source from each computer, inputs it to the voltage detection circuit, and analyzes the power on / off state of the computer.

Next, the power of the shared I / O device is turned on / of.
The means for controlling f inputs a signal obtained by analyzing the on / off state of the power supply of each computer, and if at least one of the signals has a signal obtained by analyzing the on state of the power supply of the computer, the shared I Outputs an output signal for turning on the power of the I / O device, and if all the input signals indicate the off state of the power supply of the computer, the shared I / O
A logic circuit that outputs an output signal that turns off the power supply of the device is used.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a system configuration diagram as an embodiment of the present invention. In the figure, a personal computer 6 (hereinafter abbreviated as PC) and a workstation 8 (hereinafter also abbreviated as WS) are connected to the network 5 as computers,
A printer 31 or the like is connected as a shared I / O device. Also, 6a and 8a are power supply input lines to the PC6 and WS8, respectively, and 6b and 8b are output lines of the power supply from the PC6 and WS8, respectively.

Reference numeral 10 is a power supply controller for the shared I / O device, which is the main subject of the present invention, and 10a is an input line of the power supply to the controller 10. This power control device 10 has a P
The aforementioned power supply output lines 6b and 8b interlocked with the power supply input lines 6a and 8a of the main bodies of C6 and WS8, respectively, are input. The input line 3a of the power supply to the shared I / O device described in FIG. 3 is used as an output line from the power supply control device 10 to connect the power supply control device 10 and the target shared I / O device (the printer 31 in this example). It is provided between.

FIG. 2 is a block diagram showing an internal circuit of the power supply control device 10 of FIG. 1. Reference numeral 13 is a PC power supply voltage detection for detecting the presence or absence of the power supply voltage of the PC 6 with the PC power supply output line 6b as an input. Similarly, the circuit 14 is the WS power output line 8
WS that detects the presence or absence of the power supply voltage of WS8 by inputting b
It is a power supply voltage detection circuit. Further, reference numeral 15 is a logic circuit for performing a logical operation of the outputs of the power supply voltage detection circuits 13 and 14, and 16 is a power supply input line 1 for the control device according to the output signal of the logic circuit 15.
0a and the shared I / O power supply input line 3a are opened / closed.

Next, the operation of the power supply controller 10 will be described with reference to FIGS. First, the power supply 3 of the printer 31
When a is automatically turned on, that is, the power supply control device 10
The power supply from the printer 31 to the printer 31 will be described.
The power source 3a of the printer 31 is turned off in P
This is when both the power supplies 6a and 8a of C6 and WS8 are off. Here, when the power supply 6a of the PC 6 is turned on, the PC power supply output line 6b of FIG. 1 outputs the power supply voltage in cooperation with the power supply 6a of the main body of the PC 6. As a result, the power supply voltage detection circuit 13 of FIG. 2 outputs the signal 13a indicating the on state of the power supply to the logic circuit 15. Therefore, the logic circuit 15
Outputs a signal 15a indicating that the power supply control device 10 should supply the power supply voltage to the shared I / O device. Accordingly, the shared I / O power supply voltage detection circuit 16 connects the control device power supply input line 10a and the shared I / O power supply input line 3a, and the printer 31
Is a power supply voltage output circuit 1 for shared I / O of the power supply control device 10.
Power is supplied from 6.

Similarly, when the power source 8a of the WS 8 is turned on instead of the power source 6a of the PC 6, the WS power source output line 8 of FIG.
b outputs the power supply voltage in cooperation with the power supply 8a of the main body of WS8. As a result, the power supply voltage detection circuit 14 of FIG. 2 outputs the signal 14a indicating the on state of the power supply to the logic circuit 15.
Therefore, the logic circuit 15 outputs a signal 15a indicating that the power supply voltage should be supplied to the shared I / O device. The logic circuit 15 outputs the signal 15a indicating that the power supply voltage should be supplied even when both the input signals 13a and 14a indicate the on state. Therefore, when the power supply 8a is turned on only for WS8, and
Even when both the power supplies 6a and 8a of the WS6 and WS8 are turned on, the printer 31 is supplied with power.

Next, the case where the power supply 3a of the printer 31 is automatically turned off, that is, the case where the power supply from the power supply control device 10 is turned off will be described. The power supply 3a of the printer 31 is on when at least one of the PC 6 and the WS 8 is on.
Here, when both the power supplies 6a and 8a of the PC 6 and the WS 8 are turned off, the power output lines 6b and 8b of the PC 6 and the WS 8 of FIG.
Both are off in cooperation with a and 8a. Therefore, the power supply voltage detection circuits 13 and 14 of FIG. 2 output signals 13a and 14a indicating the off state of the power supply to the logic circuit 15. Therefore, in the logic circuit 15, the power supply controller 10 outputs the output of the power supply voltage of
The signal 15a to the effect that f should be output is output. Therefore, shared I /
The power supply voltage output circuit 16 for O is the power supply input line 10 for the control device.
a and the shared I / O power input line 3a are disconnected,
As a result, the power supply to the printer 31 is turned off.

The case where the number of computers on the network 5 is two, that is, the PC 6 and the WS 8, has been described above. However, even when there are two or more computers on the network, and when there is a shared I / O device other than the printer. The present invention is similarly applied to.

[0018]

According to the present invention, the presence / absence of power supply to a plurality of computers on a network is monitored, and the power of a shared I / O device on the network is automatically turned on if at least one computer is on. However, the power of multiple computers is all o
When turned off, the power of the shared I / O device is automatically turned off.
Therefore, conventionally, the state of individual use of the computer is checked and the power of the shared I / O device is manually turned on / off.
Compared with the above, it is less troublesome, and it is possible to prevent the mistake of starting the use of the computer while the shared I / O device is in the off state.

[Brief description of drawings]

FIG. 1 is a system configuration diagram as an embodiment of the present invention.

FIG. 2 is a block circuit diagram inside the power supply control device of FIG.

FIG. 3 is a conventional system configuration diagram corresponding to FIG.

[Explanation of symbols]

 3a Power input line for shared I / O 5 Network 6 Personal computer (PC) 6a Power input line for personal computer 6b Power output line for personal computer 8 Workstation (WS) 8a Power input line for workstation 8b Power output line for workstation 10 Shared I / O power supply control device 10a Control device power supply input line 13 Personal computer power supply voltage detection circuit 14 Workstation power supply voltage detection circuit 15 Logic circuit 16 Shared I / O power supply voltage output circuit 31 Printer

Claims (1)

[Claims] 1. A system in which a plurality of computers use a common input / output device (hereinafter referred to as a shared I / O device) via a network, the on / off state of each of the computers is monitored, If there is a computer that is turned on, the shared I
A power supply control device for a shared I / O device, comprising means for closing the power supply line for the I / O device and opening the power supply line for the shared I / O device if there is no computer in a power-on state.