JPH04296141A - Remote power supply controller - Google Patents

Abstract

PURPOSE:To make the distance of an interface between an RPC and a master set long and to improve the maintenance performance of the RPC. CONSTITUTION:Relays 24, 25, 28 are used as an interface circuit between an RPC 21 and a master set 22. Thus, interface signal lines 5, 6 are almost immune to the effect of external noise and the long distance interface is attained. When the power supply of the RPC 21 is turned off, since no current flows to the interface signal lines 5, 6, the removal of the RPC is attained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote power control device that receives a specific message from a host device via a communication line and controls the power of a parent device.

0002

2. Description of the Related Art Conventionally, a remote power control device has been placed in an information processing system connected to a host device, for example, a host computer via a communication line. The method is to turn on the power. FIG. 3 is a block diagram showing such a remote power supply control method.

In FIG. 3, a remote power control device (hereinafter referred to as RPC) 3 is connected to a host computer 1 as a host device via a communication line 2. As shown in FIG. RPC3
connects the interface signal line 5 to the parent device (computer) 4
, 6, of which 5 is a power-on signal line for the RPC 3 to instruct the parent device 4 to turn on the power, and 6 is a ready line for the parent device 4 to notify the RPC 3 that the power has been turned on. It is a signal line.

[0004] When the host computer 1 attempts to turn on the power to the parent device 4, the host computer 1 first transmits a power-on message to the RPC 3 via the communication line 2. When RPC3 receives this power-on message,
The parent device 4 is instructed to turn on the power using the power-on signal line 5. The parent device 4 thereby powers on. When the power-on is completed, the parent device 4 notifies the RPC 3 of the completion of power-on using the ready signal line 6. This completes the power-on sequence.

Power-on signal line 5 and ready signal line 6
TTL is generally used as the electrical interface. FIG. 4 schematically shows an example of a conventional interface circuit in the RPC 3 and the parent device 4. In the figure, 9 is a ground signal line for indicating the reference level of the TTL signal, 10 is a TTL driver that drives a power-on signal, 11 is a TTL driver that drives a ready signal, and 12 is a TTL receiver that receives a ready signal. 13 indicates the power supply of the parent device 4. The power supply 13 is turned on by detecting the sink current of the TTL driver 10 of the RPC 3.

[0006] Furthermore, if there is only one communication line 2 between the RPC 3 and the host computer 1, there is a possibility that the communication line 2 may become unable to send the power-on message due to a failure or the like. Another communication line and RPC may be prepared as a detour route. FIG. 5 shows a conventional example in which a detour route is provided. In the figure, 7 is a communication line separately provided as a detour route, and 8 is a separately provided RPC, which are provided in case of failure of communication line 2 and RPC3.

[0007]

However, in the conventional device described above, since the interface between the RPC and the parent device is TTL, there are the following problems. That is, the first
Furthermore, if the signal line between the RPC and the parent device receives external noise, there is a risk that the TTL will malfunction, and in order to minimize the influence of external noise, the signal line cannot be made long. Therefore, the relative placement of the RPC and the parent device is restricted.

Second, RPC maintenance must be performed when a power-on message is not sent from the host computer. Since a power-on message may be sent when the parent device is powered off, it is necessary to perform RPC maintenance while the parent device is powered on. However, if you attach or remove the RPC while the power to the parent device is on, there is a risk that both TTL drivers and TTL receivers will be destroyed due to overcurrent caused by the difference in ground potential between the devices. At this time, RPC maintenance cannot be performed.

Third, when multiple RPCs are connected as shown in FIG. 5, maintenance of one RPC may have an adverse effect on the other RPCs. For example, when one RPC is attached or detached, a current flows through the interface signal line as in the case of only one RPC, and this may be mistakenly recognized as a power-on signal or a ready signal.

The present invention has been made in view of the above-mentioned problems, and its purpose is to use a relay as an interface between the RPC and the parent device, thereby realizing a long-distance interface and reducing maintenance of the RPC. The objective is to provide an excellent device that improves safety during operation.

[0011]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a remote control system that receives a power-on message from a communication line, issues a power-on instruction to a parent device, and receives a power-on completion notification from the parent device. In the power supply control device, the transmitting end of the power-on instruction signal and the transmitting/receiving end of the power-on completion notification signal are electrically connected/disconnected by the contacts of the relay.

0012

[Operation] The present invention having the above configuration allows a relatively large current to flow through the power-on instruction signal line and the power-on completion notification signal line, making it less susceptible to external noise and increasing the length of the signal line. becomes possible.

Furthermore, since both of the signal lines are connected and disconnected at the relay contacts, if the power to the remote power control device is turned off, current will no longer flow through both signal lines, and therefore maintenance of the remote power control device will be difficult. can be done safely.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. Note that elements common to each drawing are given the same reference numerals.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, an RPC 21 is connected to a host computer 1 via a communication line 2. RPC2
1 is also connected to a parent device (computer) 22 by interface signal lines 5, 6. The RPC 21 is a device that controls the power supply of the parent device 22 according to instructions from the host computer 1, and its operation is controlled by the line control section 23. The line control section 23 is connected to the TTL driver 10 and the TTL receiver 12. The output side of the TTL driver 10 is connected to a relay 24, and the input side of the TTL receiver 12 is connected to a relay 25. relay 2
4 sends a power-on instruction to the parent device 22 via the interface signal line 5. Further, the relay 25 receives a notification signal sent from the parent device 22 via the interface signal 6 and controls the input of the TTL receiver 12. Each relay 24, 25 is supplied with power from a power source (not shown) within the RPC 21. Also relay 25 and TT
A pull-up resistor 26 is connected between the L receiver 12 and the L receiver 12 .

The parent device 22 is equipped with a control section 27 and a power source 13 for controlling the operation of the device. The TTL driver 11 is connected to the control section 27, and a relay 28 is further connected to the output side thereof. Relay 28 is RPC21
It sends a ready signal to the interface signal line 6 via the interface signal line 6, and is driven by the TTL driver 11.

Next, the power supply control operation will be explained.

First, the host computer 1 sends a power-on message to the RPC 21 via the communication line 2. When the line control unit 23 of the RPC 21 receives this message, it drives the relay 24 via the TTL driver 10. This causes current to flow through the coil 24a of the relay 24, making the contact 24b. When the contact 24b is made, the power supply 13 of the parent device 22 detects this and turns on the power.

When the control unit 27 of the parent device 22 recognizes that the power has been turned on, it drives the relay 28 via the TTL driver 11. As a result, current flows through the coil 28a of the relay 28, and the contact 28b is closed. Contact 2
8b is made, a current flows through the interface signal line 6 to the coil 25a of the relay 25 of the RPC 21. This causes the contact 25b to close. The current flowing through the pull-up resistor 26 flows to the relay 25 side, the input of the TTL receiver 12 becomes OV, and a ready signal indicating the completion of power-on is input to the line control unit 23. The line control unit 23 thereby recognizes that power-on of the parent device 22 has been completed, and executes the subsequent processing.

[0020] By connecting the interface signal between the RPC 21 and the parent device 22 through the relays 24, 25, and 28 in this way, a relatively large current can be passed as the interface signal, so that external noise etc. This makes it less susceptible to influence, and therefore it becomes possible to extend the distance of the interface signal line.

Next, we will explain the case of maintaining the RPC 21. In this case, first, the power supply (not shown) in the RPC 21 is turned off. As a result, power is not supplied to the relays 24 and 25, and both relays 24 and 25 do not operate. Therefore, the currents flowing through the interface signal lines 5 and 6 are both “
0", regardless of whether the parent device 22 is on or off. In this state, the RPC 21 can be detached from the parent device 22, and at this time, the RPC 21 and the parent device 2
This has no effect on the TTL driver and receiver in 2.

FIG. 2 shows an embodiment in which a plurality of (two) RPCs are provided to prepare a detour route for the communication line.

In the figure, a detour route communication line 30 is connected to the host computer 1, and this communication line 3
RPC31 is connected to 0. The structure of RPC31 is RP
It is similar to that of C21.

A relay device 32 is provided between the RPCs 21 and 31 and the parent device 22. In the relay device 32, the interface signal line 5 from the relay 24 of the RPC 21 and the interface signal line 33 from the relay 24 of the RPC 31 are connected in parallel. The relay device 32 is provided with a relay 34 for distributing the contact signal of the relay 28 in the parent device 22 to the RPCs 21 and 31. That is, the relay 34 has two contacts 3.
4a and 34b are provided and connected to the relays 25 of the RPCs 21 and 31, respectively. In this embodiment, since there are two RPCs, the number of contacts of the relay 34 is two, but the number of contacts of the relay 34 is provided in accordance with the number of RPCs installed.

The power control operation of the parent device 22 will now be described. Both RPCs 21 and 31 are powered on, and the relay device 32 is also powered on. In this state, the parent device 2
2 power control operation is performed.

First, the host computer 1 sends a power-on message to the RPC 21 or 31 via the communication line 2 or 30. Upon receiving this message, the RPC 21 or 31 sends the message to the parent device 2 via the interface signal line 5 or 33.
Sends a power-on instruction to 2. As a result, the power source 13 of the parent device 22 is turned on.

When the control unit 27 of the parent device 22 recognizes that the power has been turned on, it drives the relay 28 via the TTL driver 11. This causes contact 2 of relay 28 to
8b is made, and the coil 3 of the relay 34 of the relay device 32
A current flows through 4c. When current flows through the coil 34c,
Contacts 34a and 34b are made, and current flows through interface signal lines 6 and 35. This allows RPC2
1 or 31 confirms that power-on of the parent device 22 has been completed.

Next, the operation during maintenance will be explained. One RP
C, for example, when maintaining RPC21, first RPC2
Turn off the power of 1. As a result, the relay 25 is also turned off, and no current flows through the interface signal line 6. At this time, the other RPC 31 is in the on state, and current may be flowing through the interface signal line 35, but in the relay 34, the interface signal line 6 and 35
Since the interface signal line 6 is connected to separate contacts 34a and 34b, no current flows into the interface signal line 6. Therefore, the RPC 21 can be inserted or removed without affecting the RPC 31 or the parent device 22.

[0029]

[Effects of the Invention] As explained in detail above, according to the present invention, a relay is used in the interface circuit between the RPC and the parent device to transmit signals, making it less susceptible to external noise. This makes it possible to extend the distance of the interface.

Furthermore, by using a relay in the interface circuit, when maintaining the RPC, if the RPC power is turned off, no current will flow through the interface signal line, so the RPC can be safely attached and detached.

[0031] Furthermore, when using multiple RPCs, R
By providing a relay that has contacts corresponding to the number of PCs, maintenance of the RPC can be performed without affecting other RPCs or the parent device.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing an embodiment according to the present invention.

FIG. 2 is a block configuration diagram showing an embodiment in which a plurality of RPCs are provided.

FIG. 3 is a block diagram showing a conventional remote power supply control method.

FIG. 4 is a block configuration diagram showing an example of a conventional interface circuit.

FIG. 5 is a configuration diagram showing a conventional example in which a detour route is provided.

[Explanation of symbols]

1 Host computer 2 Communication line 5, 6 Interface signal line 21 RPC 22 Parent device 24, 25, 28 Relay

Claims (1)

[Claims] Claim 1: In a remote power control device that receives a power-on message from a communication line, instructs a parent device to turn on the power, and receives a power-on completion notification from the parent device, the sending end of the power-on instruction signal and the power-on A remote power supply control device characterized in that the transmitting and receiving ends of the completion notification signal are electrically connected and disconnected by the contacts of a relay.