JPH03273325A - Interface control system - Google Patents

Abstract

PURPOSE:To easily continue the operation in an interface in preceding stages even at the time of turning off the power source of a power supply system in the next stage by providing each power supply system with a terminating circuit and an interface switching circuit. CONSTITUTION:When power is supplied to enclosures 1 and 2, a control signal 18 from a power supply circuit 11 goes to logical '1', and a switching circuit 8 connects interface lines 13 and 14 and disconnects lines 13 and 17. At this time, devices 4 to 7 are connected to a controller 3, and the interface is terminated by a terminating circuit 10. When the power source on the side of the enclosure 2 is turned off, the signal 18 from the circuit 11 goes to logical '0', and the circuit 8 disconnects interface lines 13 and 14 and connects lines 13 and 17, and a terminating circuit 9 is connected. Thus, the interface operation is easily continued only with the power source on the side of the enclosure 1 through the power source on the side of the enclosure 2 is turned off.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an interface system, especially a plurality of 1i
This invention relates to a control method for an interface that connects devices in a T-source supply system and transfers information.

[Conventional technology]

Conventionally, this type of Q) interface IIIaJ has been implemented by connecting a termination circuit for impedance matching to the termination.

[Problem to be solved by the invention]

In the conventional interface control method described above, if the t source to the termination circuit is cut off, the interface will not function properly, so the power supply is provided to one system for all devices included in the interface and the termination circuit. Alternatively, it was necessary to change the connection of interface D, move the termination circuit to the power supply system, and disconnect it from the power supply disconnection section.

[Means to solve the problem]

The method of the present invention is divided into an interface (σ) control method that connects devices across multiple power supply systems and transfers information, and controls information transfer, and a control device connected to the start end of the interface, and a control method that controls information transfer. A number of devices are connected in the middle of the interface to perform the transfer, a terminating circuit is connected to the final end of the interface to match the impedance O, and a terminal circuit is connected to the break in the power supply system of the interface to connect the power supply circuit to the next stage power supply circuit. The i source on/off signal disconnects the interface to the next stage and switches the connection to the terminal circuit waiting at the current stage.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention 1Af11.

In this embodiment, the power supply system is divided into two units, 1 and 2.

3 is a control device that controls a plurality of devices; 4゜5.6.
7 is number one. Second. Third. The fourth device 8 is a switching circuit, and 9.10 is a termination circuit.

The interface connecting the control circuit 3 and each device 1 to 4 is an interface line 19.1 via the switching circuit 8.
2, 13, 14, 15, and 16 through the termination circuit 101. The switching circuit 8 is connected to the termination circuit 9 through an interface □17? Further, a control signal 18 from the t source circuit 11 is input.

Next, the operation of the present invention will be explained.

When power is supplied to both the power source 1 and the power source 2, the control signal 18 from the power supply circuit 811 becomes logic 11".
Assume that the switching circuit 8 connects the interface lines 13 and 14, and 13 and 17 are in the off-ffr state. At this time, all of the devices 1 to 4 are connected to the control device 3, and this interface is terminated with the termination circuit 10.

When the t source on the housing and body 2 side is turned off, the source circuit 11
The control signal 18 from the terminal becomes logic "O", the switching circuit 8 acts to disconnect the interface lines 13 and 14 and connect the interface lines 13 and 17, and the termination circuit 9 is connected. As a result, even if the power to the body 2 side is cut off, the body 1
Only @II can continue operation of the interface.

〔Effect of the invention〕

As explained above, the present invention provides a termination circuit and an interface switching circuit for each power supply system, so that even if the power of the next stage power supply system is cut off, the operation in the interface of the previous stage can be maintained. This has the effect of making it easier to continue.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention. 1.2...Kyoto body, 3...Using restraint device, 4
~7...device, 8...switching circuit, 9
．． 20...terminal circuit, 11... source circuit.

Claims (1)

[Claims] A control method for an interface that connects and transfers information between devices across a plurality of power supply systems, comprising: a control device that controls the information transfer and is connected to a starting end of the interface; In the middle of the interface, there is a termination circuit that connects multiple devices to the final end of the interface to match the impedance, and a termination circuit that matches the impedance of the interface, and is connected to a break in the power supply system of the interface and is connected to the next stage by a power on/off signal from the power supply circuit of the next stage. An interface control system comprising a switching circuit that disconnects the interface of the stage and switches the connection to the terminal circuit of the stage itself.