KR100493271B1 - Node Control Method in Bus System - Google Patents

Abstract

The node control method in the bus system is unnecessary when a command is sent from a node other than the node reserved as a RESERVEd node by returning reservation information to the node that sent the command with a reject response. A method of controlling a node in a bus system that controls a reserved node, wherein the reservation information of a reserved node is acquired without a transaction. Retrieving the audio / video control response frame by recording the rejection in an audio / video control response frame if the search result is reserved, and adding reservation information after recording the rejection. Returning the audio / video control command (AVC command) frame to the transmitting node. That's the point.

Description

Node Control Method in Bus System

The present invention relates to a bus system, and more particularly, to a node control method in a bus system.

Hereinafter, a node control method in a bus system according to the related art will be described with reference to the accompanying drawings.

FIG. 1 is an exemplary view showing a RESERVE state in a bus system according to the prior art, which includes a server 1, first and second DTVs 2 and 3, and first and second DVCRs 4. 5), a PC 6, and a camera 7.

FIG. 2 is a diagram showing the format of a RESERVE control command frame used in FIG. 1, which shows an area representing audio / video format data, a ctype area for recording a command, and A subunit_type area for recording the type of the device included in the device, a subunit_ID area for recording the ID of the device included in the device to be reserved, and a reservation status A reservation area for making a reservation, a priority area for recording priority, and a plurality of operand areas.

Although FIG. 2 is a part of a Function Control Protocol (FCP) format, although not shown, a 1394 header is added to transmit a packet to a corresponding node.

3 is a view illustrating a format of an audio / video control command (AVC command), an area representing audio / video format data, a ctype area for recording a command, and an apparatus included in a device to be reserved. A subunit_type area for recording a type of a subunit, a subunit_ID area for recording an ID of a device included in the device to be reserved, an opcode area, and a plurality of Number of operand areas and zero pad bytes areas.

4 is a view illustrating an audio / video control response (AVC response) format, an area representing audio / video format data, a response area representing a response, and an apparatus included in a device to be reserved. A subunit_type area for recording a type, a subunit_ID area for recording an ID of a device included in the device to be reserved, an opcode area, and a plurality of It consists of an operand area and a zero pad byte area.

A method of controlling a node in a bus system according to the related art configured as described above will be described in detail with reference to the accompanying drawings.

First, as shown in FIG. 1, a first DTV 2 reserves a second DVCR 5 for use in a home network connected with a 1394 serial bus as shown in FIG. A RESERVE control command frame indicating reservation is sent to the second DVCR 5.

The second DVCR 5 is then RESERVEed to the first DTV 2 at a priority determined according to a reserve control command sent from the first DTV 2.

An audio / video control command (AVC command) frame as shown in FIG. 3 is then sent to the second DVCR 5 to control the second DVCR 5 at another node (e.g., the second DTV 3). send.

Then, the second DVCR 5 has audio as shown in FIG. 4 since it is already reserved by the first DTV 2 according to the transmitted AVC command frame. A reject is recorded in the AVC response frame and transmitted to the second DTV 3.

However, in the method of controlling a node in a bus system according to the prior art, when a command is transmitted from a node to a reserved node, only the audio / video control response frame in which a reject is recorded is returned. There is a problem in that the node receiving the unknown reason is not known.

In addition, the prior art also has a problem that unnecessary transactions occur because a node that receives a reserved command from a RESERVE node must query the rejected node for the reason for rejection.

Accordingly, the present invention has been made to solve the above problems, and when a command is transmitted from a node other than the reserved node as a reserved node, the reserved node commands reservation information together with a reject response. It is an object of the present invention to provide a node control method in a bus system in which the reservation information of a reserved node can be grasped without unnecessary transactions by replying to the transmitted node.

A feature of a node control method in a bus system according to the present invention for achieving the above object is an audio / video control command (AVC command) in a node control method in a bus system for controlling a RESERVE node. If a frame is received, searching for a reservation (RESERVE); if the search result is reserved (RESERVE), recording a reject in an audio / video control response (AVC response) frame, and rejecting the reject And adding the RESERVE information after recording to return the audio / video control response frame to the node that has transmitted the audio / video control command frame.

Another feature of the method for controlling a node in a bus system according to the present invention for achieving the above object is that the reservation (RESERVE) information indicates a reservation area (RESERVE) indicating a reservation status and a free indicating the priority of the reservation. It consists of a priority area.

Hereinafter, a preferred embodiment of a node control method in a bus system according to the present invention will be described with reference to the accompanying drawings.

FIG. 5 is a diagram illustrating an audio / video control response frame applied to a node control method in a bus system according to the present invention. FIG. 5 is an area representing audio / video format data and a response to represent a response. (response) area, a subunit_type area for recording the type of the device included in the device to be reserved, and a subunit_ID for recording the ID of the device included in the device to be reserved. subunit_ID), an opcode area, a plurality of operand areas, a zero pad bytes area, a reserved area, and a reservation indicating the reservation status. ), A priority area indicating the priority of the RESERVE, and a plurality of operand areas.

6 is a flowchart illustrating a method for controlling a node in a bus system according to the present invention.

Such a node control method in the bus system according to the present invention will be described in detail with reference to the accompanying drawings.

Since the components to which the present invention is applied are the same as those shown in FIG. 1, the description thereof will be omitted.

First, as shown in FIG. 1, a first DTV 2 reserves a second DVCR 5 for use in a home network connected with a 1394 serial bus as shown in FIG. A RESERVE control command indicating reservation is sent to the second DVCR 5.

The second DVCR 5 is then RESERVEed to the first DTV 2 at a priority determined according to a RESERVE control command sent from the first DTV 2.

An audio / video control command (AVC command) frame as shown in FIG. 3 is then sent to the second DVCR 5 to control the second DVCR 5 at another node (e.g., the second DTV 3). send.

The second DVCR 5 then receives the transmitted AVC command frame and searches whether it is RESERVEed (S1, S2).

If the search result is not reserved (RESERVE), the second DVCR (5) performs a control command according to the audio / video control command (AVC command) frame (S3).

If the search result is already reserved by the first DTV 2, the second DVCR 5 rejects the audio / video control response frame as shown in FIG. 5. After recording, the reservation information is additionally recorded and transmitted to the second DTV 3 (S4 to S6).

Accordingly, the second DTV 3 detects the reservation information of the first DTV 2 from the transmitted AV / Response frame of the reserved node, so that the first DTV 2 detects the reservation information of the first DTV 2 for some reason. It can be determined whether it has been rejected from.

As described above, in the method for controlling a node in the bus system according to the present invention, when a command is transmitted from a node other than a node reserved as a reserved node, the reserved node receives reservation information together with a reject response. By returning to the node that sent the command, it is possible to grasp the reservation information of the reserved node without unnecessary transactions.

1 is an exemplary view showing a RESERVE state of a node control method in a bus system according to the prior art.

FIG. 2 is a diagram illustrating a format of a RESERVE control command frame used in FIG. 1.

3 is a diagram illustrating a format of an audio / video control command (AVC command) frame.

4 illustrates the format of an Audio / Video Control Response (AVC response) frame.

5 is a view showing a format of an audio / video control response (AVC response) frame applied to a node control method in a bus system according to the present invention.

6 is a flowchart illustrating a method for controlling a node in a bus system according to the present invention.

Claims (2)

In a node control method in a bus system for controlling a RESERVE node, Searching for a reservation if an audio / video control command (AVC command) frame is received; Recording a reject in an audio / video control response frame if the search result is reserved; And recording the rejection and adding reservation information to return the audio / video control response frame to the node that transmitted the audio / video control command frame. Node control method. The method of claim 1, The reservation (RESERVE) information includes a reservation area (RESERVE) indicating a reservation state and a priority area indicating a priority of the reservation.