JPH04129346A - Communication system provided with duplicate address detection function - Google Patents

Abstract

PURPOSE:To prevent an operation defect due to the setting of a duplicate address in the home bus system by detecting duplicate assignment of an address set to a terminal equipment so as to avoid the operation of the communication system while a duplicate address is assigned. CONSTITUTION:When a duplicate address detection request means 7 generates a detection request, the means 7 requests it to an opposite station address setting means 5 that an address same as its own station address is set to an opposite station address and a frame is sent to a transmission line 1 via a communication means 3. If a terminal equipment having a same address exists, the terminal equipment returns an acknowledge, an acknowledge detection means 6 detects the acknowledge and a duplicate detection means 8 detects the duplicate address. That is, when the duplicate assignment of the address is detected as above, it is informed in sound or display. Thus, improper operation in the operation of the communication system while an address is assigned in duplicate is prevented.

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention is applicable to home automation.
This paper relates to a communication system equipped with an address duplication detection function for detecting duplicate assignment of addresses set to terminal devices in network communication.

(b) Conventional technology Domestic networks in home automation include home bus systems and the like.

Each of these terminal devices has an address and sends a frame that includes the address of the other station. Only the terminal device whose address of the other station matches its own address receives the frame, and when the reception is completed, the frame is received. Send back a confirmation signal.

As the reception confirmation signal, ACK indicating that the signal was received correctly and NAK indicating that a reception error has occurred are often used.

In such a communication system, it is necessary to check whether there is any terminal device with the same address within the system. Conventionally, the method for performing this kind of confirmation is to send a frame that includes the address of the own station in addition to the address of the other station, and the terminal device constantly monitors the own address part of the transmitted frame, and if it is the same as the address of the own station. Confirmation is performed by detecting the address (Japanese Patent Application Laid-Open No. 2-76
Refer to Publication No. 432: j However, with this type of confirmation method, unless another terminal device sends a message, it cannot be confirmed whether there is a terminal device with the same address in the system, and duplicate addresses may be assigned. However, there was a possibility that the system would be put into operation.

(c) Problems to be Solved by the Invention The present invention has been made in view of the above points, and detects duplicate assignment of addresses set in terminal devices without expecting transmission from other terminal devices. This is the issue.

(d) Means for Solving the Problems The present invention provides a means for solving the problems of a terminal device that has an address in each terminal device, transmits a frame including a partner station address, and matches the partner station address in the frame with its own address. In a communication system in which only one station receives a frame and returns a reception confirmation signal when reception is complete, a certain terminal device sends a frame with the address assigned to it as the other station's address, and sends a reception acknowledgement. By being returned,
This method is characterized by detecting duplicate allocation of addresses.

(E) Effects According to the present invention, since duplicate assignment of addresses set in terminal equipment is detected, it is possible to avoid operating the communication system with duplicate addresses assigned.
To prevent malfunctions due to duplicate address settings in a home bus system.

(F) EXAMPLE The present invention in a home bus system will be described in detail below.

First, FIG. 2 shows frames transmitted and received in the home bus system.

The frame has its own address (b) indicating the source address.
, the partner station address (C) that specifies the address of the partner station to be received, and the data n (f) that records the data to be sent.
, a message length (e) that indicates the number of data, a check code (g) used for error detection, and a confirmation signal (h) that the receiving terminal equipment notifies the sending terminal equipment of completion of reception. .

In a home bus system, each terminal device has an address, and when a certain terminal device transmits the above-mentioned frame, only the terminal device whose own station address matches the partner station address in the frame will receive the frame. When the reception is completed, a reception confirmation signal is sent back.

At this time, even if a certain terminal #& device sends a frame with the address assigned to its own station as the destination station address, the terminal device that can receive this frame if the address is set without duplication on each terminal device. should not exist,
No acknowledgment of receipt will be sent back. However, if there is a terminal device with the same address, this terminal device will return a reception confirmation response, and the sending terminal device can detect that the address assigned to it is duplicated. .

FIG. 1 is a block diagram illustrating a duplicate address detection function according to the present invention.

In the figure, 1 is a transmission path, 2 is a terminal device A, and the terminal device A has a communication means 3, a local station address setting means 4, a partner station address setting means 5, and a reception confirmation signal detection means 6, Via the transmission path 1, it is connected to other terminal equipment such as terminal equipment B shown at 9.

Therefore, when a detection request is issued from the duplicate address detection requesting means 7, a request is made to the partner station address setting means 5 to set the same address as the own address as the partner station address, and the request is sent via the communication means 3. Send a frame to transmission path l. If a terminal device with the same address exists, a reception confirmation response is returned from this terminal device, reception confirmation signal detection means 6 detects this, and duplication detection means 8 detects a duplicate address.

For example, when connecting a terminal device or turning on power to the terminal device, the frame shown above is sent, and if it is detected that an address has been assigned duplicately, this can be notified by sound or display. The communication system will not be operated with multiple assignments.

(F) Effects of the Invention As described above, in the communication system according to the present invention, a certain terminal device transmits a frame (data) to its own address, and a reception confirmation signal is returned, resulting in duplicate address allocation. Since the system is designed to detect this, it is possible to prevent the communication system from being operated with duplicate addresses assigned.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a duplicate address detection function in the communication system of the present invention, and FIG. 2 is an explanatory diagram of frames transmitted and received in the home bus system. 2-m - terminal equipment A, 3-m = communication means 4 --- own station address setting means 5 - m - partner station address setting means 6 - - reception confirmation signal detection means 7 --- duplicate address detection request means

Claims (1)

[Claims] 1) Each terminal device has an address and sends a frame that includes the partner station address, and only the terminal device whose partner station address and own station address in the frame match will receive the frame and the reception is complete. Then, in a communication system that returns a reception confirmation signal, a certain terminal device sends a frame with the address assigned to its own station as the address of the other station, and a reception confirmation response is returned, thereby detecting duplicate assignment of addresses. A communication system equipped with an address duplication detection function.