JPH0564898B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a method for managing the addresses of devices connected to a multi-drop network. and a management device that is connected to the transmission path and manages the addresses of the plurality of managed devices, and transmits data between the management device and the managed devices and the management device by packets sent to the transmission path. The present invention relates to a method for detecting duplicate addresses on a transmission path in a network configured to transmit data between managed devices.

(Prior art) In response to the rapid progress in informationization of the home due to the increasing sophistication and complexity of home devices including new media equipment, disaster prevention, and crime prevention equipment due to the recent advances in microelectronics, these home information devices have been developed. The development and standardization of home information and communications networks, so-called home buses (transmission lines), which aim to centrally accommodate and organically connect information and communications networks, are underway both in Japan and abroad. The following is an overview of the home bus (transmission line) standardization that is being promoted in Japan.

The transmission path is composed of one control channel and multiple information channels. A digital control signal is transmitted to the control channel, and an arbitrary information signal is transmitted to the circuit-switched information channel.
These channels take the form of space division, frequency division, or a combination of both.

Figure 3 shows the configuration of the home bus system.

In FIG. 3, 21 is the aforementioned transmission line (home bus), 22 is a home bus controller (hereinafter referred to as HBC 22), and 23 is an interface unit (hereinafter referred to as IFU 23).

Both the HBC 22 and the IFU 23 are devices connected to the transmission line 21. The HBC 22 is a type of transmission path management/monitoring device that performs circuit switching of information channels, address management of the IFU 23, initialization of the system, and measures when an abnormality occurs in the transmission path 21. On the other hand, the IFU 23 is a so-called general device having an application service, and is managed by the HBC 22 at the logical level of the transmission path 21. this
The IFU 23 does not necessarily use all the information channels; it uses only the ones it needs, but all IFU 23s must use the control channel according to a predetermined protocol (communication control procedure). Must be.

The outline of the protocol is shown below.

In the transmission method, when there is no signal on the control channel, the transmitting IFU 23 attaches a destination to the transmitted data and transmits it, and the receiving IFU 23 constantly monitors the channel, and if there is a signal addressed to it, it sends it. A packet transmission method of receiving is used. Figure 4 shows the packet format.

In FIG. 4, 30 is a packet, and the priority bit (PR), which determines the priority in the case of packet contention,
Self address SA, destination address DA, control code (CW) indicating the meaning of the packet, data count (DC) indicating the data length, transmission data
DATA, a frame check code (FCC) for detecting packet transmission errors,
The length of all data other than the transmission data DATA is determined.

Each of the HBC 22 and IFU 23 in FIG. 3 has its own address determined, and when transmitting a packet, its own address is attached to its own address SA, and the other party's address is attached to the other party's address DA.

IFU where the other address DA is your own address
23, after receiving the packet 30 in Fig. 4, checks the packet 30 for errors using a frame check code (FCC), etc., and if there is no error, the time
After T _D, an acknowledge signal indicating reception completion (hereinafter referred to as
(described as ACK signal) 31 is returned. T _r is a pause period until the next packet 32 is transmitted, and the next packet 32 can only be transmitted after the pause period T _r has elapsed.

When there is no signal on the control channel, packets can be sent at any time, but when there is a signal, packets can be sent after the pause period T _r shown in FIG. 4 has elapsed.

However, when two or more IFUs 23 attempt to transmit packets at the same time, packet contention occurs. One of the levels of the digital signal on the control channel is given electrical priority; for example, when logic "0" is given priority,
When logic "1" and "0" conflict on a channel, a logic "0" results.

At this time, if you transmit a packet while comparing your own transmitted signal and received signal, you will immediately know that you have lost the competition, so you will stop transmitting from that point on. Then, the packet that wins the competition is transmitted as is. Comparison of transmitted and received signals is performed bit by bit, and this is called a winning/remaining method based on bit matching.

Bit verification is performed only between the priority bit (PR) at the head of packet 32 in FIG. 4 and the self address SA. This is because when there is a packet conflict, the self-address SA will never match, so after the self-address SA portion is transmitted, only the packet with the highest priority is transmitted.

Both the HBC 22 and IFU 23 follow the above protocol regarding packet transmission and reception, but their application functions are different.

Regarding home bus system management, HBC2
2 will be the parent unit, and IFU23 will be the slave unit. H.B.C.
22 must know the address of the connected IFU 23 in order to perform circuit switching of the information channels used by the IFU 23. This is because it is generally performed in the procedure of registering information including the address of the connected device from the IFU 23 to the HBC 22 when the system is initialized when the power is turned on.

According to the draft standard, the device address length and HBC2
The relationship with address 2 is fixed. for example,
If the address length is 1 byte, the address of the HBC 22 is φφH. The address of the IFU23 is not fixed, and must be set using a switch when connecting to the system. That is, IFU2 from the beginning.
This is because if a fixed address is assigned to 3, IFUs 23 of the same type will have the same address and will not be able to connect to one system. That is, HBC22, IFU23 connected to the system
This address is unique on the system, and there is no other address that is the same.

In the above home bus system,
There are problems as shown below.

That is, when connecting the IFU 23 to the system, settings are made using a switch or the like so that the address does not overlap with other IFUs 23.

However, there is no guarantee that addresses will never overlap.

There is no problem if the installer confirms the address, but as the number of connected devices increases (looking at the address alone, 256 devices can be connected if the address length is 1 byte), it becomes extremely difficult to confirm.
There is also the possibility of human error.

Furthermore, if a duplicate address is set, this will not immediately cause a system error; instead, when a packet is sent to that address, the IFU 23 of the duplicate address will react, and the IFU 23 of the duplicate address will respond. The reality is that address duplication becomes apparent only after an inconvenience occurs.

Because of the above problems, an automatic confirmation method is needed.

However, automatic confirmation methods cannot be easily implemented for the following reasons.

That is, the IFU23 is connected to the system and powered on.
When turned on, register the address of that IFU23.
Since this is done in the HBC 22, it is likely that duplicate addresses can be detected by comparing with addresses already registered in the HBC 22.

However, only that IFU23 turns off and restarts.
If you turn it on, the same address will be registered again, so
HBC22 considers it to be a duplicate. Therefore, this method is unreasonable.

In addition, the IFU23 of the duplicate address in the system
In order to check whether HBC22 exists,
Even if a request is issued from the IFU 23 and a response is obtained from each IFU 23, the identical response packets will be sent at the same timing from the IFU 23 of the duplicate address, so it will not be of any use in detecting duplicate addresses.

(Object of the Invention) The present invention has been made in view of the above circumstances, and provides a method that can reliably detect duplicate addresses of IFUs connected to transmission lines and prevent duplicate address registration. The purpose is to provide.

(Structure of the invention) In order to achieve such an object, the present invention has the following features:
A plurality of managed devices and a management device that manages the addresses of each of these managed devices are connected to each other via a transmission path, and packets are transmitted from the managed devices and the management device to the transmission path, respectively. In a method used in a network configured to transmit data between managed devices and managed devices, and between managed devices,
It has the following structure.

That is, in the first invention, each managed device detects whether the address of a newly connected managed device overlaps with the address of a managed device already connected to the transmission path. The address duplication detection means includes an address duplication detection means that, when the managed device receives a registration packet transmitted due to a new connection of the managed device, a response packet outputted from the managed device in response to the registration packet is It is checked whether the response packet corresponds to the transmission of the registration packet, and if a response packet is received while the registration packet has not been transmitted, the reception of this response packet is determined to be an address duplication. It is a feature.

Further, in the second invention, each managed device detects whether an address of a newly connected managed device overlaps an address of a managed device already connected to the transmission path. The address duplication detection means is equipped with an address duplication detection means that, when a managed device is newly connected to a transmission path, sends a dummy packet with its own address set as the destination, while sending a dummy packet to the already connected managed device. It is checked whether or not a response packet is returned to this dummy packet from the source, and if the response packet is returned to the managed device that is the sender, the reception of this response packet is determined to be an address duplication. , is characterized by.

In the first invention, if there is address duplication registration for a newly connected managed device, a response packet that should not arrive at the already connected managed device is received, so the address duplication detection provided in the managed device is This can be detected by means. Therefore, the burden of detecting address duplication of managed devices can be extremely light.

Further, in the second invention, if a newly connected managed device transmits a dummy packet with the destination set to the same as the source, and a response packet is returned from the already connected managed device, Address duplication can be detected by the address duplication detection means provided in the newly connected managed device. Therefore, in this case as well, the burden of detecting address duplication of managed devices can be extremely light.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

<Embodiment 1> FIG. 1 is a schematic configuration diagram of a transmission path duplicate address detection method showing an embodiment according to the first invention.

The HBC 12 and n IFUs 13 are already connected to the transmission line 11. The addresses of each IFU 13 are A ₁ to A _o and have been registered.

If the address of the newly connected IFU13a is n
Assume that it matches one of the addresses of IFU13. For example, the address A _o of the nth IFU 13
Assume that the IFU 13a has the same address as .

The IFU 13a newly connected to the transmission line 11 and powered on transmits the registration packet P _B1 to the HBC 12. When the HBC 12 receives the registration packet P _B1 , it sends the registration confirmation packet P _B2 to the already connected IFU 13 with address A _o and the newly connected IFU 13a without performing an address duplication check, and both IFUs 13, 13a receives registration confirmation packet _B2 . The newly connected IFU 13a sends a registration packet P _B1 and a registration confirmation packet _B2.
There is no problem as you will receive it.

However, even though the already connected IFU 13 has not sent the registration packet P _B1 ,
Since the registration confirmation packet P _B2 is received, it is known that the IFU 13a with the same address _Ao has been newly connected to the transmission path 1.

In this case, a warning can be displayed on the already connected IFU 13, and the address duplication can also be confirmed on the HBC 12 by sending a packet indicating address duplication from the already connected IFU 13 to the HBC 12. .

In addition, connect the new IFU13a and turn on the power.
Even if the IFU 13 is only turned on and off, and the IFU 13 sends a registration packet P _B1 each time it turns on and off, and the HBC 12 sends a registration confirmation packet P _B2 to the IFU 13, the same HBC unless IFU13 with the address of
Registration confirmation packet P _B2 from 12 is that IFU13
Therefore, the situation described in FIG. 1 does not occur, and address duplication is not detected.

Also, when starting up the system, the IFU13 power supply is turned off.
If the IFU 13 with the same address performs the same operation due to the fact that the HBC 12 is powered on before the HBC 12 or both are powered on almost at the same time, the address overlap may not be detected. .

Therefore, when starting up the system, HBC12
Turn on the power first and power each IFU13 in turn.
After turning on or turning on all power, IFU13
Register packets one by one by resetting them one by one.
If you send P _B1 repeatedly, you can reliably check for duplicate addresses.

<Second Embodiment> An embodiment according to the second invention will be described with reference to the flowchart of FIG. 2 and the configuration of FIG. 3.

In other words, it is connected to transmission line 1 and the power is turned on.
In addition to registering the address in HBC2, IFU3 sets its own address in the destination address (DA) part of the packet, and also sends a dummy packet in which the transmission data (DATA) part has no meaning. do. At that time, if another IFU3 with the same address as that IFU3 exists, that other IFU3 receives the dummy packet, and when it is completed, the ACK (acknowledge) signal 31 in FIG. 4 is sent from that other IFU3 according to the protocol. Sent. Since this ACK signal 31 is received by the IFU 3 that sent the dummy packet, the duplication of addresses is known. That is, if the addresses do not overlap, the ACK signal 31 will not be transmitted.

Figure 2 shows IFU3 for checking address duplication.
This shows the flowchart at the start of the process.

At step S3a, power on IFU3 or
Press the reset switch. In step S3b, the destination address (DA) is set to its own address, and a dummy packet is transmitted. In step S3c, it is determined whether the ACK signal 31 has been received.

If ACK signal 31 is not received, step
The process moves to S3d, displays that there is no duplicate address, and returns to the normal state in step S3e.

If ACK signal 31 is received, step
The process moves to S3f, displays that there is a duplicate address, returns to step S3g, and resets the address.

At system startup, if the power is turned on at the same time, packet congestion will occur, but there will be no problem as long as packets from multiple IFUs 3 with duplicate addresses are not sent at exactly the same time.

As a preventive measure in case packets are sent at exactly the same time, turn on the power of IFU3 in sequence or press the reset switch in sequence.
If the sequence shown in FIG. 2 is performed separately for each IFU 3 in terms of timing, address duplication can be checked reliably.

In this embodiment, a dummy packet is used as the packet 30 in FIG. 4, and address duplication is checked based on the presence or absence of the ACK signal 31. However, instead of a dummy packet, a packet called address duplication check is sent and received. A method may also be adopted in which the IFU 3 with the duplicate address (that is, the IFU 3 with the duplicate address) returns a packet indicating that there is a duplicate address.
As a means of checking address duplication, the
The only difference is whether the ACK signal 31 is used or a packet level response signal is used.

The method of the second embodiment is characterized in that it sends a packet to the same address as itself and waits for a response.

Note that there is no problem no matter how many times the sequence shown in FIG. 2 is performed by turning ON/OFF the power of only the IFU 3.

(Effect of the invention) According to the present invention, the following effects are achieved.

That is, in the first invention, if there is duplicate address registration for a newly connected managed device, the previously connected managed device receives a response packet that should not arrive, so the address set for that managed device is This can be detected by the duplication detection means.

Further, in the second invention, if a newly connected managed device transmits a dummy packet with the destination set to the same as the source, and a response packet is returned from the already connected managed device, Address duplication can be detected by the address duplication detection means provided in the newly connected managed device.

In this way, in both the first invention and the second invention, since the managed device side can check whether or not to set duplicate addresses without having to set them on the managed device side, duplicate addresses can be set within a short period of time. In addition, the managed device only needs to check the correspondence between sending and receiving packets instead of directly comparing addresses, saving the effort of detecting duplicate addresses. Therefore, the burden of detecting duplicate addresses on the entire system can be extremely light. Moreover, since the presence or absence of duplicate addresses can be reliably detected, a highly reliable network system can be easily constructed without increasing costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram according to a first embodiment of the present invention, FIG. 2 is a flowchart for explaining the second embodiment of the present invention, and FIG. 3 is a general schematic configuration diagram of a home bus system. , FIG. 4 is a general schematic diagram of the home bus system, and FIG. 4 is a schematic diagram of the packet format of signals on the home bus system control channel. 1, 11...Transmission line (home bus), 2, 12
...HBC (home bus controller, management equipment),
3,13...IFU (interface unit)
managed device), 13a...newly connected managed device,
30...Packet, SA...Self address, DA
...Recipient address, DATA...Transmission data, 3
1...ACK (acknowledge signal), 32...Next packet, P _B1 ...Registration packet, P _B2 ...Registration confirmation packet.

Claims (1)

[Scope of Claims] 1. A plurality of managed devices and a management device that manages the addresses of each of these managed devices are connected to each other via a transmission path, and each of the managed devices and the management device has a transmission path. A method used in a network configured to transmit data between a managed device and a managed device, and between managed devices, using packets sent to each of the managed devices. comprises an address duplication detection means for detecting whether an address of a newly connected managed device overlaps with an address of a managed device already connected to the transmission path, and the address duplication detection means The means is to determine whether a response packet outputted from the management device in response to the registration packet by the management device receiving a registration packet transmitted due to a new connection of the managed device corresponds to the transmission of the registration packet. A method for detecting duplicate addresses on a transmission path, characterized in that if a response packet is received while a registration packet has not been sent, the reception of the response packet is determined to be an address duplication. 2. A plurality of managed devices and a management device that manages the addresses of these managed devices are connected to each other via a transmission path, and packets sent from each of the managed devices and the management device to the transmission path,
A method used in a network configured to transmit data between managed devices and managed devices, and between managed devices, in which each managed device is connected to a newly connected managed device. The address duplication detection means detects whether or not the address of the device overlaps with the address of the managed device already connected to the transmission path. When a new connection is made to a device, it sends a dummy packet with its own address set as the destination, checks whether a response packet to this dummy packet is returned from the previously connected managed device, and checks if the response packet is returned. A duplicate address detection method for a transmission path, characterized in that, if a response packet is returned to a managed device that is a sender, reception of this response packet is determined as an address duplication.