JPH0254986B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention utilizes an adapter of a device in a LAN (Local Area Network) communication system,
The present invention relates to a group address communication system that has the ability to flexibly transfer data to multiple arbitrary devices at the same time.

[Conventional technology]

Recently, LAN (Local Area Network) systems such as Xerox's Ethernet,
network) communication method is used. That is, within a relatively limited area, as shown in FIG. 3, terminal devices such as office processing (OA) equipment 1 to 5 are connected to the common bus 6 in a chain-like manner. When sharing such a common bus, there are usually many methods, such as a method that grants exclusive rights under the control of a higher-level device, or a method that gives priority to use based on the response to an inquiry signal, but all of these methods require control of the higher-level device. be. In contrast, the LAN communication method does not require control from a higher-level device, and each device autonomously detects and confirms the signal state of the common bus.
One example of this is the
There is a CSMA/CD (carrier sense multiple access collision detection) method.
That is, when making a call, it is checked by an adapter provided in each device connected to the network whether or not another device is transmitting. If no other device is transmitting, it starts transmitting to the other party and monitors for a certain period of time whether or not the other device's transmission appears, and detects whether or not there is a collision of transmission carriers.

If a collision occurs, retransmission is performed after an appropriate time that varies depending on the device. In this way, the dedicated time for the common bus can be obtained and desired data transfer can be performed.

In this case, the adapter of the LAN originating terminal can of course access the addresses of each other terminal, but it is also possible to perform so-called broadcasting, which allows access to all other terminals simultaneously.

[Problem that the invention seeks to solve]

When the above LAN communication method is applied to transaction devices and OA equipment, data can be sent from a sending terminal to each terminal separately or to all terminals, but rather data can be sent to a group of combined terminals depending on the purpose. There are many cases where it is desired to send other data to a different combination of terminals. In such cases, in the past, each terminal had to be selected and sent one by one, which was time consuming and inefficient.
In this way, it has been difficult to deal with cases where the combination of destination terminals changes flexibly depending on the purpose and use of data from the originating terminal.

An object of the present invention is to provide a group address communication system that uses a device adapter in the LAN communication system and has a function of flexibly transferring data to any plurality of devices at the same time.

[Means for solving problems]

In order to achieve the above object, the group address communication system of the present invention includes a plurality of devices connected to a common bus within a relatively limited area, and the devices detect the state of the common bus and the collision of signals. In a local area network communication system that includes an adapter that has the function of dedicating a common bus, accessing each device individually, and accessing all devices at the same time, one transmission data sent from the adapter. By setting a group address that collectively indicates multiple addresses that are to be grouped together in a frame and sending it out on the local area network, each device that receives this transmission data frame can connect to the adapter. Therefore, when a self-address is detected in this frame, the transmitting device sets itself as a member of the group address, and transmits subsequent data addressed to the group address using the set group address. It is characterized by:

[Effect]

With the above configuration, the adapter of the LAM transmitting device sets a group address to a device with multiple addresses on the first access, then accesses with this group address to transfer data, and then releases it after the transfer is completed. do. In this way, data can be flexibly transferred to multiple devices in any combination at the same time.

〔Example〕

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention,
FIGS. 2A and 2B are explanatory diagrams of the operation.

In FIG. 1, the configuration of terminal devices 1 to 5 includes LAN adapters 1 ₁ to 5 ₁ each containing hardware for accessing a local network, and frame control programs (FCP) 1 ₂ to 5 _{2 .}
is the program that controls it. The LAN adapter internally has one individual address PA and eight group addresses GA. This group address GA consists of four fixed addresses and four variable addresses, and is used to handle data frames flowing on the network. If the destination address matches one of these addresses that it owns, it has a function to capture this frame. Four fixed addresses among the group addresses GA are set during initial program setting (iPL). The remaining four variable addresses are flexibly set as one of the groups upon request from the higher-level program.

In the same figure, if the individual addresses PA of terminal devices 1, 2, ..., 5 are #10, #20, ..., #50, respectively, then device 1 in #10 is now connected to devices 2, 4 in #20, #40. The procedure for setting a group with group address GA#100 will be explained using FIG. 2.

Figures 2 through 4 show the procedure from GA assumption to release, and the frame formats sent in each procedure are shown on the right.

The frame format starts with the destination address.
DA, then your address SA, and a data section below. By setting all "1"s in the destination address DA, the data frame is broadcast, that is, the data frame is sent to all other devices. In contrast, the present invention uses multicasting, that is, the same data frame is flexibly sent only to devices in a desired combination group, and released after completion.

Data line in Figure 1 ~ and procedure in Figure 2 ~
are shown correspondingly. In other words, for device 1 in #10, enter the individual addresses #20 and #40 of the devices you want to group in the data section of the frame, and
Set address #100 for that group and broadcast (DA=all “1”)
Send with . This data path is shown by cross-hatched data lines.

Each device takes in the broadcast data frame, and if its own individual address is not specified as a group like #30 or #50, it will be ignored and will not respond, and if it is specified like #20 or #40. In this case, the applicable device sets group address GA#100 in the variable group address setting area,
Return response to #10. This data path is shown by a diagonally hatched data line.

Group address GA to destination address DA
By setting #100 and transferring data, multicast data is accessed only to #20 and #40. This is shown by a blank data line.

After the above multicast ends, a frame notifying group release, that is, the data part is blank, is sent by broadcast (DA = all "1"), and group #100 of #20, #40 is sent.
release.

〔Effect of the invention〕

As explained above, according to the present invention, the LAN
The first access from the adapter of the transmitting device sets a group address for devices with multiple addresses, then accesses with this group address to transfer data, and releases it after the transfer is completed.
This allows you to flexibly set/set group addresses.
Since it can be changed, a certain device can belong to various groups depending on its purpose and use. Furthermore, in the case where the combination of groups is variable, it is possible to send items at the same time, which would otherwise be unavoidable than sending them sequentially, thereby improving transfer efficiency.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, Fig. 2 is an explanatory diagram of operation showing the procedure of the embodiment, and Fig. 3 is an explanatory diagram of the configuration of an embodiment of the present invention.
This is a general explanatory diagram of a LAN. In the figure, 1 to 5 are terminal devices, 1 ₁ to 5 ₁ are LAN adapters, 1 ₂ to 5 ₂ are frame control programs, 6 is a common bus, PA is an individual address, and GA is a group. Indicates address.

Claims (1)

[Claims] 1. A plurality of devices connected to a common bus within a relatively limited area, and the device has a function of detecting the state of the common bus and signal collision to dedicate the common bus. In a local area network communication system that includes an adapter that has the function of accessing each device and simultaneously accessing all devices, arbitrary data that is to be grouped in one transmission data frame sent from the adapter is provided. By setting a group address that collectively indicates multiple addresses and the group and sending it out on the local area network, each device that receives this transmission data frame will have its own address written in this frame by the adapter. When detecting a group address, the transmitting device sets itself as a member of the group address, and the transmitting device transfers subsequent transmission data addressed to the group address using the set group address. .