JPH02301248A - Network system - Google Patents

Abstract

PURPOSE:To prevent the occurrence of transmission of an undesired data to a branch network to which no communication party belongs by providing a group address registration means to register a group address assigned to branch networks. CONSTITUTION:When a group address is registered in a group address registration means, header information whose destination address field is set with the group address is added to a frame data sent from nodes 14-1, 14-8 on branch networks 13-1, 13-8 and the resulting data is sent to a trunk line network 11. Then the sent data is received in a network adaptor 15 in which the group address is registered in the group address registration means when the group address and the content of the destination address field of the sent data are coincident and not received when they are dissident. Thus, only a network adaptor 15 receiving the data sends the required part of the data to the connected branch networks 13-1, 13-8.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention relates to a network system in which a branch network is connected to a main network by a network adapter of a station, and particularly relates to a network system in which a branch network is connected to a main network by a network adapter of a station, and in particular, a network system in which a communication partner is determined in advance. The present invention relates to a communication method suitable for cases where

(Prior Art) In a network system in which a branch network is connected to a trunk network by a station network adapter, the network adapter constantly receives data (frame data) on the connected branch network.

The frame data format generally applied in network systems includes a destination address field DA, a source address field SA, and a data field DATA, as shown in FIG. 6(a). When the frame shown in FIG. 6(a) is transmission data on a branch network (segment), the field DA contains an individual address indicating the destination for individual communication as shown in FIG. 6(b). The destination node address (address of the destination node) is, or the broadcast address for broadcast communication (hereinafter referred to as broadcast address) as shown in FIG. 6(c).
is set, and the source node address is set in field SA.

When the network adapter receives frame data from the branch network, it checks whether the source node address set in the field SA is registered in the address translation table. This address conversion table is used to register address information including a pair of a node address and a segment address indicating the branch network to which the node to which this node address is assigned belongs. If it is not registered, address information including the pair of the source node address and the segment address of the connected branch network,
For example, it is registered in the entry of the address translation table corresponding to the node address using the hash method. The network adapter also uses field D of the received frame data.
Check A, and if the destination node address is set in the same field DA, check whether this node address is registered in the address translation table (and if so, which branch network it is connected to). ).

If the destination node address is not registered, the network adapter registers the field DA where the broadcast address is set and the address of the connected branch network (own segment) (source segment address), as shown in Figure 6(d). ) is set, and a data field DATA is set with the received frame shown in FIG. 6(b). Frame data is generated and sent onto the trunk network. On the other hand, if the destination node address is registered, and therefore if the segment address (destination segment address) indicating the branch network to which the destination node belongs is registered (as a pair with the node address), the network adapter , 6th
As shown in Figure 6(e), field DA is set with the destination segment address, field SA is set with the address of the connected branch network (own segment) (source segment address), and field SA is set as shown in Figure 6(b). Frame data consisting of a data field DATA set with the received frame shown is generated and transmitted onto the trunk network. However, if the branch network indicated by the destination segment address is the connected branch network (own segment), the network adapter discards the received frame and sends it to the trunk network, since this is individual data transmission within the connected branch network. Does not send frames.

If the frame data on the main network has a destination segment address (individual address) set in field DA of the data, it will be received by the network adapter of the station corresponding to the branch network indicated by that address, and a broadcast address will be set. If so, it will be received by the network adapters of all stations connected to the main network. The network adapter registers address information including a pair of the source segment address set in the field SA of the received frame data from the trunk network and the source node address in the field DATA in its own address translation table. Next, the network adapter reads the field DATA of the received frame data.
The content of is sent out onto the connected branch network. Data on this connected branch network will be received by the node at that address if an individual address (destination node address) is set in field DA of the data, and if a broadcast address is set, the data will be received on the connected branch network. Received by all nodes.

Now, the node that has received the data on the connected branch network uses the content of the field SA of the received data as the destination, generates a response frame with its own node as the source, and sends it onto the connected branch network. When the stage network adapter connected to this branch network receives a response frame on the branch network, it checks the address translation table described above.

In this case, the node address indicating the destination node and the connecting branch network of the destination node (i.e. the destination segment)
Address information having a pair of segment addresses indicating the address is registered in the address conversion table. Therefore, the network adapter sets the segment address in the above address information to field DA, its own segment address to field SA, and the data received from the branch network (response frame from the node) to field DATA. 6. A new response frame in the format shown in FIG. 6(e) is generated and sent onto the trunk network. This response frame on the trunk network is received at the network adapter of the station corresponding to the segment indicated by its field DA. When this network adapter receives the above response frame, it checks the source segment address set in the field SA of the frame and the field DATA.
The address information, including the source node address, is registered in its own address translation table.

Therefore, the network adapter that has received the above response frame can send the frame to the trunk network using the individual address when transmitting to the same node from now on.

As mentioned above, according to the conventional communication method using an address conversion table, once a broadcast communication using a broadcast address is performed, the branch network to which the destination node and the same node belong is known from the response frame, and the node Address information including an address and a corresponding segment address can be registered in the address conversion table using the hash method. Therefore, communication using the individual address can be performed with the same node from now on.

However, in the conventional method described above, even in communication between branch networks where the destination node (communication partner) is determined in advance, the first transmission data (packet) to the destination node is -
It is transmitted by broadcast communication, and is transmitted not only to the trunk network but also to all branch networks connected to the trunk network.

(Problem to be Solved by the Invention) As mentioned above, conventionally, data sent to a communication partner (destination node) that is not registered in the address translation table is
Even if this communication partner is predetermined in inter-branch network communication, - Since it is sent to all branch networks by simultaneous broadcast transmission, unnecessary data is also sent to branch networks to which the communication partner does not belong. There was a problem.

This invention was made in view of the above circumstances, and its purpose is to prevent unnecessary data transmission to a branch network to which this communication partner does not belong, when a communication partner is determined in advance in communication between branch networks. The purpose is to provide a network system.

[Structure of the Invention (Means for Solving the Problems) This invention provides a network adapter of each station on a trunk network that communicates with a specific branch line of each node on the branch network connected to its own network adapter. A group address registration means for registering a group address (intra-group broadcast address) mutually assigned to each branch network when the network is limited to each node on the network, and a branch network connected to the own network adapter. If the node address indicating the destination of the frame data sent from the node above is not registered in the address conversion table of the own network adapter, and the group address is registered in the group address registration means, the same address will be used as the destination. If a group address is registered in the first trunk network interface means that adds the header information set in the address field to the transmission frame data and sends it on the trunk network, and the group address registration means, this group When the address matches the content of the destination address field of the frame data transmitted via the trunk network,
a second trunk network interface means for receiving the frame data; and a branch network interface for transmitting a predetermined portion of the frame data received by the second trunk network interface means onto a branch network connected to the own network adapter. The invention is characterized in that it is provided with means.

(Function) According to the above configuration, the node address indicating the destination of frame data sent from a node on the branch network is not registered in the address conversion table, and therefore communication is not performed using individual addresses but is broadcast all at once. Communication is necessary, and furthermore, the communication partners of the nodes on the branch network are limited to nodes on a specific branch network, so the group address (intra-group broadcast address) is registered in the group address registration means. If so, header information in which this group address is set in the destination address field is added to the frame data sent out from the node on the branch network and sent out on the main network. Data sent out on this trunk network is communicated to the network adapters of all stations in the system. The transmitted data is received by the network adapter whose group address is registered in the group address registration means when the group address matches the content of the destination address field of the transmitted data, If they do not match, they will not be received. Then, only the network adapter that has received the data sends a predetermined portion of the data to the connected branch network. That is, according to the present invention, when transmission data from a node on a branch network is sent onto the trunk network for broadcast communication, it is known in advance that the data cannot be a communication partner of the branch network. The data is not received by the network adapter connected to the branch network, and no unnecessary data is sent to the branch network.

(Embodiment) Fig. 1 is a system configuration diagram of a network system according to an embodiment of the present invention, Fig. 2 is a block diagram of the network adapter shown in Fig. 1, and Fig. 3 is a block diagram of intra-group broadcast communication. FIG. 4 is a block diagram of the main part of the ring interface shown in FIG. 2.

In FIG. 1, reference numeral 11 indicates a ring network as a trunk network, and 12-1 to 12-8 indicate stations (ST) on the ring network 11. In FIG.

13-1 to 13-8 are branch networks, such as bus networks, and 14-1 to 14-8 are nodes (N) on the bus networks 13-1 to 13-8.

The nodes 14-1 to 14-8 are terminals, workstations, servers, etc. For example, the node 14-8 is a file server equipped with a disk device, etc.
Reference numeral 4-7 is a client that reads data etc. from the disk device of the node (file server) 14-8.

The bus-type networks 13-1 to 13-8 are connected to network adapters (NA) called ring bus controllers (RBC) provided in the stations 12-1 to 12-8.
) 15 to the ring network 11. Note that the number of network adapters 15 is not limited to one for each station.

Now, in the system of FIG. 1, station 12-1.
Nodes H-1 and 14-2 under station 12-2 access each other, but nodes under other stations do not. Also, station 12-3.
Nodes 14-3 and 14-4 under 12-4 access each other, and nodes 14-3 and 14-4 under stations 12-6 to 12-8 access each other.
-6°14-8 access each other, but nodes under other stations do not.

Therefore, in this embodiment, one group is formed for each station group where mutual access occurs, that is, station 12-1.12-2 forms group 16, station 12-3, 12-4 forms group 17, and so on. Group 18 by stations 12-6 to 12-8,
Each group is formed so that simultaneous broadcast communication can be performed only within the group. In this intra-group broadcast communication, an intra-group broadcast address (group address) is set in the destination address field DA of the transmission frame, as shown in Figure 3, and basically the same address is used. Only stations within the indicated group will receive the data.

This intra-group broadcast address and a predetermined upper part of the broadcast address for normal simultaneous broadcast communication targeting the entire system are broadcast communication specification data indicating broadcast communication, and this predetermined part allows individual addresses and broadcast addresses (
(including intra-group broadcast address), that is, individual transmission and broadcast communication (including intra-group broadcast communication) can be distinguished. On the other hand, groups 16-18
Station 12-5, which does not belong to any of the groups, receives frames transmitted by intra-group broadcast communication in the same way as in normal broadcast communication. The network adapter 15 of the station 12-5 is connected to each station 12-1 to 12-1 on the ring network 11.
, 12-8, and further a monitoring device 19 for system operation of the above groups, etc. is connected.

FIG. 2 shows station 12-1 (i-1) shown in FIG.
8) is a block configuration diagram of the network adapter 15 in FIG. In the same figure, 21 is network adapter 1
22 is a program ROM in which a microprogram for defining the operation of the microprocessor 21 is stored, and 23 is a RAM. The RAM 23 includes an address translation table (ATT) 24 for registering address information including a pair of a node address and a segment address using a hash method based on the node address, as well as a data buffer and a control buffer (not shown). ), etc. will be ensured.

25 is an interface (hereinafter referred to as a ring interface) that performs transmission and reception with the ring type network 11 shown in FIG. 1, and 2B is an interface with the bus type network 13-i (i-1 to i-8) shown in FIG. This is an interface (hereinafter referred to as a bus interface) that performs transmission and reception between devices. The ring interface 25 includes a reception data buffer that temporarily stores reception data from the ring network 11, a transmission data buffer that temporarily stores transmission data from the bus interface 26 (the bus network 13-1 provided via the bus interface 26), and It has a built-in activation circuit (both not shown) for starting transmission to the ring network II and the bus network 13-1. The ring interface 25 further includes a receiving section having a reception determination circuit 25a that determines whether data (frame data) on the ring network 11 can be received.

As shown in FIG. 4, the reception availability determination circuit 25a is connected to the network adapter 1 having a ring interface 25 that includes a circuit 25a that matches the contents of the field DA of frame data transmitted via the ring network 11.
5 and the address of the bus-type network 13-1 connected to it (i.e., its own segment address) to detect a match; A match is detected by comparing the upper parts (the predetermined parts) U and the lower parts of the broadcast address (for broadcast communication within the group to which the corresponding station belongs) or the intra-group broadcast address (for simultaneous broadcast communication within the group to which the corresponding station belongs). Comparator 42.
It has 43. The reception availability determining circuit 25a includes an OR gate (OR) 44 for masking the output signal of the comparator 43 with a mask signal M, and an AND gate (OR) for calculating the logical product of the output signal of the OR gate 44 and the output signal of the comparator 42. AND) 45, and an OR gate (O
R) 4B. The above self-segment address, broadcast address (or intra-group broadcast address), and mask signal M are set when the station is started up.

Referring again to FIG. 2, reference numeral 27 is an interface (hereinafter referred to as a monitoring device interface) for transmitting and receiving data to and from the monitoring device. However, in this embodiment, the monitoring device interface 27 of the network adapter 15 of the station 12-5 among the stations 12-1 to 12-8
Therefore, a monitoring device (19) is connected as shown in FIG. 28 is a non-volatile RAM used for registering information indicating the grouping described above (in-group broadcast address here), and 29 is a microprocessor 21. Internal bus for coupling program ROM 22, RAM 23, ring interface 25, monitoring device interface 27 and non-volatile RAM 2g, 3
0 is ring interface 25 and bus interface 2
31 is an internal bus 29.B for coupling with the internal bus 29.
30 and transmits and receives control signals between the microprocessor 21 and the bus interface 27.

Next, the operation of one embodiment of the present invention will be explained with reference to the flowchart of FIG. 5 as appropriate. First, station 1
2-1 (i-1 to 8) network adapter 15
The microprocessor 21 provided in the station performs the following setup operation according to the program stored in the program ROM 22 when starting up the station. That is, the microprocessor 21 transfers its own segment address (the address of the bus network 13-1 connected to the network adapter 15 of the station 12-1), which is preset by a dip switch or the like, to the ring interface via the internal bus 29. 25 is set in the reception availability determination circuit 25a. The microprocessor 21 also refers to the nonvolatile RAM 28 and
M28 is the broadcast address within the group.

If it is not registered, the system-specific broadcast address indicated by the program stored in the program ROM 22 is set in the reception permission determination circuit 25a, and the mask signal M is set to logic "1". On the other hand, if the intra-group broadcast address is registered in the non-volatile RAM Z8, the microprocessor 21 extracts this intra-group broadcast address and sends it to the reception permission determination circuit 25a instead of the normal broadcast address. At the same time, the mask signal M is set to logic "0". In this embodiment, the group 1B is stored in the nonvolatile RAM 28 in the network adapter 15 of the station 12-1.12-2.
The in-group broadcast address indicating the network adapter 15 of station 12-3.12-4
In the non-volatile RAM 28 in the non-volatile RAM 28, there is an intra-group broadcast address indicating group 17, and in the non-volatile RAM 28 in the network adapter 15 of Suan Yong 12-6 to 12-8, an intra-group broadcast address indicating group 18 is stored. , respectively, are set. Further, it is assumed that no intra-group broadcast address is set in the nonvolatile RAM 2g in the network adapter 15 of the station 12-5. Therefore, in this embodiment, the reception availability determination circuit 25a in the network adapter 15 of the station 12-1, 12-2 is connected to the bus network 13-1.
．． A segment address indicating group 13-2, an intra-group broadcast address indicating group 16, and a logical “
02 mask signal M is transmitted to station 12-3.12-
Receivability determination circuit 2 in the network adapter 15 of No. 4
5a includes a bus network 13-3. The segment address indicating group 13-4, the intra-group broadcast address indicating group 17, and the mask signal M of logic "0" are sent to the reception permission determination circuit 25a in the network adapter 15 of the station 12-5 via the bus network 13-5. , a broadcast address unique to the system, and a mask signal M of logic "1", and the reception permission determination circuit 25a in the network adapter 15 of the stations 12-6 to 12-8 is connected to the bus network 13-6. The segment address indicating 13-8, the intra-group broadcast address indicating group 18, and the mask signal M of logic "0" are
Each is set.

With the above station startup completed, for example, node 1 (below station I2-8) in group 18
4-8 is in the same group 18 (station 12-
Assume that data is to be transmitted to node 14-6 (below node 14-6). In this case, the destination address field DA contains node 14.
-6 is set, and the node address of node 14-8 is set in the source address field SA, frame data in the format shown in FIG. 6(b) is sent from node 14-8 via bus Network 1
3-8.

The frame data on this bus type network 13-8 is received by the bus interface 26 provided in the network adapter 15 of the station 12-8, and sent via the internal bus 30 to a transmission data buffer (not shown) in the ring interface 25. temporarily stored. When the operation of storing the received frame data in the transmission data buffer is completed, the microprocessor 21 is notified of this (reception completion notification) via the bus controller 31.

When the microprocessor 21 receives the completion notification from the bus interface 26 via the bus controller 31,
Ring interface 25 (transmission data buffer within)
The content of the source address field SA (source node address) in the received frame data from the bus network 13-8 stored in the bus network 13-8 is extracted. The microprocessor 21 then retrieves the source node address (
It is checked whether the address information (with address information) is registered in the address conversion table 24 in the RAM 23 (step Sl). If the microprocessor 21 is not registered, the microprocessor 21 generates address information including a pair of a source node address (here, the node address of the node 14-8) and its own segment address (the address of the bus network 13-8). is registered in the entry of the address translation table 24 corresponding to the node address using the hash method (step S2).

Next, the microprocessor 21 extracts the contents of the destination address field DA in the received frame data from the bus network 13-8 stored in the ring interface 25 (transmission data buffer therein). Then, the microprocessor 21 determines that if the content of the retrieved field DA is the destination node address (in this case, the node address of the node 14-6), this node address (address information having it) is registered in the address conversion table 24. It is checked whether or not (steps S3 and S4).

The operation up to this point is the same as the conventional one.

Now, the destination node address set in field DA of the received frame data is
If the address is not registered in the non-volatile RAM 28, the microprocessor 21 refers to the non-volatile RAM 28 and determines whether the in-group broadcast address is registered in the RAM 28 (that is, the corresponding station 12-8 belongs to one group). Check (step S5)
. If the intra-group broadcast address is registered as in this example, the microprocessor 21 proceeds to step S6 and transmits the received frame data to all stations belonging to the group indicated by the intra-group broadcast address via intra-group simultaneous broadcasting. What should be done is header information in which the intra-group broadcast address indicating the group 18 registered in the non-volatile RAM 28 is set in the field DA, and the own segment address (address of the bus network 13-8) is set in the field SA. generate. The microprocessor 21 then receives the generated header information from the node 14-8 (destination is the node 14-6) of the bus network 13-8, which is stored in the ring interface 25 (transmission data buffer therein). It is added to the frame data, and then requests the ring interface 25 to start transmitting to the ring network 11.

As a result, transmission frame data for broadcast communication within a group (here, within group 18) in the format shown in FIG. is sent. In addition, non-volatile RAM
If the intra-group broadcast address is not registered in 28, the process proceeds to step S7, where the received frame data is processed into transmission frame data for normal broadcast communication in the format shown in FIG. type network II.

Next, reception of frame data for intra-group 18 broadcast communication transmitted on ring network II will be explained. The frame data for simultaneous broadcast communication within the group 18 in the format shown in FIG. ~12-7 is transmitted to the ring interface 25 in the network adapter 15. The reception determination circuit 25a in each ring interface 25 of the stations 12-1 to 12-7 is set in advance based on the contents of the field DA of the frame data transmitted via the ring network 11 and the setup described above. A comparison is made with the own segment address and the broadcast address (or in-group broadcast address), and it is determined whether or not the frame data should be received according to the comparison result. The specific operation of this reception availability determination circuit 25a will be explained below.

First, the comparator 41 in the reception determination circuit 25a compares the contents of the field DA of the frame data with its own segment, and outputs a logic "1" signal only when the two match. Further, the comparators 42 and 48 in the reception availability determination circuit 25a compare the field DA of the frame data.
content and broadcast address (station 12
-5) or in-group broadcast address (stations 12-1 to 12-4, 12-6 to 1)
2-7) in the case of the reception availability determination circuit 25a in the ring interface 25).
The U's and the lower parts are compared, and a logic "1" signal is output only if they match. The output signal of the comparator 43 (comparison result of the lower part) is supplied to the OR gate 44 together with the mask signal M.

If the mask signal M is logic "1" (in the case of the reception availability determination circuit 25a in the ring interface 25 of station 12-5), the OR gate 44 outputs logic "1" regardless of the state of the output signal of the comparator 43. Outputs the signal. That is, in the case of M-1, the comparison result between the contents of the field DA of the frame data and the lower part of the broadcast address by the comparator 43 is masked. On the other hand, if the mask signal M is logic mO' (station 12-
1 to 12-4 and 12-6 to 12-7), the OR gate 44 outputs a signal that matches the state of the output signal of the comparator 41.

The output signal of this OR gate 44 can be supplied to an AND gate 45 together with the output signal of the comparator 42. and gate 4
5 outputs a logic "1" signal indicating coincidence detection only when the output signals of the comparator 42 and the OR gate 44 are both logic "1".

In this way, if the mask signal M is "1", and therefore if a broadcast address is set in the reception permission determination circuit 25a, the content of the field DA of the frame data and the upper part U of the broadcast address are
If only they match, the output signal of the AND gate 45 becomes logic "1".

Therefore, not only when the content of the field DA is a broadcast address, but also when it is an address within a group, the output signal of the AND gate 45 is a logic "1".
". On the other hand, if the mask signal M is "0°," and therefore if the intra-group broadcast address is set in the reception permission determination circuit 25a, the contents of the field DA of the frame data and the intra-group broadcast address Only if the broadcast addresses match exactly,
The output signal of the AND gate 45 becomes logic "1".

The output signal of AND gate 45 is supplied to OR gate 46 together with the output signal of comparator 41. Orgate 46 is
Only when either the output signal of the AND gate 45 or the output signal of the comparator 41 is logic "1", a logic "1" signal indicating reception is possible is output.

Logic "1" is output from the OR gate 46 of the reception availability determination circuit 25a.
” is output, the receiving unit in the ring interface 25 receives the frame data on the ring network 11 and stores it in the received data buffer in the same interface 25. In this embodiment, the network 11 is An intra-group broadcast address indicating group 18 is set in field DA of the frame data in the format shown in FIG. 12-6.12
-7, and only the ring interface 25 in station 12-5, which does not belong to any group. i.e. group 18
The above frame data is not received by the ring interfaces 25 in the stations 12-1 to 12-4 that belong to a different group (groups 16 and 17).

Now, when the ring interface 25 completes the storing operation of the above received frame data, the microprocessor 2
1 to that effect. microprocessor 21
When receiving the completion notification from the ring interface 25, the data field DAT of the received frame data from the ring network 11 (see FIG. 3) stored in the ring interface 25 (in the received data buffer)
Extract the source node address contained in A. The microprocessor 21 then checks whether the extracted source node address (address information having it) is registered in the address conversion table 24 in the RAM 23. If it is not registered, the microprocessor 21 sets the source node address (in this case, the node address of the node 14-8) and the source address field SA of the received frame data from the ring network 11. Address information including a pair of segment addresses (addresses of the bus network 13-8) is registered in the entry of the address translation table 24 corresponding to the node address using the hash method. If the source node address is registered, the microprocessor 21 converts the segment address registered in the corresponding entry of the address translation table 24 to the source node address of the received frame data to Rewrite to the segment address set in address field SA.

Next, the microprocessor 21 determines whether the address indicating the destination included in the data field DATA of the received frame data (see FIG. 3) from the ring network 11 is a node address (destination node address). If it is a node address as in this example, it is checked whether the same address (address information having it) is registered in the address translation table 24. If it is not registered, the microprocessor 21 extracts the contents of the destination address field DA of the received frame data, and determines whether the contents are a broadcast address (including an intra-group broadcast address) or a destination segment address (individual address). Check whether As in this example, in the case of an intra-group broadcast address, the microprocessor 21 reads the header information (fields DA, SA) in the received frame data from the ring network 11 stored in the ring interface 25 (receive data buffer). part) is deleted, and the same data (see FIG. 3) is converted into data for the bus type network 13-1 in the format shown in FIG. 6(b). This also applies when the content of the DA is a normal broadcast address. On the other hand, if the content of the DA is a destination segment address, the address information having the pair of the destination node address and the content of the DA (destination segment address) is stored in the address translation table 2.
4, the above data conversion is performed. Note that the above destination node address is in the address translation table 24.
If the data is registered in , the above data conversion will be performed immediately.

When the microprocessor 21 performs the above conversion, a notification to that effect is sent to the bus interface 2 via the bus controller 31.
B is notified. As a result, the bus interface 2B transfers data from the ring interface 25 (receiving data buffer therein) from which the header information has been deleted (i.e., the data from the node 14).
-6 as the destination and the node 14-8 as the source) is taken out via the internal bus 30 and sent to the bus network 13-1. In this example, source node 14-
station 12-8.17 belonging to the same group 18 as station 12-8 to which 8 is connected (via bus network 13-8), and only station 12-5 which does not belong to any group in the system. ,
In group 18 from ring network 11 -
Since frame data for broadcast communication is received, the field DATA part of the frame data (node 1
4-6 as the destination and the node 14-8 as the source) is sent by the bus interface 2B of the ring interface 25 in the stations 12-5 to 12-7.
It is sent only to bus networks 13-5 to 13-7, and not to bus networks 13-1 to 13-4.

Now, the data sent to the bus networks 13-5 to 13-7, whose destination is the node 14-6 and whose source is the node 14-8, is sent only by the node 14-6 on the bus network 13-6. Received. Node 14-6
Upon receiving the above data addressed to itself, node 14-
8 as the destination and the node itself (node 14-"8) as the source, in the format shown in FIG.
Send upward. Frame data on this bus network 13-B is received by the bus interface 26 in the network adapter 15 of the station 12-6 and stored in the ring interface 25. When this receiving operation is completed, the bus type network 1 by the ring interface 25 of the station 12-8 is
The same process as when receiving data from 3-8 (see the flowchart in FIG. 5) is performed. However, in this case, the content of the destination address field DA in the received frame data (response frame data) from the bus network 13-6, that is, the node address (address information having) indicating the destination node 14-8 is stored in the address conversion table 24. Since it is registered in , the process advances from step S4 to step S8. In this step S8, after the segment address (segment address of the bus network 13-8 to which the node 14-8 is connected) that forms a pair with the node address of the destination node 14-8 is extracted from the address conversion table 24, This segment address is set in field DA, and the own segment address (bus type network 13-6
Header information is generated in which the segment address) is set in the field SA. Then, the node 1 of the bus network 13-6 in which this header information is stored in the ring interface 25 (in the transmission data buffer)
New response frame data added to the received frame data from 4-6 (with node 14-8 as the destination) is generated, and the response frame data on ring network 11 that is sent onto ring network 11 is ,
Since the destination segment address indicating the bus network 13-8 is set in the field DA,
It is received only by ring interface 25 in network adapter 15 of station 12-8. In this case, the microprocessor 21 in the network adapter 15 of the station 12-8 uses the source segment address (here, Bus type network 13
-6 segment address) and field DA
Address information including a pair of source node addresses in the TA (here, the node address indicating the node 14-6 on the bus network 13-6) is registered in its own address translation table 24. As a result, from now on, node 14-6
, the ring interface 25 of the station 12-8 uses the segment address (to which the node 14-6 is connected) that is registered in the address translation table 24 as a pair with the node address of the node It becomes possible to send frame data to the ring network 11 by specifying an individual address using the segment address of the bus network 13-6, and intra-group broadcast communication is no longer performed.

Note that the registration of broadcast addresses within a group to the nonvolatile RAM 2g by grouping is performed by the monitoring device 1.
This can be done from 9. Therefore, system changes and expansions can be made freely. For example, if a group 16 is to be formed by stations 12-1, 12-2, the monitoring device 19
frame data addressed to station 12-1.12-2, whose field DATA contains group 16
frame data in which information requesting the setting of an intra-group broadcast address indicating the address is input, and the frame data is sequentially transmitted from the network adapter 15 of the station 12-5 to the ring network 1.
Send on 1. This ensures that if station 12-
If the data is addressed to station 1, the data is sent to station 12.
-1 received by network adapter 15 in
The microprocessor 21 in the network adapter 15 registers the intra-group broadcast address in the received data in the nonvolatile RAM 2g.

Although the above description has been made regarding the case where the present invention is implemented in a system using a bus network as a branch network, the present invention is not limited to this, and the present invention can be similarly applied to a system using a ring network or a star network. .

[Effects of the Invention] As detailed above, according to the present invention, it is necessary to transmit data from a source node using broadcast communication in communication between branch networks in which communication partners are determined in advance. In this case, the same data is transmitted within a group by using a group address (intra-group broadcast address) unique to the group to which the mutual communication branch networks commonly belong, rather than a conventional broadcast address, as the destination address. In addition, each station's network adapter transmits the same data as data on the trunk network if the group address in the data on the trunk network matches the group address specific to the group to which it belongs. network adapters of stations in different groups,
In other words, the above-mentioned data (data for intra-group broadcast communication) will not be received by a network adapter connected to a branch network that is known in advance to be a partner for inter-branch network communication. Unnecessary data transmission to the connected branch network can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a network system according to an embodiment of the present invention, FIG. 2 is a block configuration diagram of the network adapter shown in FIG. 1, and FIG. 3 is a frame data diagram for intra-group broadcast communication. FIG. 5 is a flowchart for explaining the operation, and FIG. 6 is a diagram showing the general format of frame data. 11...Ring network (trunk network)
, 12-1 to 12-8...station (ST),
13-1 to 13-8... Bus type network (branch network adapter (NA), 16 to W... Group, 19... Monitoring device, 21... Microprocessor, 22... Program ROM , 24...Address translation table (ATT), 25...Ring interface, 25a...Reception availability determination circuit, 26...Bus interface, 27...Monitoring device interface, 2
8...Nonvolatile RAM (group address registration means), 41-43...Comparator, M...Mask signal. Applicant's agent Patent attorney Takehiko Suzue 11 Ring-type network/work
15 ・Network adapter 12-1-12-8-
Station 19° Monitoring device 13
-1 to 13-8... Bus type network Figure 1 Figure 2 Figure 3 Frame data Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] A plurality of stations interconnected by a trunk network, and independent branch networks respectively connected to the trunk network via network adapters of the stations, each network adapter having a node address. In a network system that is provided with an address conversion table for registering address information including a pair of segment addresses indicating the branch network to which the node to which this node address is assigned belongs, each of the above network adapters is connected to its own network adapter. group address registration means for registering group addresses mutually assigned to branch networks when the communication partner of each node on the branch network is limited to each node on the specific branch network; and the node address indicating the destination of the transmission frame data from the node on the branch network connected to the local network adapter is not registered in the address conversion table, and the group address is not registered in the group address registration means. If the address is registered, the first trunk network interface means adds header information in which the same address is set in the destination address field to the transmission frame data and sends it onto the trunk network; and the group address registration means. If the above group address is registered in A network interface means; and a branch network interface means for transmitting a predetermined portion of the frame data received by the second trunk network interface onto the branch network connected to the own network adapter. network system.