JPH0710070B2 - Data transfer device between networks - Google Patents

Description

TECHNICAL FIELD The present invention relates to a data transfer device between networks.

[Prior Art] First, a conventional data transfer between networks will be described with reference to FIGS. 6 to 18.

FIG. 6 is a block diagram of the entire conventional network. In the figure, (1) is connected to network 1 (hereinafter NT1), (2) is connected to network 2 (hereinafter NT2), and (3) is connected to NTI (1). Station b, (4) is station a connected to both NT1 (1) and NT2 (2), and (5) is station c connected to NT2 (2). Next, FIG. 7 (a) is a memory area diagram of a link device 1 (6) for storing control information of station a (4) and station b (3) in the related art, and FIG. 6 is a memory area diagram of a link device 2 (7) storing control information of station a (4) and station c (5) in FIG. In FIG. 7 (a), (8) is a memory area for storing control information of station a (4), and (9) is a memory area for storing control information of station b (3). Further, (10) in FIG. 7 (b) is a memory area for storing the control information of the station a (4),
(11) is a memory area for storing control information of the c station (5).

FIG. 8 is a detailed block diagram of station b (3) in the conventional apparatus. In the figure, (12) is a controlled section controlled by the b station (3), (13) is a user processing means for controlling the controlled section (12) of the B station (3), and (14) is a b station (3). ) And a network control means 1 (15) as a first network control means for performing a data link with another station have a link device 1 (6) in a memory area, and the user control means 1 (13) also controls the network. The storage means 1 is a first storage means that can be accessed from the means 1 (14). Further, FIG. 9 is a detailed configuration diagram of the station a (4) in the conventional apparatus. In the figure (1
6) is a controlled unit controlled by the a station (4), (17) is user processing means 2 for controlling the controlled unit, and (18) is network control means 2, (19) for performing data link of NT1 (1). ) Is NT2
Network control means 3 for performing the data link of (2),
(22) is a link device 1 (6) and a link device 2
The inter-network data transfer processing means A, (23) for performing data transfer with the (7) according to a predetermined procedure is composed of the user processing means 2 (17) and the inter-network data transfer processing means A (22). Programmable controller (hereinafter referred to as pc), (20) is the link device 1
The storage means 2, (21), which is the second storage means having (6) in the memory area and accessible by both the pc (23) and the network control means 2 (18), stores the link device 2 (7) in the memory area. The storage means 3 is a third storage means that can be accessed by both the pc (23) and the network control means 3 (19).

FIG. 10 is a block diagram based on the hardware configuration of station b (3) in the conventional apparatus. In the figure, (45) is NT
1 Input signal from (1) to station b (3), (46) is output signal from station b (3) to NT1 (1), (47) is CPU of programmable controller pc (43), (48) Is the system program memory where the system program is stored,
(49) is a user program memory in which a user program is stored, (50) is a data memory used for a work area, etc. (51) is output information to the controlled part (12) and from the controlled part (12). It is an I / O memory for storing input information. (52) is the CPU of the network control means 1 (14), (5
3) is a system program memory in which the system program is stored, (54) is a data memory used for a work area, etc., (55) is a transmission controller for transmitting transmission data to NT1 (1), (56) NT1 (1 ) Is a receiving controller that receives the received data from

FIG. 11 is a block diagram based on the hardware configuration of station a (4) in the conventional apparatus. In the figure, (24) is NT1
Input signal from (1) to station a (4), (25) is output signal from station (4) to NT1 (1), and (26) is NT2 (2)
Signal from station a to station (4), (27) from station a (4)
This is the output signal to NT2 (2). Further, (28) is the CPU of the programmable controller pc (23), (29) is the system program memory in which the system program is stored,
(30) is a user program memory in which a user program is stored, (31) is a data memory used for a work area, etc. (32) is output information to the controlled unit (16) and input from the controlled unit (16) An I / O memory for storing information. Furthermore, (33) is the network control means 2 (18)
The CPU (34) is the system program memory of the network control means 2 (18), and (35) is the network control means 2
A data memory used by the CPU (33) of (18) as a work area, etc., (36) a controller for sending data to the NT1 (1), and (37) receiving data input from the NT1 (1). It is a receiving controller. Also, (38)
Is a CPU of the network control means 3 (19), (39) is a system program memory of the network control means 3 (19),
(40) is a data memory used as a work area,
Reference numeral (41) is a transmission controller for transmitting data to NT2 (2), and (42) is a reception controller for receiving data input from NT2 (2).

FIG. 12 is a block diagram showing an example of the overall configuration of data transfer between networks in a conventional device, and shows an example in which the number of stations in each network shown in FIG. 6 is increased. First
In Fig. 12, (58) is the network 1a, (59) is the network 2a, and (60) is the two networks (58), (5).
It is station A connected to 9) and configured to transfer data between two networks (58) and (59) as shown in FIGS. 9 and 11. (61) to (66) are B station, C station, D station, E station, and G station having the configurations shown in FIGS. 8 and 10. In the example of FIG. 12, the network 1a (58) is the common station A station (6
0), B station (61), C station (62), D station (63), which is a common station of network 2a (59).
0), E station (64), F station (65), G station (66).

Next, in order to clarify the contents of the prior art, the network control means 1 (14) and the network control means provided in each of the stations A (60) to G (66) in the network shown in FIG. 2 (18) and the operation of the network control means 3 (19) will be described, and the information transmission method in the network 1a (58) and the network 2a (59) will be described. Since the information transmission method in the network 1a (58) and the information transmission method in the network 2a (59) are the same, the network 1a (58) will be described. The station A (60) has a storage means 2 (20) as shown in FIGS. This storage means 2 (20) is the network control means 2
It is connected to (18) and pc (23) and can be accessed from the pc (23) side as well as from the network control means 2 (18). Similarly, stations B (61) to D (63) have storage means 1 (15) that can be accessed by the user processing means 1 (13) and the network control means 1 (14). These storage means 1
(14) and 2 (20) have a link device 1a (67) having the memory area shown in FIG. 13 (a). The memory area of this link device 1a (67) is network 1a (5
8) is divided into the number of stations, and each divided area is allocated to each station and stores input / output information about the controlled device of the station, internal relay information, and the like. The area allocated to the station A (60) includes an area for data transfer between the network 1a (58) and the network 2a (59) in addition to the input / output information and internal relay information about the controlled device. I'm out. In FIG. 13 (a), (68) is the information area of station A assigned to station A (60),
(69) is the information area of station B assigned to station B (61),
(70) is the information area of C station assigned to C station (62),
(71) is the information area of the D station allocated to the D station (63). Each of the stations A (60) to D (63) has a link device 1a (67), and its own information area has a pc of its own station.
Although it can be written by (13) and (23), the information area of another station can be read from its own pc (13) (23) but not written. For example, in the information area (68) of station A, station A (60) can write, but stations B (61) to D (63) cannot write, and station A (60) is station B. Information Area (69) ~ Station D Information Area (71)
Cannot be written to. The A station (60) can read the information area (68) of the A station to the information area (71) of the D station (63). Also, network 1a
The contents of the link device 1a (67) of each station (60), (61), (62), (63) in (58) are controlled so that they are always the same. The communication control method in which each station in the network has the information of all stations in the network in the link device at all times is to increase the memory capacity of the link device in each station or to simplify the communication in the network, resulting in the communication speed. Is a method that is generally widely used because it often improves.

Each station (60), (61), in the network 1a (58)
The operation of making the contents of the link devices 1a (67) of (62) and (63) the same is performed by the network control means 2 (18) in FIGS. 9 and 11 and the network in FIGS. 8 and 10. The control means 1 (14) does this. FIG. 14 is a flow chart showing an example of the operation. In the flowchart of FIG. 14, first, in step (S100), the network 1a
When the data communication in (58) is started, the next step (S1
In 01), the only station (hereinafter referred to as the master station) that has the transmission right among the stations in the network 1a (58) displays the contents of the memory area allocated to the master station of the link device 1a (67) in the network 1a. Send to a station in (58) that does not have the transmission right (hereinafter referred to as a slave station). For example, if the B station (61) is the master station, the contents of the setting range (69) of the B station are the A station (60) and the C station (62).
And to the D station (63). Next, in step (S102), the slave station that receives the data transmitted by the master station in step (S101) becomes the information area of the master station in the memory area of the link device 1a (67) of the own station. Write the received data in the area where it is present. , For example, when the master station is station B (61), station A (60), station C (62), and station D (6
The received data is written in the information area (69) of the B station in the link device 1a (67) owned by 3). Then, in step (S103), it is determined whether the transmission has been completed for all the stations in the network 1a (58). If not, the transmission destination transmitted by the master station in step (S104). Step to change the slave station of another slave station that has not yet transmitted (S1
Return to 01). In step (S103), the network 1a (5
When the transmission to all the slave stations in 8) is completed, the process proceeds to the next step (S105). All stations in network 1a (58) can become master stations with transmission rights,
As shown in the next step (S106), one station in the network 1a (58), which was a slave station until now, is made a master station, and the station which was a master station until now is changed to a slave station. In step (S105), it is determined whether all stations in the network have become master stations and steps (S101) to (S104) have been repeatedly executed. If this condition is not satisfied, step (S10)
Return to 6), network 1a (58), which was a child station until now
Make one of the stations that is not the master station the master station,
Return to step (S101). If the determination condition is satisfied in step (S105), the information transmission in the network 1a (58) is completed. When controlling a factory conveyor line with a transmission line having a transmission speed of 9600 BPS, which is generally used, if the number of stations in one network increases, the information transmission time becomes too long and the control cannot keep up. Therefore, when the number of stations in a factory is large, a method is adopted in which multiple networks are used and control is performed by a relatively large-scale control device such as a factory automation controller. At this time, the amount of information that needs to be communicated between the networks is configured to be smaller than the amount of information that is communicated within the network so that the load on the factory automation controller, etc. is reduced and the processing speed is not slowed down. I have to. In FIG. 12, the pc (23) of the A station (60) plays such a role as the factory automation controller. This is pc when there are two networks and data communication between them is handled.
This is because by providing a function for exchanging between networks, it is often in time without using a factory automation controller.

Next, the operation of the pc (23) in FIGS.
This will be described with reference to the flowchart of FIG. In the network having the configuration shown in FIG. 6, in step (S201), c of pc (23)
The pu (28) executes a control program or the like of the controlled unit (16) that does not include data transfer between networks (hereinafter referred to as user processing), and then in step (S202), the network 1 (1) to the network 2 Data is transferred to (2), data is transferred from the network 2 (2) to the network 1 (1) in step (S203), and then the process returns to step (S201) again for user processing. By repeating the above operation, the station a (4) controls the controlled unit (16) and also the network 1 (1) and the network 2
Data transfer processing during (2) is performed. The 16th
The figure shows an example of the data transfer (401) performed in step (S202). In this example, storage means 1 (20) of station a (4)
The data (L200) to (L219) of the area storing the data to be transferred to the network 2 (2) in the information area (9) of the link device 1 (6) b station of the station a (4)
Of the link device 2 (7) in the storage means 2 (21) of
The data is transferred to the areas (L0) to (L19) of the station information area (8). In this way, when there is information to be transferred to the network 2 (2) among the information in the network 1 (1), this is the information area of the station a of the link device 2 (7) of the network 2 (2). The station c (5) in the network 2 (2) transfers to the link device 2
By reading the information in the information area (10) of station a in (7), network 1 (1) to network 2
Data transfer to (2) is performed. In step (S203) of FIG. 15, from network 2 (2) to network 1
Data transfer to (1) is performed, and the operation is the same as the operation described in step (S202).

In the case of the network having the configuration shown in FIG. 12, the operation of step (S202) is (401-1) (402-
Data transfer, an example of which is shown in 1) and (403-1), is shown in the operation flow chart of FIG.
In step (S301) of FIG. 18, data transfer of (401-1) shown in FIG. 17, specifically, B station of link device 1a (67) in storage means 1 (20) of A station (60). Data (L200) of the area that stores the data to be transferred to the network 2a (59) in the information area (69) of
~ (L219) is the information area (L0) to (L19) of the A station of the link device 2a (72) in the storage means 2 (21) of the A station (60).
Transfer to. In step (S302), the data transfer of (402-1) shown in FIG. 17, specifically link device 1
a (67) C station information area (70) (L360) ~ (L379)
Contents of the link device 2a (72) station A information area (7
Transfer to (L20) to (L39) in 3). Step (S303)
Then, the data transfer of (403-1) shown in FIG. 17, specifically, the information area of the D station of the link device 1a (67) (L4
30) to (L449) of the link device 2a (72) to the information area (73) of the station A (L40) to (L59).

As described above, when there is information to be transferred to the network 2a (59) among the information in the network 1a (58), this is the information area of the station A of the link device 2a (72) of the network 2a (59) ( 73) transfer data to the network
The stations (64), (65), and (66) in 2a (59) read from the information in the information area (73) of station A of the link device 2a (72) to connect from network 1a (58) to network. Data is being transferred to 2a (59). Data transfer from the network 2a (59) to the network 1a (58) in step (S203) of FIG. 15 is performed in the same manner as above.

[Problems to be Solved by the Invention] A conventional inter-network data transfer device is configured as described above, and a PC user processing program in a station connected to both the first network and the second network is used for the network. Since the data transfer processing program between the two is serially incorporated, the data transfer speed between networks depends on the processing time of the user processing program, but when the user processing is completed, the transfer processing in the previous network is not completed Or wait until it ’s done,
Since the data transfer between networks having the same contents as the previous time is performed again, there is a problem that the processing speed of the user processing program becomes slow.

Since the present invention has been made to solve the above problems, it speeds up data transfer between networks and saves time and effort for serially incorporating a program for data transfer between networks into a user processing program. An object of the present invention is to provide an inter-network data transfer processing device that prevents the processing speed of the user processing program of the pc from decreasing due to the effect of the inter-network data transfer processing.

[Means for Solving the Problems] An inter-network data transfer apparatus according to the present invention stores first network control means for performing data link of a network and information of its own station and other stations in the network, A station having a first storage means accessible from one network control means, a first network connecting a plurality of the stations, a second network connecting a plurality of the stations, the first network and the second network Second network control means connected to both of the networks for performing the data link of the first network, third network control means for performing the data link of the second network, its own station and the first network Second storage means for storing information of other stations in the network and accessible from the second network control means; Third storage means for storing information of its own station and other stations in the second network and accessible from the third network control means, and the first storage of a plurality of stations in the first network. Upon completion of the information transmission in which the means are controlled so as to have the same information, respectively, from the first network stored in the second storage means by an interrupt signal generated by the second network control means. By writing the data to be transferred to the second network in the area for writing the information of the own station of the third storage means, the data is transferred from the first network to the second network, and the second network is transferred. When the information transmission is completed in which the first storage means of the plurality of stations in the network are controlled to have the same information, respectively, the third storage means
The data to be transferred from the second network to the first network, which is stored in the third storage means, is written in the information of its own station in the second storage means by an interrupt signal generated by the network control means. And a common station having inter-network data transfer processing means for transferring data from the second network to the first network by writing in the area.

[Operation] In the inter-network data transfer device according to the present invention, the second network control means is generated when the information transmission is controlled so that the storage means of the plurality of stations in the first network have the same information respectively. The data to be transferred to the second network in the second storage means for storing information of the stations other than the common station and the common station in the first network by the embedded signal are transferred to the second station in the common station and the second network. Write in the area for writing information of the common station of the third storage means for storing information of stations other than the common station, thereby performing data transfer from the first network to the second network, and from the second network. Since the data transfer to the first network is performed in the same manner, when the information transfer in the network is completed, another network is automatically Data transfer to the network.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a station (4) in FIG. 6 explained in the conventional example.
The configuration of an embodiment of the present invention corresponding to the A station (60) in FIG. 12 is shown. In Fig. 1 and Fig. 2, interrupt signal line 1 (73) and interrupt signal line 2 (74) are added, pc (2
It is the same as FIG. 9 and FIG. 11 in the conventional example except that there are changes described below in 3). That is, the inter-network data transfer processing device B (75) shown in FIG. 1 is the inter-network data transfer processing means A of the conventional example shown in FIG.
Compared to (22), it has a table pointer (80) and a data transfer table (77), and uses a network control means 2 (18) and a third network control which are second network control means for trigger signals for data transfer between networks. It has a function of receiving data from the network control means 3 (19) as a means and performing inter-network data.

B station (3), c station (5), B station (61), C station (6
2), D station (63), E station (64), F station (65) and G station (66) have the same configurations as shown in FIGS. 8 and 10 in the conventional example.

Next, regarding the operation of the apparatus of this embodiment, FIG.
This will be described with reference to (b) and FIGS. 4 (a), (b) and (c). When the intra-network data communication shown in the flow of FIG. 14 is completed, the network and the work control means 2 (18) or the network control means 3 in FIG. 1 or 2 are completed.
Sends an interrupt signal (73) or an interrupt signal (74) to the pc (76). This interrupt signal causes the inter-network data transfer processing means B (75) to be STAR in the flow chart of FIG. 3 (a).
Set to T (S1) state. The data transfer table (77) shown in FIG. 4 (b) has a data transfer source device address column (7
8) and a data transfer destination device address column (79), and a data transfer source device address column (78) has a data transfer start address (80) and a data transfer end of the link device 1 (6) of the data transfer source. The address (81), the data transfer destination device address column (79), the data storage start address (82) of the link device 2 (7) of the data transfer destination.
Write the data storage end address (83) in advance. At this time, the memory area of the data transfer destination link device 2 (7) designated by the data storage start address (82) and the data storage end address (83) must be within the setting range of the station a (4). The data transfer table (77) is stored in the memory of the pc (76) of the station a (4).

In the flow of FIG. 3A, the table pointer (84) of the data transfer table (77) is cleared in step (S2). Next, in step (S3), it is checked whether the data transfer address information (80), (81), (82), (83) is written at the position indicated by the table pointer (84) of the data transfer table (77). To do. If it is written, the process proceeds to the next step (S4) and the data transfer process is performed.
That is, at the position indicated by the table pointer (84) of the data transfer table (77), the data transfer table (7
The contents of the link device 1 (6) of the data transfer source specified by the data transfer start address (80) and the data transfer end address (81) written in the data transfer source device address column (78) of 7) Information on the data transfer destination a station (4) specified by the data storage start address (82) and data storage end address (83) written in the data transfer destination device address column (79) of the data transfer table (77) Write to the memory area which is the area.

Then, in step (S5), the table pointer (8
In step (S3) which counts up 4) and returns to step (S3), data transfer address information (80), (81), (8) is set at the position indicated by the table pointer (84).
If 2) and (83) are not written, the data transfer ends.

FIG. 4 shows the contents of the addresses (L200) to (L219) where the information for data transfer to the link device 2 (7) in the information area of station b of the link device 1 (6) is stored in the data transfer destination. An example of storing at addresses (L0) to (L19) in the information area of the station a of the link device 2 (7) is shown. In this example, an example of data transfer from the link device 1 (1) to the link device 2 (2) is shown, but the link device 2 (2) to the link device 1
Also in the case of data transfer to (1), the inter-network data transfer processing program is activated by the in-network information transfer completion signal of the network 2 (2) and processed in the same manner.

FIG. 5 shows the data transfer table (77) used in the data transfer between networks shown in FIG. 12 and FIG.
The case where data transfer is performed between the link device 1a (67) and the link device 2a (72) is shown. In the figure, in the information area (86) of the station B of the link device 1a (67), the contents of the addresses (L200) to (L219) where the information to be transferred to the link device 2 (72) is stored, and the link device The contents of the addresses (L360) to (L379) where the information to be transferred to the link device 2a (72) is stored in the information area (87) of the station C of 1a (67), and the link device
Link device in information area (88) of station D in 1a (67)
The contents of addresses (L360) to (L379) where the information for data transfer is stored in 2a (72) and the link device 1a (6
Link device 2a (7) of station D information area (88)
2) Address where the information to be transferred is stored (L
430) ~ (L449) and the link device 2 of the transfer destination
Address (L0) to (L of the information area (85) of station A of a (72)
19), address (L20) to (L39), address (L40) to
An example of storing the data in (L59) is shown.

From network 2a (72) to network 1a (67)
Data transfer to the network 2a (72) is similarly processed by starting the inter-network data transfer processing program from the network 2a (72) to the network 1a (67) by the in-network information transmission completion signal of the network 2a (72).

As described above, bidirectional data transfer between networks is possible, and in addition, station a (4) or station 12 in FIG.
The pc (72) of the A station (60) in the figure does not need to insert the user processing program and the data program between serial networks, and the operation flow is only the user processing of step (S10) shown in FIG. 3 (b). .

In the above embodiment, the case where the station connected to both the first network and the second network is configured by using pc is shown, but it may be configured by using the factory automation controller instead of pc. The same effect as that of the above embodiment is obtained.

Further, in the above embodiment, the first network is composed of two or four stations including the common station, and the second network is also composed of two or four stations including the common station, but the stations connected to the first network. , And the number of stations connected to the second network may be arbitrary.

Further, although two networks are connected to the common station in the above embodiment, the same effect can be obtained even if an arbitrary number of networks of two or more are connected.

[Effects of the Invention] As described above, according to the present invention, when the information transmission in the first network or the second network is completed, an interrupt process is activated in the common station to perform data transfer between networks. Since the data transfer processing means is provided, the information transfer between the networks can be automatically performed when the information transfer within the networks is completed, and the processing speed of the program controlling the controlled unit in the common station is improved, There is also an effect that the data transfer processing can be speeded up.

[Brief description of drawings]

1 is a block diagram of a common station according to an embodiment of the invention, FIG. 2 is a block diagram based on a hardware configuration of a common station according to an embodiment of the invention, and FIG. 3 (a) is an embodiment of the invention. 3 is a flow chart of data transfer between networks using a data transfer table according to an example, FIG. 3 (b) is a flow chart of a processing program of a common station according to an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. FIG. 3 is a diagram showing data transfer between a link device 1 and a link device 2 according to
FIG. 5 is a diagram showing a memory area of the link device 1, a data transfer table, and a memory area of the link device 2. FIG. 5 is a memory area of the link device 1a, a data transfer table, and a memory of the link device 2a according to another embodiment of the present invention. FIG. 6 is a diagram showing the entire area of the network according to the related art and one embodiment of the present invention, and FIG. 7 (a) is a memory area diagram of the link device 1 according to the related art and one embodiment of the present invention. FIG. 7 (b) is a memory area diagram of the link device 2 according to the related art and one embodiment of the present invention, FIG. 8 is a block diagram of stations other than the common station according to the related art and one embodiment of the present invention, and FIG. 10 is a block diagram of a common station in FIG. 10, and FIG. 10 is a block diagram based on a hardware configuration of a station other than the common station according to the conventional and one embodiment of the present invention.
FIG. 11 is a block diagram based on the conventional hardware configuration of a common station, FIG. 12 is a configuration diagram of an entire network according to another embodiment of the present invention, and FIG. 13 (a) is a conventional and another embodiment of the present invention. FIG. 13 (b) is a memory area diagram of a link device 1a according to an embodiment, FIG. 13 (b) is a memory area diagram of a link device 2a according to another embodiment of the present invention, and FIG.
FIG. 15 is a flow chart of information transmission in a network according to the related art and the present invention, FIG. 15 is a flow chart of data processing of a common station according to the related art, and FIG. 16 is a link device 1 and a link device 2 according to an embodiment of the related art and the present invention. And FIG. 17 is a diagram of data transfer between the link device 1 and the link device 1 and the memory region of the link device 2, and FIG. 17 shows a link device 1a and a link device 2a according to a conventional example and another embodiment of the present invention. And FIG. 18 is a diagram of data transfer between the memory device and the link device 1a, showing the memory region of the link device 1a and the memory region of the link device 2a, FIG. 3 is a detailed flowchart of FIG. (1) is network 1, (2) is network 2,
(3) is a station b connected to the network 1, and (4) is a connected to both the network 1 and the network 2.
Station, (5) is station c connected to network 2, (6)
Is a link device 1 of network 1, (7) is a link device 2 of network 2, (73) is an interrupt signal, (7
4) is an interrupt signal, and (77) is a data transfer table. In the figure, the same reference numerals indicate the same or corresponding portions.

Claims (1)

[Claims] 1. A first network control means for performing a data link of a network, and a first storage means for storing information of its own station and other stations in the network and accessible from the first network control means. A station having the same, a first network having a plurality of the stations connected, a second network having a plurality of the stations connected, both the first network and the second network connected, and a data link of the first network Second network control means for performing the above, third network control means for performing the data link of the second network, information of its own station and other stations in the first network, and storing the second network control means. Secondly, storage means that can be accessed from the network control means, and information about its own station and other stations in the second network are stored. A third storage unit that can be accessed from the third network control means, when the information transmission a first plurality of stations in the network the first storage means is controlled such that each have the same information has been completed,
The data to be transferred from the first network to the second network, which is stored in the second storage means, by the interrupt signal generated by the second network control means is stored in the third storage means itself. Data is transferred from the first network to the second network by writing information in the station information area so that the first storage means of a plurality of stations in the second network each have the same information. When the information transmission controlled by the third network control means is completed, an interrupt signal generated by the third network control means transfers the information from the second network stored in the third storage means to the first network. Data to be written in the area for writing information of its own station in the second storage means so that the second data can be transmitted from the network to the first storage area. Common station, network data transfer apparatus comprising a comprising a network between the data transfer processing means for performing data transfer to Ttowaku.