JPH03188734A - Inter-network data transfer equipment - Google Patents

Abstract

PURPOSE:To quicken the data transfer processing between networks by providing an inter-network data transfer processing means starting an interrupt processing in a common station at the end of information transmission in a 1st or 2nd network and transferring the data between the networks. CONSTITUTION:When an in-network data communication is finished, a network control means 2(18) or a network control section 3(19) sends an interruption signal (73) or (74) to a pc(76) to bring an inter-network data transfer processing means B(75) into the START state. Thus, bidirectional data transfer between networks is attained in such a manner and the insertion of an inter-network data transfer program in series with a user processing program is not required and the operation flow is needed for only the user processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a data transfer device between networks.

[Prior Art] First, conventional data transfer between networks will be explained using FIGS. 6 to 18.

Figure 6 is a configuration diagram of a conventional network gold body. In Figure 1, (1) is Network I (hereinafter referred to as NTI), (2) is Network 2 (hereinafter referred to as NT2), and (3) is NTI (1).
Station b, (4) connected to NTI (1) and NT2
Station a connected to both (2), (5) is N T 2
(2) is the 0 station connected to. Next, Fig. 7 (a
) is a memory area diagram of the link device 1 (6) that stores the control information of the a station (4) and the b station (3) in the conventional system, and FIG. Bureau (5)
FIG. 4 is a memory area diagram of the ring device 2 (7) that stores control information of the ring device 2 (7). In FIG. 7(a), (8) is a memory area for storing control information for station a (4), and (9) is a memory area for storing control information for station b (3). Also,
In FIG. 7(b), (10) is a memory area that stores control information for station a (4), and (11) is a memory area that stores control information for station 0 (5).

FIG. 8 is a detailed configuration diagram of station b (3) in the conventional device. In the figure, (12) is the controlled unit controlled by station b (3), (13) is the user processing means 1 that controls the controlled unit (12) of station b (3), and (14) is the controlled unit controlled by station b (3). ) and other stations; network control means 1. (I
s) has link device 1 (6) in the memory area,
It is a storage means l that can be accessed from both the user processing means 1 (13) and the network control means 1 (14).

Further, FIG. 9 is a detailed configuration diagram of station a (4) in the conventional device. In the figure, (16) is the controlled unit controlled by station a (4), (17) is the user processing means 2 that controls the controlled unit, and (1g) is the network control unit 2 that performs the data link of NTI (1). , (19) is N T
2 Network control means for performing the data link in (2) 3. (22) is an inter-network data transfer processing means A that transfers data between link device 1 (6) and link device 2 (7) according to a predetermined procedure;
(23) is a programmable controller (hereinafter referred to as PC) consisting of user processing means 2 (17) and inter-network data transfer processing means A (22);
0) has link device 1 (6) in the memory area p
Storage means 2 (21), which can be accessed from both c (23) and network control means 2 (18), has link device 2 (7) in its memory area p c (
23) and network control means 3 (19).

FIG. 10 is a block diagram based on the hardware configuration of station b (3) in the conventional device. In the figure (45)
is the input signal from NTI (1) to station b (3), (46
) is the output signal from station b (3) to NTI (1), (4
7) is the CPU of the programmable controller PC (43), (4g) is the system program memo 1c where the system program is stored (49) is the user program memo 1c (50) where the user program is stored.
) is data memo 1c (51) used for work area etc.
is an I10 memory for storing output information to the controlled unit (12) and input information from the controlled unit (12). (
52) is the CPU of the network control means 1 (14),
(53) is the system program memory 1c where the system program is stored. (54) is the data memory used for the work area etc. (55) is the transmission controller that sends the transmission data to NTI (1). (56) is NTI
This is a reception controller that receives received data from (1).

FIG. 11 shows a conventional device. It is a block diagram based on the hardware configuration of a station (4). In the figure (24)
is the input signal from NTI (1) to station a (4), (25
) is the output signal from station a (4) to NT1 (1), (2
6) is the input signal from NT 2 (2) to station a (4),
(27) is the output signal from station a (4) to N T 2 (2). Moreover, (2g) is the CPU of the programmable controller p c (23).

(29) is the system program memory where the system program is stored, (30) is the user program memory where the user program is stored, (31) is the data memory used for the work area, etc., and (32) is the controlled unit (I6). ) and human power information from the controlled unit (16). Furthermore, (33) is C of network control means 2 (1g)
PU (34) is the system program memory of the network control means 2 <18>, (35) is the data memory used by the CPU (Ll) of the network control means 2 (18) as a work area, etc., and (36) is the NTI (18) )
(37) is a receiving controller that receives data input from NTI (1). (3g) is the cpu of the network control means 3 (19), (39) is the system program memory of the network control means 3 (19),
(40) is a data memory used as a work area, etc., (41) is a transmitting controller that transmits data to NT2 (2), and (42) is a receiving controller that receives data input from NT2 (2). It is a controller.

FIG. 12 is a block diagram showing an example of the overall configuration of inter-network data transfer in a conventional device, and shows an example in which the number of stations in each network shown in FIG. 6 is increased. In Figure 12, (5g) Network la: (59
) is connected to network 2a, (60) is connected to two networks (58) and (59), and two networks are connected.

Station A has the configuration shown in FIG. 9 and FIG. 1I, which transfers data between networks (5g) and (59). (6
1) to (66) are stations B, C, D, E, F, and G having the configurations shown in FIG. 8 and FIG. 1O. 12th
In the example shown in the figure, network l a (5g) includes common stations A station (60), B station (61), C station (62),
Network 2 a (59) is composed of four stations: D station (63), and four common stations: A station (60), E station (64), F station (65), and G station (66). It consists of stations.

Next, in order to clarify the content of the prior art, in the network shown in FIG. 12, stations A (6o) to G (66
) Network control means 1 (1
4), describes the operations of network control means 2 (18) and network control means 3 (19), and describes the operations within network 1 a (58) and network 2 a (59).
) will be explained about the information transmission method within. Since the information transmission method within network 1 a (5g) and the information transmission method within network 2 a (59) are the same, network 1 a (5g) will be explained. Station A (60
) is stored in the storage means 2 (20
)have. This storage means 2 (2G) is connected to the network control means 2 (18) and PC (23), and is also connected from the PC (23) side to the network control means 2 (1
8) can also be accessed. Station B (61) to Station D (63
) has a storage means 1 (15) which can likewise be accessed by both the user processing means 1 (13) and the network control means 1 (14).

These storage means 1 (14) and 2 (2G) are the 13th
It has a link device 1a (67) having the memory area shown in Figure (a). This link device l a
The memory area of (67) is network l a (58
) Each area divided into one area is assigned to each station, and stores input/output information, internal relay information, etc. regarding the controlled device of the station. The area allocated to the A station (60) includes input/output information regarding the controlled device, internal relay information, as well as network l a (58) and network 2 a (
59) includes an area for data transfer between 1st
In Figure 3(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), and (70) is the information area of station B assigned to station A (60). Station C (62
) is the information area of station C allocated to station D, and (71) is the information area of station D allocated to station D (63). Each of the stations A (60) to D (63) has a link device 1a (67), and the information area of the own station contains the PC of the own station.
(13) and (23), but the information area of another station is configured so that it can read from the own station's p c (13) and (23) but cannot write to it. For example, for the information area (68) of station A,
0) can be written, but stations B (61) to D (63)
) cannot be written to, and station A (60) cannot write to information area (69) of station B to information area (71) of station D. Station A (60) cannot write to information area of station A (60). (68
) to D station (63) information area (71) can be read. In addition, network I a (5g
) Each station (60).

(61), (62), (6:) The contents of the link device l a (67) of Communication control methods that have information about stations are generally widely used because they often increase the memory capacity of link devices possessed by each station, or simplify communication within the network, resulting in improved communication speed. This is the way to be.

Each station (6G) in network l a (58),
(61).

(62), (63) have link device 1 a (
67) is the same as that of network control means 2 (18) in FIGS. 9 and 11, and
Network control means 1 (14
) is being carried out. FIG. 14 is a flow diagram showing an example of the operation. In the flow diagram of Figure 14, first step
When the knob (S100) starts data communication within the network l a (58), the second step knob (Slot
), the only station (hereinafter referred to as the master station) that has transmission rights among the stations in the network l a (58) stores the contents of the memory area allocated to the master station in the link device 1a (67). is transmitted to a tX station (hereinafter referred to as a slave station) that does not have the transmission right within the network l a (58). For example, if station B (61) is the master station, the setting range for station B (69)
The contents of station A (60), station C (62) and station D (6
3) Send to. Next, in step (S102),
The slave station receives the data transmitted by the master station using the Ste Knob (Slot) and uses its own link device l a (67
), the received data is written into the part of the memory area that is the information area of the master station. For example, when station B (61) is the master station, stations A (60) and C (62)
), and link device l a owned by station D (63)
The received data is written in the information area (69) of station B in (67). Subsequently, in step (S l 03), it is determined whether transmission has been completed to all stations in network 1 a (5g), and if it has not been completed,
In step (S104), the master station changes the transmission destination slave station to another slave station that is not transmitting data yet.
Return to OI). In step (S103), if transmission to all slave stations in network l a (5g) is completed, the process proceeds to the next step (3105). All stations in network l a (58) can become master stations with transmission rights, and the first step (S106)
As shown in Figure 1, network l a which was a slave station until now
(58) Make one of the stations the master station and change the stations that have been the master station to slave stations. In step (S105), all stations in the network become master stations, and step (S105)
It is determined whether steps (lot) to Ste.knob (S104) have been repeatedly executed, and if this judgment condition is not satisfied, the process returns to Ste.knob (S106) and the network la (5g), which has been a slave station, is One station that has not yet become a master station is made the master station, and the process returns to step (SIOl). If the determination condition is satisfied in step (S105), the information transmission within the network l a (5g) is completed. When controlling a factory conveyor line using a commonly used transmission line with a transmission speed of around 9600 BPS, the information transmission time becomes too long as the number of stations in one network increases.

Control cannot keep up. Therefore, when there are many stations in a factory, a method is used in which multiple networks are provided and control is performed using a relatively large-scale control device such as a factory automation controller. At this time, the amount of information that needs to be exchanged between networks is configured to be smaller than the amount of information that is exchanged within the network, to reduce the load on factory automation controllers, etc., and to avoid slowing down processing speed. I have to. In FIG. 12, the role of such a factory automation controller, etc. is the PC of station A (60).
(23) plays a role. This is because when there are two networks and data communication between them is handled, it is often possible to do without using a factory automation controller by providing a PC with an inter-network exchange function.

Next, the operation of p c (23) in FIGS. 9 and 11 will be explained with reference to the flowchart in FIG. 15. In the network configured as shown in FIG.
), and c p u (2g) of p c (23) is
Controlled unit (16) that does not include data transfer between networks
In the first step (S202), the network 1 (1
) to network 2 (2), and step 1. In step (2003), data is transferred from network 2 (2) to network 1 (1), and then the process returns to step (S201) again to perform user processing. By repeating the above operations, station a (4)
) and performs data transfer processing between network 1 (1) and network 2 (2). In addition,
FIG. 16 shows an example of data transfer (401) performed in step (S202). In this example, data to be transferred to network 2 (2) is stored in the information area (9) of station b of link device 1 (6) of storage means 1 (20) of station a (4). Area data (1,200)
~(1,219).

Area (LO) of the information area (8) of the link device 2 (7) in the storage means 2 (21) of the a station (4) ~
(Li2). In this way, when there is information in network 1 (1) that you want to transfer to network 2 (2), you can transfer it to network 2 (2).
2), the information area (lO
), and the 0 station (5) in network 2 (2)
reads the information in the information area (10) of station a of link device 2 (7), and establishes network l (
Data transfer is performed from network 1) to network 2 (2). In step (S203) in FIG. 15, data is transferred from network 2 (2) to network 1 (1), and the operation is similar to that described in step (S202).

In addition, in the case of a network having the configuration shown in FIG. 12, the operation of step (S202) is
) (402-1) and (403-1) are examples of data transfer.
It will look like the figure. In FIG. 18, step (S301
), the data transfer (401-1) shown in FIG. Among them, data in area (L200) where data to be transferred to network 2a (59) is stored.
) to (L219) are stored in the storage means 2 (2
1) is transferred to the information area (LO) to (Li2) of the A station of the link device 2a (72). Step (83
02), the data transfer (402-1) shown in FIG. 17, specifically the 0 of link device 1 a (67)
The contents of (L360) to (L379) of the station information area (70) are transferred to (L20) to (L39) of the A station information area (73) of the link device 2 a (72). In step (S303), (403-
1) Data transfer, specifically link device l a
(67) Information area of station D (L430) ~ (L449
) is transferred to ([,40) to (L59) of the information area (73) of the A station of the link device 2a (72).

As mentioned above, when there is information that you want to transfer to network 2 a (59) among the information in network l a (5g), it is transferred to station A of link device 2 a (72) of network 2 a (59). information area (7
3) Transfer data to network 2 a (59)
Stations (64), (65), (66) in network l a (5g
) to network 2 a (59). Note that in step (3203) in FIG.
Data transfer to a (5g) is also performed in the same manner as described above.

[Problems to be Solved by the Invention] The conventional inter-network data transfer device is configured as described above, and the network Since the data transfer processing program between networks is built in serial, the data transfer speed between networks depends on the processing time of the user processing program, but when the user processing is completed, the previous transfer processing within the network has not been completed. Wait until the time is complete, or
Since inter-network data transfer with the same content as the previous one is performed again, there is a problem in that the processing speed of the user processing program is slowed down.

This invention was made to solve the above-mentioned problems, and it not only speeds up data transfer between networks, but also eliminates the trouble of serially incorporating a program for data transfer between networks into a user processing program. Due to the influence of data transfer processing between networks,
An object of the present invention is to obtain an inter-network data transfer processing device that reduces the reduction in the processing speed of a user processing program.

[Means for Solving the Problems] An inter-network data transfer device according to the present invention includes a first network control unit that performs a data link of a network, and a first network control unit that stores information about its own station and other stations in the network. a first network to which a plurality of the above-mentioned stations are connected; a second network to which a plurality of the above-mentioned stations are similarly connected; a first network connected to both the first network and the second network; a second network control means for performing a data link of the second network; a third network control means for performing a data link of the second network; and a third network control means for storing information of the own station and information of other stations in the first network. The storage means of the first network and the storage means of the plurality of stations in the first network are controlled so that they each have the same information.The second network control means triggers an interrupt signal generated by the second network control means when the information transmission is completed. The data to be transferred to the second network in the storage means is transferred to the third network.
Data is transferred from the first network to the second network by writing the information of the own station in the storage means in the write area, and the data is transferred from the second network to the first network in the same way. Data transfer between networks is performed by a common station having data transfer processing means.

[Function] In the inter-network data transfer device according to the present invention, the second network control means generates an interrupt when information transmission is completed in which the storage means of a plurality of stations in the first network are controlled so that they each have the same information. The data to be transferred to the second network stored in the second storage means for storing information of stations other than the common station in the common station and the first network is transmitted to the common station and the second network by the input signal. Information on the common station is written in the writing area of the third storage means for storing information on stations other than the common station, thereby data is transferred from the first network to the second network, and data is transferred from the second network to the second network. Since data transfer to one network is performed in the same way, when information transfer within the network is completed, inter-network data transfer to the other network is automatically performed.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be explained with reference to figures. Figure 1 corresponds to station a (4) in Figure 6 and station A (60) in Figure 12 described in the conventional example. 1 shows the configuration of an embodiment of this invention. FIGS. 1 and 2 are similar to the conventional example shown in FIG. 9, except that interrupt signal line 1 (73) and interrupt signal line 2 (74) are added, and the PC (23) is changed as described below. It is the same as FIG. 11. That is, the inter-network data transfer processing means B (7
5), the table pointer (
80), has a data transfer table (77), and transmits a trigger signal for inter-network data transfer to network control means 2 (1g) and network control means 3 (19).
The receiver has the function of transferring data between networks.

B station (3), C station (5), B station (61
), Station C (62), Station D (63), Station E (64)
, F station (65), and G station (66) have the same configuration as shown in FIGS. 8 and 10 in the conventional example.

Next, regarding the operation of this embodiment device, FIGS. 3(a) and (b)
), and will be explained with reference to FIGS. 4(a), (b), and (c). When the intra-network data communication shown in the flowchart of FIG. 14 is completed, network control means 2 (1g) or network control means 3 (19) in FIG. ) or interrupt signal (
74) to p c (78). This interrupt signal is
In the flow diagram of Figure (a), the inter-network data transfer processing means B (75) is
state. The data transfer table (
77) has a data transfer source device address column (78) and a data transfer destination device address column (79), and the data transfer source device address column (78) contains the data transfer source link and device 1 (6). The data transfer start address (80) and data transfer end address (81) are entered in the data transfer destination device address field (79).
82) and the data storage end address (83) are written in advance. At this time, the memory area of the link device 2 (7), which is the data transfer destination, indicated by the data storage start address (82) and the data storage end address (83) must be within the setting range of the a station (4). The data transfer table (77) is the p c (76
) is stored in memory.

In the flow of FIG. 3(a), in step (S2), the table pointer (84) of the data transfer table (77) is
Clear. Next, in step (S3), data transfer address information (80), (81) is placed in the position indicated by the table pointer (84) of the data transfer table (77).
, (82).

Check if (83) is written. If it has been written, the process advances to the secondary step (S4) and data transfer processing is performed. That is, the data transfer start address (80) written in the data transfer source device address column (78) of the data transfer table (77) at the position indicated by the table pointer (84) of the data transfer table (77)
) and the data transfer end address (81) specify the contents of the data transfer source link device 1 (6), and store the data written in the data transfer destination device address column (79) of the data transfer table (77). Start address (82
) and the data storage end address (83) are written in the memory area, which is the information area of station a (4), which is the data transfer destination.

Subsequently, in step (S5), the table pointer (
84) and returns to step (S3), the data transfer address information (+110) is added to the position indicated by the table pointer (84).
.

If (81), (82), and (83) are not written, data transfer ends.

FIG. 4 shows the contents of addresses (L200) to (L219) where information to be transferred to link device 2 (7) is stored in the information area of station b of link device 1 (6), as the data transfer destination. An example is shown in which the information is stored at addresses (LO) to (Ll 9) in the information area of station a of link device 2 (7). In this example, link device 1
Although an example of data transfer from link device 2 (1) to link device 2 (2) is shown, data transfer from link device 2 (2) to link device 1 (1) also involves network 2
The inter-network data transfer processing program is activated by the intra-network information transfer completion signal in (2) and similarly processed.

FIG. 5 shows data transfer between link device l a (67) and link device 2 a (72) using a data transfer table (77) in data transfer between networks shown in FIGS. 12 and 13. This shows the case when doing this. In the figure, link device l a (67)
Of the information areas (86) of the eight stations, link device 2 (
72) and the contents of addresses (L200) to (L219) storing information to be transferred to link device 2a (72) in the information area (87) of the 0th station of link device la (67). The contents of the addresses (L360) to (L379) where information is stored and the information area of the D station of link device 1 a (67) (
88), addresses (L36(1) to
(L379) and link device 1 a (67
) of the information area (88) of station D, the link device 2a
The contents of addresses (L430) to (L449) storing information to be transferred to (72) are transferred to the information area (8
5) Address (LO) ~ (Ll9), Address (L
20) ~ (L39), address (L40) ~ (L5
9) shows an example of storing.

Note that data transfer from network 2 a (72) to network l a (67) is performed using network 2 a
(72)'s intra-network information transmission completion signal causes the network 2 a (72) to be transferred from network l a (
67) is activated and similarly processed.

As described above, data can be transferred bidirectionally between networks.
The PC (72) of the A station (60) in Figure 2 does not need to insert an inter-network data transfer program serially with the user processing program, and the operation flow is similar to that of the user in the step (SIO) shown in Figure 3(b). Processing only.

In addition, although the above embodiment shows the case where the station connected to both the first network and the second network is configured using a PC, it can also be configured using a factory automation controller instead of a PC. The same effects as in the above embodiment are achieved.

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.

The number of stations connected to the first network and the number of stations connected to the second network may be arbitrary.

Further, in the above embodiment, two networks are connected to the common station, but the same effect can be achieved even if any number of networks greater than or equal to two are connected.

[Effects of the Invention] As described above, according to the present invention, when information transmission within the first network or the second network is completed, interrupt processing is activated in the common station and data transfer between networks is started. Since we have provided an inter-network data transfer processing means, it is possible to automatically transfer information between networks when the information transfer within the network is completed, which improves the processing speed of the program that controls the controlled unit in the common station. This has the effect of speeding up data transfer processing between networks.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a common station according to an embodiment of the present invention, FIG. 2 is a block diagram based on the hardware configuration of a common station according to an embodiment of the present invention, and FIG. 3(a) is a block diagram of a common station according to an embodiment of the present invention. A flowchart of inter-network data transfer using a data transfer table according to an embodiment, FIG. 3(b) is a flowchart of a common station processing program according to an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. Link device 1 by example
4(a) is a memory area diagram of the link device 1, and FIG.
Figure (b) is a diagram of the data transfer table, Figure 4 (c) is a diagram of the memory area of link device 2, and Figure 1g 5 (a).
is a memory area diagram of a link device Ia according to another embodiment of the present invention, FIG. 5(b) is a diagram showing a data transfer table according to another embodiment of the present invention, and FIG. FIG. 6 is a block diagram of the entire network according to a conventional example and an example of the present invention, and FIG. 7(a) is a memory area diagram of a link device 2a according to an embodiment of the invention. 7(b) is a memory area diagram of the link device 2 according to the conventional technology and an embodiment of the present invention. FIG. 8 is a block diagram of a station other than the common station according to the conventional technology and an embodiment of the present invention. . FIG. 9 is a block diagram of a conventional common station, and FIG. 10 is a block diagram based on the hardware configuration of stations other than the common station according to the conventional and an embodiment of the present invention. FIG. 11 is a block diagram of the hardware configuration of a conventional common station. Based on <flock diagram,
FIG. 12 is a block diagram of the entire network according to the conventional method and another embodiment of the present invention. FIG. 13(a) is a memory area diagram of the link device 1a according to the conventional method and another embodiment of the present invention. FIG. 13(b) 14 is a flow diagram of intra-network information transmission according to the conventional method and the present invention, and FIG. 15 is a conventional flow diagram of data processing in a common station. , FIG. 16 is a diagram of data transfer between link device 1 and link device 2 according to a conventional example and an embodiment of the present invention, FIG. 16(a) is a memory area diagram of link device 1, and FIG. ) is a memory area diagram of the link device 2, FIG. 17 is a diagram of data transfer between the link device 1a and the link device 2a according to the conventional and other embodiments of the present invention, and FIG. 17(a) is a diagram of the link device l.
The memory area diagram of a, FIG. 17(b) is the link device 2
FIG. 18 is a detailed flowchart of 5202 in FIG. 15 according to the conventional method and another embodiment of the present invention. (1) is network 1. (2) is network 2゜(
3) is station b connected to network l, (4) is station a connected to both network 1 and network 2,
(5) is station C connected to network 2. (6) is link device 1 of network 1. (7) is link device 2 of network 2. (73) is an interrupt signal, (74) is an interrupt signal, and (77) is a data transfer table. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A station having a first network control means for performing a network data link and a first storage means for storing information of the own station and other stations in the network and accessible from the first network control means; A first network that connects multiple stations, and a second network that connects multiple stations mentioned above.
a second network control means that is connected to both the first network and the second network and performs a data link of the first network; and a third network control unit that performs a data link of the second network. A second storage means that stores information on other stations in the first network and that can be accessed from the second network control means and information on the own station and information on other stations in the second network. Memorize the station information and repeat the 3rd step above.
When the information transmission is completed, the third storage means accessible from the network control means and the storage means of the plurality of stations in the first network are controlled so that they each have the same information. Writing the data stored in the second storage means to be transferred from the first network to the second network in response to the generated interrupt signal in an area of the third storage means in which information about the own station is written. When the information transmission is completed, the data is transferred from the first network to the second network, and the storage means of the plurality of stations in the second network are controlled so that they each have the same information. The data to be transferred from the second network stored in the third storage means to the first network is transferred to the own station information in the second storage means by an interrupt signal generated by the network control means. An inter-network data transfer device comprising a common station, and inter-network data transfer processing means for transferring data from the second network to the first network by writing in a write area.