JP2002198982A - System and method for data communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct an industrial real time network which is efficient in terms of software on a TCP/IP protocol stack of stations by using a universal Ethernet (registered trademark) switching hub. SOLUTION: Logical bidirectional rings 201a-d and 202a-d are formed of a switching hub 101 and a plurality of stations 102a-d. The station device 102a transmits a cyclic data which the own station transmits to adjoining both stations 102b and 102d. The stations 102b and 102d transmit the cyclic data which is received to the adjoining station device 102c. The station 102c which receives the same cyclic data in duplicate from the stations 102b and 102d discards one of the duplicate cyclic data before finishing transfer. The same process is performed with the cyclic data transmitted from other stations 102b-d in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a system for realizing real-time communication in an industrial network using, for example, an Ethernet switching hub device, and more particularly to a cyclic transmission system.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 2000-92109 discloses a technique for realizing an industrial real-time network using an Ethernet hub device. JP 2000-921A
According to 09, as shown in FIG. 25, special functions such as a circulation timer unit 1309, a transmission time counting unit 1308, a transmission monitoring unit 1310, and a pause frame generation unit 1311 are newly incorporated in the full-duplex Ethernet hub device 1301. A method is disclosed. In order to realize an industrial real-time network using an Ethernet hub device, for example, according to JOP-1001 “FL-net protocol specification”, as shown in FIG. 26, a station device 1401a having an Ethernet interface In the industrial network consisting of to d, the token is circulated between the station devices, and the station device 1 holding the token 1402
A method is disclosed in which only 401 obtains the right to transmit data.

Next, the operation will be described. JP 2000
According to -92109, the circulation timer unit 1309 outputs a one-time period, and the transmission time counting unit 1308 counts the data transmission time of each of the station devices 1302a to 1302d connected to the full-duplex Ethernet hub device 1301. The transmission monitoring unit 1310 calculates an allowable data transmission time to be equally allocated to each of the station devices 1302a to 130d based on the one cycle time output from the circulation timer unit 1309, and counts the allowable data transmission time and the transmission time counting unit 1308. The data transmission times are compared. When the data transmission time exceeds the allowable data transmission time, the pause frame generation unit 1311 transmits the
A pause frame (pause time is equal to or longer than one cycle time) is generated and transmitted according to 802.3x. This allows
The station device stops transmitting data. When one cycle time has elapsed, the circulation timer unit 1309 newly outputs one cycle time, so that each station device 1302a to 1302d is newly given an allowable data transmission time. At this time, since the full-duplex Ethernet hub device 1301 sends a pause frame with the pause time set to 0 to the station that sent the pause frame, the station device that has stopped transmitting can transmit data again. .

[0004] On the other hand, according to JOP-1001 "FL-net protocol specification", the station devices 1401a to 1401d connected to the industrial network transmit a message which is a non-real-time communication only when possessing a token. Is performed only for one frame, and then cyclic transmission, which is real-time communication, is performed. At this time, the token 1402 is added to the last frame of the cyclic transmission and transmitted. Unicast is used for 1: 1 message transmission, and broadcast is used for 1: N message transmission. Then, cyclic transmission (token 140
Broadcast is used for the transmission (including the transmission of No. 2). Broadcast cyclic data and tokens 1402
Each of the station devices 1401 a to 140 d receiving the token 1402 stores the cyclic data in the shared memory area,
Only the station device 1401 that is to receive the token 1402 has the token 1402. The order in which the tokens 1402 are owned is determined in advance.

[0005]

SUMMARY OF THE INVENTION Conventional Japanese Patent Application Laid-Open No. 2000-2000
In 92109, in order to realize an industrial real-time network using an Ethernet hub device, Japanese Unexamined Patent Application Publication No.
It is necessary to use a special full-duplex Ethernet hub device having the function described in 000-92109. for that reason,
There is a problem in that an off-the-shelf full-duplex Ethernet hub device cannot be used, and the introduction cost of the full-duplex Ethernet hub device increases. On the other hand, in the FL-net, since only the station device that owns the token has the transmission right, other station devices that do not own the token cannot perform data transmission, which is inefficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and uses an off-the-shelf general-purpose Ethernet switching hub to efficiently implement an industrially efficient software on the TCP / IP protocol stack of each station device. Build a real-time network for Since the functions required for an industrial real-time network are built on the TCP / IP protocol stack, that is, on the application layer, it is possible to reduce the installation cost and to install in an environment where industrial equipment and general personal computers are mixed. It is possible to do.

[0007]

A data communication system according to the present invention has a plurality of data communication devices, and a relay device for relaying data communication between the plurality of data communication devices, and via the relay device. A data communication system that configures a cyclic route for circulating data in two directions between the plurality of data devices, wherein each data communication device transmits its own transmitted data to both sides of itself in the cyclic route. A data communication device located as a destination is transmitted to the relay device, and other transmission data other than the own transmission data is received via the relay device from a data communication device located on one side of both sides of the self in the circuit path. And transmitting the received other transmission data to the relay device with the data communication device located on the other side of both sides of the self in the circuit route as a destination. It is characterized in.

When receiving the self-originating data, the relay device receives the self-originating data received from data communication devices located on both sides of the self-originating data communication device that transmitted the self-originating data on the circuit route. Send data,
Each of the adjacent data communication devices located on both sides of the self-originating data communication device on the circuit route, the self-originating data transmitted from the self-originating data communication device located on one of both sides of the self on the circuit route. The other transmission data is received from the relay device, and the received other transmission data is transmitted to the relay device as a destination with the data communication device located on the other side of both sides of the self in the circuit path. When receiving the other transmission data from each of the adjacent data communication devices, the data communication devices located on both sides of each of the adjacent data communication devices on the circuit path may include data communication devices other than the self-originating data communication device. And transmitting the other transmission data.

Each of the data communication devices transmits, as the self-originating data, time-limited data required to reach all of the other data communication devices within a predetermined time to the relay device at a predetermined cycle. It is characterized by doing.

The data communication system is an Ethernet data communication system in which the relay device is an Ethernet switching hub, and each of the data communication devices is a data communication device having an Ethernet interface.

[0011] Each of the data communication devices is the same as the already-received data already received by the other transmission data received via the relay device from the data communication device located on either side of the data communication device on the circuit route. In some cases, the received other transmission data is not transmitted to the relay device.

When each of the data communication devices receives the self-originated data from the data communication device located on either side of itself on the circuit route via the relay device, the data communication device transmits the received self-originated data to the data communication device. It is not transmitted to the relay device.

Each of the data communication devices transmits the self-originated data to the relay device asynchronously with another data communication device.

Each of the data communication devices transmits the self-originated data to the relay device in synchronization with a transmission instruction instructing the data communication device to transmit the self-originated data.

When each of the data communication devices receives the other transmission data via the relay device from the data communication device located on either side of the data communication device on the circuit route, the data communication device receives the other transmission data. The acknowledgment is transmitted to a data communication device located on one side of both sides of the self in the circuit route.

A data communication system according to the present invention is a data communication system having a plurality of data communication devices and a relay device for relaying data communication between the plurality of data communication devices. The time data required to reach all of the other data communication devices within a certain time is transmitted to the other data communication device via the relay device at a certain cycle, and the relay device is
The time data received from each data communication device is broadcast to all data communication devices other than the data communication device that transmitted the time data.

The data communication system is an Ethernet data communication system in which the relay device is an Ethernet switching hub, and each of the data communication devices is a data communication device having an Ethernet interface.

[0018] At least one of the plurality of data communication devices transmits fault detection data for fault detection, and the relay device transfers the fault detection data to the plurality of data communication devices. And circulating the failure detection data between the plurality of data communication devices.

Each of the data communication devices transmits the time data to the relay device in synchronization with a transmission instruction instructing the data communication device to transmit the time data.

Each of the data communication devices receives timed data transmitted from another data communication device via the relay device, and confirms reception of the received timed data with respect to the data communication device that has transmitted the timed data. And transmitting the data via the relay device.

Each of the data communication devices transmits non-timed data that is not required to reach all of the other data communication devices within a certain time to the relay device while not transmitting the timed data. It is characterized by doing.

A data communication method according to the present invention uses a plurality of data communication devices and a relay device for relaying data communication between the plurality of data communication devices, and forms an adjacency between the plurality of data devices. A data communication method for circulating data in two directions between the plurality of data devices,
Each data communication device transmits its own transmitted data,
A data communication device located on both sides of the self is transmitted to the relay device as a destination, and other transmission data other than the self-originated data is received from the data communication device located on one side of the self via the relay device. And transmitting the received other transmission data to the relay device with the data communication device located on the other side on both sides of the own device as a destination.

When receiving the self-originated data, the relay device transmits the received self-originated data to data communication devices located on both sides of the self-originated data communication device that transmitted the self-originated data. Each of the adjacent data communication devices located on both sides of the self-originating data communication device is configured to relay the self-originating data transmitted from the self-originating data communication device located on one of the two adjacent neighbors as the other transmission data. Receiving from the device, and transmitting the received other transmission data to the relay device with the data communication device located on the other side of both sides of itself as the destination, the relay device transmits the other transmission data from each adjacent data communication device. Is received, among the data communication devices located on both sides of each of the adjacent data communication devices, the data communication device other than the self-originating data communication device And transmitting the other outgoing data.

Each of the data communication apparatuses transmits, as the self-originated data, time-limited data required to reach all of the other data communication apparatuses within a predetermined time to the relay apparatus at a predetermined cycle. It is characterized by doing.

A data communication method according to the present invention is a data communication method using a plurality of data communication devices and a relay device for relaying data communication between the plurality of data communication devices. The time data required to reach all of the other data communication devices within a certain time is transmitted to the other data communication device via the relay device at a certain cycle, and the relay device is The time data received from each data communication device is broadcast to all data communication devices other than the data communication device that transmitted the time data.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a physical system configuration diagram showing a data communication system according to the present embodiment. In FIG. 1, reference numerals 102a to 102d denote station devices (data communication devices) such as industrial equipment and personal computers having an Ethernet interface, and 101 denotes an Ethernet switching hub (relay device) accommodating a plurality of station devices 102a to 102d. The switching hub device 101 and the station devices 102a to 102d are STP (Shielded).
Twist Pair cable) or UTP (Uns
shielded Twist Pair cable)
Are connected by various communication cables 103a to 103d. Each of the station devices 102a to 102d is a switching hub device 1
A star network centered on 01 is constructed.

In order to share the memory space between the station devices, each of the station devices 102a to 102d periodically transmits the memory space of the own station device to the other station device, and transmits information to the other station at irregular intervals. Performs transient transmission for exchange. Cyclic transmission is a real-time communication that constantly requires network resources and needs to complete communication within a certain time. On the other hand, transient transmission is a non-real-time communication that requires network resources in bursts and does not require completion of communication within a certain time. The information transmitted by cyclic transmission is called cyclic data (timed data). High-speed cyclic transmission that communicates this cyclic data at a high cycle and low-speed cyclic transmission that communicates cyclic data at a low cycle is there. Information transmitted by transient transmission is called transient data (non-timed data).

The switching hub device 101 is a ready-made Ethernet switching hub. Here, IEEE
An Ethernet switching hub device 101 that supports full-duplex communication in accordance with E802.3x;
Station devices 102a to 102c provided with an Ethernet interface that supports a full-duplex communication function conforming to 02.3x.
When d is used, full-duplex communication can be performed between the switching hub device 101 and each of the station devices 102a to 102d. Therefore, it is possible to avoid collision between the data going from the switching hub device 101 to the station device 102 and the data going from the station device 102 to the switching hub device 101 on the communication cable 103.

Next, the operation will be described. FIG. 2 shows the switching hub device 101 when performing cyclic transmission.
FIG. 1 is a logical system configuration diagram including a network device and station devices 102a to 102d. This system configuration is mainly used for transmitting low-speed cyclic data. In this system configuration for cyclic transmission, routes 201a-d for transmitting cyclic data clockwise through the station devices 102a-d and routes 202a-d for transmitting cyclic data counterclockwise are shown.
To form a logical bidirectional ring (circular path). In the present embodiment, when cyclic data is circulated clockwise, a station apparatus in front of a certain station apparatus is referred to as a preceding station, and a preceding station apparatus is referred to as a next station. That is, when the station apparatus 102a is viewed mainly, the station apparatus 102d is referred to as a previous station, and the station apparatus 102b is referred to as a next station.

The basic procedure of cyclic transmission in the present embodiment will be described below. (1). Each of the station devices 102a to 102d asynchronously transmits cyclic data to the preceding station and the next station at regular intervals. (2). When cyclic data is received from a neighboring station, Ack is returned. (3). If the received cyclic data is new, the data is stored and then transferred to an adjacent station. If the received cyclic data is the same as the previously received cyclic data or is older than the previously received cyclic data, it is discarded. (1) is processing for transmitting cyclic data transmitted from the own station, and (2) and (3) are processing for transferring cyclic data transmitted from another station. for that reason,
(1), (2) and (3) are processed in parallel.

FIGS. 3 to 5 are diagrams showing the behavior of the cyclic data transmitted from the station device 102a. The behavior of the cyclic data transmitted from the station device 102a will be described below with reference to FIGS. (1). First, as shown in FIG.
2a transmits cyclic data to the next station 102b (301). Specifically, the station device 102a transmits cyclic data to the switching hub device 101, and the switching hub device transfers the received cyclic data to the next station 102b. (2). Next, as shown in FIG.
2b receives the cyclic data of the station device 102a and returns Ack to the station device 102a (302). At this time, the station device 102b stores the received cyclic data of the station device 102a. On the other hand, the station device 102a transmits the cyclic data to the preceding station 102d (30
3). 3A and 3B, the station device 102b
The cyclic data is transmitted at different timings to the station device 102d and the station device 102d. However, this is for convenience of explanation, and the station device 102b and the station device 1 are actually transmitted.
The cyclic data is transmitted almost simultaneously to 02d. (3). Next, as shown in FIG.
2b transmits the cyclic data of the station device 102a to the next station 102c (304). On the other hand, the station device 102d
The cyclic data of the station device 102a is received, and Ack is returned to the station device 102a (305). At this time, the station device 1
02d stores the received cyclic data of the station device 102a. (4). Next, as shown in FIG.
2c receives the cyclic data of the station device 102a from the station device 102b and returns Ack to the station device 102b (306). At this time, the station device 102c stores the received cyclic data of the station device 102a. On the other hand, the station device 102d transmits the cyclic data to the previous station 102c (307). (5). Next, as shown in FIG.
2c transmits the cyclic data of the station device 102a to the next station 102d (308). On the other hand, the station device 102c
The cyclic data of the station device 102a is transmitted to the station device 102d.
And returns an Ack to the station device 102d (30
9). At this time, the station device 102c already has the same station device 10c.
Since the cyclic data of 2a is received, the cyclic data of the station 102a received from the station 102d is discarded without being transferred to the station 102b. (6). Next, as shown in FIG.
2d receives the cyclic data of the station device 102a from the station device 102c and returns Ack to the station device 102c (310). At this time, since the station device 102d has already received the cyclic data of the same station device 102a,
The cyclic data of the station device 102a received from the station device 102c is discarded without being transferred. Same as above,
This occurs in parallel for all the cyclic data transmitted from each of the station devices 102a to 102d.

In this cyclic transmission, each station device always receives an Ack for the transmitted cyclic data, but Ac for the transmitted cyclic data.
If k is not received several times in a row, it is determined that a failure has occurred in the destination station apparatus 102 or the communication cable 103 between the switching hub apparatus 101 and the destination station apparatus 102. Also, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

In this cyclic transmission, the communication protocol used may be TCP / IP or UDP / IP. However, in the case of TCP / IP, the Ack for cyclic data can be replaced with the Ack of TCP / IP.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and a switching hub, a logical bidirectional ring is formed between the station devices to circulate cyclic data in both directions. If the cyclic data received from the station is received for the second time, it is discarded without being transferred to the other adjacent station to perform cyclic transmission for real-time communication and transient transmission for non-real-time communication. Further, it is possible to detect a failure of the station device.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

Embodiment 2 Next, a data communication system according to the second embodiment will be described. In the present embodiment, as in the first embodiment, a logical system configuration as shown in FIG. 2 is employed, and is mainly used for transmitting low-speed cyclic data. The basic procedure of cyclic transmission in the present embodiment will be described below. (1). Each of the station devices 102a to 102d asynchronously transmits cyclic data to the preceding station and the next station at regular intervals. (2). When cyclic data is received, it is checked whether the data is cyclic data transmitted from the own station device. If the cyclic data is transmitted from a device other than the own station device, the received cyclic data is stored. Then, transfer to the neighboring station. If the received data is cyclic data transmitted from the own station device, the received cyclic data is discarded. (1) is a process for transmitting the cyclic data of the own station, and (2) is a process for performing the cyclic data passed from another station. for that reason,
(1) and (2) are processed in parallel.

FIGS. 6 to 8 are diagrams showing the behavior of the cyclic data transmitted from the station device 102a. The behavior of the cyclic data transmitted from the station device 102a will be described below with reference to FIGS. (1). First, as shown in FIG.
2a transmits cyclic data to the next station 102b (401). (2). Next, as shown in FIG.
2a transmits cyclic data to the preceding station 102d (402). On the other hand, the station device 102b is
The cyclic data of the station device 102a is transmitted to the next station 102c (403).
At this time, the station device 102b stores the received cyclic data of the station device 102a. (3). Next, as shown in FIG.
2d receives the cyclic data of the station device 102a and transmits the cyclic data of the station device 102a to the preceding station 102c (404). At this time, the station device 102d
The received cyclic data of the station device 102a is stored. On the other hand, the station device 102c receives the cyclic data of the station device 102a, and sends the cyclic data to the next station 102d.
Is transmitted (405). At this time,
The station device 102c stores the received cyclic data of the station device 102a. (4). Next, as shown in FIG.
2c receives the cyclic data of the station device 102a and transmits the cyclic data of the station device 102a to the previous station 102b (406). At this time, the station device 102c
Since the cyclic data of the station device 102a has already been received once, the cyclic data of the station device 102a received again may be saved or may be discarded as it is. On the other hand, the station device 102d
The cyclic data of the station device 102a is transmitted to the next station 102a (40).
7). At this time, the station device 102d has already
Since the cyclic data of 2a has been received, the cyclic data of the station device 102a received again may be saved or may be discarded as it is. Then, the station apparatus 102a receives the cyclic data of the station apparatus 102a and receives the cyclic data of the own station, and discards the cyclic data. (5). Next, as shown in FIG.
Receives the cyclic data of the station device 102a and transmits the cyclic data of the station device 102a to the previous station 102a (408). At this time, since the station device 102b has already received the cyclic data of the station device 102a once, the cyclic data of the station device 102a received again may be stored or may be discarded as it is. Then, the station apparatus 102a receives the cyclic data of the station apparatus 102a and receives the cyclic data of the own station, and discards the cyclic data. Same as above,
This occurs in parallel for all the cyclic data transmitted from each of the station devices 102a to 102d.

In this cyclic transmission, if the local station that has transmitted cyclic data does not receive its own cyclic data transmitted several times in succession once or twice, any of the cyclic transmission paths Station device 102
Alternatively, it is determined that a failure has occurred in the communication cable 103 between the switching hub device 101 and the station device 102. Also, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

In this cyclic transmission, the communication protocol used may be TCP / IP or UDP / IP.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and switching hubs, a logical bidirectional ring is formed between the station devices to cyclically circulate cyclic data, and If the cyclic data received from the station is cyclic data of another station device, it is always transferred to the other neighboring station, and if the cyclic data received from the neighboring station is cyclic data of the own station device, it is discarded. This makes it possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of the station device.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

Embodiment 3 Next, a data communication system according to the third embodiment will be described. FIG. 9 is a logical system configuration diagram including the switching hub device 101 and the station device 102 when performing cyclic transmission. The system configuration shown in FIG. 9 is mainly used for transmitting low-speed cyclic data. In the system configuration for this cyclic transmission, a station device that generates a trigger among the station devices is called a master station (station device 102a in FIG. 9), and a master station (station device 102a) and a signal between the master station (station device 102a).
a path 501 for transmitting the trigger established for b to d;
A logical bi-directional ring is formed from routes 502a-d for transmitting cyclic data clockwise through the station devices 102a-d and routes 503a-d for transmitting cyclic data counterclockwise. Note that the trigger is a transmission instruction for instructing each of the station devices 102a to 102d to transmit cyclic data. Further, in the present embodiment, when cyclic data is circulated clockwise, a station apparatus in front of a certain station apparatus is referred to as a preceding station, and a preceding station apparatus is referred to as a next station. That is, the station device 102a
, The station device 102d is the previous station, the station device 102
b is called the next station.

The basic procedure of cyclic transmission according to the present embodiment will be described below. (1). The master station broadcasts the trigger at regular intervals. (2). Each station device 1 triggered by the master station
Nos. 02a to 02d periodically transmit the cyclic data transmitted by the own station to the preceding station and the next station in synchronization with the trigger. (3). When cyclic data is received from a neighboring station, Ack is returned. (4). If the received cyclic data is new, the data is stored and then transferred to a neighboring station. If the received cyclic data is the same as the previously received cyclic data or is older than the previously received cyclic data, it is discarded. (1) and (2) are processes for transmitting cyclic data transmitted from the own station, and (3) and (4) are processes for transferring cyclic data transmitted from another station. Therefore, (1),
(2), (3) and (4) are processed in parallel.

FIGS. 10 to 13 show the case where the master station is the station apparatus 10.
FIG. 2B is a diagram showing the behavior of cyclic data transmitted from the station device 102a as 2a. The behavior of cyclic data transmitted from the station device 102a will be described below with reference to FIGS. (1). First, as shown in FIG. 10A, the master station (station device 102a) transmits a trigger to each of the station devices 102a to 102d (601). (2). Next, as shown in FIG. 10B, upon receiving a trigger, the station device 102a transmits cyclic data to the next station 102b (602). (3). Next, as shown in FIG.
02b receives the cyclic data of the station device 102a and returns Ack to the station device 102a (603). At this time, the station device 102b stores the received cyclic data of the station device 102a. On the other hand, the station device 102a transmits the cyclic data to the preceding station 102d (60
4). (4). Next, as shown in FIG.
02b transmits the cyclic data of the station device 102a to the next station 102c (605). On the other hand, the station device 102d
Receives the cyclic data of the station device 102a and returns Ack to the station device 102a (606). At this time, the station device 102d stores the received cyclic data of the station device 102a. (5). Next, as shown in FIG.
02c receives the cyclic data of the station device 102a and returns Ack to the station device 102b (607). At this time, the station device 102c stores the received cyclic data of the station device 102a. On the other hand, the station device 102d transmits the cyclic data to the preceding station 102c (60
8). (6). Next, as shown in FIG.
02c transmits the cyclic data of the station device 102a to the next station 102d (609). On the other hand, the station device 102c
Receives the cyclic data of the station device 102a and returns Ack to the station device 102d (610). At this time, since the station device 102c has already received the cyclic data of the same station device 102a, it discards the received cyclic data of the station device 102a. (7). Next, as shown in FIG.
Receives the cyclic data of the station device 102a and returns Ack to the station device 102c (611). At this time, since the station device 102d has already received the cyclic data of the same station device 102a, it discards the received cyclic data of the station device 102a. The same thing as the above (2) to (7) occurs in parallel for all the cyclic data transmitted from each of the station devices 102a to 102d.

In this cyclic transmission, each station device 1
02a to 02d represent A to the transmitted cyclic data.
ck is always received, but if Ack for the transmitted cyclic data is not received several times in a row,
Destination station device 102 or switching hub device 1
It is determined that a failure has occurred in the communication cable 103 between the communication device 01 and the destination station device 102. In addition, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

The master station (station device 102a) may generate a trigger for each cycle of transmitting the cyclic data, or may generate a trigger at intervals of several cycles. When the trigger is generated every cycle, each of the station devices 102a to 102d performs cyclic transmission each time the trigger is received. On the other hand, when the trigger occurs at intervals of several cycles, each of the station devices 102a to 102d not only performs the cyclic transmission each time the trigger is received, but also each of the station devices 102a to 102d between the triggers. Cyclic transmission is performed by counting one cycle interval independently. In this case, the main role of the trigger is to match the shift of the cycle of each of the station devices 102a to 102d.

Further, each of the station devices 102a to 102d may perform the cyclic transmission at the same time as receiving the trigger, or wait for a minute interval (must be smaller than one cycle) after receiving the trigger, and then perform the cycle. Click transmission may be performed. If cyclic transmission is performed after waiting for a small interval, the instantaneous load on the switching hub can be reduced.

In this cyclic transmission, the communication protocol used may be TCP / IP or UDP / IP. However, regarding the trigger, each station device 102a
To d at the same time, and it is natural to use UDP / IP. In the case of TCP / IP, Ack for cyclic data can be replaced with Ack for TCP / IP.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and a switching hub, a certain station device sends a trigger by broadcast notification,
At the timing of receiving the trigger, cyclic data is bidirectionally circulated using the logical bidirectional ring formed between the station devices, and the cyclic data arriving from the neighboring station is
If it has been received for the first time, it is discarded without being transferred to the other neighboring station, so that cyclic transmission for real-time communication and transient transmission for non-real-time communication are performed, and furthermore, failure of the station device is detected. It becomes possible.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

Embodiment 4 FIG. Next, a data communication system according to the fourth embodiment will be described. In the present embodiment, a logical system configuration as shown in FIG. The basic procedure of cyclic transmission in the present embodiment will be described below. (1). The master station broadcasts the trigger at regular intervals. (2). Each station device 1 triggered by the master station
02a to 02d periodically transmit cyclic data to the previous station and the next station in synchronization with the trigger. (3). When cyclic data is received, it is checked whether the data is cyclic data transmitted from the own station device. If the cyclic data is transmitted from a device other than the own station device, the received cyclic data is stored. Then, transfer to the neighboring station. If the received data is cyclic data transmitted from the own station device, the received cyclic data is discarded. (1) and (2) are processes for transmitting cyclic data transmitted by the own station, and (3) are processes for cyclic data transmitted from another station. Therefore, (1), (2) and (3) are processed in parallel.

FIGS. 14 to 16 show the case where the master station is the station apparatus 10.
FIG. 2B is a diagram showing the behavior of cyclic data transmitted from the station device 102a as 2a. The behavior of cyclic data transmitted from the station device 102a will be described below with reference to FIGS. (1). First, as shown in FIG. 14A, the master station (station device 102a) transmits a trigger to each of the station devices 102a to 102d (701). (2). Next, as shown in FIG. 14B, upon receiving a trigger, the station device 102a transmits cyclic data to the next station 102b (702). (3). Next, as shown in FIG.
02a transmits cyclic data to the preceding station 102d (703). On the other hand, the station device 102b is
, And transmits the cyclic data of the station device 102a to the next station 102c (704).
At this time, the station device 102b stores the received cyclic data of the station device 102a. (4). Next, as shown in FIG.
02d receives the cyclic data of the station device 102a and transmits the cyclic data of the station device 102a to the preceding station 102c (705). At this time, the station device 102d
The received cyclic data of the station device 102a is stored. On the other hand, the station device 102c receives the cyclic data of the station device 102a, and sends the cyclic data to the next station 102d.
Is transmitted (706). At this time,
The station device 102c stores the received cyclic data of the station device 102a. (5). Next, as shown in FIG.
02c receives the cyclic data of the station device 102a and transmits the cyclic data of the station device 102a to the preceding station 102b (707). At this time, the station device 102c
Since the cyclic data of the station device 102a has already been received once, the cyclic data of the station device 102a received again may be saved or may be discarded as it is. On the other hand, the station device 102d
a, and transmits the cyclic data of the station device 102a to the next station 102a (70).
8). At this time, the station device 102d has already
Since the cyclic data of 2a has been received, the cyclic data of the station device 102a received again may be saved or may be discarded as it is. Then, the station apparatus 102a receives the cyclic data of the station apparatus 102a and receives the cyclic data of the own station, and discards the cyclic data. (6). Next, as shown in FIG.
02b receives the cyclic data of the station device 102a and transmits the cyclic data of the station device 102a to the preceding station 102a (709). At this time, the station device 102b
Since the cyclic data of the station device 102a has already been received once, the cyclic data of the station device 102a received again may be saved or may be discarded as it is. Then, the station device 102a is
Since the cyclic data of 2a is received and the cyclic data of the own station is received, this is discarded.

The same as the above (2) to (7) occurs in parallel with respect to all the cyclic data transmitted from each of the station devices 102a to 102d.

In this cyclic transmission, if the local station that has transmitted cyclic data does not receive its own cyclic data transmitted several times in succession once or twice, any of the cyclic transmission paths Station device 102
Alternatively, it is determined that a failure has occurred in the communication cable 103 between the switching hub device 101 and the station device 102. Also, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

The master station (station device 102a) may generate a trigger for each cycle of transmitting the cyclic data, or may generate a trigger at intervals of several cycles. When the trigger is generated every cycle, each of the station devices 102a to 102d performs cyclic transmission each time the trigger is received. On the other hand, when the trigger occurs at intervals of several cycles, each of the station devices 102a to 102d not only performs the cyclic transmission each time the trigger is received, but also each of the station devices 102a to 102d between the triggers. Cyclic transmission is performed by counting one cycle interval independently. In this case, the main role of the trigger is to match the shift of the cycle of each of the station devices 102a to 102d.

Further, each of the station devices 102a to 102d may perform the cyclic transmission at the same time as receiving the trigger, or wait for a minute interval (must be smaller than one cycle) after receiving the trigger, and then perform the cycle. Click transmission may be performed. If cyclic transmission is performed after waiting for a small interval, the instantaneous load on the switching hub can be reduced.

In this cyclic transmission, the communication protocol used may be TCP / IP or UDP / IP. However, regarding the trigger, each station device 102a
To d at the same time, and it is natural to use UDP / IP.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and a switching hub, a certain station device sends out a broadcast notification from a certain station device and forms it between the station devices at the timing of receiving the trigger. The cyclic data is bidirectionally circulated using the logical bidirectional ring, and if the cyclic data received from the neighboring station is cyclic data of another station device, the cyclic data is always transferred to the other neighboring station. By discarding if the cyclic data received from the station is the cyclic data of the own station device,
It is possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of a station device.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

Embodiment 5 FIG. Next, a data communication system according to the fifth embodiment will be described. FIG. 17 is a logical system configuration diagram including the switching hub device 101 and the station device 102 when performing the cyclic transmission. This system configuration is mainly used for transmission of high-speed cyclic data. In the present system configuration for cyclic transmission, a logical unidirectional ring composed of paths 801a to 801d for transmitting a failure detection token (failure detection data) circulating between the station devices 102a to 102d, It comprises a path 802a-f for transmitting cyclic data between the devices 102a-d. Routes 802a to 802f through which cyclic data flows are established so that each station device is connected in a mesh.

The basic procedure of cyclic transmission according to the present embodiment will be described below. (1). When a token is received from a neighboring station, the token is transferred to the other neighboring station. (2). Each of the station devices 102a to 102d sends cyclic data to all other stations at regular intervals regardless of the behavior of the token. The process (1) relating to the token and the process (2) relating to the cyclic data are independent. Therefore, (1) and (2) are processed in parallel.

FIGS. 18 to 20 are diagrams showing tokens circulating between the station devices 102a to 102d and the behavior of cyclic data transmitted from the station device 102a. The behavior of the token circulating between the station devices 102a to 102d will be described below with reference to FIGS. (1). As shown in FIG. 18A, the station device 102a
Is in the state where the token is held, the neighboring station device 102b
(901). (2). Next, as shown in FIG.
02b receives the token transmitted from the station device 102a and transfers it to the station device 102c (902). (3). Next, as shown in FIG.
02c receives the token transmitted from the station device 102b and transfers it to the station device 102d (903). (4). Next, as shown in FIG.
02d receives the token transmitted from the station device 102c and transfers it to the station device 102a (904). At the initial stage of the cyclic transmission, one of the station devices 102a to 102d generates a token and starts to loop the token.

Further, referring to FIG.
The behavior of cyclic data transmitted from a will be described. (1). As shown in FIG. 20, the station device 102a simultaneously transmits cyclic data to each of the station devices 102b to 102d asynchronously with the token (905a to 905c).
The same thing as described above occurs in parallel for all the cyclic data transmitted from each of the station devices 102a to 102d. Also, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

In this cyclic transmission, the token is circulated to detect the occurrence of a failure in each of the station devices 102a to 102d. Therefore, when the token is circulated using TCP / IP, transmission of the token to the neighbor station is attempted, and a failure occurs in the neighbor station when TCP / IP Ack for the token transmission does not return. Detect that On the other hand, when the token is circulated using UDP / IP, an Ack is returned to the transmission source in response to the token reception, an attempt is made to transmit the token to a neighboring station, and the Ack for the token transmission does not return. At that point, it detects that a fault has occurred in the neighboring station. Alternatively, when the token is circulated using UDP / IP, if the token does not circulate for a certain period of time (the time required for the token to make one round), a failure occurs in any of the station devices. Detects the occurrence.

The cyclic data is transmitted to each station device 10.
When transmitting to 2a-d, either TCP / IP or UDP / IP may be used. However, when TCP / IP or UDP / IP unicast is used, it must be transmitted to each of the station devices 102a to 102d one by one. When using UDP / IP broadcast, it is possible to transmit to each station device 102a-d at once.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and a switching hub, a token circulates between a plurality of station devices connected via a switching hub, and each station device transmits a token. Performs cyclic transmission for real-time communication and transient transmission for non-real-time communication by broadcast notification of the local station's cyclic data at its own timing asynchronously, and detects faults in the station apparatus. Becomes possible.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

Embodiment 6 FIG. Next, a data communication system according to Embodiment 6 will be described. FIG. 21 is a logical system configuration diagram including the switching hub device 101 and the station device 102 when performing cyclic transmission. Each of the station devices 102a to 102d has a route 1001a to 100f.
Are connected in a mesh form. The system configuration for cyclic transmission is mainly used for transmitting high-speed cyclic data. In this system configuration for cyclic transmission, a station that generates a trigger in a station device is called a master station (station device 102a in FIG. 21) and is established between the master station (station device 102a) and each of the station devices 102b to 102d. The trigger is transmitted from the master station (station device 102a) 102a to each of the station devices 102b to 102d via the routes 1001a, 100d, and 100e.

The basic procedure of cyclic transmission according to the present embodiment will be described below. (1). The master station broadcasts the trigger at regular intervals. (2). Each station device 1 triggered by the master station
02a-d periodically sends cyclic data to all other stations in synchronization with the trigger.

FIG. 22 is a diagram showing the behavior of cyclic data transmitted from the station device 102a when the master station is the station device 102a. Hereinafter, the behavior of the cyclic data transmitted from the station device 102a will be described with reference to FIG. (1). As shown in FIG. 22A, the master station (station device 102a) transmits a trigger to each of the station devices 102a to 102d (1101a to 110c). (2). Next, as shown in FIG. 22B, upon receiving a trigger, the station device 102a transmits cyclic data to the station devices 102b to 102d simultaneously (1102a).
~ C). The same thing as the above (2) is performed in each of the station devices 102a to
This occurs in parallel for all cyclic data sent from d.

If each of the station devices 102a to 102d does not receive cyclic data from a certain station device several times in a row, a failure occurs in a station device that has not transmitted cyclic data several times in a row. Judge that there is. Also, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

The trigger may be generated for each cycle of transmitting the cyclic data, or may be generated at intervals of several cycles. When the trigger is generated every cycle, each of the station devices 102a to 102d performs cyclic transmission each time the trigger is received. On the other hand, when the trigger is generated at intervals of several cycles, each of the station devices 102a to 102d performs cyclic transmission each time the trigger is received, and between the triggers.
d performs cyclic transmission by counting one cycle interval independently. In this case, the trigger is each station device 102
The main role is to adjust the shift of the periods a to d.

Further, each of the station devices 102a to 102d may perform the cyclic transmission at the same time as receiving the trigger, or wait for a minute interval (must be smaller than one cycle) after receiving the trigger, and then perform the cycle. Click transmission may be performed. If cyclic transmission is performed after waiting for a small interval, the instantaneous load on the switching hub can be reduced.

In this cyclic transmission, the communication protocol used may be TCP / IP or UDP / IP. However, regarding the trigger, each station device 102a
To d at the same time, and it is natural to use UDP / IP. On the other hand, with regard to cyclic data transmission, when TCP / IP or UDP / IP unicast is used, it must be transmitted to each of the station devices 102a to 102d one by one. When using the UDP / IP broadcast, it is possible to transmit to the station devices 102a to 102d at once.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and a switching hub, a certain station device transmits a broadcast notification of a trigger, and each station device transmits its own notification at the timing of receiving the trigger. By broadcasting the cyclic data of the device, it is possible to perform the cyclic transmission for performing the real-time communication and the transient transmission for performing the non-real-time communication, and to detect the failure of the station device.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

Embodiment 7 Next, a data communication system according to the seventh embodiment will be described. In the present embodiment, a logical system configuration as shown in FIG. 21 is adopted similarly to the sixth embodiment, and is mainly used for transmitting high-speed cyclic data. (1). The master station broadcasts the trigger at regular intervals. (2). Each station device 1 triggered by the master station
02a-d periodically sends cyclic data to all other stations in synchronization with the trigger. (3). Station device 102 that has received the cyclic data
a to d are Ack to the source station device of the cyclic data.
return it. (1) and (2) are processes for transmitting cyclic data of the own station, and (3) are processes for cyclic data transmitted from another station. for that reason,
(1), (2) and (3) are processed in parallel.

FIGS. 23 and 24 are diagrams showing the behavior of cyclic data transmitted from the station device 102a when the master station is the station device 102a. The behavior of cyclic data transmitted from the station device 102a will be described below with reference to FIGS. (1). As shown in FIG. 23A, the master station (station device 102a) transmits a trigger to each of the station devices 102a to 102d (1201a to 1201c). (2). Next, as shown in FIG. 23B, upon receiving a trigger, the station device 102a transmits cyclic data to the station devices 102b to 102d all at once (1202a).
~ C). (3). Next, as shown in FIG.
Station devices 102b to 102d that have received the cyclic data of
Returns Ack to the station device 102a (1203a
~ C). The same thing as the above (2) to (3) is performed by each station device 1
Occurs in parallel for all of the cyclic data sent from 02a-d.

Each of the station devices 102a to 102d continuously transmits the Ack if the Ack does not return from the certain station device several times in response to the cyclic data transmitted from the own station.
It is determined that a failure has occurred in the station device that did not return the. Also, when performing the transient transmission, the transmission is performed while the cyclic transmission is not being performed.

The trigger may be generated for each cycle of transmitting the cyclic data, or may be generated at intervals of several cycles. When the trigger is generated every cycle, each of the station devices 102a to 102d performs cyclic transmission each time the trigger is received. On the other hand, when the trigger is generated at intervals of several cycles, each of the station devices 102a to 102d performs cyclic transmission each time the trigger is received, and between the triggers.
d performs cyclic transmission by counting one cycle interval independently. In this case, the trigger is each station device 102
The main role is to adjust the shift of the periods a to d.

Further, each of the station devices 102a to 102d may perform the cyclic transmission at the same time as receiving the trigger, or wait for a minute interval (must be smaller than one cycle) after receiving the trigger, and then perform the cycle. Click transmission may be performed. If cyclic transmission is performed after waiting for a small interval, the instantaneous load on the switching hub can be reduced.

In this cyclic transmission, the communication protocol used may be TCP / IP or UDP / IP. However, regarding the trigger, each station device 102a
To d at the same time, and it is natural to use UDP / IP. On the other hand, with regard to cyclic data transmission, when TCP / IP or UDP / IP unicast is used, it must be transmitted to each of the station devices 102a to 102d one by one. When TCP / IP is used, Ack for cyclic data is set to T
It can be replaced with Ack of CP / IP. U
When using the DP / IP broadcast, it is possible to transmit to each of the station devices 102a to 102d at once. Even when using UDP / IP broadcast, Ack naturally uses UDP / IP unicast for the purpose of reducing unnecessary network traffic.

As described above, in an industrial Ethernet LAN composed of a plurality of station devices and a switching hub, a certain station device transmits a broadcast notification of a trigger, and each station device transmits its own notification at the timing of receiving the trigger. Broadcast notification of the cyclic data of the device, the station device receiving the cyclic data returns an Ack to the source station device, thereby performing cyclic transmission for real-time communication and transient transmission for non-real-time communication. Further, it is possible to detect a failure of the station device.

Although the data communication system has been described in the present embodiment, the data communication method according to the present invention can be realized by the same processing as described above.

The features of the present invention described above are summarized as follows. An object of the present invention is to perform high-speed (high-period) / low-speed (low-period) cyclic transmission for real-time communication and transient transmission for non-real-time communication in an Ethernet LAN composed of a plurality of station devices and a switching hub. It is possible to perform transient transmission between high-speed / low-speed cyclic transmissions, and it is a real-time communication system capable of detecting a failure of a station device.

Further, according to the present invention, in the low-speed cyclic transmission system, a plurality of station devices connected via a switching hub constitute a logical bidirectional ring, and each station device is asynchronous (with its own timing). While simultaneously transmitting the cyclic data of the own station device to both adjacent station devices in the logical bidirectional ring, the cyclic data of the other station device received from the adjacent station is transferred to the other adjacent station, and the cyclic data is transmitted. It is a real-time communication system for circulating data in a logical two-way ring.

According to the present invention, in a low-speed cyclic transmission system, a plurality of station devices connected via a switching hub form a logical bidirectional ring, and each station device is broadcasted from a certain station device. In synchronization with the trigger, the cyclic data of the own station apparatus is simultaneously transmitted to both adjacent station apparatuses in the logical bidirectional ring, and the cyclic data of the other station apparatus received from the adjacent station is transmitted to the other adjacent station. And a real-time communication system in which cyclic data is circulated in a logical bidirectional ring.

Further, according to the present invention, in a high-speed cyclic transmission system, a token is circulated between a plurality of station devices connected via a switching hub, and each station device is asynchronous with the token (at an independent timing). It is a real-time communication system for broadcasting the cyclic data of the own station device.

Further, according to the present invention, in a high-speed cyclic transmission system, each station connected via a switching hub transmits cyclic data of its own station in synchronization with a trigger broadcast from a certain station. It is a real-time communication system for giving notification.

Further, according to the present invention, in the low-speed cyclic transmission system, each station device constituting the logical bidirectional ring receives the cyclic data from the adjacent station for the second time. It is a real-time communication system that discards data without transferring it to a neighboring station.

Further, according to the present invention, in the low-speed cyclic transmission system, each station device constituting the logical bidirectional ring must transmit the other data if the cyclic data received from the adjacent station is another device. This is a real-time communication method in which the data is transferred to a neighboring station and is discarded if the cyclic data received from the neighboring station is cyclic data of the own station.

Further, according to the present invention, in a high-speed cyclic transmission system, each station connected via a switching hub transmits an Ack to a transmission source at the time of receiving cyclic data to be broadcast. It is characterized by a communication method.

[0093]

Industrial Applicability The present invention uses an off-the-shelf general-purpose Ethernet switching hub without using a special full-duplex Ethernet hub device, and implements an industrially efficient software on the TCP / IP protocol stack of each station device. By constructing a real-time network for use, it becomes possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to further detect a failure of a station device.

Further, according to the present invention, a logical bidirectional ring is formed between the station devices to cyclically circulate cyclic data, and the cyclic data arriving from the neighboring station is received for the second time. If so, by discarding without transmitting to the other adjacent station, it is possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of the station device. Further, according to the present invention, unnecessary traffic to OA devices and the like existing on the same network is small, and therefore, it is possible to realize cyclic transmission with little influence on OA devices and the like.

Further, according to the present invention, a logical bidirectional ring is formed between the station devices to cyclically circulate cyclic data, and the cyclic data received from the adjacent station is transmitted to the other station device. If it is, transfer to the other neighbor station without fail, and if the cyclic data received from the neighbor station is the cyclic data of the own station device, discard it.
It is possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of a station device. Further, according to the present invention, unnecessary traffic to OA devices and the like existing on the same network is small, and therefore, it is possible to realize cyclic transmission with little influence on OA devices and the like.

Further, according to the present invention, a trigger is transmitted from a certain station device by broadcast notification, and at the timing when the trigger is received, both cyclic data are transmitted using a logical bidirectional ring formed between the station devices. Cyclic transmission and non-real-time communication, in which real-time communication is performed by discarding cyclic data received from a neighboring station if it is received for the second time without transferring it to the other neighboring station. , And it is possible to detect a failure of the station device.

Further, according to the present invention, a broadcast notification of a trigger is transmitted from a certain station device, and at the timing of receiving the trigger, both cyclic data are transmitted using a logical bidirectional ring formed between the station devices. If the cyclic data received from the neighboring station is cyclic data of another station device, it is always transferred to the other neighboring station, and the cyclic data received from the neighboring station is transmitted to the local station device. Then, by discarding, it is possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of the station device.

According to the present invention, an industrial Ethernet LA comprising a plurality of station devices and a switching hub is provided.
N, the token is circulated between a plurality of station devices connected via the switching hub, and each station device broadcasts its own cyclic data at its own timing asynchronously with the token, thereby It is possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of a station device.

According to the present invention, an industrial Ethernet LA comprising a plurality of station devices and a switching hub is provided.
In N, a certain station device sends a broadcast notification of a trigger, and each station device broadcasts the cyclic data of its own device at the timing of receiving the trigger, thereby performing real-time communication cyclic transmission and non-real-time communication. It is possible to perform transient transmission for communication and to detect a failure of the station device.

According to the present invention, an industrial Ethernet LA comprising a plurality of station devices and a switching hub is provided.
At N, a certain station transmits a broadcast notification of a trigger, and each station broadcasts its own cyclic data at the timing of receiving the trigger, and the station that has received the cyclic data transmits to the source station. By returning Ack to the device, it is possible to perform cyclic transmission for performing real-time communication and transient transmission for performing non-real-time communication, and to detect a failure of the station device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a physical system configuration of a data communication system according to the present invention.

FIG. 2 is a diagram showing a logical system configuration of the data communication system according to the first and second embodiments.

FIG. 3 is a diagram showing an operation example of the data communication system according to the first embodiment.

FIG. 4 is a diagram showing an operation example of the data communication system according to the first embodiment.

FIG. 5 is a diagram showing an operation example of the data communication system according to the first embodiment.

FIG. 6 is a diagram showing an operation example of the data communication system according to the second embodiment.

FIG. 7 is a diagram showing an operation example of the data communication system according to the second embodiment.

FIG. 8 is a diagram showing an operation example of the data communication system according to the second embodiment.

FIG. 9 is a diagram showing a logical system configuration of the data communication system according to the third and fourth embodiments.

FIG. 10 is a diagram showing an operation example of the data communication system according to the third embodiment.

FIG. 11 is a diagram showing an operation example of the data communication system according to the third embodiment.

FIG. 12 is a diagram showing an operation example of the data communication system according to the third embodiment.

FIG. 13 is a diagram showing an operation example of the data communication system according to the third embodiment.

FIG. 14 is a diagram showing an operation example of the data communication system according to the fourth embodiment.

FIG. 15 is a diagram showing an operation example of the data communication system according to the fourth embodiment.

FIG. 16 is a diagram showing an operation example of the data communication system according to the fourth embodiment.

FIG. 17 is a diagram showing a logical system configuration of a data communication system according to a fifth embodiment.

FIG. 18 is a diagram showing an operation example of the data communication system according to the fifth embodiment.

FIG. 19 is a diagram showing an operation example of the data communication system according to the fifth embodiment.

FIG. 20 is a diagram showing an operation example of the data communication system according to the fifth embodiment.

FIG. 21 is a diagram showing a logical system configuration of a data communication system according to the sixth and seventh embodiments.

FIG. 22 is a diagram showing an operation example of the data communication system according to the sixth embodiment.

FIG. 23 is a diagram showing an operation example of the data communication system according to the seventh embodiment.

FIG. 24 is a diagram showing an operation example of the data communication system according to the seventh embodiment.

FIG. 25 shows a conventional system (Japanese Patent Laid-Open No. 2000-9210).
The figure which shows the structure of 9).

FIG. 26 shows a conventional system (JOP-1001 FL-
FIG.

[Explanation of symbols]

101 switching hub device, 102 station device, 10
3 communication cable, 201 clockwise logic ring, 20
2 counterclockwise logic ring, 501 trigger transmission path, 502 clockwise logic ring, 503 counterclockwise logic ring, 801 token transmission path, 802 mesh transmission path, 1001 mesh transmission path.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Nagasawa 1071 Kami 5-chome, Higashi-Osone-cho, Kita-ku, Nagoya-shi, Aichi Inside Mitsubishi Electric Mechatronics Software Co., Ltd. (72) Inventor Hobo Fukatsu Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 2-3, Mitsui Electric Co., Ltd. 5K033 AA01 BA03 CA15 CB01 DA01 DA15 DB02

Claims (19)

[Claims] 1. A data communication device comprising: a plurality of data communication devices; and a relay device for relaying data communication between the plurality of data communication devices, wherein data is transmitted in two directions between the plurality of data devices via the relay device. A data communication system configuring a cyclic route to be circulated, wherein each data communication device transmits its own transmitted data to the data communication devices located on both sides of itself in the cyclic route to the relay device. The other transmission data other than the own transmission data is received via the relay device from the data communication device located on one of both sides of the self in the traveling route, and the received other transmission data is received in the traveling route. A data communication system, wherein a data communication device located on the other side of its own is transmitted to the relay device as a destination. 2. The relay device, upon receiving the self-originated data, receiving the self-originated data from a data communication device located on both sides of the self-originated data communication device that transmitted the self-originated data on the circuit route. Each of the adjacent data communication devices located on both sides of the self-originating data communication device on the circuit route is transmitted from the self-originating data communication device located on one of both sides of the self-originating data communication device on the circuit route. Received the self-originated data as the other transmission data from the relay device, and the received other transmission data to the relay device with the destination of the data communication device located on the other side of both sides of the self in the circuit path. Transmitting, the relay device, upon receiving the other transmission data from each adjacent data communication device, The data communication system according to claim 1, characterized in that transmitting the other outgoing data to the data communication apparatus other than the self outgoing data communication apparatus of the communication device located on both sides of the contact data communication apparatus. 3. Each of the data communication devices transmits, to the relay device at predetermined intervals, time-limited data necessary to reach all of the other data communication devices within a predetermined time as the self-originated data. The data communication system according to claim 1 or 2, wherein the data communication is performed. 4. The data communication system according to claim 1, wherein the relay device is an Ethernet switching hub, and each of the data communication devices is a data communication device having an Ethernet interface. The data communication system according to any one of claims 1 to 3. 5. The data communication device according to claim 1, wherein the other transmission data received via the relay device from a data communication device located on one of both sides of the data communication device on the circuit route includes an already received data already received. The data communication system according to any one of claims 1 to 4, wherein when the data is the same, the received other transmission data is not transmitted to the relay device. 6. When each of the data communication devices receives the self-originated data via the relay device from a data communication device located on one of both sides of the data communication device, the received self-originated data is received. The data communication system according to any one of claims 1 to 4, wherein the data communication is not transmitted to the relay device. 7. The data communication device according to claim 1, wherein each of the data communication devices transmits the self-originated data to the relay device asynchronously with another data communication device. A data communication system as described. 8. Each of the data communication devices transmits the self-originated data to the relay device in synchronization with a transmission instruction for instructing the data communication devices to transmit the self-originated data. The data communication system according to claim 1, wherein: 9. When each of the data communication devices receives the other transmission data via the relay device from a data communication device located on one of both sides of the data communication device on the circuit route, receiving the other transmission data. 5. A acknowledgment to the data communication device located on one side of both sides of the self in the circuit route.
The data communication system according to any one of the above. 10. A data communication system comprising: a plurality of data communication devices; and a relay device for relaying data communication between the plurality of data communication devices, wherein each data communication device transmits another data communication device within a predetermined time. The time data required to reach all of the data communication devices is transmitted to the other data communication device via the relay device at regular intervals, and the relay device is received from each data communication device. A data communication system wherein the time data is broadcast to all data communication devices other than the data communication device that transmitted the time data. 11. The data communication system according to claim 1, wherein the relay device is an Ethernet switching hub, and each of the data communication devices is a data communication device having an Ethernet interface. The data communication system according to claim 10. 12. At least one of the plurality of data communication devices transmits failure detection data for failure detection, and the relay device transmits the failure detection data to the plurality of data communication devices. The data communication system according to claim 10, wherein the data communication device transfers the failure detection data between the plurality of data communication devices. 13. The data communication device according to claim 1, wherein each of the data communication devices transmits the timed data to the relay device in synchronization with a transmission instruction for instructing the data communication device to transmit the timed data. Item 13. The data communication system according to any one of Items 10 to 12. 14. The data communication device, wherein each of the data communication devices receives timed data transmitted from another data communication device via the relay device, and confirms reception of the received timed data by transmitting the timed data. The transmission is performed through the relay device to the communication device.
14. The data communication system according to claim 13. 15. The relay device according to claim 1, wherein each of the data communication devices transmits non-timed data that is not required to reach all of the other data communication devices within a predetermined time while the timed data is not transmitted. The data communication system according to claim 3, wherein the data communication system can transmit the data. 16. Using a plurality of data communication devices and a relay device for relaying data communication between the plurality of data communication devices, forming an adjacency between the plurality of data devices, and A data communication method in which data is circulated in two directions, wherein each data communication device transmits its own transmission data to the relay device with the data communication devices located on both sides of itself as destinations. A data communication device which receives other transmission data other than the own transmission data from the data communication device located on one of both sides of the own device via the relay device, and receives the received other transmission data on the other side of the self. Data transmission to the relay device as a destination. 17. The relay device, when receiving the self-originated data, transmits the self-originated data received to data communication devices located on both sides of the self-originated data communication device that transmitted the self-originated data. Transmitting, each of the adjacent data communication devices located on both sides of the self-originating data communication device, the self-originating data transmitted from the self-originating data communication device located on one of both sides of the own as the other transmission data The other transmission data received from the relay device and transmitted to the relay device with the data communication device located on the other side of both sides of the self being transmitted to the relay device, and the relay device transmits the other transmission data from each adjacent data communication device. When receiving outgoing data, data communication devices other than the self-originating data communication device among the data communication devices located on both sides of each of the adjacent data communication devices Data communication method of claim 16, wherein the transmitting the other outgoing data for. 18. The data communication device according to claim 1, wherein the self-originated data transmits, to the relay device at regular intervals, timed data necessary to reach all the other data communication devices within a fixed time. The data communication method according to claim 16, wherein the data is transmitted. 19. A data communication method using a plurality of data communication devices and a relay device that relays data communication between the plurality of data communication devices, wherein each data communication device transmits another data communication device within a predetermined time. The time data required to reach all of the data communication devices is transmitted to the other data communication device via the relay device at regular intervals, and the relay device is received from each data communication device. A data communication method, wherein timed data is broadcast to all data communication devices other than the data communication device that transmitted the timed data.