JP2672746B2 - Cyclic map change method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a local area network provided with a controller and connected to a plurality of nodes (data way devices) having memories of the same structure, and more particularly to a data transmission area (cyclic area) of the memory. ) Is related to the cyclic map change method that can be changed online.

[0002]

2. Description of the Related Art FIG. 7 is a system configuration diagram of a conventional local area network (LAN). In FIG. 7, 60 is a local area network (LA).
N) and 2 are the nodes (1) to which the network 5 is connected.
(3) and 11 are mounted on the node 2 (1) to node 2 (3), and cyclic memory (1) to store cyclic data to be transmitted and received cyclic data (1) to
(3) and 6 are controllers (1) to (3) respectively connected to the nodes 2 (1) to 2 (3) and controlling these nodes. The cyclic memory 11 of each node has the same memory capacity, and a data transmission area corresponding to each node (station) is assigned. Then, when data is written in the data transmission area assigned to a certain node, the written data is reflected in the same data transmission area of the respective cyclic memories 11 of all the nodes. That is, the cyclic memory 11 is allocated according to the cyclic map shown in FIG. The cyclic map of FIG. 8 is divided into a node address, a start address of the cyclic memory 11, and a data length item. The node address is a number corresponding to the nodes 2 (1) to 2 (N), and the top address of the cyclic memory is an address value in which the data of the nodes 2 (1) to 2 (N) of the cyclic memory 11 is stored. , Data length is the length of the data you want to send. According to this cyclic map, the cyclic memory 11 is allocated as shown in FIG. In FIG. 9, the data transmission area of the node 2 (1) is from the address of 100H, the data transmission area of the node 2 (2) is from the address of 150H, 20
It is allocated from the address of 0H to the data transmission area of the node 2 (3), and from the address of F00H to the data transmission area of the node 2 (N).

Cyclic communication in a conventional local area network has been performed as follows. First,
The cyclic memory 11 is fixedly allocated as shown in FIG. 9 according to the cyclic map of FIG. 8, and an application installed in the controller of each node is created. For example, the cyclic memory 11 of the node 2 (1)
The data to be transmitted is stored in the data transmission area from the first address 100H to 10H of, and is transmitted to the data transmission area of the same address in the cyclic memory 11 of each node 2 (2), 2 (3) by the local area network 6. It Similarly, each node 2 (2),
Also in 2 (3), an application is installed according to the cyclic map of FIG. 8 to perform cyclic communication.

[0004]

In the conventional cyclic communication in the local area network, since the cyclic memory is fixedly allocated, the communication can be made only by a predetermined cyclic map.
Expansion of cyclic area by system expansion,
If you want to change the cyclic map such as reduction or movement,
There is a problem that the system is forced to stop or the application is changed and the system lacks flexibility.

The present invention has been made to solve the above problems, and even if the data transmission area is changed due to system expansion or node backup,
The purpose is to obtain a flexible cyclic map changing method that can change the data transmission area while online.

[0006]

In the cyclic map changing system according to the present invention, as shown in FIG. 1, a plurality of nodes 4 each having a controller 6 and having memories of the same structure are connected to a local area network 5. , The data in the transmission area (data transmission area) of the memory assigned to the own node is sequentially broadcast to other nodes according to the transmission area information (cyclic map information) assigned to the memory of each predetermined node. Then, in the cyclic map communication in which another node receives the data and stores it in a predetermined transmission area of its own memory,
Each node is provided with a transmission area information table (cyclic map table 7) that stores the transmission area information of all the nodes, and when the node changes the transmission area of the memory with the permission of the controller, When the transmission area information is broadcast to other nodes at a constant cycle, the other nodes expand the transmission area information in the transmission area information table and change the transmission area of the memory of the own node based on the information, After the change, it is configured to notify the controller of the local node of the change.

Further, in the cyclic map changing system according to the present invention, as shown in FIG. 2, a response is requested to all the nodes that have received the transmission frame (cyclic map transmission frame 20) forming the transmission area information. Bit map information such as a request flag to be executed is provided.

[0008]

In the cyclic map changing method according to the present invention, when a certain node changes the transmission area of the memory with the permission of the controller, the transmission area information of the transmission area which the node changes via the local area network is changed to another one. Broadcast to nodes at regular intervals. The other nodes expand the transmission area information in the transmission area information table, change the transmission area of the memory based on the information, and notify the controller of the own node after the change. Therefore, each node can change the transmission area of the memory in an online state, and a more flexible system can be constructed.

Further, the cyclic map system according to the present invention is provided with bitmap information such as a request flag for requesting a response to all the nodes that have received the transmission frame constituting the transmission area information. It is possible to reliably confirm the change of the transmission area of the memory in the node and detect the failure of the node.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram of a system showing an embodiment of the present invention. In FIG. 1, 5 is a local area network, 4 is a node (1) to node (4) connected to the local area network 5, and 6 is a node connected to each of the nodes (1) to (4). A controller, 8 is a cyclic map control unit that controls cyclic map management / monitoring and cyclic communication, and 9 is a memory that stores cyclic map information as transmission area information regardless of whether the node is powered ON / OFF. EE
PROM), 10 is a cyclic memory for storing cyclic data from the controller 6 (1) and cyclic data received from the local area network 5, and 7 is a transmission area information table for storing current cyclic map information. A cyclic map table, 14 is a cyclic map change notification from the cyclic map control unit 8 to the controller 6 (1), and 15 is a cyclic map change request from the controller 6 (1).

FIG. 2 is a structural diagram of a cyclic map transmission frame which constitutes the cyclic map information.
In FIG. 2, reference numeral 20 is a cyclic map transmission frame, 20A is a counter that increments each time a cyclic map transmission frame is transmitted, a type indicating the identification of the cyclic map transmission frame, DA and SA information areas, and 20B is each. A bit map consisting of a flag of the ACK request information of the node, 20C is an area of the cyclic map information of the own node. The area 20B is divided into areas of the number of nodes connected to the local area network 5, and in FIG. 2, 0 corresponds to the ACK request flag of the node 1 and 31 corresponds to the ACK request flag of the node 32. , N-1 correspond to the ACK request flag of the node N. Further, the area 20C is divided into the area of the cyclic start address and the area of the data length shown in the conventional example of FIG. 8. By setting the types of the area 20A to 01H, 02H, and 03H, various modes can be set. it can. FIG.
Then, 01H is a fixed cycle, 02H is an ACK request, and 03H.
Is the ACK response.

FIG. 3 is a block diagram showing an ACK response frame returned when a node sets an ACK request. In FIG. 3, reference numeral 30 denotes an ACK response frame, which has an area of a counter (same value as the counter of the cyclic map transmission frame) and a type (for example, ACK of 03H).
It is divided into a response area, a DA area, and an SA area. In addition, FIG. 4 is a state diagram when the cyclic map is transmitted at a fixed cycle. As shown in FIG. 4, node 4
When the cyclic map information is transmitted from (1) to the node 4 (2), the cyclic map transmission frame 20 of FIG. 2 is transmitted in the order of the area 20A, the area 20B, and the area 20C.

The operation of this embodiment will be described. First, each node 4 (1) to 4 (4) has a controller 6
The cyclic map information shown in FIG. 2 from (1) to 6 (4) is stored in the EEPROM 9 and the cyclic map table 7.
Shall be stored in The meaning of storing cyclic map information in the EEPROM 9 is that the EEPROM 6 is not used by the controller 6 when the node is started up.
This is because the cyclic map is set according to the contents of OM9. Next, it is assumed that the node 4 (1) newly joins the local area network 5 with the nodes 4 (2) to 4 (4) joining. The node 4 (1) enters with all the cyclic map table 7 set to "0", and transmits the cyclic map information of its own node in the cyclic map transmission frame of FIG. 2 at regular intervals. Other node 4
(2) to the node 4 (4) compare the received cyclic map information of the node 4 (1) with the cyclic map information of the own node in the cyclic map table 7.
In this case, since the node 4 (2) to 4 (4) is a node 4 (1) cyclic map information is "0" with the own node, regarded as new entrants node, in the local node
The cyclic map of a certain node 4 (1) is rewritten with the received cyclic map information. At the same time, the controller 6 is notified by the cyclic map change notification 14.
Notify (2) to 6 (4) that the cyclic map has been changed. In addition, the node 4 (1) is the other node 4
(2) to 4 (4) receive the cyclic map information transmitted in a fixed cycle, and cyclic map table 7
Expand to On the other hand, conversely, the local area network 5
When leaving from, all of the cyclic map table 7 is set to "0". This is because the map on the local area network may be updated while leaving, so that the cyclic maps do not overlap when re-entering. By such an operation, all nodes can hold the same cyclic map table.

Next, the case where the node 4 (1) changes the cyclic map will be described with reference to FIGS. FIG. 5 shows a flowchart of a node on the side of changing the cyclic map, and FIG. 6 shows a flowchart of a node on the side of receiving the change of the cyclic map. First, the node 4 (1) is cycled from the controller 6 (1).
Upon receiving the lick map change request 15,
The type of the area 20A of the transmission frame 20 is 02H.
Cyclic with (ACK request) changed in area 20C
Set lickmap information. Next, the cyclic map control unit 8 broadcasts the cyclic map transmission frame 20 (step S53). The contents of the cyclic transmission frame 20 at this time are, for example, the type of the area 20A is 02H, an ACK request, the bit map of the area 20B validates the bit corresponding to the node number currently connected to the local area network, and the bit map of the area 20C. The cyclic map information of the own node is the changed cyclic map information. The cyclic map control unit 8 transmits the cyclic map transmission frame 20 to all the nodes 4 (2) ...
4 (4), and waits for the ACK response frame 30 of FIG. 3 to be returned from the node set in the bitmap of the area 20B. Node 4 (1) after a certain time
Judges whether or not there is an ACK response from all the nodes participating in the local area network 5 (steps S54, 55), and if all are present, the change ends. Also,
If there is no ACK response, the bitmap is set (ON) only for the node that does not have an ACK response (step S56), and the cyclic map transmission frame (ACK request) is transmitted again (step S53). If there is no ACK response from all the nodes even after performing the above operation several times, it is considered that the node has a single failure, and the cyclic map changing operation is terminated. On the other hand, nodes 4 (2) to 4 on the side that receives the ACK request
(4) first expands the received cyclic map information of the node 4 (1) in the cyclic map table 7 (step S61), and notifies the cyclic map change notification 14
To the controller 6 (1) (step S6
2). When the controller reads the changed cyclic map information (step S63), the nodes 4 (2) to 4 (4) transmit an ACK response to the node 4 (1). As described above, it is possible to always provide the latest cyclic map information to the controller using the cyclic map table of each node when the node joins or leaves the network or when the map is changed online by the above operation. In the above embodiment, the designation of the cyclic area is not limited to the cyclic start address, and the network is described in the ring form in the above embodiment, but the invention is not limited to this.

[0015]

As described above, according to the present invention, each node broadcasts cyclic map information to be changed of its own node at regular intervals and reflects it on the cyclic map table of other nodes. Since the controller is notified after the change, it is possible to change the cyclic area while online, and it is possible to construct a flexible system. Also,
Since all nodes that have received the cyclic map information transmission frame are provided with bitmap information such as a request flag for requesting a response, there is an effect that the change can be surely made.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a system of a local area network that performs cyclic communication according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a cyclic map transmission frame used in the system of FIG.

3 is a block diagram of an ACK response frame used in the system of FIG. 1. FIG.

FIG. 4 is a state diagram at the time of cyclic map fixed period transmission in the present invention.

FIG. 5 is a flowchart showing a modification of the cyclic map on the transmitting side according to the present invention.

FIG. 6 is a flowchart showing a modification of the cyclic map on the receiving side according to the present invention.

FIG. 7 is a configuration diagram of a conventional local area network (LAN) system that performs cyclic communication.

8 is a diagram of a cyclic map used in the cyclic communication of the system of FIG.

9 is a diagram showing cyclic allocation of a cyclic memory according to the cyclic map of FIG.

[Explanation of symbols]

 4 nodes (1) to (4) 5 local area network 6 controllers (1) to (4) 7 cyclic map table 8 cyclic map control section 9 EEPROM 10 cyclic memory 14 cyclic map change notification 15 cyclic map change request

Claims (2)

(57) [Claims] 1. A plurality of nodes, each having a controller and having a memory of the same configuration, are connected to a local area network, are assigned to a predetermined memory of each node, and are assigned to the own node according to transmission area information. When data in the transmission area is sequentially broadcast to other nodes, the other nodes receive the data and store it in a predetermined transmission area of their own memory. A transmission area information table that stores area information is provided, and when a node changes the transmission area of the memory with the permission of the controller, the transmission area information of the transmission area changed by the node is broadcast to other nodes at regular intervals. Then, another node expands the transmission area information in the transmission area information table and based on the information. A cyclic map change method characterized by changing the transmission area of the memory of the own node and notifying the change to the controller of the own node after the change. 2. The cyclic map changing method according to claim 1, further comprising bitmap information such as a request flag for requesting a response to all nodes that have received the transmission frame forming the transmission area information.