JPH0630000A - Dual control system for communication line - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the application from burdening the management of which of the duplexed communication lines is available. In a communication system in which a plurality of control devices 10, 20, 30, ... 40 are connected to duplicated communication lines 1 and 2, each of the control devices has a respective communication line 1, 2.
A control table from the control device A to the control device B is provided with a conversion table between a logical address and a physical address that unifies two sets of communication addresses (logical address 1, physical address 1, and logical address 2, physical address 2) corresponding to When transmitting to the device, referring to the conversion table, the logical data 1 of the controller A, the logical address 1 of the controller B, the physical address 2 of the controller A, and the physical address 2 of the controller B are combined to transmit data. Make up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a duplication control system applicable to a cooling and heating plant, a control device for a boiler or the like, between control devices connected by a duplication communication line.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a communication system having a conventional duplicated communication line. Communication lines 2 and 3
, A plurality of nodes, node A10 in FIG.
B20, C30, and D40 are connected, and these can be regarded as a control device.

Each node is connected by two lines of communication lines 1 and 2 because one of the communication lines is broken or the communication control circuits 13, 14, 23 provided in the nodes A10, B20, C30, D40. , 24, 33, 34, 4
This is to secure a normal communication line and a communication control circuit and maintain a communicable state even if any of the components 3, 44 (described later) fails.

A node A10 shown in FIG. 3 comprises a system bus 11, a CPU 12, communication control circuits 13 and 14, and a memory 15. System bus 11
Is the CPU 12, the memory 15, the communication control circuits 13 and 14
Connect to each other. The CPU 12 is the center of the control device, and executes control of the communication control circuit 13 and the like, control of the memory 15 and the like, processing given to the control device, and the like. The communication control circuit 13 is connected to the communication line 1, and the communication control circuit 14
Is connected to the communication line 2. A conversion table between the logical address and the physical address as shown in FIG. 4 is stored in the memory 15 for each of the communication line 1 and the communication line 2.

Since the configurations of the node B20, the node C30, and the node D40 are the same as those of the node A10, the description thereof will be omitted.

Next, a logical address and a physical address will be described in order to explain a method of communication between nodes. The logical address is an address used by the application program (application 100) executed in the control device (node), and is expressed by a combination of each node number and communication line number.

For example, the node number hostid for the node A10
= 1 and the communication line used is communication line 1 and communication line number netid = 1, the logical address of node A is (ne
tid, hostid) = (1,1). When the node A uses the communication line 2, (netid, hostid) = (2, 1) becomes a logical address. Therefore, if the communication line is duplicated, each node will have two logical addresses.

If the communication is performed from the node A10 to the node C30 using the communication line 1, the communication is from the logical address (1,1) to (1,3).

The data structure used when communicating between nodes is as shown in FIG. FIG. 5A shows the communication processing hierarchy, and FIG. 5B shows the data structure corresponding to each hierarchy.

First, the application 100 (node A
If it is 10, it is realized by the application program stored in the CPU 12 and the memory 15) data 1 to be transmitted
03, the logical address 106 of the transmission destination and the transmission source are added, and the processing is passed to the network processing 101. The network processing 101 reconfigures the data 104, which is a combination of the data 103 and the logical address, into the data 104, and the communication control circuit 1
A physical address that can be recognized by 3, 33 is obtained from the conversion table shown in FIG. 4, and the physical address pair 107 is sent to the hardware 102 together with the previous data 104. The hardware 102 is the same as the communication control circuit 13 shown in FIG.

Since the communication control circuit 102 is hardware, it cannot be recognized unless it is a physical address rather than a logical address. The communication control circuit 102 uses the parameter 107
And the data section 104 are combined and sent to the communication line 1. At this time, as shown by the data 105 in FIG.
(Frame header) is added.

[0012]

In the case of such a conventional configuration, when the communication control circuit 33 of the node C30 connected to the duplicated communication line fails, the logical address (1,3) is assigned. It cannot be used as a destination.

That is, when the communication control circuit 33 is out of order, an attempt to transmit from the logical address (1,1) of the node A10 to the logical address (1,3) of the node C30 fails. In this case, the application 100 of the node A10 receives the report that the transmission is impossible even if the transmission request is issued to the network processing 101.
The application 100 will stop using communication line 1 and try to send again using communication line 2. That is, the transmission from the logical address (2,1) to (2,3) is tried.

As described above, when the communication line is duplicated, the application 100 needs to know which is available. For the application 100, managing such details on the hardware is a heavy burden on the software configuration.

The present invention has been made in view of the above points, and does not burden the application with management of which of the duplexed communication lines can be used. It is an object of the present invention to provide a computerized control method.

[0016]

According to the present invention, in a communication system in which a plurality of control devices are connected to a duplicated communication line, each of the control devices has two sets of communication corresponding to each communication line. When a transmission table is provided from the control device A to the control device B, it is provided with a conversion table between a logical address and a physical address that unifies addresses (logical address 1, physical address 1, and logical address 2, physical address 2).
The transmission data is configured by referring to the conversion table and combining the logical address 1 of the control device A, the logical address 1 of the control device B, the physical address 2 of the control device A, and the physical address 2 of the control device B. And

[0017]

According to this structure, since two sets of communication addresses corresponding to the duplicated communication lines are unified, for example, a logical address corresponding to one communication line of the destination cannot be used. Even in this case, the transmission data can be easily configured by using the communication address corresponding to the other communication line.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of the configuration of a communication system to which the duplex control method according to the embodiment is applied. FIG. 1 is similar to FIG. 3 used for explaining the conventional technique,
A plurality of nodes, nodes A10, B20, C30, and D40 (these can be regarded as control devices) in FIG. 1, are connected to the two communication lines 1 and 2.

The node A10 has a system bus 11 and a CP.
It is composed of U12, communication control circuits 13 and 14, a memory 15, and a memory 16. System bus 11
Is a CPU 12, memories 15 and 16, a communication control circuit 1
3 and 14 are mutually connected. The CPU 12 is the center of the control device and controls the communication control circuit 13 and the memory 1
The control of 5, 16 and the like, the processing given to the control device and the like are executed. The communication control circuit 13 is connected to the communication line 1, and the communication control circuit 14 is connected to the communication line 2. The memory 16 stores the correction conversion table for the communication lines 1 and 2 between the logical address and the physical address as shown in FIG.

Since the configurations of the node B20, the node C30, and the node D40 are the same as those of the node A10, the description thereof will be omitted.

Next, the function and effect of the embodiment will be described. As shown in FIG. 1, the correction conversion tables as shown in FIG. 2 are stored in the memories 16, 26, 36, and 46, respectively, in each control device (node) in this embodiment. Since the conversion table in the conventional control device is stored in the memory 51 separately for the communication line 1 and the communication line 2,
Although they are not related to each other, in the present invention, as shown in FIG. As a result, for example, the logical address (1,1) (1,2) of the node A10 is 100
0 or 5000 can be used.

That is, if the conversion table as shown in FIG. 2 is used, even if the logical address (1, 3) of the node C30 fails, it will be transmitted as a pair of physical addresses to the destination 200.
If 0, the sender 5000 is used and the logical address pair (1, 1) (1, 3) is used as it is, without notifying the application 100 that the communication line 1 cannot be used. It becomes possible to use the communication line 2 in the network processing 101.

Therefore, for the application 100, the processing load is reduced because it is relieved from managing the details associated with the hardware such as duplication of the communication line.

[0024]

As described above, according to the present invention, communication is performed on the basis of a conversion table between a logical address and a physical address in which one duplexed communication line is associated with each other. Since the control is performed, the application does not need to manage the details of the hardware, and thus the processing load of the application can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a communication system to which a duplex control method according to an embodiment of the present invention is applied.

FIG. 2 is a diagram for explaining an example of a correction address conversion table in this embodiment.

FIG. 3 is a diagram showing a configuration example of a conventional communication system having a duplexed communication line.

FIG. 4 is a diagram for explaining an example of a conventional address conversion table.

FIG. 5 is a diagram for explaining a communication processing layer and a data structure in each layer.

[Explanation of symbols]

1, 2 ... Communication line, 10, 20, 30, 40 ... Node, 12, 22, 32, 42 ... CPU, 13, 14, 2
3, 24, 33, 34, 43, 44 ... Communication control circuit, 1
5, 25, 35, 45, 16, 26, 36, 46 ... Memory.

Claims (1)

[Claims] 1. In a communication system in which a plurality of control devices are connected to a duplicated communication line, each of the control devices corresponds to each communication line.
A set of communication addresses (logical address 1, physical address 1,
And a conversion table between a logical address and a physical address that unifies the logical address 2 and the physical address 2), and when transmitting from the control device A to the control device B, the conversion device is referred to by referring to the conversion table. Logical address 1 of A and control device B
The communication line duplication control method is characterized in that transmission data is configured by combining the logical address 1 of the above, the physical address 2 of the control device A, and the physical address 2 of the control device B.