JP2002237822A - Communication control system and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deliver and receive data by reducing the number of communication channels at a low cost and freely externally commanding a controller. SOLUTION: A communication control system comprises the step of time dividing transmitting/receiving data to be transmitted/received between a controller 1, a controller 2 and a monitor 3 at a time in response to a necessary communication frequency between the controller 1, the controller 2 and the monitor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control system and method for efficiently using a communication line.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional communication connection between controllers. Controller 1, 2
Is a control device for controlling a predetermined control target. The monitor 3 is a monitor for monitoring the state of the controller 1. As shown in FIG. 6, the controller 1 and the controller 2 have a communication function, and one communication line is established between the controller 1 and the controller 2. Another communication line is also established between the controller 1 and the monitor 3. Since the monitor 3 only monitors the state of the controller 1 as necessary, the amount of communication traffic between the controller 1 and the monitor 3 is smaller than the amount of communication traffic between the controller 1 and the controller 2. ing.

As shown in FIG. 6, conventionally, when trying to communicate between controllers and the like, a communication line is required for each communication partner. Therefore, even for communication with a small communication traffic amount such as communication between the controller 1 and the monitor 3, that is, communication with a low communication frequency, it is necessary to add a communication line, and there is a problem that the cost increases. Was.

FIG. 7 is a block diagram showing a conventional communication connection between a plurality of controllers. As shown in FIG. 7, one communication line is opened between the master controller 4 and the slave controllers 5 and 6, and one between the master controller 4 and the slave controller 7. The master controller 4 and the slave controllers 5 to 7 perform synchronous communication via respective communication lines. However, the synchronous communication between the master controller 4 and the slave controllers 5 and 6 is, for example,
It is assumed that the communication is performed every 1 ms, and the synchronous communication between the master controller 4 and the slave controller 7 is performed every 125 μs.

As shown in FIG. 7, when performing synchronous communication with a plurality of controllers, a dedicated communication line different from this communication line is used for communication with controllers having different synchronous communication periods. Need to be added, and there is a problem that the cost increases.

[0006]

As described above, the conventional communication system has the following two problems. (1) When communication between controllers or the like is to be performed, a communication line is required for each communication partner. Therefore, even when trying to communicate with a communication partner with a low communication frequency, it is necessary to newly add a communication line, which increases the number of communication lines and increases the cost. (2) When performing synchronous communication with a plurality of controllers, it is necessary to add a dedicated communication line different from other communication lines for communication with a controller having a different synchronous communication cycle. However, the number of communication lines increases and the cost increases.

[0007] It is an object of the present invention to provide a communication control system and method capable of reducing the number of communication lines.

[0008]

In order to solve the above-mentioned problems, the present invention provides a first control device, a plurality of second control devices communicating with the first control device, and the first control device. In a communication control system including a control device and a communication line connecting the second control device, one communication line connecting the first control device and each of the second control devices is provided. The transmission / reception data to be transmitted / received is time-divided into respective transmission / reception data between the first control device and each of the second control devices.

In the communication control system of the present invention, transmission / reception between the first control device and the plurality of second control devices is performed by time-dividing the transmission / reception data into a time corresponding to the communication frequency between the control devices. Since it can be realized by one communication line, the number of communication lines can be reduced.

In another communication control system according to the present invention, a first control device, a plurality of second control devices for performing synchronous communication with the first control device, the first control device, In a communication control system including a communication line connecting each second control device, transmission / reception data transmitted / received on one communication line connecting the first control device and each second control device is: , A predetermined period of all synchronous communication between the first control device and each of the second control devices is time-divided by a unit time that can be completely divided, and the first control device and each of the second control devices are time-divided. The transmission / reception data transmitted / received to / from the two control devices is, for each predetermined cycle,
The data is allocated and output as data within the unit time.

In the communication control system according to the present invention, even when synchronous communication is performed, transmission / reception data is divided into unit times that can divide all predetermined periods of each synchronous communication without fail, and each unit time is divided into predetermined unit times. For each cycle, the first control device and the plurality of second control devices can be assigned to each communication. Therefore, in the communication control system of the present invention, the synchronous communication between the first control device and each of the second control devices can be realized by one communication line, so that the number of communication lines can be reduced. Can be.

[0012]

Next, a communication control system and method according to an embodiment of the present invention will be described in detail with reference to the drawings. In all the drawings, the components denoted by the same reference numerals all indicate the same components.

(First Embodiment) First, a communication control system and method according to a first embodiment of the present invention will be described. FIG. 1 is a block diagram illustrating a configuration of a communication control system according to the present embodiment. As shown in FIG. 1, the communication control system of the present embodiment is different from the communication control system of FIG. 6 in that the controllers 1, 2 and the monitor 3 are connected by only one communication line. . In the communication control system of the present embodiment, a controller 1 as a first control device, a controller 2 as a second control device, and a monitor 3
The transmission / reception data transmitted / received through one communication line that connects the two is time-divided into transmission / reception data between the controller 1 and the controller 2 and the monitor 3 according to the ratio of the respective communication frequencies.

FIG. 2 is a diagram showing an example of transmission / reception data transmitted / received through a communication line of the communication control system according to the present embodiment. FIG. 2A shows data transmitted from the controller 2 and the monitor 3 to the controller 1.
This data is sent from the command from the controller 2 and the monitor 3
It is time-shared with the command from. Controller 2
A command is issued to the communication line at times t _{0 to} t ₁ and times t _{2 to} t ₃ ,
The monitor 3 transmits the time-division transmission data shown in FIG. 2A to the controller 1 via the communication line if the monitor 3 issues a command to the communication line at times t _{1 to} t ₂ and times t _{3 to} t ₄ . can do. Note that such time-division data may be synchronous communication defined at a predetermined timing,
The controller 2 and the monitor 3 may communicate data asynchronously while checking whether a communication line is free.

FIG. 2B shows data transmitted from the controller 1 to the controller 2 and the monitor 3. This data is sent to the controller 2
It is time-divided into monitor information for the monitor 3. Controller 1, time t ₅ ~t _6, issues a response to the controller 2 to the communication line to the time t ₇ ~t _8, time t ₆ ~t _7, time t
If the ₈ ~t ₉ to emit monitor information to a communication line,
The time-division data shown in FIG. 2B can be transmitted to the controller 2 and the monitor 3 via a communication line. The controller 2 receives data to be transmitted to the time t ₅ ~t _6, time t ₇ ~t ₈ as data to itself, the monitor 3
Receives data transmitted at times t _{6 to} t ₇ and times t _{8 to} t ₉ as data to itself. It should be noted that such time-division data may be synchronous communication defined at a predetermined timing, or may be performed asynchronously by adding a code for identifying a transmission partner to the first data of the transmission data. Asynchronous communication may be performed.

As described above, in the communication control system according to the present embodiment, one controller transmits data to a plurality of partners and a plurality of controllers transmits one data to the same partner.
Since it can be sent together in one transmission data,
Communication with a plurality of partners can be realized by one communication line. Therefore, the communication control system of the present embodiment
The number of communication lines can be reduced.

In the communication control system according to the present embodiment, the command data transmitted from the controller 2 and the monitor 3 to the controller 1 is time-divided as shown in FIG. 2 (a). Is not limited to this, and may be time-divided as shown in FIG.
In the communication control system of the present invention, the time division ratio of data can be arbitrarily determined according to the communication frequency of the communication partner, and the allocation pattern is also arbitrary.

(Second Embodiment) Next, a communication control system and method according to a second embodiment of the present invention will be described. FIG. 4 is a block diagram illustrating a configuration of the communication control system according to the present embodiment. As shown in FIG. 4, in the communication control system of the present embodiment, the master controller 4 as the first control device and the slave controllers 5 to 7 as the second control devices are connected by one communication line. This is different from the communication control system of FIG. In the communication control system according to the present embodiment, transmission / reception data transmitted through one communication line connecting the master controller 4 and the slave controllers 5 to 7 includes all data transmitted and received between the master controller 4 and the slave controllers 5 to 7. The predetermined period of the synchronous communication is time-divided by a unit time that can be completely divided, and the master controller 4 and the slave controllers 5 to 5
7 is output as data within a unit time at each predetermined cycle.

FIG. 5 is a diagram showing an example of transmission / reception data transmitted / received through a communication line of the communication control system according to the present embodiment. This data is data transmitted from the master controller 4 to the slave controllers 5 to 7 during one cycle. The head of the communication data is synchronization data for synchronization between the transmission side and the reception side. Thereafter, data for the slave controller 5, data for the slave controller 6, data for the slave controller 5, data for the slave controller 7, data for the slave controller 5,...

In the communication control system of this embodiment, one cycle is 1 ms, and the division time of each piece of communication data is 62.5 μs, which is a unit time that can be transmitted to up to eight stations in one cycle. Therefore, the communication from the master controller 4 to the slave controller 5 is synchronous communication every 125 μs, and the communication from the master controller 4 to the slave controllers 6 and 7 is synchronous communication every 1 ms.

Although FIG. 5 shows data transmitted from the master controller 4 to the slave controllers 5 to 7, the same time-divisional assignment is also performed for data transmitted from the slave controllers 5 to 7 to the master controller 4. It will be readily understood by those skilled in the art.

As described above, in the communication control system according to the present embodiment, even when synchronous communication is performed, transmission / reception data is transmitted at a predetermined period of 1 ms (1000 μm) for each synchronous communication.
s), a unit time capable of dividing 125 μs as much as possible
The time is divided into 5 μs, and each unit time of 62.5 μs can be allocated to the communication between the master controller 4 and the slave controllers 5 to 7 at predetermined intervals of 1 ms and 125 μs. Therefore, in the communication control system of the present invention, the synchronous communication between the master controller 4 and the slave controllers 5 to 7 can be realized by one communication line, so that the number of communication lines can be reduced.

In the communication control system of the present embodiment, the unit time is set to 62.5 μs. However, the communication control system of the present invention is not limited to this, and may vary depending on the period required for synchronous communication. Those skilled in the art will readily understand that various settings are possible.

[0024]

As described above, the communication control system and method of the present invention have the following two effects. (1) By time-dividing the time according to the communication frequency between the control devices, transmission and reception between the control devices can be realized by one communication line, so that the number of communication lines can be reduced. , Cost can be reduced. Also,
A command can be freely transmitted from the outside to the control device, and data can be exchanged with the control device without adding a communication line. (2) Even in the case of performing synchronous communication, transmission / reception data is divided into unit times that can divide all the predetermined periods of each synchronous communication without fail, and each unit time is divided into a plurality of units by the master controller every predetermined period. It can be assigned to each communication with the slave controller. for that reason,
Since the synchronous communication between the master controller and each slave controller can be realized by one communication line, the number of communication lines can be reduced, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a communication control system according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of transmission / reception data transmitted / received through a communication line of the communication control system according to the first embodiment of the present invention.

FIG. 3 is a diagram showing another example of transmission / reception data transmitted / received in a communication line of the communication control system according to the first embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a communication control system according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of transmission / reception data transmitted / received in a communication line of a communication control system according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing a conventional communication connection mode between controllers.

FIG. 7 is a block diagram showing a conventional communication connection mode between a plurality of controllers.

[Description of Signs] 1, 2 Controller 3 Monitor 4 Master Controller 5, 6, 7 Slave Controller

Claims (4)

[Claims] 1. A first control device, a plurality of second control devices communicating with the first control device, and a connection between the first control device and the second control device. In a communication control system including a communication line, transmission / reception data transmitted / received through one communication line connecting the first control device and each of the second control devices includes the first control device and the respective A communication control system characterized in that transmission / reception data is time-divided into transmission / reception data according to a ratio of a communication frequency with a second control device. 2. A first control device, a plurality of second control devices that perform synchronous communication with the first control device, and a connection between the first control device and each of the second control devices. In a communication control system including a communication line, transmission / reception data transmitted / received through one communication line connecting the first control device and each of the second control devices includes the first control device and the respective A predetermined period of all synchronous communication with the second control device is time-divided by a unit time that can be divided without any excess, and is transmitted and received between the first control device and each of the second control devices. A communication control system, wherein each transmission / reception data is allocated and output as data within the unit time at each predetermined cycle. 3. A first control device, a plurality of second control devices communicating with the first control device, and a connection between the first control device and the second control device. A communication control method for a system including a communication line, wherein the transmission and reception data transmitted and received by one communication line connecting the first control device and each of the second control devices is transmitted to the first control device. A communication control method for transmitting and receiving data in a time-division manner according to a ratio of a communication frequency between a device and each of the second control devices. 4. A first control device, a plurality of second control devices performing synchronous communication with the first control device, and the first control device;
A communication control method for a system comprising a control device and a communication line connecting each of the second control devices, wherein one of the first control device and each of the second control devices is connected. The transmission / reception data transmitted through the communication line is transmitted to the first
A predetermined period of all synchronous communication between the first control device and each of the second control devices is time-divided by a unit time that can be divided without excess, and the first control device and each of the second control devices are divided. A communication control method of allocating transmission / reception data transmitted / received to / from the communication line for each predetermined cycle as data within the unit time and outputting the data to the communication line.