KR101275640B1 - Programmable logic controller using multiple buses - Google Patents

Abstract

A logic operation control device is provided. The logic operation control device may be a communication path between a main control unit and at least one I / O module, and may be a communication path between a first bus and a main control unit and at least one I / O module controlled by the main control unit. Including a second bus controlled by the I / O module of the present invention, it is possible to provide a high-performance bus technology specialized for the logic operation controller.

Description

Programmable logic controller using multiple buses

The present invention relates to a logic operation control device, and more particularly, to a logic operation control device using a plurality of buses.

The input / output system bus for constructing the logic operation control device generally uses a backplane bus structure. For the implementation of the backplane bus, the proven system bus standards VME64, CPCL and VXI can be used. However, the standard bus has a complicated structure for compatibility with various systems, and is not optimized for a specific field of logic operation controller.

Although a standard such as VME64 may be used to implement a system bus of a logic continuous controller, it is common in the industry to design and use a bus specialized for a logical operation controller. Since the bus structure designed by the company is not disclosed to the outside, it is difficult to objectively evaluate the bus performance of each company, and it is difficult to refer to or use the technology when developing a new logic operation control device.

If you want to develop your own logic operation control device, you have to design your own bus structure and verify the stability of the operation.

Accordingly, there is a demand for a method for developing a high-performance bus technology specialized for a logic operation control device.

The present invention has been made to solve the above problems, an object of the present invention, the first bus and the main control unit which is the communication path of the main control unit and at least one I / O module and the communication is controlled by the main control unit And a second bus which is a communication path of at least one I / O module and is controlled by the at least one I / O module.

According to an embodiment of the present invention for achieving the above object, a logic operation control apparatus, the main control unit for performing a logic operation; At least one I / O module for inputting and outputting data; A first bus that is a communication path between the main control unit and the at least one I / O module and in which communication is controlled by the main control unit; And a second bus that is a communication path between the main control unit and the at least one I / O module and is controlled by the at least one I / O module.

And connect each of the at least one I / O module with the first bus and the second bus, communicate between each of the at least one I / O module and the first bus and the at least one I / O module. At least one I / O bus controller for controlling the communication between each and the second bus; may further include.

The I / O bus controller may further include an input / output interface unit configured to transmit / receive data by modifying it according to a protocol of the I / O module; A bus controller which encodes and decodes data transmitted and received through the first bus or the second bus; An event generator configured to generate an input / output event when an event occurs in the I / O module; And a bus interface unit configured to transmit and receive data transmitted and received by the bus controller and the event generator in accordance with a bus protocol.

The event generator may transmit the generated input / output event to the main bus controller through the second bus.

The apparatus may further include a main bus controller connecting the main control unit with the first bus and the second bus and controlling communication between the main control unit and the first bus and communication between the main control unit and the second bus. You may.

The main bus controller may include: a main interface unit configured to transmit and receive data by modifying the data according to a protocol of the main controller; A bus controller which encodes and decodes data transmitted and received through the first bus or the second bus; An event handler for sorting the input / output events received from the I / O bus controller according to priority and transmitting them to the main controller; And a bus interface unit configured to transmit and receive data transmitted and received by the bus control unit and the input / output event handler according to a bus protocol.

The input / output event handler may receive the input / output event from the I / O bus controller via the second bus.

The at least one I / O module may determine whether to communicate with the main controller through the second bus by using a token including priority information.

According to various embodiments of the present disclosure, a communication path between a first bus and a main control unit and at least one I / O module, which is a communication path between a main control unit and at least one I / O module and whose communication is controlled by the main control unit, It is possible to provide a logic operation controller including a second bus which is controlled by at least one I / O module, thereby providing a high performance bus technology specialized for the logic operation controller.

1 is a block diagram showing the configuration of a logical operation control apparatus according to an embodiment of the present invention;
2 is a diagram illustrating a configuration of a main bus controller and an I / O bus controller according to an embodiment of the present invention;
3 is a diagram illustrating a communication method of an event bus according to an embodiment of the present invention.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

1 is a block diagram showing the configuration of a logic operation control apparatus 100 according to an embodiment of the present invention. As shown in FIG. 1, the logic operation controller 100 may include a main controller 110, a main bus controller 115, a first I / O module 120, a first I / O bus controller 125, Second I / O module 130, second I / O bus controller 135, third I / O module 140, third I / O bus controller 145, data bus 150, and event bus 160.

The main controller 110 performs a logical operation. In addition, the controller 110 controls the overall operation of the logic operation control device 100 and processes the input event by priority.

The main bus controller 115 connects the main controller 110 with the data bus 150 and the event bus 160, communicates between the main controller 110 and the data bus 150, and communicates with the main controller 110 and the event bus. Control communication between the 160. In detail, the main bus controller 115 controls the main controller 110 to transmit a command packet and a data request packet to the I / O modules 120, 130, and 140 through the data bus 150. The main bus controller 115 controls the main controller 110 to receive input / output events from the I / O modules 120, 130, and 140 through the event bus 160.

The first I / O module 120, the second I / O module 130, and the third I / O module 140 respectively input and output data to and from connected external devices.

The first I / O bus controller 125, the second I / O bus controller 135, and the third I / O bus controller 145 connect the I / O modules 120, 130, and 140 to the data bus 150 and the event bus, respectively. And control the communication between the I / O modules 120, 130, 140 and the data bus 150, and the communication between the I / O modules 120, 130, 140 and the event bus 160, respectively. In detail, the first I / O bus controller 125, the second I / O bus controller 135, and the third I / O bus controller 145 may include the I / O modules 120, 130, and 140, respectively. Control to receive the command packet and the data request packet from the main control unit 110 through. In addition, the first I / O bus controller 125, the second I / O bus controller 135, and the third I / O bus controller 145 are connected to the I / O modules 120, via the event bus 160. 130 and 140 control the main controller 110 to transmit an input / output event.

The data bus 150 becomes a communication path between the main controller 110 and the I / O modules 120, 130, and 140, respectively, and communication is controlled by the main controller 110. The data bus 150 is connected to the main controller 110 and the I / O modules 120, 130, and 140, respectively.

Specifically, the data bus 150 is a synchronous method and has a master / slave structure. At this time, the main control unit 110 of the logical operation control device 100 becomes a master of the network, the other I / O modules 120, 130, 140 becomes a slave. The synchronization signal is generated by the master, and no bus control signals exist except for the synchronization signal. The data bus 150 uses a 24-bit parallel bus shared by all modules including the main control unit 110 and the I / O modules 120, 130, and 140, but a special collision avoidance mechanism is required because only the master initiates communication. Not. The slave always waits for packets sent from the master. There are two main types of packets transmitted from the main controller 110, which is a master, that is, a command packet and a data request packet. The command packet is a control command sent from the master to the slave, such as a reset command, a channel setting command, or an output signal of an input / output channel. The data request packet is a data request packet for the master to read the current register state of the slave and the received signal of the input / output channel. In the data bus 150, the slave may not actively occupy the data bus under any circumstances, and the master periodically polls whether there is data to be transmitted from the slave as necessary. As such, it may be confirmed that the data bus 150 is controlled by the main controller 110.

The event bus 160 becomes a communication path between the main controller 110 and the I / O modules 120, 130, and 140, and is controlled by the I / O modules 120, 130, and 140. The event bus 160 is connected to the main controller 110 and the I / O modules 120, 130, and 140, respectively. The event bus 160 determines an I / O module occupying a bus among the I / O modules 120, 130, and 140 according to the priority of the generated input / output event. Accordingly, the event bus 160 is occupied by one of the I / O modules 120, 130, and 140 at regular intervals.

Specifically, the event bus 160, like the data bus 150, is a synchronous 24-bit parallel bus and has a master / slave structure. At this time, the main control unit 110 of the logical operation control device 100 becomes a master of the network, the other I / O modules 120, 130, 140 becomes a slave. The synchronization signal is generated by the master. The event bus 160 may have a slave actively occupying the bus. That is, the event bus 160 may be occupied by the I / O modules 120, 130, and 140 that are slaves. Since a plurality of slave I / O modules 120, 130, and 140 are simultaneously connected to the event bus 160, data collision may occur when the slave occupies the bus at the same time. To solve this problem, a token method is used for communication of the event bus 160. Token contains priority information of I / O event. In addition, the slave I / O modules 120, 130, and 140 determine whether to communicate with the main controller 110 through the event bus 160 by using a token including priority information. Tokens are delivered via the daisy chain bus. Here, the daisy chain bus is a logical bus within the event bus 160 for carrying tokens. The daisy chain bus is cyclic in the order of the main control unit 110 → the first I / O module 120 → the second I / O module 130 → the third I / O module 140 → the main control unit 110. Tokens are sent through this path. The slave must always monitor the tokens coming in through the daisy chain in order to use the event bus 160.

The daisy chain represents the path through which the token for the slave to occupy the event bus is passed through the event bus 160. The daisy chain has a total of four buslines, a sync line to carry the sync signal, a busy signal line to indicate that the bus is currently busy, a data line to send serial data, and finally another data directly connected to the master. There is a line. The generation and use of the token will be described later in detail.

2 is a diagram illustrating the configuration of the main bus controller 115 and the first I / O bus controller 125 according to an embodiment of the present invention. Since the second I / O bus controller 135 and the third I / O bus controller 145 have the same configuration as the first I / O bus controller 125, the first I / O bus controller 125 will be described below. Only the configuration of will be described.

As shown in FIG. 2, the main bus controller 115 includes a main interface unit 210, a bus controller 220, an event handler 230, and a bus interface unit 240.

The main interface unit 210 transmits and receives data modified according to the protocol of the main control unit 110. That is, the main interface unit 210 transforms the data transmitted and received by the bus controller 220 according to the protocol of the main controller 110, and then transmits and receives the modified data to the main controller 110.

The bus controller 220 encodes and decodes data transmitted and received through the data bus 150 or the event bus 160. In detail, the bus controller 220 packet-decodes a data packet for input to the main controller 110, and encodes and outputs data to be output to the data bus 150 or the event bus 160.

The event handler 230 arranges the input / output events received from the I / O bus controller 125 through the event bus 160 in order of priority and transmits them to the main controller 110. In detail, the event handler 230 receives an input / output event from the I / O bus controller 125 via the event bus 160. The event handler 230 arranges the received input / output events according to the priority of each preset input / output event and transmits them to the main controller 110.

The bus interface unit 240 transmits and receives data transmitted and received by the bus controller 220 and the input / output event handler 230 in accordance with the bus protocol. That is, the bus interface unit 240 transforms the data transmitted and received by the bus controller 220 and the input / output event handler 230 according to the protocol of the data bus 150 and the event bus 160, and then converts the modified data into data. Transmission and reception are performed on the bus 150 and the event bus 160.

The main bus controller 115 of this structure may control the main controller 110 to receive input / output events from the I / O modules 120, 130, and 140 through the event bus 160.

In addition, as shown in FIG. 2, the first I / O bus controller 125 includes an input / output interface unit 250, a bus control unit 260, an event generator 270, and a bus interface unit 280. do.

The input / output interface unit 250 transmits and receives data by modifying the data in accordance with the protocol of the first I / O module 120. That is, the input / output interface unit 250 transforms the data transmitted and received by the bus controller 260 according to the protocol of the first I / O module 120 and then converts the modified data into the first I / O module 120. Send and receive

The bus controller 260 encodes and decodes data transmitted and received via the data bus 150 or the event bus 160. In detail, the bus controller 260 packet-decodes a data packet for input to the first I / O module 120, and packetizes and outputs data to be output to the data bus 150 or the event bus 160. Done.

The event generator 270 generates an input / output event when an event occurs in the first I / O module 120. The input / output event represents an event generated from the inside of the first I / O module 120 or an input signal. For example, the input / output event may be an input error event or a failure event. In addition, the event generator 270 transmits the input / output event to the main bus controller 115 through the event bus 160 when the priority of the generated input / output event is higher than other events.

The bus interface 280 transmits and receives data transmitted and received by the bus controller 260 and the event generator 270 in accordance with the bus protocol. That is, the bus interface unit 280 transforms the data transmitted and received by the bus controller 260 and the event generator 270 according to the protocol of the data bus 150 and the event bus 160, and then converts the modified data into data. Transmission and reception are performed on the bus 150 and the event bus 160.

The first I / O bus controller 125 having such a structure controls the input / output event generated in the first I / O module 120 to be transmitted to the main controller 110 through the event bus 160 according to priority. You can do it.

Hereinafter, a process of transmitting an input / output event through the event bus 160 will be described with reference to FIG. 3. 3 is a diagram illustrating a communication scheme of the event bus 160 according to an embodiment of the present invention.

In FIG. 3, the dotted line represents the event bus 160, and the solid arrows represent the daisy chain 300. Tokens 310 and 320 are transmitted over the event bus 160 in the order of the daisy chain.

When the logic operation controller 100 is initially driven, as shown in FIG. 3, the master main controller 110 generates a token in the form of a start packet, and the main bus controller 115 daisyes. The token including the start packet is transmitted to the nearest slave along the chain 300. The start packet contains an 8 bit start bit and the module ID.

The first I / O bus controller 125 of the first I / O module 120, which is the closest slave (S1), receives the token and sends an ACK signal to the main bus controller 115.

The first I / O bus controller 125 adds its own slave packet S1 to the back of the start packet of the received token. The slave packet S1 includes an 8-bit bit mask indicating the start, an ID of the module, information indicating the external device connected to the module (FUNC), and an 8-bit bit mask indicating priority of the input / output event data to be sent last. Include.

The bit mask displays packets transmitted through the event bus 160 in eight priorities. Among the contents of the I / O bus controllers 125, 135, and 145 adding their information to the token packet, the bit mask indicates that there is a packet to send. The most significant bit of the bit mask represents the highest priority packet, and the last bit represents the lowest priority packet. Herein, the packet may be an input / output event or may be another packet. For example, if the value of the bit mask is '01000100', this indicates that there are two packets to be transmitted, that is, a packet of priority 2 and a packet of priority 6. As such, the bit mask indicates that there is a packet waiting to be transmitted by priority.

Thereafter, the first I / O bus controller 125 adds the slave packet S1 to the token and then sends the token to the second I / O bus controller 135 along the daisy chain. Thereafter, the second I / O bus controller 135 and the third I / O bus controller 145 also sequentially attach their slave packets S2 and S3 to the token. Since the third I / O bus controller 145 cannot receive the ACK signal, the third I / O bus controller 145 may know that it is the last one, and the completed token 320 may be returned to the main bus controller along the daisy chain of the event bus 160. To pass.

After this, the token 320 is continuously along the daisy chain 'main bus controller 115 → the first I / O bus controller 125 → the second I / O bus controller 135 → the third I / O bus The controller 145 is cyclically transferred in the order of the main bus controller 115 '. Each I / O bus controller 125, 135, and 145 transmits the bit mask value of the priority area to the bit mask of the token 320 when an input / output event to be transmitted to the main controller 110 occurs. Record 1 ". When each of the I / O bus controllers 125, 135, and 145 receives the token 320, the I / O bus controllers 125 and 135 compare the bit masks with each other to determine whether another module has a higher priority than its input / output event. If the I / O bus has the highest priority, the I / O bus controller occupies the event bus 160 and transmits the corresponding I / O event to the main bus controller 115 through the event bus 160. . The I / O bus controller clears the bit mask to '0' and transmits the token 320 along the daisy chain to the next I / O bus controller.

On the other hand, if the I / O bus controller does not have the highest priority, the corresponding I / O bus controller transmits the token 320 along the daisy chain to the next I / O bus controller.

For example, the bit mask of the first I / O bus controller 125 is '00100000', the bit mask of the second I / O bus controller 135 is '10000010', and the third I / O bus controller ( Assume that the bit mask of 115) is '00000001'.

Then, when cycling through the first daisy chain, the bit mask of the second I / O bus controller 135 has the highest priority, so that the second I / O bus controller 135 has an I / O event corresponding to priority 1. To the main bus controller 115.

When the first daisy chain cycle ends, the bit mask of the first I / O bus controller 125 is '00100000', the bit mask of the second I / O bus controller 135 is '00000010', and the third I The bit mask of the / O bus controller 115 becomes '00000001'. In the second daisy chain cycle, the first I / O bus controller 125 first sends an I / O event of priority 3 to the main bus controller 115, and then the second I / O bus controller 135 first takes precedence. The I / O event having a rank of 7 is transmitted to the main bus controller 115, and finally, the third I / O bus controller 145 transmits an I / O event having a priority of 8 to the main bus controller 115.

Therefore, in the case of the above assumption, No. 2 completes the transmission of all input / output events through the daisy chain cycle.

As such, based on the priority indicated in the bit mask of the token 320, the event bus 160 may be controlled for communication. In addition, the token 320 passes through the I / O bus controllers one by one, allowing a plurality of I / O bus controllers to communicate using the event bus 160 without collision.

In the present embodiment, it has been described that there are three I / O modules, but this is for convenience of description, and the number of I / O modules may be at least one.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

100: logical operation control device 110: main control unit
120: first I / O module 130: second I / O module
140: third I / O module

Claims (8)

A main controller which performs a logical operation;
At least one I / O module for inputting and outputting data;
A first bus that is a communication path between the main control unit and the at least one I / O module and in which communication is controlled by the main control unit; And
And a second bus that is a communication path between the main control unit and the at least one I / O module and is controlled by the at least one I / O module.
The at least one I / O module,
And determining whether to communicate with the main controller through the second bus by using a token including priority information.
The method of claim 1,
Connect each of the at least one I / O module to the first bus and the second bus, communicate between each of the at least one I / O module and the first bus, and each of the at least one I / O module; And at least one I / O bus controller for controlling communication between the second buses.
The method of claim 2,
Each of the I / O bus controller,
An input / output interface unit configured to transmit / receive data by modifying the data according to the protocol of the I / O module;
A bus controller which encodes and decodes data transmitted and received through the first bus or the second bus;
An event generator configured to generate an input / output event when an event occurs in the I / O module; And
And a bus interface unit configured to transmit / receive data transmitted and received by the bus controller and the event generator in accordance with a bus protocol.
The method of claim 3,
The event generator,
And transmitting the generated input / output event to the bus controller through the second bus.
The method of claim 1,
And a main bus controller connecting the main control unit with the first bus and the second bus and controlling communication between the main control unit and the first bus and communication between the main control unit and the second bus. Logic operation control device characterized in that.
The method of claim 5,
The main bus controller,
A main interface unit for transmitting and receiving data by modifying the protocol of the main controller;
A bus controller which encodes and decodes data transmitted and received through the first bus or the second bus;
An event handler for sorting the input / output events received from the I / O bus controller according to priority and transmitting them to the main controller; And
And a bus interface unit configured to modify and transmit data transmitted and received by the bus control unit and the event handler in accordance with a bus protocol.
The method according to claim 6,
The event handler is
And receiving the input / output event from the I / O bus controller via the second bus.
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