Communication device capable of communication through backplane, and method therefor

Abstract

The present invention relates to a communication method between PLC devices connected to the same backplane. Communication between the PLC devices can be performed even without passing through a CPU module by sharing, through the backplane, a message including position information of the PLC devices connected to the backplane, and an external device can easily identify the states of other devices connected to the PLC devices by forming a routing path between the PLC devices through a channel opening or closing message between the PLC devices.

Description

Communication device and method capable of communicating via a backplane

[0001] The present invention relates to communication technology, and more particularly to communication technology between PLC devices sharing a backplane.

[0002] A PLC (Programmable Logic Controller) device is a control device used for automatic control or monitoring of a factory. It receives sensor values, performs logical operations according to a preset user program, and controls externally connected devices based on the results.

[0003] Recent control systems are increasingly utilizing network-based distributed control systems to facilitate flexible installation, management, and expansion. Therefore, PLC systems are also equipped with various communication modules to enable connection to multiple networks.

[0004] Typically, each network operates separately from the others to avoid interference between different networks, taking into account the real-time nature and application of control data for control purposes. However, situations arise where data exchange between different networks is required without additional equipment or operations, such as for maintenance or production management, such as the Manufacturing Execution System (MES).

[0005] In a system comprised of PLC devices, PLC devices sharing a single PLC backplane, i.e., communication modules with different communication methods, can form a single system. In such cases, the network cannot access information about PLC devices connected to other networks or external devices connected to PLC devices, making it impossible to exchange data.

[0006] The inventors of the present invention have dedicated research efforts to overcome the communication limitations of these conventional PLC devices. After extensive research and development, they have developed a communication device and method capable of exchanging data between different networks without the need for additional equipment or circuit installation, ultimately resulting in the present invention.

[0007] An object of the present invention is to provide a communication device and method capable of transmitting messages to each other even if the network types are different between PLC devices sharing the same backplane.

[0008] In addition, another object of the present invention is to provide a communication device and method capable of transmitting data (Pass Through) without change without intervention of a CPU module or the like.

[0009] Meanwhile, other unspecified purposes of the present invention will be additionally considered within the scope that can be easily inferred from the detailed description and effects thereof below.

[0010] The communication device according to the present invention,

[0011] A control unit including one or more processors and memories; and a communication unit; wherein the control unit transmits or receives a message including location information of another communication device connected to the backplane through the communication unit, and communicates with another communication device connected to a location indicated by the location information.

[0012] The above communication device is characterized in that it is a PLC (Programmable Logic Controller) device.

[0013] The above message is characterized by including location information of a message transmitting device and location information of a message receiving device.

[0014] The control unit is characterized in that it checks the base number and slot number of the message receiving device of the message shared on the backplane, and receives the data included in the message if the base number and slot number correspond to its own.

[0015] The above message is characterized in that it includes a channel opening message for requesting a routing service between a communication device connected to the backplane for communication between a device outside the backplane and a communication device connected to the backplane, a channel closing message for terminating the routing service, and a data exchange message for exchanging data through the routing service.

[0016] The above channel opening message is characterized in that it includes necessary setting information according to the communication method of the routing service.

[0017] A communication method according to another embodiment of the present invention,

[0018] It is characterized by comprising: a step of generating a message including location information of another communication device connected to the backplane; and a step of sharing the message to the backplane.

[0019] It is characterized by further including a step of checking the location information of the message receiving device of the message shared on the backplane and receiving the data included in the message if the location information corresponds to the location information.

[0020] According to the present invention, there is an effect that data can be exchanged with each other regardless of the network type of PLC devices connected to the same backplane.

[0021] Additionally, there is an advantage in that devices outside the backplane can access and exchange data with PLC devices regardless of the network type of the PLC devices connected to the backplane.

[0022] Meanwhile, even if the effect is not explicitly mentioned herein, it is added that the effect and its provisional effect described in the following specification expected by the technical features of the present invention are treated as described in the specification of the present invention.

[0023] Figure 1 is a schematic structural diagram of a communication device according to a preferred embodiment of the present invention.

[0024] Figures 2 and 3 illustrate the overall structure of a network-based PLC system to which a communication device according to a preferred embodiment of the present invention is applied.

[0025] FIG. 4 illustrates an example of a message format for data exchange of a communication device according to a preferred embodiment of the present invention.

[0026] FIG. 5 illustrates an example of a message format when requesting a routing service through a communication device in an external network according to a preferred embodiment of the present invention.

[0027] FIG. 6 illustrates an example of a message format associated with a routing path generated according to a preferred embodiment of the present invention.

[0028] Figure 7 is a schematic flowchart of a communication method according to another preferred embodiment of the present invention.

[0029] Figure 8 is a schematic structural diagram of a communication method according to another preferred embodiment of the present invention.

[0030]

[0031] ※ It is to be noted that the attached drawings are provided for reference only to help understand the technical concept of the present invention, and the scope of the rights of the present invention is not limited thereby.

[0032] Hereinafter, with reference to the drawings, the configuration of the present invention, guided by various embodiments thereof, and the effects resulting from such configurations will be examined. In describing the present invention, detailed descriptions of related, well-known functions that are obvious to those skilled in the art and that may unnecessarily obscure the gist of the present invention will be omitted.

[0033] Terms such as "first" and "second" may be used to describe various components, but the components should not be limited by these terms. These terms may only be used to distinguish one component from another. For example, without departing from the scope of the present invention, a "first component" may be referred to as a "second component," and similarly, a "second component" may also be referred to as a "first component." Furthermore, singular expressions include plural expressions unless the context clearly dictates otherwise. Terms used in the embodiments of the present invention may be interpreted as having meanings commonly known to those of ordinary skill in the art, unless otherwise defined.

[0034] Hereinafter, with reference to the drawings, the configuration of the present invention guided by various embodiments of the present invention and the effects resulting from the configuration will be examined.

[0035]

[0036] Figure 1 is a schematic structural diagram of a communication device according to a preferred embodiment of the present invention.

[0037] A communication device (100) according to the present invention may include a control unit (110) and a communication unit (120).

[0038] The control unit (110) performs an operation to control various communication methods of the communication device (100). To this end, the control unit (110) may include one or more processors (112) and memories (114). That is, the control unit (110) may control the communication device (100) to transmit and receive data with other communication devices connected to the same backplane.

[0039] The control unit (110) may include, for example, a hardware processor (112) or a software process executed on the processor, but is not limited thereto.

[0040] The memory (114) stores various information necessary for the operation of the communication device (100). The information stored in the memory (114) may include, but is not limited to, various data received from other communication devices connected to the communication device (100), data transmitted to other communication devices, information for the control operation of the processor (112), program information related to the control method of the processor (112), etc.

[0041] For example, the memory (114) may include, but is not limited to, a hard disk type, a magnetic media type, a compact disc read only memory (CD-ROM), an optical media type, a magneto-optical media type, a multimedia card micro type, a flash memory type, a read only memory type, or a random access memory type, depending on its type. In addition, the memory (114) may include, but is not limited to, a cache, a buffer, a main memory, an auxiliary memory, or a separately provided storage system depending on its use / location.

[0042] For the purpose of explanation below, the communication device (100) will be described as an example of a PLC device, but it is not limited thereto, and it goes without saying that the present invention can be used in communication devices other than PLC devices.

[0043] Figures 2 and 3 show the overall structure of a network-based PLC system to which a communication device (100) according to the present invention is applied.

[0044] Figure 2 shows an example of an expansion system in which an Ethernet module, which is an example of a communication device (100), is mounted on a PLC system and an Ethernet-based remote I / O is connected thereto.

[0045] Remote I / O can include various types of actuators and other sub PLC systems can be connected.

[0046] Additionally, a production control system such as a management PC or MES connected to an external network manages the operation of the PLC system and obtains information from the PLC system.

[0047] Figure 3 is a more detailed structural diagram of this PLC system.

[0048] A backplane is connected to the bottom surface, and a power module, a CPU module, and a communication device (100) (communication module) are mounted on top of it. In addition to the communication module, various PLC modules (PLC devices) can be mounted depending on the control purpose of the PLC system.

[0049] To distinguish which backplane a mounted PLC device is installed on, location information, i.e., the base number (Base #) and slot number (Slot #), are used. Using this, it is possible to determine where the PLC device, i.e., the communication device (100), is mounted in the PLC system. It goes without saying that the present invention can be implemented in other communication systems as well, using location information corresponding to the base number and slot number.

[0050] In this way, data from the communication module is transmitted to the CPU module, and after processing, the data is then transmitted back to the communication module. Therefore, there is no path for the communication module to transmit data to other communication modules or external devices connected to other communication modules.

[0051] Accordingly, the communication device (100) according to the present invention provides a method of transmitting data to another network using the pass-through concept by utilizing the communication module, backplane, communication cable, etc. of an already installed PLC system without the need for additional network equipment or communication cable installation.

[0052] To this end, the control unit (110) can transmit data to another communication device by identifying the base number and slot number to which the other communication device is connected and generating a message including the base number and slot number.

[0053] For convenience of explanation, base numbers and slot numbers will be used below. However, it is obvious that the present invention can be implemented by location information corresponding to base numbers and slot numbers even in a communication system that does not use base numbers and slot numbers.

[0054] Figure 4 shows an example of a message format for data exchange between each module located in a slot among the message formats for this.

[0055] Size indicates the size of the message shared through the backplane.

[0056] BC is a field that indicates that the data following the Size field is a format for exchanging data between modules.

[0057] DST Base No and Slot No indicate the base number and slot number, respectively, of the module to which the message is to be delivered.

[0058] SRC Base No and Slot No represent the base number and slot number, respectively, on which the module generating the message to be transmitted is mounted.

[0059] Service ID is a field that indicates what service is provided.

[0060] Frame Cmd represents a command for each Service ID. For example, a Frame Cmd of 1 could mean a request, while a Frame Cmd of 2 could mean a response.

[0061] An Invoke ID is an identifier generated by the module that generates and transmits a message. The module that receives this message and generates a response message must return this Invoke ID.

[0062] Finally, Payload represents user data. Payload may contain data to be delivered to the module mounted in the destination base number and slot number.

[0063] In this way, the message format includes the base number and slot number of the message sending device and the message receiving device, thereby enabling the PLC device sending or receiving the message to identify the source and destination of the message.

[0064] The control unit (110) can generate a message in this format and share it with the backplane to transmit the message to the desired destination module.

[0065] Alternatively, the control unit (110) can check the destination base number and slot number of the message shared on the backplane, and if it corresponds to the base number and slot number on which the communication device (100) is mounted, it can receive the data included in the payload of the message.

[0066] Figure 5 shows the message format when requesting a routing service through a communication device in an external network.

[0067] Figure 5 (a) shows the basic message format for routing service.

[0068] BaseNo and SlotNo represent the base number and slot number where the destination communication device is mounted, respectively.

[0069] The Service ID indicates the type of service provided through routing. A Service ID of 1 indicates a diagnostic information access service for the communication device, 2 indicates a CP message (MSG) object access service for the communication device, and 3 indicates message pass-through.

[0070] Since the communication device (100) according to the present invention provides a message transmission (pass through) function using a routing service, the Service ID can be set to 3, i.e., a pass through service.

[0071] Figure 5 (b) shows the Channel Open message format for such routing service.

[0072] In order to provide a data pass-through function according to the present invention, a routing path must be established in advance between different types of networks. Therefore, it is necessary to establish a routing path through a channel opening message. In other words, a direct path, such as a tunnel, can be established between communication modules.

[0073] The Channel Open Request message includes a base number, a slot number, and a service ID, as in (a) of Fig. 5, and may additionally include a Frame Cmd (frame command) according to the service ID and data for opening a channel.

[0074] The frame command indicates the type of service the message is requesting.

[0075] A frame command can be defined as follows:

[0076] typedefenum

[0077] {

[0078] TNL_PASS_THRU_FC_INVALID=0, / * 0 * /

[0079] TNL_PASS_THRU_FC_OPEN_REQ, / * 1* /

[0080] TNL_PASS_THRU_FC_OPEN_RES, / * 2 * /

[0081] TNL_PASS_THRU_FC_OPEN_RES_ERR, / * 3 * /

[0082] TNL_PASS_THRU_FC_CLOSE_REQ, / * 4 * /

[0083] TNL_PASS_THRU_FC_CLOSE_RES, / * 5 * /

[0084] TNL_PASS_THRU_FC_CLOSE_RES_ERR, / * 6 * /

[0085] TNL_PASS_THRU_FC_DATA_REQ, / * 7 * /

[0086] TNL_PASS_THRU_FC_DATA_RES, / * 8 * /

[0087] TNL_PASS_THRU_FC_DATA_RES_ERR, / * 9 * /

[0088] TNL_PASS_THRU_FC_MAX

[0089] }E_TNL_PASS_THRU_FC;

[0090]

[0091] That is, the frame command includes a request and response for opening a channel, and a response error, a request and response for closing a channel, and a response error, a data request and response, and a response error, etc.

[0092] The data for opening a channel will include the settings required for each communication method to support pass-through functionality for different communication methods.

[0093] For example, if the destination communication device supports IP communication, it may include information such as IP address, port number, and TCP / UDP.

[0094] If the destination communication device is a device that supports UART communication, it may include information such as baudrate, start, stop, and parity required for UART communication, as well as settings required for a UART-based communication protocol (Modbus).

[0095] As shown in (b) of Fig. 5, the channel open request message has a frame command (FrameCmd) of 1 and contains channel open data. The channel open response message has a frame command of 2 and contains a handle value. Here, the handle value represents the handle returned by the responding communication device.

[0096] The channel open error response has a frame command of 3 and includes an error code (ErrorCode), examples of which are as follows:

[0097] typedefenum

[0098] {

[0099] SVC_ERROR = 0x9001, / * 0x9001, Service error * /

[0100] SVC_ERR_MEM_ALLOC_FAIL, / * 0x9002, memory allocation failed * /

[0101] SVC_ERR_BAD_PRM, / * 0x9003, bad parameter * /

[0102] SVC_ERR_BAD_CMD, / * 0x9004, * /

[0103] SVC_ERR_BAD_SEQUENCE, / * 0x9005, * /

[0104] SVC_ERR_RESOURCE_BUSY, / * 0x9006, * /

[0105] SVC_ERR_BAD_QUEUE, / * 0x9007, * /

[0106] SVC_ERR_RESOURCE_ALLOC_FAIL, / * 0x9008, * /

[0107] SVC_ERR_NO_ITEM, / * 0x9009, * /

[0108] SVC_ERR_INVALID_HANDLE, / * 0x900A, * /

[0109] SVC_ERR_WRONG_SIZE, / * 0x900B, * /

[0110] } E_TNL_PASS_THRU_ERR

[0111] That is, the error code indicates various errors that occur during the channel opening process, such as memory allocation failure (SVC_ERR_MEM_ALLOC_FAIL), parameter error (SVC_ERR_BAD_PRM), and resource allocation failure (SVC_ERR_RESOURCE_ALLOC_FAIL).

[0112] In this way, messages generated by an external device can be transmitted to a destination communication device, thereby creating a routing path between the external device and the destination communication device. After the routing path is created, the message can be transmitted as is through the pass-through function even if the network types are different.

[0113] Figure 6 (a) shows a message format for data exchange using the routing path generated in this way.

[0114] The message format for data exchange includes the same base number, slot number, and service ID fields as the basic message format.

[0115] A message for requesting data can have a frame command of 7 here, and can further include a handle value and a payload for user data.

[0116] A message for a data response may have a frame command of 8 and may further include a payload for user data.

[0117] Data response errors may include additional error codes, specific examples of which are as discussed above.

[0118] Figure 6 (b) shows a message format for closing the generated routing path.

[0119] When a generated routing path is no longer in use, the routing path must be destroyed via a channel close message.

[0120] A channel close request message can have a frame command of 4 in the basic message format and can additionally include a handle value.

[0121] The channel close response message can have a frame command of 5 in the basic message format.

[0122] Finally, the channel close error response has a frame command of 6 and may further include an error message field, as discussed above.

[0123] By creating a routing path in this way, messages can be passed between communication devices mounted on the PLC system using the pass-through function, enabling data exchange between communication devices without the complex intervention of the CPU model.

[0124] Figure 7 is a schematic structural diagram of a communication method according to another preferred embodiment of the present invention.

[0125] The communication method according to the present invention can be performed by a communication device including one or more processors and memory.

[0126] Hereinafter, the communication device will be described as an example of a communication module included in a PLC system, but the present invention is not limited to a communication module included in a PLC system.

[0127] The communication device generates a message including the base number and slot number of another communication device connected to the backplane (S110).

[0128] Since the message can be shared by all PLC devices (communication devices) connected to the backplane via the backplane, the message can be transmitted via the base number and slot number equipped with the message destination, i.e. the message receiving device (PLC device).

[0129] The generated message is shared through the backplane (S120).

[0130] Backplane sharing enables message transmission between PLC devices in a pass-through manner without complex intervention or processing by the CPU module.

[0131] The communication device checks the base number and slot number of the message receiving device included in the message to confirm that the destination of the message shared on the backplane is itself (S130), and if it is confirmed that the base number and slot number correspond to itself, it receives the data included in the message (S140).

[0132] The format and specific values ​​of the messages used in this data exchange are as described above.

[0133] Figure 8 is a schematic structural diagram of a communication method according to another preferred embodiment of the present invention.

[0134] According to the present invention, an external device connected to a communication device (PLC device) connected to a backplane can create a routing path for performing communication with another communication device connected to the backplane using a different type of network method, and can use the routing path to perform communication.

[0135] The communication device can receive a channel opening message from an external device (S210) and transmit a response message thereto (S220).

[0136] The format and specific examples of channel open messages, channel response messages, and channel response error messages are as discussed above.

[0137] Once the channel opening is completed and a routing path is created, data is exchanged through it (S230).

[0138] When a routing path is created according to the present invention, there is an advantage in that messages can be transmitted regardless of the network type, such as IP communication or UART communication.

[0139] When the routing path is no longer needed, a channel close message is received (S240) and a channel close response message is transmitted to complete channel closing (S250).

[0140] Once the channel is closed, the resources and handles used to create the routing path are available for other tasks.

[0141]

[0142] According to the communication device and method of the present invention as described above, a method is provided for transmitting messages in a pass-through manner regardless of the network type without intervention of a CPU module between communication devices (PLC devices) connected to each other by a backplane, thereby providing the effect of supporting various network communication methods without additional work such as cable laying for network path creation.

[0143]

[0144] The scope of protection of the present invention is not limited to the description and expression of the embodiments explicitly described above. Furthermore, it should be noted that the scope of protection of the present invention may not be limited by obvious modifications or substitutions within the technical field to which the present invention pertains.

Claims

1. In a communication device capable of communicating via a backplane: A control unit including one or more processors and memory; and Department of Communications; Including, but not limited to, A communication device characterized in that the control unit transmits or receives a message including location information of another communication device connected to the backplane through the communication unit, and communicates with another communication device connected to a location indicated by the location information.

2. In paragraph 1, A communication device, characterized in that the above communication device is a PLC (Programmable Logic Controller) device.

3. In paragraph 1, A communication device, characterized in that the above message includes location information of a message transmitting device and location information of a message receiving device.

4. In paragraph 3, A communication device characterized in that the control unit checks the location information of the message receiving device included in the message shared on the backplane and, if the location information corresponds to its own, receives the data included in the message.

5. In paragraph 1, A communication device, characterized in that the message includes a channel opening message for requesting a routing service between a communication device connected to the backplane for communication between a device outside the backplane and a communication device connected to the backplane, a channel closing message for terminating the routing service, and a data exchange message for exchanging data through the routing service.

6. In paragraph 5, A communication device, characterized in that the above channel opening message includes necessary setting information according to the communication method of the routing service.

7. A communication method performed by a communication device including one or more processors and memory: A step for generating a message including location information of another communication device connected to the backplane; and A step of sharing the above message to the above backplane; A communication method, characterized by including a.

8. In paragraph 7, A communication method, characterized in that the communication device is a PLC device.

9. In paragraph 7, A communication method, characterized in that the message includes location information of a message transmitting device and location information of a message receiving device.

10. In paragraph 9, A step of checking the location information of the message receiving device included in the message shared on the backplane and receiving the data included in the message if it is the location information corresponding to the device; A communication method, characterized by further comprising:

11. In paragraph 7, A communication method, characterized in that the message includes a channel opening message for requesting a routing service between a communication device connected to the backplane for communication between a device outside the backplane and a communication device connected to the backplane, a channel closing message for terminating the routing service, and a data exchange message for exchanging data through the routing service.

12. In paragraph 11, A communication method, characterized in that the above channel opening message includes necessary setting information according to the communication method of the routing service.

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