Communication device capable of communicating through backplane and method thereof

Abstract

The present invention relates to a communication method between PLC devices connected to the same backplane, which shares a message containing location information of the PLC devices connected to the backplane through the backplane, thereby enabling communication between the PLC devices without passing through a CPU module, and forms a routing path between the PLC devices by opening or closing the message through a channel between the PLC devices, thereby enabling the communication between the PLC devices. Therefore, the external device can easily grasp the state of the other device connected with the PLC device.

Description

TECHNICAL FIELD

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

[0002] A programmable logic controller (PLC) device, which is a control device used in automatic control or monitoring in a factory, is a device that receives input of a sensor value, performs a logical operation according to a user's program set in advance, and controls a device connected to the outside according to a result thereof.

[0003] A recent control system has a tendency to use a network-based distributed control system to be able to flexibly cope with setting, management, or expansion. Accordingly, a PLC system is also installed with various communication modules to be able to connect to each network.

[0004] Each network is generally operated separately from each other to avoid interference between networks different from each other by considering real-time of control data and application according to a control purpose. However, in order to maintain or manage production such as a manufacturing execution system (MES), there is a case where data exchange is required between networks different from each other without an additional device or work.

[0005] In a system composed of PLC devices, PLC devices (i.e., communication modules different from each other in communication method) sharing one PLC backplane can constitute one system. In this case, since information of a PLC device connected to another type of network or an external device connected to the PLC device cannot be known in one network, there is a problem that data cannot be exchanged with each other.

[0006] The present inventor has been making efforts to overcome the limitation of the communication method of the prior art PLC device. In order to accomplish a communication device and method capable of exchanging data between networks different from each other without an additional device or line setting, after many efforts, the present invention was finally completed. SUMMARY

[0007] Problems to be Solved by the Invention

[0008] The present invention is to provide a communication device and method capable of transmitting messages to each other even if network types of PLC devices sharing the same backplane are different from each other.

[0009] In addition, another object of the present application is to provide a communication device and a communication method capable of transmitting data without change (Pass Through) without intervention of a CPU module or the like.

[0010] On the other hand, other objects of the present application which are not explicitly mentioned can be further considered within the scope which can be easily inferred from the following detailed description and its effects.

[0011] Technical solution to the problem

[0012] The communication device according to the present application is characterized by comprising: a control section including one or more processors and memories; and a communication section; the control section transmits or receives a message including position information of another communication device connected to the backplane through the communication section, and communicates with another communication device connected to a position indicated by the position information.

[0013] The communication device is a Programmable Logic Controller (PLC) device.

[0014] The message includes position information of a message transmitting side device and position information of a message receiving side device.

[0015] The control section confirms a base number and a slot number of the message receiving side device of the message shared to the backplane, and receives data included in the message if the base number and the slot number correspond to itself.

[0016] The message includes: a channel open message by which a device outside the backplane requests a routing service between a communication device connected to the backplane in order to communicate with the communication device connected to the backplane; a channel close message for ending the routing service; and a data exchange message for exchanging data through the routing service.

[0017] The channel open message includes setting information required according to a communication method of the routing service.

[0018] The communication method according to another embodiment of the present application is characterized by comprising: a step of generating a message including position information of another communication device connected to a backplane; and a step of sharing the message to the backplane.

[0019] The communication method further includes a step of confirming position information of a message receiving side device of the message shared to the backplane, and receiving data included in the message if the position information corresponds to itself.

[0020] Effects of the invention

[0021] According to the present application, there is an effect that the PLC devices connected to the same backboard can exchange data with each other regardless of the network type of the PLC devices.

[0022] In addition, there is an advantage that the devices outside the backboard can access the PLC devices and exchange data regardless of the network type of the PLC devices connected to the backboard.

[0023] On the other hand, it is to be supplemented that even the effects not explicitly mentioned herein, the effects expected according to the technical features of the present application and the potential effects described in the following specification, are all considered to have the same effect as the content described in the specification of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a communication device according to a preferred embodiment of the present application.

[0025] Figure 2 and Figure 3 shows the overall structure of a network-based PLC system to which the communication device according to a preferred embodiment of the present application is applied.

[0026] Figure 4 shows an example of a message format for data exchange of the communication device according to a preferred embodiment of the present application.

[0027] Figure 5 shows an example of a message format when a routing service is requested from an external network through the communication device according to a preferred embodiment of the present application.

[0028] Figure 6 shows an example of a message format related to a routing path generated according to a preferred embodiment of the present application.

[0029] Figure 7 is a schematic flowchart of a communication method according to another preferred embodiment of the present application.

[0030] Figure 8 is a schematic structural diagram of a communication method according to still another preferred embodiment of the present application.

[0031] * It is to be noted herein that the drawings are illustrated as reference examples for the understanding of the technical concept of the present application, and the scope of the claims of the present application is not limited thereto. DETAILED DESCRIPTION

[0032] Hereinafter, the configuration of the present application guided by various embodiments of the present application and effects resulting from these configurations will be described with reference to the accompanying drawings. In explaining the present application, since the related known functions are matters apparent to those skilled in the art, a detailed description thereof will be omitted if it is judged that the related known functions can unnecessarily confuse the gist of the present application.

[0033] The terms "first", "second", and the like can be used to describe various constituent elements, but the constituent elements should not be limited by the above terms. The above terms are used only for the purpose of distinguishing one constituent element from another constituent element. For example, a "first constituent element" can be named a "second constituent element", and likewise, a "second constituent element" can be named a "first constituent element", without departing from the scope of the claims of the present application. In addition, the expression of the singular includes the expression of the plural, unless the context clearly dictates otherwise. Unless otherwise defined in the context, the terms used in the embodiments of the present application can be interpreted as having meanings commonly known to those skilled in the corresponding technical field.

[0034] Hereinafter, the configuration of the present application guided by various embodiments of the present application and effects resulting from these configurations will be described with reference to the accompanying drawings.

[0035] Figure 1 is a schematic configuration diagram of a communication device according to a certain embodiment of the present application.

[0036] The communication device 100 according to the present application can include a control section 110 and a communication section 120.

[0037] The control section 110 performs an action of controlling various communication modes of the communication device 100. To this end, the control section 110 can include one or more processors 112 and a memory 114. That is, the control section 110 can control the communication device 100 to perform data transmission and reception with other communication devices connected to the same backplane.

[0038] For example, the control section 110 can include a processor 112 as hardware or a process as software executed by the processor, but is not limited thereto.

[0039] The memory 114 stores various information required for the action of the communication device 100. As the stored information of the memory 114, various data received from other communication devices connected to the communication device 100 or data transmitted to other communication devices, information for a control action of the processor 112, program information related to a control method of the processor 112, and the like can be contained, but are not limited thereto.

[0040] For example, the memory 114 may be of various types, including, but not limited to, hard disk type, magnetic media type, CD-ROM (compact disc read-only memory), optical media type, magneto-optical media type, multimedia card micro type, flash memory type, read-only memory type, or random access memory type. Furthermore, depending on its purpose / location, the memory 114 may be a cache, buffer, main storage device, or auxiliary storage device, or it may be a stand-alone storage system.

[0041] For the purpose of explanation, the communication device 100 will be described using a PLC device as an example, but it is not limited thereto. Obviously, the present invention can also be used in other communication devices besides PLC devices.

[0042] Figure 2 and Figure 3 The overall structure of a network-based PLC system using the communication device 100 according to the present invention is shown.

[0043] Figure 2 An example of an extension system is shown, in which an Ethernet module is installed in a PLC system as a communication device 100, and an extension system is connected to the Ethernet-based remote I / O.

[0044] Remote I / O can include actuators of various types and can also be connected to other sub-PLC systems.

[0045] In addition, management systems such as PCs or MES connected to the external network manage the operation of the PLC system and obtain information from the PLC system.

[0046] Figure 3 This is a further detailed structural diagram of this PLC system.

[0047] The back panel is connected to the bottom surface, and a power module, CPU module, and communication device 100 (communication module) are mounted on it. In addition to the communication module, various PLC modules (PLC devices) can also be installed depending on the control purpose of the PLC system.

[0048] To distinguish which backplane the installed PLC device is located on, location information, namely the base number (Base#) and slot number (Slot#), is used. This allows us to determine the location of the PLC device (i.e., communication device 100) within the PLC system. Clearly, this invention can be implemented not only in PLC systems but also in other communication systems using the location information corresponding to the base number and slot number.

[0049] In this way, data from the communication module is transmitted to the CPU module, and the data transmitted to the CPU module is transmitted back to the communication module after processing. Therefore, the communication module has no path to transmit data to other communication modules or external devices connected to other communication modules.

[0050] Therefore, the communication device 100 according to the present invention provides a method for transmitting data to other networks using the communication modules, backplanes, communication cables, etc. of an existing PLC system in a pass-through manner, without the need to lay additional network equipment or communication cables.

[0051] To this end, the control unit 110 generates a message containing the base number and slot number to which other communication devices are connected, thereby enabling it to transmit data to other communication devices.

[0052] For ease of explanation, the base number and slot number will be used below, but it is obvious that the present invention can also be implemented in communication systems that do not use the base number and slot number, using the position information corresponding to the base number and slot number.

[0053] Figure 4 An example of a message format used here for data exchange between modules located in a slot is shown.

[0054] Size indicates the size of a message shared through the backplane.

[0055] BC, as a block command, is a field that indicates the format of the data following the size field, which is used for exchanging data between modules.

[0056] The DST base number and slot number represent the base number and slot number of the module to be transmitted, respectively.

[0057] The SRC base number and slot number represent the base number and slot number of the module that generates the message to be transmitted, respectively.

[0058] The Service ID is a field that tells you what service is provided.

[0059] The Frame Cmd represents the instruction for each Service ID. For example, if the Frame Cmd is 1, it can refer to a Request, and if it is 2, it can refer to a Response.

[0060] The Invoke ID is an identifier generated in the module that generates and sends the message. The module that receives the message and generates a response message needs to return this Invoke ID.

[0061] Finally, the payload represents user data. The payload may contain data to be transmitted to the module installed at the destination base number and slot number.

[0062] Thus, the message format includes the base number and slot number of the message sending device and the message receiving device, enabling the PLC device that sends or receives the message to know the origin and destination of the message.

[0063] The control unit 110 can generate messages in this format and share them to the backplane, thereby transmitting the messages to the desired destination modules.

[0064] Alternatively, the control unit 110 can confirm the destination base number and slot number of such a message shared to the backplane, and if they correspond to the base number and slot number on which the communication device 100 is installed, receive the data contained in the message payload.

[0065] Figure 5 This illustrates the message format used when requesting routing services from an external network via a communication device.

[0066] Figure 5 (a) shows the basic message format used for routing services.

[0067] The Base No. and Slot No. represent the base number and slot number where the destination communication device is installed, respectively.

[0068] The Service ID indicates the type of service provided via routing. If the Service ID is 1, it indicates the diagnostic information access service for the communication device; if it is 2, it indicates the CP message (MSG) object access service for the communication device; and if it is 3, it indicates message pass-through.

[0069] The communication device 100 according to the present invention provides a message transmission (pass-through) function utilizing routing services; therefore, the service ID can be set to 3, i.e., pass-through service.

[0070] Figure 5 (b) shows the Channel Open message format used for this routing service.

[0071] To provide the data pass-through function according to the present invention, routing paths need to be pre-defined between networks of different types. Therefore, routing paths need to be defined via channel opening messages. That is, direct paths such as tunnels can be defined between communication modules.

[0072] Channel Open Request message and Figure 5 (a) similarly includes the base number, slot number, and service ID, and may also include a frame instruction (Frame Cmd) based on the service ID and data for opening the channel.

[0073] The frame instruction indicates the type of service requested by the message.

[0074] A frame instruction can be defined as follows.

[0075] typedef enum

[0076] {

[0077] TNL_PASS_THRU_FC_INVALID =0, / 0 /

[0078] TNL_PASS_THRU_FC_OPEN_REQ , / 1 /

[0079] TNL_PASS_THRU_FC_OPEN_RES , / 2 /

[0080] TNL_PASS_THRU_FC_OPEN_RES_ERR , / 3 /

[0081] TNL_PASS_THRU_FC_CLOSE_REQ , / 4 /

[0082] TNL_PASS_THRU_FC_CLOSE_RES, / 5 /

[0083] TNL_PASS_THRU_FC_CLOSE_RES_ERR, / 6 /

[0084] TNL_PASS_THRU_FC_DATA_REQ, / 7 /

[0085] TNL_PASS_THRU_FC_DATA_RES, / 8 /

[0086] TNL_PASS_THRU_FC_DATA_RES_ERR, / 9 /

[0087] TNL_PASS_THRU_FC_MAX

[0088] }E_TNL_PASS_THRU_FC; That is, frame instructions include requests and responses to open channels and response errors, requests and responses to close channels and response errors, data requests and responses and response errors, etc.

[0089] The data used to open the channel includes the settings required for each communication to support pass-through functionality for different communication methods.

[0090] For example, if the destination communication device supports IP communication, it can include information such as IP address, port number, TCP / UDP.

[0091] If the destination communication device is a device that supports UART communication, it can include information required for UART communication such as baud rate, start, stop, parity, and settings required for the UART-based communication protocol (Modbus).

[0092] confirm Figure 5In (b), the frame instruction (FrameCmd) of the channel open request message is 1, and it contains channel open data. The frame instruction of the channel open response message is 2, and it contains a handle value. Here, the handle value represents the handle returned by the responding communication device.

[0093] The frame instruction for the channel opening error response is 3, and it includes an error code (ErrorCode). An example of the error code is shown below.

[0094] typedef enum

[0095] {

[0096] SVC_ERROR = 0x9001, / 0x9001, Service error /

[0097] SVC_ERR_MEM_ALLOC_FAIL, / 0x9002, memory allocation failed /

[0098] SVC_ERR_BAD_PRM, / 0x9003, bad parameter /

[0099] SVC_ERR_BAD_CMD, / 0x9004, /

[0100] SVC_ERR_BAD_SEQUENCE, / 0x9005, /

[0101] SVC_ERR_RESOURCE_BUSY, / 0x9006, /

[0102] SVC_ERR_BAD_QUEUE, / 0x9007, /

[0103] SVC_ERR_RESOURCE_ALLOC_FAIL, / 0x9008, /

[0104] SVC_ERR_NO_ITEM, / 0x9009, /

[0105] SVC_ERR_INVALID_HANDLE, / 0x900A, /

[0106] SVC_ERR_WRONG_SIZE, / 0x900B, /

[0107] } E_TNL_PASS_THRU_ERR

[0108] In other words, error codes represent 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).

[0109] In this way, messages generated by an external device can be transmitted to the destination communication device, thereby creating a routing path between the external device and the destination communication device. After the routing path is generated, messages can be transmitted directly through the pass-through function even if the network types are different.

[0110] Figure 6 (a) shows the message format used for data exchange utilizing the routing path thus generated.

[0111] The message format used for data exchange includes the same base number, slot number, and service ID fields as the basic message format.

[0112] Here, the frame instruction for the data request message can be 7, and can also include a handle value and a payload for user data.

[0113] The frame instruction for the message used for data response can be 8, and can also include a payload for user data.

[0114] Data response errors can include error codes, with specific examples of error codes as described above.

[0115] Figure 6 (b) shows the message format used to close the generated route path.

[0116] When a generated route path is no longer in use, it needs to be eliminated via a channel close message.

[0117] In the basic message format of the channel close request message, the frame instruction can be 4, and it can also include a handle value.

[0118] In the basic message format of the channel closure response message, the frame instruction can be 5.

[0119] Finally, the frame instruction for the channel close error response can be 6, and can also include an error message field, as described above.

[0120] Thus, by generating routing paths and utilizing the pass-through function to transmit messages between communication devices installed in the PLC system, data exchange between communication devices can be achieved even without the complex intervention of the CPU model.

[0121] Figure 7 This is a schematic structural diagram of a communication method according to another preferred embodiment of the present invention.

[0122] The communication method according to the present invention can be executed by a communication device including one or more processors and a memory.

[0123] The following description of the communication device will take the communication module included in the PLC system as an example, but the present invention is not limited to the communication module included in the PLC system.

[0124] The communication device generates a message containing the base number and slot number of other communication devices connected to the backplane (S110).

[0125] Messages can be shared by all PLC devices (communication devices) connected to the backplane via the backplane, thus enabling message transmission via the base number and slot number of the destination device (i.e., the message receiving device (PLC device)) on which the message is installed.

[0126] The generated messages are shared via the backplane (S120).

[0127] Backplane sharing enables message transmission between PLC devices in a pass-through manner without the complex intervention or processing of CPU modules.

[0128] The communication device confirms the base number and slot number of the message receiving device contained in the message to confirm whether the destination of the message shared to the backplane is itself (S130). If it is confirmed that the base number and slot number are the same as its own, the device receives the data contained in the message (S140).

[0129] The message format and specific values ​​used in this data exchange are as described above.

[0130] Figure 8 This is a schematic structural diagram of a communication method according to another preferred embodiment of the present invention.

[0131] According to the present invention, a routing path can be generated for external devices connected to a communication device (PLC device) connected to a backplane to communicate with other communication devices connected to a backplane using other types of networking, and communication can be performed thereon.

[0132] The communication device can receive a channel opening message from an external device (S210) and can send a response message to it (S220).

[0133] The format and specific examples of channel open messages, channel response messages, and channel response error messages are as described above.

[0134] Thus, if the channel is opened and a routing path is generated, data is exchanged through this (S230).

[0135] According to the present invention, if a routing path is generated, it has the advantage of being able to transmit messages regardless of network types such as IP communication and UART communication.

[0136] If the routing path is no longer needed, receive the channel closure message (S240), send the channel closure response message and complete the channel closure (S250).

[0137] Once the channel closure is complete, the resources and handles used in route path generation can be used for other tasks.

[0138] According to the communication apparatus and method of the present invention as described above, a method is provided that enables the transmission of messages in a pass-through manner between communication devices (PLC devices) connected to each other via a backplane without the intervention of a CPU module, regardless of the network type. This method has the effect of supporting various network communication methods even without additional work such as cable laying for generating network paths.

[0139] The scope of protection of this invention is not limited to the embodiments described and expressed above. Furthermore, it is reiterated that the scope of protection of this invention is not limited by obvious modifications or substitutions within the technical field to which this invention pertains.

Claims

1. A communication device capable of communication via a backplane, characterized in that, include: The control unit includes one or more processors and memory; as well as Ministry of Communications; The control unit sends or receives messages containing location information of other communication devices connected to the backplane through the communication unit, and communicates with other communication devices connected to the location indicated by the location information.

2. The communication device according to claim 1, characterized in that, The communication device is a PLC device.

3. The communication device according to claim 1, characterized in that, The message contains location information of the message sending device and the location information of the message receiving device.

4. The communication device according to claim 3, characterized in that, The control unit confirms the location information of the message receiving device contained in the message shared with the backplane. If the location information corresponds to its own, it receives the data contained in the message.

5. The communication device according to claim 1, characterized in that, The message includes: A channel open message is sent when a device outside the backplane requests routing services between itself and a communication device connected to the backplane in order to communicate with the communication device connected to the backplane. A channel close message is used to terminate the routing service; and Data exchange messages are used to exchange data through the routing service.

6. The communication device according to claim 5, characterized in that, The channel opening message contains configuration information required according to the communication method of the routing service.

7. A communication method, executed by a communication device including one or more processors and a memory, characterized in that, include: The step of generating a message containing location information of other communication devices connected to the backplane; as well as The step of sharing the message to the backplane.

8. The communication method according to claim 7, characterized in that, The communication device is a PLC device.

9. The communication method according to claim 7, characterized in that, The message contains location information of the message sending device and the location information of the message receiving device.

10. The communication method according to claim 9, characterized in that, Also includes: The step of confirming the location information of the message receiving device contained in the message shared to the backplane, and if it is the location information corresponding to itself, then receiving the data contained in the message.

11. The communication method according to claim 7, characterized in that, The message includes: A channel open message is sent when a device outside the backplane requests routing services between itself and a communication device connected to the backplane in order to communicate with the communication device connected to the backplane. A channel close message is used to terminate the routing service; and Data exchange messages are used to exchange data through the routing service.

12. The communication method according to claim 11, characterized in that, The channel opening message contains configuration information required according to the communication method of the routing service.

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