Communication device and method capable of communication via a backplane

Abstract

The present invention relates to a communication method between PLC devices connected to the same backplane. By sharing a message containing location information of the PLC devices connected to the backplane via the backplane, it enables communication between PLC devices without going through the CPU module. Furthermore, by forming a routing path between PLC devices via channel opening / closing messages between PLC devices, it has the advantage that external devices can easily ascertain the status of other devices connected to the PLC devices.

Description

Technical Field

[0001] [1] The present invention relates to communication technology, and particularly to the communication technology between PLC devices sharing a backplane.

Background Art

[0002] [2] A PLC (Programmable Logic Controller) device is a control device used for automatic control and monitoring in a factory. It receives sensor values as inputs, performs logical operations according to a preset user program, and controls devices connected externally based on the results.

[0003] [3] Recent control systems tend to utilize a distributed control system of a network infrastructure so as to be flexibly adaptable to installation, management, and expansion. For this reason, various communication modules are installed in PLC systems so that they can be connected to multiple networks.

[0004] [4] Each network is generally separated and operated in consideration of the real-time nature and application of control data according to control purposes so that interference does not occur between different networks. However, for production management such as maintenance and MES (Manufacturing Execution System), there are situations where data exchange is required between different networks without separate additional equipment or operations.

[0005] [5] In a system composed of PLC devices, etc., PLC devices sharing one PLC backplane, that is, communication modules with different communication methods can form one system. In that case, there is a problem that data cannot be exchanged with each other because information such as PLC devices connected to other types of networks or external devices connected to PLC devices in one network cannot be known.

[0006] [6] The inventors of the present invention have made extensive research efforts to overcome the limitations of communication methods of such conventional PLC devices. They have made great efforts to complete a communication device and method that can exchange data between different networks without the installation of additional devices or lines, and have now completed the present invention. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] [7] The object of the present invention is to provide a communication device and method that can transmit messages to each other between PLC devices sharing the same backplane, even if the network types are different.

[0008] [8] Another object of the present invention is to provide a communication device and method that can transmit data without modification (Pass Through) without intervention by a CPU module or the like.

[0009] [9] On the other hand, other purposes not explicitly stated in the present invention are to be considered to the extent that can be easily inferred from the following detailed description and its effects. [Means for solving the problem]

[0010]

[10] The communication device according to the present invention is

[11] A control unit comprising one or more processors and memory; and a communication unit; wherein the control unit transmits or receives messages containing location information of other communication devices connected to the backplane via the communication unit, and communicates with other communication devices connected to the location indicated by the location information.

[0011]

[12] The communication device is characterized by being a PLC (Programmable Logic Controller) device.

[0012]

[13] The message is characterized in that it includes location information of the message sending device and location information of the message receiving device.

[0013]

[14] The control unit checks the base number and slot number of the message receiving device of the message shared with the backplane, and if the base number and slot number match those of the device, it receives the data contained in the message.

[0014]

[15] The message is characterized by including a channel open message requesting a routing service between communication devices connected to the backplane for communication between a device outside the backplane and a communication device connected to the backplane, a channel close message for terminating the routing service, and a data exchange message for exchanging data via the routing service.

[0015]

[16] The channel open message is characterized in that it includes configuration information necessary according to the communication method of the routing service.

[0016]

[17] A communication method according to another embodiment of the present invention is

[18] The method is characterized by including the steps of: generating a message that includes location information of other communication devices connected by the backplane; and sharing the message with the backplane.

[0017]

[19] The device further includes the step of checking the location information of the message receiving device of the message shared with the backplane, and if the location information corresponds to itself, receiving the data contained in the message. [Effects of the Invention]

[0018]

[20] According to the present invention, data can be exchanged between PLC devices and other network devices connected to the same backplane, regardless of the network type.

[0019]

[21] Also, there is an advantage that a device outside the backplane can access the PLC device and exchange data regardless of the network type of the PLC device connected to the backplane.

[0020]

[22] On the other hand, even for effects not explicitly mentioned here, the effects described in the following specification expected by the technical features of the present invention and their provisional effects shall be handled as described in the specification of the present invention.

Brief Description of Drawings

[0021] [Figure 1]

[23] FIG. 1 is a schematic structural diagram of a communication device according to a preferred embodiment of the present invention. [Figure 2]

[24] FIG. 2 shows the overall structure of a network-based PLC system to which a communication device according to a desirable embodiment of the present invention is applied. [Figure 3] FIG. 3 shows the overall structure of a network-based PLC system to which a communication device according to a desirable embodiment of the present invention is applied. [Figure 4]

[25] FIG. 4 shows an example of a message format for data exchange of a communication device according to a desirable embodiment of the present invention. [Figure 5]

[26] FIG. 5 shows an example of a message format when requesting a routing service from an external network via a communication device according to a desirable embodiment of the present invention. [Figure 6]

[27] FIG. 6 shows an example of a message format related to a routing path generated according to a desirable embodiment of the present invention. [Figure 7]

[28] FIG. 7 is a schematic flowchart of a communication method according to another desirable embodiment of the present invention. [Figure 8]

[29] FIG. 8 is a schematic configuration diagram of a communication method according to another desirable embodiment of the present invention.

[0022]

[30]

[31] The attached drawings are provided by way of example for reference in understanding the technical idea of the present invention, and the scope of rights of the present invention is not limited thereby.

Embodiments for Carrying Out the Invention

[0023]

[32] Hereinafter, the configuration of the present invention shown by various embodiments of the present invention and the effects resulting from the configuration will be described with reference to the drawings. In describing the present invention, when it is determined that the related known functions are obvious to those skilled in the art and may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

[0024]

[33] Terms such as "first" and "second" can be used to describe various components, but the components should not be limited by the terms. The terms can be used only for the purpose of distinguishing one component from another. For example, within the scope not departing from the scope of rights of the present invention, "the first component" can be named "the second component", and similarly, "the second component" can also be named "the first component". Also, the singular expression includes the plural expression unless the context clearly indicates otherwise. The terms used in the embodiments of the present invention can be interpreted as having the meanings commonly known to those having ordinary knowledge in the technical field unless otherwise defined.

[0025]

[34] Hereinafter, the configuration of the present invention shown by various embodiments of the present invention and the effects resulting from the configuration will be described with reference to the drawings.

[0026]

[35]

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

[0027]

[37] The communication device 100 according to the present invention can include a control unit 110 and a communication unit 120.

[0028]

[38] The control unit 110 performs operations to control multiple communication methods of the communication device 100. For this purpose, the control unit 110 may include one or more processors 112 and memory 114. That is, the control unit 110 can control the communication device 100 and transmit and receive data with other communication devices connected to the same backplane.

[0029]

[39] The control unit 110 may include, but is not limited to, a hardware processor 112 or a software process running on the processor.

[0030]

[40] The memory 114 stores various information necessary for the operation of the communication device 100. The information stored in the memory 114 includes, but is not limited to, various data received from other communication devices connected to the communication device 100, data to be transmitted to other communication devices, information for the control operation of the processor 112, and program information related to the control method of the processor 112.

[0031]

[41] For example, the memory 114 may include, but is not limited to, a 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, ROM type (read-only memory type), or RAM type (random access memory type), depending on its type. The memory 114 may also be, but is not limited to, a cache, buffer, main memory, or auxiliary memory, depending on its use and location, or a separately provided storage system.

[0032]

[42] Hereinafter, for the purpose of explanation, the communication device 100 will be described as a PLC device, but it goes without saying that the present invention can be used with other communication devices other than PLC devices, and is not limited thereto.

[0033]

[43] Figures 2 and 3 show the overall structure of a network infrastructure PLC system to which the communication device 100 according to the present invention is applied.

[0034]

[44] Figure 2 shows an example of an expanded system in which an Ethernet module, which is an example of a communication device 100, is installed in the PLC system, and remote I / O of an Ethernet infrastructure connected to it is linked.

[0035]

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

[0036]

[46] In addition, production control systems such as management PCs and MES connected to an external network manage the operation of the PLC system and acquire information from the PLC system.

[0037]

[47] Figure 3 is a more detailed structural diagram of such a PLC system.

[0038]

[48] ​​The backplane is connected to the bottom surface, on which the power module, CPU module, and communication device 100 (communication module) are mounted. In addition to the communication module, various PLC modules (PLC devices) may be mounted depending on the control purpose of the PLC system.

[0039]

[49] To distinguish which backplane the installed PLC device is installed 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., the communication device 100, within the PLC system. Of course, the present invention can also be carried out in communication systems other than PLC systems using location information corresponding to the base number and slot number.

[0040]

[50] Thus, 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 the calculation is completed. Therefore, there is no path for the communication module to transmit data to other communication modules or external devices connected to other communication modules.

[0041]

[51] Accordingly, the communication device 100 according to the present invention provides a method for transmitting data to other networks by the concept of pass-through, utilizing the communication modules, backplanes, and communication cables of an already installed PLC system, without the need to install additional network devices or communication cables.

[0042]

[52] The control unit 110 can transmit data to other communication devices by determining the base number and slot number to which the other communication devices are connected and by generating a message that includes these.

[0043]

[53] For the sake of convenience in the following explanation, we will use base numbers and slot numbers, but it goes without saying that even in communication systems that do not use base numbers and slot numbers, the present invention can be implemented by location information corresponding to base numbers and slot numbers.

[0044]

[54] Figure 4 shows an example of a message format for this purpose, specifically a message format for data exchange between modules located in a slot.

[0045]

[55] Size indicates the size of the message shared over the backplane.

[0046]

[56] BC is a Block Command, and the fields following the Size field indicate that the data is in a format for exchanging data between modules.

[0047]

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

[0048]

[58] The SRC Base No. and Slot No. indicate the base number and slot number, respectively, of the module that generates the message to be transmitted.

[0049]

[59] The Service ID is a field that indicates which service to provide.

[0050]

[60] Frame Cmd indicates a command specific to the Service ID. For example, if Frame Cmd is 1, it means a Request, and if it is 2, it means a Response.

[0051]

[61] The Invoke ID is an identifier generated by the module that generates and sends the message. The module that receives this message and generates a response message should convert this Invoke ID.

[0052]

[62] Finally, the Payload represents user data. The Payload may include data transmitted to the module mounted in the destination base number and slot number.

[0053]

[63] The message format thus includes the base number and slot number of the message sending device and the message receiving device so that the PLC device sending or receiving the message can determine the origin and destination of the message.

[0054]

[64] The control unit 110 can transmit messages to desired destination modules by generating messages in this format and sharing them with the backplane.

[0055]

[65] Alternatively, the control unit 110 can check the destination base number and slot number of such a message shared on the backplane and receive the data contained in the message payload if it matches the base number and slot number on which the communication device 100 is installed.

[0056]

[66] Figure 5 shows the message format when requesting routing services from an external network via a communication device.

[0057]

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

[0058]

[68] BaseNo and SlotNo indicate the base number and slot number to which the destination communication device is installed, respectively.

[0059]

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

[0060]

[70] 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., the Pass Through service.

[0061]

[71] Figure 5(b) shows the channel open message format for such a routing service.

[0062]

[72] In order to provide the data pass-through function according to the present invention, routing paths must be pre-configured between different types of networks, and therefore it is necessary to configure the routing paths via channel open messages. That is, direct paths such as tunnels between communication modules can be configured.

[0063]

[73] A Channel Open Request message may include the same base number, slot number, and service ID as in Figure 5(a), and may also include a Frame Cmd (frame command) and data for opening the channel, depending on the service ID.

[0064]

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

[0065]

[75] Frame commands are defined as follows:

[0066]

[76] typedef enum

[77] {

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

[79] TNL_PASS_THRU_FC_OPEN_REQ, / * 1* /

[80] TNL_PASS_THRU_FC_OPEN_RES, / * 2 * /

[81] TNL_PASS_THRU_FC_OPEN_RES_ERR, / * 3 * /

[82] TNL_PASS_THRU_FC_CLOSE_REQ, / * 4 * /

[83] TNL_PASS_THRU_FC_CLOSE_RES, / * 5 * /

[84] TNL_PASS_THRU_FC_CLOSE_RES_ERR, / *6* /

[85] TNL_PASS_THRU_FC_DATA_REQ, / * 7 * /

[86] TNL_PASS_THRU_FC_DATA_RES, / *8* /

[87] TNL_PASS_THRU_FC_DATA_RES_ERR, / * 9 * /

[88] TNL_PASS_THRU_FC_MAX

[89] }E_TNL_PASS_THRU_FC;

[90]

[91] That is, frame commands include requests and responses for channel opening, as well as response errors; requests and responses for channel closing, as well as response errors; data requests and responses, as well as response errors.

[0067]

[92] The data for opening a channel includes the settings required for each communication to support the pass-through function for each different communication method.

[0068]

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

[0069]

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

[0070]

[95] Looking at Figure 5(b), 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, where the handle value indicates the handle returned by the responding communication device.

[0071]

[96] A channel open error response has a frame command of 3 and includes an ErrorCode, an example of which is:

[0072]

[97] typedef enum

[98] {

[99] 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] In other words, the error codes indicate a variety of 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).

[0073]

[0112] In this way, messages generated by an external device are 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 created, the message can be transmitted directly via the pass-through function, even if the network types are different.

[0074]

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

[0075]

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

[0076]

[0115] A message for data requests may have a frame command of 7 and may further include a handle value and a payload for user data.

[0077]

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

[0078]

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

[0079]

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

[0080]

[0119] When a generated routing path is no longer in use, it should be deleted via a channel closure message.

[0081]

[0120] A channel closure request message has a frame command of 4 in its basic message format and may further include a handle value.

[0082]

[0121] The response message for channel closure can use the basic message format, and the frame command may be 5.

[0083]

[0122] Finally, the error response for channel closure is frame command 6 and may further include an error message field, as mentioned above.

[0084]

[0123] By generating routing paths in this way and using the pass-through function to transmit messages between communication devices installed in the PLC system, data can be exchanged between communication devices without the complex intervention of the CPU model.

[0085]

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

[0086]

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

[0087]

[0126] The following description of the communication device will use a communication module included in a PLC system as an example, but the present invention is not limited to a communication module included in a PLC system.

[0088]

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

[0089]

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

[0090]

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

[0091]

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

[0092]

[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). If it confirms that the base number and slot number correspond to itself, it receives the data included in the message (S140).

[0093]

[0132] The message format and specific values ​​used for this type of data exchange are as described above.

[0094]

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

[0095]

[0134] According to the present invention, an external device connected to a communication device (PLC device) connected to a backplane can generate a routing path for communication with other communication devices connected to the backplane that use different types of network schemes, and can use this path to communicate.

[0096]

[0135] The communication device can receive a channel open message from an external device (S210) and send a response message in response (S220).

[0097]

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

[0098]

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

[0099]

[0138] The present invention has the advantage that when a routing path is generated, messages can be transmitted regardless of the type of network, such as IP communication or UART communication.

[0100]

[0139] When the routing path is no longer needed, the system receives a channel closure message (S240) and sends a channel closure response message to complete the channel closure (S250).

[0101]

[0140] Once channel closure is complete, the resources and handles used for routing path generation can be used for other tasks.

[0102]

[0141]

[0142] According to the communication device and method of the present invention described above, a method is provided that enables the transmission of messages via a pass-through method between communication devices (PLC devices) interconnected by a backplane, regardless of the network type, without the intervention of a CPU module. This has the effect of supporting a variety of network communication methods without additional work such as laying cables for network path generation.

[0103]

[0143]

[0144] The scope of protection of the present invention is not limited to the descriptions and expressions of the embodiments explicitly described above. Furthermore, it should be reiterated that the scope of protection of the present invention is not limited by obvious modifications or substitutions in the art to which the present invention pertains.

Claims

1. In a communication device capable of communication via a backplane, A control unit including one or more processors and memory; and Communications Department; Includes, The control unit is a communication device that transmits or receives messages containing location information of other communication devices connected to the backplane via 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, wherein the communication device is a PLC (Programmable Logic Controller) device.

3. The communication device according to claim 1, wherein the message includes location information of the message sending device and location information of the message receiving device.

4. The communication device according to claim 3, wherein the control unit checks the location information of the message receiving device included in the message shared with the backplane, and if the location information corresponds to itself, it receives the data included in the message.

5. The communication device according to claim 1, wherein the messages include a channel open message for a device outside the backplane to request a routing service between communication devices connected to the backplane for communication with a communication device connected to the backplane, a channel close message for terminating the routing service, and a data exchange message for exchanging data via the routing service.

6. The communication device according to claim 5, wherein the channel open message includes configuration information necessary 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, The step of generating a message that includes location information of other communication devices connected to the backplane; and A communication method, including sharing the aforementioned message with the backplane.

8. The communication method according to claim 7, wherein the communication device is a PLC device.

9. The communication method according to claim 7, wherein the message includes location information of the message sending device and location information of the message receiving device.

10. The communication method according to claim 9, further comprising the steps of: checking the location information of the message receiving device included in the message shared with the backplane, and receiving the data included in the message if the location information corresponds to itself.

11. The communication method according to claim 7, wherein the message includes a channel open message requesting routing services between a device outside the backplane and a communication device connected to the backplane, a channel close message for terminating the routing service, and a data exchange message for exchanging data via the routing service.

12. The communication method according to claim 11, wherein the channel open message includes configuration information necessary according to the communication method of the routing service.

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