Communication system for numerical control device and communication method for numerical control device

Abstract

The present invention addresses the issue of providing a communications system for numerical control devices and a communications method for numerical control devices, that have less communications traffic than is conventionally required. This communications system for numerical control devices includes a numerical control device, a converter device, and a plurality of inverter devices. This communications system for numerical control devices comprises an application unit and a determination unit. The application unit applies identification information to the inverter devices. The determination unit determines the inverter device, among the plurality of inverter devices that have had identification information applied thereto, that will be used for communications with the numerical control device and the converter device. The numerical control device comprises a numerical control communications unit that communicates with the inverter device using a first transmission path. The converter device comprises a converter communications unit that communicates with the numerical control device via: a second transmission path different from the first transmission path; the inverter device determined by the determination unit; and the first transmission path.

Description

[Technical field]

[0001] The present invention relates to a communication system for a numerical control device and a communication method for a numerical control device. [Background technology]

[0002] A machine tool has motors such as a servo motor and a spindle motor for each drive axis. A servo control system controls these motors, for example, the speed, torque, and rotor position of each motor.

[0003] Such a servo control system includes, for example, a converter device that converts AC input from a power source into DC and outputs it, and an inverter device that converts the DC output from the converter device into AC of a desired frequency for driving a motor.

[0004] In a servo control system, when a numerical control device and a converter device are directly connected, or when multiple converter devices are directly connected to each other, many transmission lines are required, which increases the cost of the transmission lines. In addition, such a servo control system also requires a large amount of communication. In addition, in order to ensure high-speed and high-precision control in such a servo control system, the numerical control device and the converter device require high-performance processors and large-capacity memories, which incurs further costs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-153607 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a communication system for a numerical control device and a communication method for a numerical control device that achieves a smaller amount of communication traffic than in the past. [Means for solving the problem]

[0007] A communication system for a numerical control device according to an embodiment includes a numerical control device, a converter device, and a plurality of inverter devices. The communication system for a numerical control device according to an embodiment includes an assigning unit and a determining unit. The assigning unit assigns identification information to the inverter devices. The determining unit determines the inverter device to be used for communication between the numerical control device and the converter device from among the plurality of inverter devices to which the identification information has been assigned. The numerical control device includes a numerical control communication unit that communicates with the inverter devices using a first transmission path. The converter device includes a second transmission path different from the first transmission path, the inverter device determined by the determining unit, and a converter communication unit that communicates with the numerical control device via the first transmission path. Effect of the Invention

[0008] According to the present invention, the amount of communication can be reduced compared to the conventional art. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a servo control system according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of a main configuration of each device that is a component of the servo control system according to the embodiment. [Diagram 3] 3 is a flowchart showing an example of processing by a processor of the numerical control device in FIG. 2; [Figure 4] 3 is a flowchart showing an example of processing by a processor of the converter device in FIG. 2; [Diagram 5] 3 is a flowchart showing an example of processing by a processor of the inverter device in FIG. 2; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a servo control system according to an embodiment will be described with reference to the drawings. Note that, for the sake of explanation, the drawings used in the following description of the embodiment may omit configurations. In addition, in each drawing and in this specification, the same reference numerals denote similar elements. The configuration of a servo control system 1 according to the embodiment will be described with reference to Figs. 1 and 2. Fig. 1 is a diagram showing an example of the configuration of the servo control system 1 according to the embodiment. Fig. 2 is a block diagram showing an example of the main configuration of each device which is a component of the servo control system 1 according to the embodiment. The servo control system 1 includes, as an example, a numerical control device 10, a power supply 20, a converter device 30, an inverter device 40, and a motor 50. Note that the number of each device is not limited to the number shown in the figure. The servo control system is also an example of a communication system for a numerical control device.

[0011] The servo control system 1 includes one or more groups G. In Fig. 1, two groups G, a group G1 and a group G2, are shown. Each group G includes one converter device 30 and one or more inverter devices 40. The converter device 30 supplies power to the inverter devices 40 in the same group. Group G1 includes, as an example, converter device 30a and inverter devices 40a to 40d. Group G2 includes, as an example, converter device 30b and inverter devices 40e to 40h. The converter device 30a and the converter device 30b are a first converter device and a second converter device. Place The inverter device 40 in the same group G as the first converter device is an example of the first inverter device. The inverter device 40 in the same group G as the second converter device is an example of the second inverter device.

[0012] The numerical control device 10 is, for example, a device that performs CNC (computerized numerical control) for a machine tool or the like. The numerical control device 10 controls the operation of a motor 50 or the like by CNC. The numerical control device 10 includes, for example, a processor 11, a ROM (read-only memory) 12, a RAM (random-access memory) 13, an auxiliary storage device 14, and a communication I / F (interface) 15.

[0013] The processor 11 corresponds to the central part of a computer that performs processes such as calculations and controls required for the operation of the numerical control device 10. The processor 11 is, for example, a central processing unit (CPU), a micro processing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 11 is a combination of a plurality of these. The processor 11 controls each part to realize various functions of the numerical control device 10 based on programs such as firmware, system software, and application software stored in the ROM 12 or the auxiliary storage device 14. The processor 11 also executes processes described below based on the programs. Note that a part or all of the programs may be incorporated in the circuit of the processor 11.

[0014] ROM 12 corresponds to the main memory device of the computer with processor 11 as its core. ROM 12 is a non-volatile memory used exclusively for reading data. ROM 12 stores, for example, firmware among the above programs. ROM 12 also stores data used by processor 11 when performing various processes.

[0015] The RAM 13 corresponds to the main memory device of the computer centered around the processor 11. The RAM 13 is a memory used for reading and writing data. The RAM 13 is used as a work area for storing data that is temporarily used when the processor 11 performs various processes. The RAM 13 is typically a volatile memory.

[0016] The auxiliary storage device 14 corresponds to an auxiliary storage device of a computer with the processor 11 as its core. The auxiliary storage device 14 is, for example, an EEPROM (electric erasable programmable read-only memory), a HDD (hard disk drive), or a flash memory. The auxiliary storage device 14 stores, for example, system software and application software among the above programs. The auxiliary storage device 14 also stores data used by the processor 11 in performing various processes, data generated by the processes in the processor 11, various setting values, and the like.

[0017] The communication I / F 15 is an interface for the numerical control device 10 to communicate with the inverter device 40 and the like via the transmission path α. The transmission path α is an example of a first transmission path. The communication I / F 15 is an example of a numerical control communication unit that communicates with the inverter device 40 using the transmission path α.

[0018] The power supply 20 is an AC power supply that supplies AC power to the converter device 30 .

[0019] The converter device 30 converts AC power supplied from the power source 20 into DC power and outputs the DC power to the inverter device 40. The converter device 30 is also called a PS (power supply), etc. The converter device 30 includes, for example, a processor 31, a ROM 32, a RAM 33, an auxiliary storage device 34, a converter circuit unit 35, and a communication I / F 36.

[0020] The processor 31 corresponds to the central part of a computer that performs processes such as calculations and controls required for the operation of the converter device 30. The processor 31 is, for example, a CPU, an MPU, an SoC, a DSP, a GPU, an ASIC, a PLD, or an FPGA. Alternatively, the processor 31 is a combination of a plurality of these. The processor 31 controls each part to realize various functions of the converter device 30 based on programs such as firmware, system software, and application software stored in the ROM 32 or the auxiliary storage device 34. The processor 31 also executes processes described below based on the programs. Note that a part or all of the programs may be incorporated in the circuitry of the processor 31.

[0021] ROM 32 corresponds to the main storage device of a computer with processor 31 as its core. ROM 32 is a non-volatile memory used exclusively for reading data. ROM 32 stores, for example, firmware among the above programs. ROM 32 also stores data used by processor 31 when performing various processes.

[0022] The RAM 33 corresponds to the main memory device of a computer with the processor 31 at its core. The RAM 33 is a memory used for reading and writing data. The RAM 33 is used as a work area for storing data that is temporarily used when the processor 31 performs various processes. The RAM 33 is typically a volatile memory.

[0023] The auxiliary storage device 34 corresponds to the auxiliary storage device of a computer with the processor 31 as its core. The auxiliary storage device 34 is, for example, an EEPROM, a HDD, or a flash memory. The auxiliary storage device 34 stores, for example, system software and application software among the above programs. The auxiliary storage device 34 also stores data used by the processor 31 in performing various processes, data generated by the processes in the processor 31, various setting values, and the like.

[0024] The converter circuit unit 35 is an electric circuit that performs functions such as converting AC power into DC power.

[0025] The communication I / F 36 is an interface for the converter device 30 to communicate with the inverter device 40 and the like via the transmission path β. In FIG. 1, the transmission path β of group G1 is shown as transmission path β1, and the transmission path β of group G2 is shown as transmission path β2. The transmission path β is an example of a second transmission path. The communication I / F 36 is also an example of a converter communication unit that communicates with the inverter device 40 using the transmission path β.

[0026] The inverter device 40 converts the DC power supplied from the converter device 30 into AC power of a desired frequency for driving the motor 50. The inverter device 40 includes an inverter device 40 for a servo motor and an inverter device 40 for a spindle motor. Based on an input from the numerical control device 10 instructing the operation of the motor 50, the inverter device 40 inputs AC power required for the operation to the motor 50. The inverter device 40 includes, for example, a processor 41, a ROM 42, a RAM 43, an auxiliary storage device 44, an inverter circuit unit 45, a first communication I / F 46, and a second communication I / F 47.

[0027] The processor 41 corresponds to the central part of a computer that performs processes such as calculations and controls required for the operation of the inverter device 40. The processor 41 is, for example, a CPU, an MPU, an SoC, a DSP, a GPU, an ASIC, a PLD, or an FPGA. Alternatively, the processor 41 is a combination of a plurality of these. The processor 41 controls each part to realize various functions of the inverter device 40 based on programs such as firmware, system software, and application software stored in the ROM 42 or the auxiliary storage device 44. The processor 41 also executes processes described below based on the programs. Note that a part or all of the programs may be incorporated in the circuitry of the processor 41.

[0028] The ROM 42 corresponds to the main storage device of the computer with the processor 41 at its core. The ROM 42 is a non-volatile memory used exclusively for reading data. The ROM 42 stores, for example, firmware among the above programs. The ROM 42 also stores data used by the processor 41 when performing various processes.

[0029] The RAM 43 corresponds to the main memory device of a computer with the processor 41 at its core. The RAM 43 is a memory used for reading and writing data. The RAM 43 is used as a work area for storing data that is temporarily used when the processor 41 performs various processes. The RAM 43 is typically a volatile memory.

[0030] The auxiliary storage device 44 corresponds to the auxiliary storage device of a computer with the processor 41 as its core. The auxiliary storage device 44 is, for example, an EEPROM, a HDD, or a flash memory. The auxiliary storage device 44 stores, for example, system software and application software among the above programs. The auxiliary storage device 44 also stores data used by the processor 41 in performing various processes, data generated by the processes in the processor 41, various setting values, and the like.

[0031] The inverter circuit section 45 is an electric circuit that performs functions such as converting DC power into AC power.

[0032] The first communication I / F 46 is an interface for the inverter device 40 to communicate with the converter device 30, other inverter devices 40, and the like via the transmission path β.

[0033] The second communication I / F 47 is an interface for the inverter device 40 to communicate with the numerical control device 10, other inverter devices 40, and the like via the transmission path α.

[0034] The motor 50 is, for example, a motor such as a servo motor or a spindle motor that drives each part of a machine tool, etc. The motor 50 is an example of a device to be controlled by the inverter device 40.

[0035] The operation of the servo control system 1 according to the embodiment will be described below with reference to Figs. 3 to 5. Note that the contents of the process in the following operation description are merely examples, and various processes capable of obtaining similar results can be appropriately used. Fig. 3 is a flowchart showing an example of the process by the processor 11 of the numerical control device 10. The processor 11 executes the process of Fig. 3 based on a program stored in, for example, the ROM 12 or the auxiliary storage device 14. Fig. 4 is a flowchart showing an example of the process by the processor 31 of the converter device 30. The processor 31 executes the process of Fig. 4 based on a program stored in, for example, the ROM 32 or the auxiliary storage device 34. Fig. 5 is a flowchart showing an example of the process by the processor 41 of the inverter device 40. The processor 41 executes the process of Fig. 5 based on a program stored in, for example, the ROM 42 or the auxiliary storage device 44.

[0036] The processor 11 of the numerical control device 10 starts the process shown in FIG. In step S11 of FIG. 3, the processor 11 generates a CNC code. The CNC code is unique identification information for each inverter device 40. For example, the processor 11 assigns CNC codes Ca to Ch to each of the inverter devices 40a to 40h. The processor 11 establishes a connection between the numerical control device 10 and the inverter device 40 for each inverter device 40 in order. The processor 11 assigns, for example, a serial number indicating the order of the connection as a CNC code. For example, the processor 11 assigns a CNC code Ca to the inverter device 40a that established a connection first, a CNC code Cb to the inverter device 40b that established a connection second, a CNC code Cc to the inverter device 40c that established a connection third, and so on. After generating the CNC code, the processor 11 instructs the communication I / F 15 to transmit the generated CNC code to the inverter device 40 to which the CNC code is to be assigned. In response to this instruction, the communication I / F 15 transmits the CNC code to the inverter device 40. The transmitted CNC code is received by the second communication I / F 47 of the inverter device 40. As described above, the processor 11 performs the process of step S11 to function as an assigning unit (first assigning unit) that assigns a CNC code to the inverter device. The CNC code is an example of first identification information.

[0037] On the other hand, the processor 31 of the converter device 30 starts the process shown in FIG. In step S21 of FIG. 4, the processor 31 generates a PS code. The PS code is unique identification information for each inverter device 40 in the same group G. For example, the processor 31 of the converter device 30a assigns PS codes C1 to C4 to the inverter devices 40a to 40d, respectively. For example, the processor 41 of the converter device 30b assigns PS codes C1 to C4 to the inverter devices 40e to 40h, respectively. In this way, the PS codes may overlap if they belong to different groups G. The processor 31 establishes a connection between the converter device 30 and the inverter device 40 in order for each inverter device 40 in the same group G as the processor 31, for example. The processor 31 assigns, for example, a serial number indicating the order of this connection as the PS code. For example, the processor 31 of the converter device 30a assigns a PS code C1 to the inverter device 40a that first establishes a connection, a PS code C2 to the inverter device 40b that second establishes a connection, a PS code C3 to the inverter device 40c that third establishes a connection, and so on. For example, the processor 31 of the converter device 30b assigns a PS code C1 to the inverter device 40e that first establishes a connection, a PS code C2 to the inverter device 40f that second establishes a connection, a PS code C3 to the inverter device 40g that third establishes a connection, and so on. After generating a PS code, the processor 31 instructs the communication I / F 36 to transmit the generated PS code to the inverter device 40 to which the PS code is to be assigned. Upon receiving this transmission instruction, the communication I / F 36 transmits the PS code to the inverter device 40. The transmitted PS code is received by the first communication I / F 46 of the inverter device 40. As described above, the processor 31 performs the process of step S21 to function as an assigning unit (second assigning unit) that assigns a PS code to the inverter device. 2 1 is an example of identification information.

[0038] On the other hand, the processor 41 of the inverter device 40 starts the process shown in FIG. 5, the processor 41 determines whether or not the CNC code has been received by the second communication I / F 47. If the CNC code has not been received, the processor 41 determines No in step S31 and proceeds to step S32. In step S32, the processor 41 determines whether or not the PS code has been received by the first communication I / F 46. If the PS code has not been received, the processor 41 determines No in step S32 and proceeds to step S33. In step S33, the processor 41 determines whether or not the first relay information has been received by the second communication I / F 47. If the first relay information has not been received, the processor 41 determines No in step S33 and proceeds to step S34.

[0039] In step S34, the processor 41 determines whether or not the first diagnostic information has been received by the first communication I / F 46. If the first diagnostic information has not been received, the processor 41 determines No in step S34 and returns to step S31. Thus, the processor 41 enters a standby state in which steps S31 to S34 are repeated until the CNC code, the PS code, the first relay information, or the first diagnostic information is received. The first relay information and the first diagnostic information will be described later.

[0040] If processor 41 receives a CNC code during the standby state of steps S31 to S34, it determines that the result is Yes in step S31, and proceeds to step S35.

[0041] In step S35, the processor 41 stores the received CNC code in the RAM 43 or the auxiliary storage device 44. After the process of step S35, the processor 41 returns to step S31.

[0042] Moreover, if the processor 41 receives a PS code during the standby state of steps S31 to S34, the result of step S32 is Yes, and the process proceeds to step S36.

[0043] In step S36, the processor 41 stores the received PS code in the RAM 43 or the auxiliary storage device 44. After the process of step S36, the processor 41 returns to step S31.

[0044] On the other hand, in step S12 of FIG. 3, the processor 11 of the numerical control device 10 acquires a connection state indicating the quality of communication when the inverter device 40 communicates with the converter device 30 in the same group as the inverter device 40 for each inverter device 40. The connection state indicates, for example, the communication distance between the converter device 30 and the inverter device 40. The processor 11 acquires the communication distance from information indicating the communication distance stored in, for example, the auxiliary storage device 14. Alternatively, the processor 11 may measure the communication distance. The communication distance can be measured using a communication delay or loss. Alternatively, the processor 11 may acquire a communication delay or loss between the converter device 30 and the inverter device 40 as the connection state. Alternatively, the processor 11 may acquire a PS code assigned to each inverter device 40 as the connection state. Usually, the shorter the communication distance, the earlier the communication is established and the PS code is assigned, so the PS code assigned as a serial number is information indicating the connection state.

[0045] In step S13, the processor 11 determines, for each group G, an inverter device 40 (hereinafter referred to as a "relay device") to be used for relaying communication when transmitting the first diagnostic information from the converter device 30 to the numerical control device 10. For example, for each group G, the processor 11 determines the inverter device 40 in the group G that is best connected. Here, a good connection state means, for example, a short communication distance, a small communication delay, or a small communication loss. Alternatively, the processor 11 may determine, as the relay device, the inverter device 40 with the smallest PS code assigned as a serial number among the inverter devices 40 in the group G, that is, the inverter device 40 to which the PS code was assigned first in step S21 of FIG. 4, by considering that the communication distance is shortest. As described above, the processor 11 performs the process of step S13, thereby functioning as a determination unit that determines a relay device.

[0046] In step S14 of FIG. 3, the processor 11 generates first relay information. The first relay information includes information indicating that a relay device is to be specified. After generating the first relay information, the processor 11 instructs the communication I / F 15 to transmit the first relay information to each of the inverter devices 40 determined in step S13. In response to this transmission instruction, the communication I / F 15 transmits the first relay information to each of the inverter devices 40. The transmitted first relay information is received by the second communication I / F 47 of each inverter device 40.

[0047] On the other hand, if the first relay information is received during the standby state of steps S31 to S34 in FIG. 5, the processor 41 of the inverter device 40 determines Yes in step S33 and proceeds to step S37. In step S37, the processor 41 generates second relay information. The second relay information includes the first relay information received in step S33, the CNC code stored in step S35, and the PS code stored in step S36. After generating the second relay information, the processor 41 instructs the first communication I / F 46 to transmit the second relay information to the converter device 30. In response to this transmission instruction, the first communication I / F 46 transmits the second relay information to the converter device 30. The transmitted second relay information is received by the communication I / F 36 of the converter device 30.

[0048] 4, the processor 31 of the converter device 30 waits for the second relay information to be received by the communication I / F 36. If the second relay information is received, the processor 31 determines Yes in step S22 and proceeds to step S23.

[0049] In step S23, the processor 31 sets a relay device to be used when transmitting the first diagnostic information. That is, the processor 31 stores the PS code included in the second relay information received in step S22 in the RAM 33 or the auxiliary storage device 34 as information indicating the relay device for transmitting the first diagnostic information.

[0050] In step S24, the processor 31 determines whether to transmit the first diagnostic information. The first diagnostic information includes, for example, information indicating the state of the converter device 30 or the power supply 20. The first diagnostic information includes, for example, alarm information of an amplifier or fan provided in the converter device 30 or the power supply 20, or information indicating an abnormality in the current or voltage in the converter device 30 or the power supply 20. Note that the alarm information is, for example, information indicating that an abnormal operation has been detected. The processor 31 determines to transmit the first diagnostic information, for example, when a predetermined timing is reached. Alternatively, the processor 31 determines to transmit the first diagnostic information, for example, when it detects that an abnormal operation has occurred in the converter device 30 or the power supply 20, or when it detects an abnormality in the current or voltage in the converter device 30 or the power supply 20. The processor 31 determines to transmit the first diagnostic information. do not If so, the processor 31 determines "No" in step S24 and repeats the process of step S24. do If so, the answer to step S24 is Yes, and the process proceeds to step S25.

[0051] In step S25, the processor 31 generates first diagnostic information by performing a self-diagnosis or the like. After generating the first diagnostic information, the processor 31 instructs the communication I / F 36 to transmit the first diagnostic information to a relay device, i.e., the inverter device 40 to which the PS code stored in step S23 has been assigned. In response to this transmission instruction, the communication I / F 36 transmits the first diagnostic information to the inverter device 40. The transmitted first diagnostic information is received by the first communication I / F 46 of the inverter device 40. After processing of step S25, the processor 31 returns to step S24.

[0052] On the other hand, if the first diagnostic information is received during the standby state of steps S31 to S34 in FIG. 5, the processor 41 of the inverter device 40 determines Yes in step S34 and proceeds to step S38. In step S38, the processor 41 generates second diagnostic information. The second diagnostic information includes the first diagnostic information received in step S34, the CNC code stored in step S35, and the PS code stored in step S36. After generating the second diagnostic information, the processor 41 instructs the second communication I / F 47 to transmit the second diagnostic information to the numerical control device 10. In response to this transmission instruction, the second communication I / F 47 transmits the second diagnostic information to the numerical control device 10. The transmitted second diagnostic information is received by the communication I / F 15 of the numerical control device 10. After processing in step S38, the processor 41 returns to step S31.

[0053] 3, the processor 11 of the numerical control device 10 waits for the second diagnostic information to be received by the communication I / F 15. If the second diagnostic information is received, the processor 11 determines "Yes" in step S15 and proceeds to step S16.

[0054] In step S16, the processor 11 performs various processes according to the contents of the received second diagnostic information. After the process of step S16, the processor 11 returns to step S15.

[0055] In the servo control system 1 of the embodiment, the numerical control device and the converter device are not directly connected, and the multiple converter devices are not directly connected to each other. Therefore, the servo control system 1 of the embodiment can reduce the communication amount compared to the conventional system. In addition, the servo control system 1 of the embodiment can reduce the cost of the transmission line compared to the conventional system.

[0056] Moreover, according to the servo control system 1 of the embodiment, the converter device 30 transmits the first diagnostic information to one inverter device 40. Therefore, the second diagnostic information transmitted to the numerical control device 10 is one from one group G. In contrast, the conventional converter device transmits diagnostic information to all inverter devices in the same group. Therefore, in the conventional servo control system, the diagnostic information is transmitted from all inverter devices to the numerical control device. As a result, the servo control system 1 of the embodiment can reduce the amount of communication required for transmitting diagnostic information compared to the conventional system.

[0057] Furthermore, according to the servo control system 1 of the embodiment, the numerical control device 10 can identify the inverter device 40 that has transmitted the second diagnostic information by using the PS code or CNC code included in the second diagnostic information. Furthermore, the converter device 30 can identify the inverter device 40 that has transmitted the second relay information by using the PS code or CNC code included in the second relay information.

[0058] Furthermore, according to the servo control system 1 of the embodiment, even if a plurality of groups G are included, the numerical control device 10 can identify the inverter device 40 that is the source of the second diagnostic information by using the CNC code.

[0059] In addition, the servo control system 1 of the embodiment determines the relay device by using the connection state of communication such as the communication distance, etc. Therefore, the servo control system 1 of the embodiment can transmit the diagnostic information by using the inverter device 40 that is considered to have the best communication state.

[0060] Furthermore, the servo control system 1 of the embodiment determines the inverter device 40 that is first in the order of PS code assignment as the relay device. Therefore, the servo control system 1 of the embodiment can easily determine the relay device only by comparing the PS codes.

[0061] The above embodiment can be modified as follows. In the above embodiment, the converter device 30 transmits the first diagnostic information to the numerical control system 10 via the inverter device 40. However, the converter device 30 may transmit information other than the first diagnostic information in a similar manner to the first diagnostic information.

[0062] In the above embodiment, the numerical control device 10 determines which inverter device 40 is to be used as a relay device. However, the converter device 30, instead of the numerical control device 10, may determine which inverter device 40 is to be used as a relay device.

[0063] The device to be controlled by the inverter device 40 may be a device other than the motor 50 .

[0064] The processor 11, the processor 31, or the processor 41 may implement part or all of the processing implemented by the program in the above-described embodiments by a hardware configuration of a circuit.

[0065] The program for implementing the process of the embodiment is transferred, for example, in a state stored in the device. However, the device may be transferred without the program stored therein. The program may then be transferred separately and written to the device. The program may be transferred, for example, by recording it on a removable storage medium or by downloading it via a network such as the Internet or a LAN (local area network).

[0066] Although the embodiment of the present invention has been described above, it is merely an example and does not limit the scope of the present invention. The embodiment of the present invention can be implemented in various forms without departing from the gist of the present invention. [Explanation of symbols]

[0067] 1. Servo control system 10 Numerical control device 11,31,41 Processor 12,32,42 ROM 13,33,43 RAM 14,34,44 Auxiliary storage 15,36 Communication I / F 20 Power supply 30 Converter device 35 Converter circuit section 40 Inverter device 45 Inverter circuit section 46 First communication I / F 47 Second communication I / F 50 Motor

Claims

1. A numerical control device, a converter device, and a plurality of inverter devices are included, an assigning unit that assigns identification information to the inverter device; a determination unit that determines the inverter device to be used for communication between the numerical control device and the converter device from among the plurality of inverter devices to which the identification information is assigned, the numerical control device includes a numerical control communication unit that communicates with the inverter device using a first transmission path, The converter device includes a second transmission path different from the first transmission path, the inverter device determined by the determination unit, and a converter communication unit that communicates with the numerical control device via the first transmission path.

2. a first converter device, a second converter device different from the first converter device, a plurality of first inverter devices in communication with the first converter device, and a second inverter device different from the first inverter device in communication with the second converter device; the numerical control device includes a first assigning unit that assigns first identification information to the inverter device, the first converter device includes a second assigning unit that assigns second identification information to the first inverter device, 2. The communication system for a numerical control device according to claim 1, wherein the determination unit determines the first inverter device to be used for communication between the numerical control device and the first converter device from among the inverter devices to which the first identification information and the second identification information have been assigned.

3. 3. The communication system for a numerical control device according to claim 1, wherein the determination unit determines the inverter device to be used for communication between the numerical control device and the converter device by using a connection state of communication using the inverter device.

4. the assigning unit included in the converter device assigns the identification information to the inverter devices in the order in which a connection with the converter device is established; 4. The communication system for a numerical control device according to claim 1, wherein the determination unit determines the inverter device to which the identification information is first assigned as the inverter device to be used for communication between the numerical control device and the converter device.

5. Provide identification information to the inverter device; determining an inverter device to be used for communication between a numerical control device and a converter device from among the plurality of inverter devices to which the identification information has been assigned; the numerical control device communicates with the inverter device using a first transmission path; A communication method for a numerical control device, in which the converter device communicates with the numerical control device via a second transmission path different from the first transmission path, the inverter device determined to be used for communication between the numerical control device and the converter device, and the first transmission path.

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