COMMUNICATION DEVICE, COMMUNICATION SYSTEM, COMMUNICATION CONTROL METHOD, AND PROGRAM

Abstract

This communication device comprises: a processing unit; and a communication unit that communicates with one or more slaves. The processing unit has a function for executing communication processing and setting processing. The communication processing involves causing the communication unit to transmit a main frame containing main data to the one or more slaves, in a first cycle. The setting processing involves setting: a second cycle which is shorter than the first cycle; and a time slot which is allocated, in each second cycle, to at least one slave from among the one or more slaves.

Description

[Technical field]

[0001] The present disclosure generally relates to a communication device, a communication system, a communication control method, and a program. More specifically, the present disclosure relates to a communication device, a communication system, a communication control method, and a program that communicate with one or more slaves. [Background technology]

[0002] Patent Document 1 discloses a communication device connected to a network in which data is updated at predetermined intervals. This communication device includes a first scheduling means and a second scheduling means. The first scheduling means secures a first communication band required for updating first data used to control a manufacturing device or production facility at predetermined intervals. The second scheduling means secures a second communication band required for second data to arrive at a destination within a specified time within a communication band other than the first communication band among the communication bands of the network.

[0003] In the communication device described in Patent Document 1, it is possible to transmit second data (sub data) in an available band other than the communication band required for communicating first data (main data). However, this communication device has a problem in that it is difficult to periodically transmit or receive the second data (sub data) in a device (slave) connected to the communication device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-64245 A Summary of the Invention

[0005] The present disclosure has been made in consideration of the above points, and aims to provide a communication device, a communication system, a communication control method, and a program that make it easy to periodically transmit or receive secondary data in a slave connected to the communication device.

[0006] A communication device according to an embodiment of the present disclosure includes a processing unit and a communication unit that communicates with one or more slaves. The processing unit has a function of executing a communication process and a setting process. The communication process is a process of causing the communication unit to transmit a main frame including main data to the one or more slaves in a first period. The setting process is a process of setting a second period that is shorter than the first period, and a time slot that is assigned to at least one of the one or more slaves for each second period.

[0007] A communication system according to another embodiment of the present disclosure includes the above-mentioned communication device and one or more slaves, the one or more slaves being connected to the communication device and communicating with the communication device.

[0008] A communication control method according to another aspect of the present disclosure includes a communication step and a setting step. The communication step is a step of causing one or more slaves connected to a communication device to transmit a main frame including main data in a first period. The setting step is a step of setting a second period shorter than the first period, and a time slot assigned to at least one slave of the one or more slaves for each second period.

[0009] A program according to another aspect of the present disclosure causes one or more processors to execute the above-described communication control method.

[0010] The present disclosure has an advantage in that sub-data can be easily transmitted or received, or transmitted and received, periodically in a slave connected to a communication device. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a block diagram illustrating an overview of a communication system including a communication device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an explanatory diagram of communication processing and division communication processing by the communication device of the above embodiment. [Diagram 3] FIG. 3 is a flowchart of a setting process performed by the communication device. [Figure 4] FIG. 4 is an explanatory diagram of a communication process performed by a communication device of the comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (1) Overview FIG. 1 is a block diagram showing an overview of a communication system 100 including a communication device 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the communication device 1 of this embodiment is connected to one or more (here, n ("n" is a natural number) slaves 2) connected to the communication device 1 directly or via a network to configure the communication system 100. In other words, the communication device 1 is a master equivalent to a higher-level device of the one or more slaves 2. The communication device 1 and the one or more slaves 2 are connected to the same network. In other words, the communication system 100 includes the communication device 1 and one or more slaves 2. The one or more slaves 2 are connected to the communication device 1 and communicate with the communication device 1.

[0013] In this embodiment, the communication device 1 and one or more slaves 2 are connected to an industrial network. The "industrial network" in this disclosure is, for example, a field network used in factory automation, and is used for communication between multiple devices installed in a factory. The industrial network may include, for example, Ethernet / IP (registered trademark), EtherCAT (registered trademark), or PROFINET (registered trademark). The devices connected to the industrial network may include, for example, a controller (for example, a PLC (Programmable Logic Controller)), a sensor (for example, a displacement sensor, a flow meter, a pressure gauge, an image sensor, or a remote I / O (Input / Output)). The devices connected to the industrial network may include, for example, a servo amplifier, an inverter, a robot, an actuator, or a valve.

[0014] Industrial networks are required to be more robust, punctual, and real-time than standard best-effort networks used in offices, etc. For example, in an industrial network, when periodically transmitting control data from a controller to a controlled device such as a servo amplifier, delays are not tolerated as much as in a best-effort network. Also, there is a demand for faster response speeds to control data.

[0015] 1, the communication device 1 of the present embodiment includes a processing unit 11 and a communication unit 12. The communication unit 12 is a communication interface for communicating with one or more slaves 2. The processing unit 11 has a function of executing a communication process and a setting process.

[0016] FIG. 2 is an explanatory diagram of a communication process and a division communication process by the communication device 1 according to an embodiment of the present disclosure. The communication process is a process of transmitting a main frame F1 including main data from the communication unit 12 to one or more slaves 2 at a first cycle CT1. That is, the communication device 1 transmits the main data to one or more slaves 2 at a first cycle CT1 by executing the communication process. For example, if the communication device 1 is a controller and one or more slaves 2 are devices to be controlled such as servo amplifiers, the main data may include control data for controlling the slaves 2. As an example, the first cycle CT1 is a few tenths of a second to several milliseconds. When each slave 2 receives the main data, it executes a process according to the received main data. For example, if the main data includes one or more control data corresponding to each of the one or more slaves 2, when each slave 2 receives the main data, it acquires the corresponding control data included in the main data and executes a process according to the acquired control data.

[0017] The setting process is a process for setting a second period CT2 (see FIG. 2) shorter than the first period CT1, and a time slot S0 (see FIG. 2). The time slot S0 is assigned to at least one slave 2 among one or more slaves 2 for each second period CT2. The time slot S0 set in the setting process is included in at least a subframe F2 (see FIG. 2). The subframe F2 is a frame transmitted from the communication device 1 in the second period CT2 set in the setting process, and has a shorter transmission time than the main frame F1. In addition, the second period CT2 is longer than the transmission time of the subframe F2. Each slave 2 can obtain data included in the corresponding time slot S0, or transmit data to another device (the communication device 1 or another slave 2) using the corresponding time slot S0.

[0018] As described above, the slave 2 to which the time slot S0 is assigned by the setting process can periodically receive secondary data using the time slot S0 for each second period CT2, separately from the main data transmitted in the first period CT1. The slave 2 to which the time slot S0 is assigned by the setting process can periodically transmit secondary data using the time slot S0 for each second period CT2, separately from the main data. In other words, this embodiment has the advantage that the slave 2 connected to the communication device 1 can easily transmit or receive secondary data periodically.

[0019] (2) Details A communication system 100 including a communication device 1 will be described in detail below with reference to FIG. 1. A plurality of (here, n) slaves 2 are connected to the communication device 1. The plurality of slaves 2 (in other words, one or more slaves 2) are daisy-chained to the communication device 1. Specifically, a first slave 21, a second slave 22, a third slave 23, ..., an n-th slave 2n are connected to the communication device 1 in a ring shape in this order. For this reason, a frame (for example, a main frame F1) transmitted from the communication device 1 is transmitted in the order of the first slave 21, the second slave 22, the third slave 23, ..., the n-th slave 2n, and the communication device 1.

[0020] In the communication system 100, one slave 2 of the multiple slaves 2 is a sensor, and the remaining slaves 2 are servo amplifiers. In other words, at least one slave 2 of the one or more slaves 2 is a motor driving device that drives a motor. In the communication system 100, the communication device 1 is a controller that controls the multiple slaves 2 (i.e., the multiple servo amplifiers and sensors) individually or as a whole.

[0021] The communication device 1 includes a processing unit 11 and a communication unit 12. The communication device 1 stores data in a memory included in the processing unit 11, but may also include a storage unit separate from the processing unit 11. Examples of the storage unit include electrically rewritable non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) and volatile memory such as a RAM (Random Access Memory).

[0022] The processing unit 11 includes, for example, a computer system. The computer system is mainly composed of a processor and a memory as hardware. The processor executes a program recorded in the memory of the computer system, thereby realizing the function of the processing unit 11. The program may be pre-recorded in the memory of the computer system, may be provided through an electric communication line, or may be recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. Note that at least a part or the whole of the communication unit 12 may be configured integrally with a part or the whole of the processing unit 11. For example, the communication unit 12 includes a computer system. In this configuration, it is also possible to realize the function of the processing unit 11 by executing a program in the computer system in the communication unit 12.

[0023] The communication unit 12 is a communication interface for communicating with a plurality of slaves 2, and includes, for example, a wired communication module conforming to the industrial Ethernet (registered trademark) protocol. The communication unit 12 transmits frames (main frame F1 and sub-frame F2) to a communication unit 202 (described later) of a slave 2 (first slave 21 in FIG. 1) at the front stage directly connected to the communication device 1. The communication unit 12 receives frames (main frame F1 and sub-frame F2) transmitted from a communication unit 202 of a slave 2 (n-th slave 2n in FIG. 1) at the last stage directly connected to the communication device 1.

[0024] The processing unit 11 has the function of executing communication processing (main communication processing), split communication processing, and setting processing. Hereinafter, the communication processing (main communication processing) will be referred to as the main communication processing to distinguish it from the split communication processing. The setting processing is processing that is executed before the communication system 100 including the communication device 1 is operated. The main communication processing and the split communication processing are both processing that are executed while the communication system 100 including the communication device 1 is operating.

[0025] The main communication process is a process in which the communication unit 12 transmits a main frame F1 to a plurality of slaves 2 at a first cycle CT1. The first cycle CT1 is set in advance in the communication device 1. In this embodiment, the communication device 1 transmits the main frame F1 to the first slave 21, whereby the main frame F1 is transmitted in the order of the first slave 21, the second slave 22, the third slave 23, ..., the n-th slave 2n.

[0026] 2, the main frame F1 includes a header D100, a main data area D1, a sub-data area D2, and a footer D101. The header D100 includes an identifier for identifying the frame received by each slave 2 as the main frame F1.

[0027] The main data area D1 is divided into a plurality of (here, n) time slots D11, D12, ..., D1n. The plurality of time slots D11, D12, ..., D1n are respectively assigned to a plurality of slaves 21, 22, ..., 2n.

[0028] The slave 2 that receives the main frame F1 can acquire the main data from the communication device 1 using the assigned time slot in the main data field D1. The main data may include control data for each slave 2 that is transmitted from the communication device 1 to each slave 2. The main data may include response data for each slave 2 to the control data.

[0029] The sub data area D2 is divided into a plurality of (here, n) time slots D21, D22, ..., D2n. Each of the plurality of time slots D21, D22, ..., D2n corresponds to the time slot S0 set by the setting process, and is assigned to a plurality of slaves 21, 22, ..., 2n, respectively. In other words, the main frame F1 includes the time slot S0. The time slot S0 is set by the setting process.

[0030] The slave 2 that receives the main frame F1 can obtain the secondary data contained in the assigned time slot S0 in the secondary data area D2, and can transmit the secondary data to another device (the communication device 1 or another slave 2) using the time slot S0. The secondary data can include various data transmitted from a slave 2 to another slave 2. In other words, the time slot S0 is used for communication between one or more slaves 2.

[0031] The division communication process is a process in which the communication unit 12 transmits the subframe F2 to multiple slaves 2 at a second period CT2. The second period CT2 is shorter than the first period CT1 and is set by the setting process. The subframe F2 includes a header D200, a subdata area D2, and a footer D201. The header D200 includes an identifier for identifying that the frame received by each slave 2 is the subframe F2.

[0032] 2, in the first cycle CT1, the processing unit 11 of the communication device 1 first executes a main communication process to transmit a main frame F1 from the communication unit 12. After that, in the first cycle CT1, the processing unit 11 of the communication device 1 executes a divided communication process to transmit a sub-frame F2 from the communication unit 12 for each second cycle CT2.

[0033] Here, in this embodiment, the processing unit 11 updates the main data for each first period CT1. Specifically, the processing unit 11 generates the main data to be included in the next main frame F1 during the period from when the main frame F1 is transmitted until the transmission of the next main frame F1 is started. That is, the processing unit 11 generates the main data and prepares the main frame F1 within a time shorter than the first period CT1. When generating the main data, the processing unit 11 refers to, for example, command information from a higher-level system of the communication device 1 and response information received from each slave 2. For example, the processing unit 11 generates control data (main data) for controlling each servo amplifier (each slave 2) by referring to detection information received from a sensor (slave 2). Therefore, the first period CT1 needs to be set to a degree that allows the processing of generating the main data to be executed, and depends on the processing performance of the processing unit 11.

[0034] The setting process is a process for setting the second cycle CT2 and the time slot S0 used in the main communication process and the divided communication process described above. In other words, the main communication process and the divided communication process are executed based on the parameters set in the setting process. The second cycle CT2 is shorter than the first cycle CT1. The processing unit 11 sets the second cycle CT2 based on the transmission time (maximum transmission time Mt) of the main frame F1 as described later. The second cycle CT2 is longer than the maximum transmission time Mt. The time slot S0 is assigned to the slave 2 for each second cycle CT2. The processing unit 11 assigns the time slot S0 to all the slaves 2. The time slot S0 assigned to each slave 2 in the setting process constitutes the above-mentioned sub-data area D2. The setting process will be described in detail in "(3) Setting Process" described later. The slot length of the time slot S0 assigned to each slave 2 may differ depending on the data size.

[0035] The slave 2 includes a processing unit 201 and a communication unit 202. The slave 2 stores data in a memory included in the processing unit 201, but may also have a storage unit separate from the processing unit 201. Examples of the storage unit include an electrically rewritable non-volatile memory such as an EEPROM, and a volatile memory such as a RAM.

[0036] The processing unit 201 includes, for example, a computer system. The computer system is mainly composed of a processor and a memory as hardware. The processor executes a program recorded in the memory of the computer system, thereby realizing the functions of the processing unit 201. The program may be pre-recorded in the memory of the computer system, may be provided through an electric communication line, or may be recorded and provided on a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that is readable by the computer system.

[0037] The processing unit 201 has a function of executing processing based on corresponding data (here, control data) from among the main data received by the communication unit 202. The processing unit 201 also has a function of executing processing based on corresponding data from among the sub data received by the communication unit 202. The processing unit 201 has a function of executing processing to transmit the sub data to another device by using an assigned time slot S0 from among the sub data region D2 of the received main frame F1 or sub frame F2.

[0038] The communication unit 202 is a communication interface for communicating with the communication device 1 or another slave 2, and includes, for example, a wired communication module conforming to the industrial Ethernet (registered trademark) protocol. The communication unit 202 receives frames (main frame F1 and sub-frame F2) transmitted from the communication unit 12 of the communication device 1 or the communication unit 202 of the slave 2, which are in the previous stage directly connected to the slave 2. The communication unit 202 transmits the received frames (main frame F1 and sub-frame F2) to the communication unit 12 of the communication device 1 or the communication unit 202 of the slave 2, which are in the subsequent stage directly connected to the slave 2. As an example, the communication unit 202 of the first slave 21 receives a frame transmitted from the communication unit 12 of the communication device 1, and transmits the received frame to the communication unit 202 of the second slave 22. At this time, the communication unit 202 of the first slave 21 may appropriately update the received frame before transmitting it.

[0039] (3) Setting process The setting process executed by the processing unit 11 of the communication device 1 of this embodiment will be described in detail below with reference to Fig. 3. Fig. 3 is a flowchart of the setting process by the communication device 1 according to the embodiment of the present disclosure.

[0040] The setting process is executed by the processing unit 11, for example, when a user performs a predetermined operation using a user interface provided in the communication device 1 before operating the communication system 100. In a stage prior to executing the setting process, the user inputs setting data required for executing the setting process to the communication device 1 using the user interface.

[0041] The setting data includes the total data size of the main data, the total data size of the sub data, and the minimum communication cycle CT min The total data size of the main data is the sum of the data sizes of the main data that can be received by each slave 2. The total data size of the sub data is the sum of the data sizes of the sub data that can be transmitted, received, or transmitted and received by each slave 2. Minimum communication cycle CT min is the minimum communication period permitted for communication between the communication device 1 and one or more slaves 2.

[0042] The setting data may be acquired by the communication device 1 from each slave 2 when establishing communication between the communication device 1 and each slave 2 and transmitting an initialization frame from the communication device 1 to each slave 2. That is, the communication device 1 acquires the setting data from each slave 2 in response to the initialization frame. In this case, it is assumed that the setting data has been set in advance in each slave 2, for example, by a user inputting the setting data.

[0043] In the setting process, when the processing unit 11 receives setting data (step ST1), the processing unit 11 first calculates the maximum transmission time Mt of the main frame F1 using the setting data (step ST2). Specifically, the processing unit 11 calculates the maximum transmission time Mt of the main frame F1 by performing calculation based on the following formula (1).

[0044]

number

[0045] In the above formula (1), "Sh" represents the data size of the header of the main frame F1, "Sm" represents the total data size of the main data, "Ss" represents the total data size of the secondary data, and "Sf" represents the data size of the footer of the main frame F1. In the above formula (1), "Tr" represents the transfer rate, "n" represents the number of devices (communication devices 1 and slaves 2) belonging to the communication system 100, "Td1" represents the delay time per device, and "Td2" represents the delay time of the entire communication system 100.

[0046] In the setting process, the processing unit 11 next determines the maximum transmission time Mt and the minimum communication cycle CT min Specifically, the processing unit 11 compares the sum of the maximum transmission time Mt and the margin time α that takes jitter into consideration with the minimum communication cycle CT min The sum of the maximum transmission time Mt and the margin time α is the smallest communication cycle CT minIf it is smaller than the minimum communication cycle CT min is set as the second cycle CT2 (step ST4). On the other hand, the communication cycle CT min In the above case (No in step ST3), the processing unit 11 sets the second period CT2 by performing calculation based on the following formula (2).

[0047]

number

[0048] In the above formula (2), "β" is the division number. The division number β is a quotient calculated by dividing the first period CT1 by the sum of the maximum transmission time Mt and the margin time α. That is, in the setting process, the processing unit 11 calculates the division number β (step ST5), and calculates the second period CT2 using the calculated division number β (step ST6).

[0049] In this way, in the setting process, the processing unit 11 calculates the transmission time (maximum transmission time Mt) of the main frame F1 based on at least the first cycle CT1, the number of slaves 2 (one or more), and the data size of the main data. Then, the processing unit 11 sets the second cycle CT2 based on the calculated transmission time (maximum transmission time Mt). In particular, the communication cycle CT2 in which the sum of the maximum transmission time Mt and the margin time α is the smallest as described above is set. min If it is smaller than the minimum communication cycle CT min In other words, in the setting process, the processing unit 11 sets the second cycle CT2 to the minimum communication cycle CT min is set as the second period CT2.

[0050] In the setting process, the processing unit 11 sets a sub data area D2 to be transmitted from the communication unit 12 for each second cycle CT2 that is set next (step ST7). In other words, the processing unit 11 assigns a time slot S0 to each slave 2. In this embodiment, the processing unit 11 assigns time slots D21, D22, ..., D2n to slaves 21, 22, ..., 2n, respectively, as the time slot S0.

[0051] A specific example of the setting process will be described below. In the following description, it is assumed that the first cycle CT1 is 500 μs. In addition, it is assumed that the communication system 100 includes three slaves 2 (first slave 21, second slave 22, and third slave 23). That is, in the following description, the number n of devices (communication devices 1 and slaves 2) belonging to the communication system 100 is four. In addition, it is assumed that the transfer rate Tr is 100 Mbps, the delay time Td1 per slave 2 is 3 μs, the delay time Td2 of the entire communication system 100 is 1.5 μs, and the margin time α is 3 μs.

[0052] First, a case where the setting data for each slave 2 is the data shown in Table 1 below will be described.

[0053] [Table 1]

[0054] In this case, the total data size Sm of the main data is 80 (=32+16+32) Bytes, and the total data size Ss of the sub data is 16 (=4+4+8) Bytes, so the maximum transmission time Mt is calculated to be 24.36 μs using formula (1). In addition, in this case, of the communication cycles that can be supported by all the slaves 21, 22, and 23, the communication cycles that can be supported by the first slave 21 and the third slave 23 are the longest, so the minimum communication cycle CT min Therefore, the sum of the maximum transmission time Mt and the margin time α (24.36μs + 3μs = 27.36μs) is the minimum communication cycle CT minSince this is smaller than the minimum communication cycle CT min (31.25μs) is set as the second period CT2.

[0055] Next, a case where the setting data for each slave 2 is the data shown in Table 2 below will be described.

[0056] [Table 2]

[0057] In this case, the total data size Sm of the main data is 160 (=64+64+32) Bytes, and the total data size Ss of the sub data is 44 (=8+4+32) Bytes, so the maximum transmission time Mt is calculated to be 33 μs using formula (1). In addition, in this case, the communication cycles that the first slave 21 and the third slave 23 can support are the longest among the communication cycles that all the slaves 21, 22, and 23 can support, so the minimum communication cycle CT min Therefore, the sum of the maximum transmission time Mt and the margin time α (33μs + 3μs = 36μs) is the minimum communication cycle CT min Since the first period CT1 is greater than the maximum transmission time Mt (31.25 μs), the processing unit 11 calculates the division number β, and calculates and sets the second period CT2 based on the calculated division number β. Here, the division number β is a quotient calculated by dividing the first period CT1 (500 μs) by the sum (36 μs) of the maximum transmission time Mt and the margin time α, so it is calculated as "13." Therefore, the second period CT2 is calculated as 38.46 μs using formula (2).

[0058] Here, if the calculated second period CT2 does not match an integer multiple of the communication period that can be supported by each slave 2, the second period CT2 is set to a value that is greater than the calculated second period CT2 and is an integer multiple of the communication period that can be supported by each slave 2. Here, the second period CT2 is set to 62.5 μs, which is twice the communication period of 31.25 μs that can be supported by each slave 2. Note that, if there are multiple types of slaves 2 that have different communication periods that can be supported, the least common multiple of the communication periods that can be supported by each slave 2 is set to the second period CT2.

[0059] The advantages of the communication device 1 of this embodiment will be described below with a comparison with a communication device of a comparative example. The communication device of the comparative example does not have a function for executing division communication processing and setting processing, that is, it does not allocate a time slot S0 for each second cycle CT2, which is different from the communication device 1 of this embodiment. When sub-data different from the main data is transmitted from the communication device 1 or the slave 2, the communication device of the comparative example transmits a sub-frame F200 including a sub-data area D2 in a free area CT10 excluding the main frame F100 in the first cycle CT1, as shown in FIG. 4. However, in the communication device of the comparative example, the second cycle CT2 is not set, and the timing for transmitting the sub-frame F200 is not specified, so the sub-data cannot be transmitted periodically. For this reason, it is difficult for the communication device of the comparative example to perform periodic communication of sub-data different from the main data that can withstand use in an industrial network.

[0060] On the other hand, in the communication device 1 of this embodiment, the slave 2 to which the time slot S0 is assigned by the setting process can periodically receive secondary data using the time slot S0 for each second period CT2, separately from the main data transmitted in the first period CT1. Also, the slave 2 to which the time slot S0 is assigned by the setting process can periodically transmit secondary data using the time slot S0 for each second period CT2, separately from the main data. That is, this embodiment has the advantage that the slave 2 connected to the communication device 1 can easily transmit or receive secondary data periodically, or transmit and receive secondary data. Therefore, this embodiment has the advantage that periodic communication that can withstand use in an industrial network can be easily performed for not only the main data but also the secondary data.

[0061] (4) Variations The above-described embodiment is merely one of various embodiments of the present disclosure. The above-described embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. In addition, the same function as the communication device 1 may be embodied in a communication control method, a (computer) program, or a non-transitory recording medium on which a program is recorded, etc.

[0062] The communication control method according to one embodiment includes a communication step and a setting step. The communication step is a step of causing one or more slaves 2 connected to a communication device 1 to transmit a main frame F1 including main data at a first cycle CT1. The setting step is a step of setting a second cycle CT2 shorter than the first cycle CT1, and a time slot S0 assigned to at least one slave 2 of the one or more slaves 2 for each second cycle CT2. Furthermore, the program according to one embodiment causes one or more processors to execute the above communication control method.

[0063] Modifications of the above-described embodiment are listed below. The modifications described below can be applied in appropriate combination.

[0064] The communication device 1 in the present disclosure includes a computer system in the processing unit 11, for example. The computer system is mainly composed of a processor and a memory as hardware. The processor executes a program recorded in the memory of the computer system, thereby realizing the function of the processing unit 11 in the present disclosure. The program may be pre-recorded in the memory of the computer system, provided through an electric communication line, or provided by recording it in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called by different names depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or the circuit partition inside the LSI, can also be adopted as a processor. The electronic circuits may be integrated in one chip or distributed among multiple chips. The chips may be integrated in one device or distributed among multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Thus, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

[0065] Moreover, it is not essential for the processing unit 11 that the multiple functions of the processing unit 11 are concentrated in one housing. The components of the processing unit 11 may be distributed across multiple housings. Furthermore, at least a part of the functions of the processing unit 11 may be realized by, for example, a server device and a cloud (cloud computing), etc. Conversely, as in the above-described embodiment, all of the functions of the processing unit 11 may be concentrated in one housing.

[0066] In the above embodiment, when a slave 2 that has a relatively long communication cycle that can be supported by the setting process belongs to the communication system 100, the processing unit 11 of the communication device 1 may align the communication cycle that the slave 2 can support with the communication cycle that the other slaves 2 can support. In other words, the communication cycle that the slave 2 can support is a cycle that is necessary when executing a process with a relatively large processing load, such as a process of generating and transmitting data. For this reason, when executing a process with a relatively small processing load, such as a process of simply acquiring data, it is also possible to set the communication cycle that the slave 2 can support short. In this way, by aligning the communication cycle that the slave 2 can support with the communication cycle that the other slaves can support, the shortest communication cycle CT min In other words, it is possible to adjust the minimum communication cycle CT min may be arbitrarily settable.

[0067] In the above embodiment, the time slot S0 may vary to a certain extent based on a predetermined time. In other words, it is preferable that the deviation of the time slot S0 is within an allowable time that is shorter than at least the second cycle CT2. Specifically, in the second cycle CT2 in which the main frame F1 is transmitted, the timing of starting transmission of the time slot S0 may be any timing as long as the slave 2 can complete reception of the time slot S0 by the end of this second cycle CT2. For example, even if the end timing of the main data area D1 is later than the example shown in FIG. 2, the deviation of the timing of starting transmission of the time slot S0 is allowed as long as the reception of the time slot S0 by each slave 2 is completed by the end of this second cycle CT2.

[0068] In the setting process of the above embodiment, when there are multiple types of slaves 2 with different compatible communication cycles, the least common multiple of the compatible communication cycles is set as the second cycle CT2, but this is not limited to this. For example, instead of all of the multiple types of slaves 2 being targets for allocation of the time slot S0, some of the slaves 2 may be excluded from the allocation of the time slot S0. For example, if only one type of slave 2 out of the multiple types of slaves 2 is to be targeted for allocation of the time slot S0, the second cycle CT2 is set to the communication cycle that this type of slave 2 can support.

[0069] In the setting process of the above embodiment, even if the calculated second period CT2 does not match an integer multiple of the communication period that each slave 2 can support, the calculated second period CT2 may be set as the second period CT2 as is.

[0070] In the above-described embodiment, the slave 2 is not limited to a motor driving device, and may be other devices such as a sensor. Also, in the above-described embodiment, the multiple slaves 2 do not necessarily have to include a motor driving device. For example, all of the slaves 2 may be sensors.

[0071] In the above-described embodiment, the communication system 100 may include one slave 2. In this aspect, the communication device 1 is capable of acquiring sub-data transmitted from the slave 2 in the second cycle CT2 while generating main data in each first cycle CT1.

[0072] In the above embodiment, the communication device 1 communicates with each slave 2 in a wired manner using a wired communication module, but this is not limited thereto. For example, the communication device 1 may communicate with each slave 2 wirelessly using a wireless communication module.

[0073] In the above-described embodiment, the processing unit 201 of the slave 2 may use, for example, a free area CT10 (see FIG. 2) excluding the main frame F1 or the sub-frame F2 in the second cycle CT2 to transmit other data other than the sub-data from the communication unit 202. As an example, the other data is data having a larger data size than the control data included in the main data, and may include images used for monitoring or managing the manufacturing process on a production line or in a factory. Unlike the main data and the sub-data, the other data does not need to be constant or real-time.

[0074] In the above embodiment, the processing unit 11 of the communication device 1 does not transmit sub-data to each slave 2 in the main communication process and the divided communication process, but may transmit sub-data to each slave 2. In other words, if the processing unit 11 has a margin in its processing performance, the processing unit 11 can execute the process of generating sub-data in parallel with the process of generating main data and transmit the generated sub-data to each slave 2.

[0075] (summary) As described above, the communication device (1) according to the first aspect includes a processing unit (11) and a communication unit (12) that communicates with one or more slaves (2). The processing unit (11) has a function of executing a communication process and a setting process. The communication process is a process of causing the communication unit (12) to transmit a main frame (F1) including main data to one or more slaves (2) in a first cycle (CT1). The setting process is a process of setting a second cycle (CT2) that is shorter than the first cycle (CT1), and a time slot (S0) that is assigned to at least one slave (2) of the one or more slaves (2) for each second cycle (CT2).

[0076] According to this aspect, it is possible to periodically transmit, receive, or transmit / receive secondary data different from the primary data using the time slot (S0), which has the advantage that it is easy to periodically transmit, receive, or transmit / receive secondary data in the slave (2) connected to the communication device (1).

[0077] In the communication device (1) according to the second aspect, in the first aspect, the main frame (F1) includes a time slot (S0).

[0078] This embodiment has the advantage that it is easy to avoid a situation in which the slave (2) transmits or receives, or transmits and receives, secondary data at intervals longer than the second cycle (CT2).

[0079] In the communication device (1) according to the third aspect, in the first or second aspect, one or more slaves (2) are daisy-chained to the communication device (1).

[0080] According to this embodiment, the communication device (1) only needs to transmit frames to the slave (2) that is directly connected to the communication device (1) among the one or more slaves (2), which has the advantage that the processing load of the communication device (1) can be easily reduced.

[0081] In a communication device (1) according to a fourth aspect, in any of the first to third aspects, in a setting process, a processing unit (11) calculates a transmission time (maximum transmission time (Mt)) of a main frame (F1) based on at least the first cycle (CT1), the number of one or more slaves (2), and the data size of the main data, and sets a second cycle (CT2) based on the calculated transmission time.

[0082] According to this aspect, it is easy to set the number of times the second cycle (CT2) is included in the first cycle (CT1) to be large, and as a result, there is an advantage in that it is easy to increase the number of times that secondary data is transmitted or received or transmitted and received in the first cycle (CT1).

[0083] In the communication device (1) according to the fifth aspect, in the fourth aspect, the processing unit (11) sets a minimum communication cycle (CT) allowed for communication with one or more slaves (2) in the setting process. min ) is set as the second period (CT2).

[0084] According to this aspect, it is easy to set the number of times the second cycle (CT2) is included in the first cycle (CT1) to be large, and as a result, there is an advantage in that it is easy to increase the number of times that secondary data is transmitted or received or transmitted and received in the first cycle (CT1).

[0085] In the communication device (1) according to the sixth aspect, in the fifth aspect, the minimum communication cycle (CT min ) can be set arbitrarily.

[0086] According to this embodiment, there is an advantage that the degree of freedom in setting the second period (CT2) can be improved.

[0087] In the communication device (1) according to the seventh aspect, in the fourth aspect, the processing unit (11) sets a cycle that is an integer multiple of a communication cycle that can be supported by one or more slaves (2) as the second cycle (CT2) in the setting process.

[0088] This embodiment has the advantage that it is easy to achieve synchronization between the communication device (1) and one or more slaves (2).

[0089] In the communication device (1) according to an eighth aspect, in any one of the first to seventh aspects, the deviation of the second cycle (CT2) falls within an allowable time that is at least shorter than the second cycle (CT2).

[0090] This embodiment has the advantage that it is easy to avoid a situation in which the slave (2) transmits or receives, or transmits and receives, secondary data at intervals longer than the second cycle (CT2).

[0091] In the communication device (1) according to the ninth aspect, in any one of the first to eighth aspects, the time slot (S0) is used for communication between one or more slaves (2).

[0092] This embodiment has the advantage that it is easy to control one or more slaves (2) using the secondary data.

[0093] In a communication device (1) according to a tenth aspect, in any one of the first to ninth aspects, at least one slave (2) of the one or more slaves (2) is a motor driving device that drives a motor.

[0094] According to this aspect, there is an advantage that the motor drive device can be easily controlled periodically using not only the main data but also the sub data.

[0095] A communication system (100) according to an eleventh aspect includes a communication device (1) according to any one of the first to tenth aspects and one or more slaves (2). The one or more slaves (2) are connected to the communication device (1) and communicate with the communication device (1).

[0096] According to this aspect, it is possible to periodically transmit, receive, or transmit / receive secondary data different from the primary data using the time slot (S0), which has the advantage that it is easy to periodically transmit, receive, or transmit / receive secondary data in the slave (2) connected to the communication device (1).

[0097] A communication control method according to a twelfth aspect includes a communication step and a setting step. The communication step is a step of causing one or more slaves (2) connected to a communication device (1) to transmit a main frame (F1) including main data in a first cycle (CT1). The setting step is a step of setting a second cycle (CT2) shorter than the first cycle (CT1) and a time slot (S0) assigned to at least one slave (2) of the one or more slaves (2) for each second cycle (CT2).

[0098] According to this aspect, it is possible to periodically transmit, receive, or transmit / receive secondary data different from the primary data using the time slot (S0), which has the advantage that it is easy to periodically transmit, receive, or transmit / receive secondary data in the slave (2) connected to the communication device (1).

[0099] A program according to a thirteenth aspect causes one or more processors to execute the communication control method of the twelfth aspect.

[0100] According to this aspect, it is possible to periodically transmit, receive, or transmit / receive secondary data different from the primary data using the time slot (S0), which has the advantage that it is easy to periodically transmit, receive, or transmit / receive secondary data in the slave (2) connected to the communication device (1).

[0101] The configurations according to the second to tenth aspects are not essential for the communication device (1) and may be omitted as appropriate. [Explanation of symbols]

[0102] 1. Communications equipment 11 Processing section 12 Communications Department 2. Slave 21 First Slave 22 Second Slave 23 Third Slave 2n nth slave 100 Communication Systems 201 Processing section 202 Communications Department F1 main frame F2 Sub-frame S0 Time Slot

Claims

1. A processing section; a communication unit that transmits a main frame including main data in a first period and communicates with at least one slave; The processing unit includes: a main communication process for generating at least the main frame within a time period shorter than the first period; a setting process for setting a plurality of time slots to be assigned to the at least one slave in the main frame and subframe, or a plurality of subframes, so that the at least one slave can communicate two or more times during a first period in a second period shorter than the first period; a division communication process for transmitting the subframe in the second cycle relative to the main frame in an empty area excluding the main frame in the first cycle, or transmitting the plurality of subframes in the second cycle; The plurality of time slots include: the at least one slave is used when periodically transmitting a plurality of sub-data to another device in each second period by using the main frame and the sub-frame or the plurality of sub-frames, or when periodically receiving the plurality of sub-data in each second period; the processing unit, in the setting process, sets the second period based on a transmission time of the main frame calculated based on at least the first period, the number of the at least one slave, and a data size of the main data, so as to be shorter than the first period and longer than the transmission time. Communications equipment.

2. 2. The communication device of claim 1, wherein the main frame includes one of the plurality of time slots.

3. The communication device according to claim 1 , wherein the at least one slave is daisy-chained to the communication device.

4. the at least one slave includes a first slave and a second slave; the plurality of sub data are communicated between the first slave and the second slave during the first period; The communication device according to claim 1 .

5. The processing unit sets, in the setting process, a minimum communication cycle permitted for communication with the at least one slave as the second cycle. The communication device according to claim 1.

6. The minimum communication cycle can be set arbitrarily.

6. The communication device according to claim 5.

7. The processing unit sets, in the setting process, a period that is an integer multiple of a communication period that can be supported by the at least one slave as the second period. The communication device according to claim 1.

8. The time slot shift is within an allowable time that is shorter than at least the second period. The communication device according to claim 1 .

9. the time slot is used for communication between the at least one slave; The communication device according to claim 1 .

10. the at least one slave is a motor driving device that drives a motor; The communication device according to claim 1 .

11. A communication device according to any one of claims 1 to 10, and at least one slave connected to the communication device to communicate with the communication device, the at least one slave periodically transmits or receives secondary data, separately from the primary data, every second period by using a plurality of time slots; Communication systems.

12. a main communication step of causing at least one slave connected to the communication device to transmit a main frame including at least main data in a first period; a setting step of setting a plurality of time slots assigned to the at least one slave in the main frame and subframe, or a plurality of subframes, so that the at least one slave can communicate two or more times during the first period for each second period shorter than the first period; a division communication step of transmitting the subframe in the second cycle relative to the main frame in a vacant area excluding the main frame in the first cycle, or transmitting the plurality of subframes in the second cycle, The plurality of time slots include: the at least one slave is used when periodically transmitting a plurality of sub-data to another device in each second period by using the main frame and the sub-frame or the plurality of sub-frames, or when periodically receiving the plurality of sub-data in each second period; In the setting step, Based on a transmission time of the main frame calculated based on at least the first period, the number of the at least one slave, and a data size of the main data, the second period is set to be shorter than the transmission time, and longer than the transmission time. Communications control method.

13. causing one or more processors to execute the communication control method according to claim 12; program.

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