JP6377943B2 - Serial communication system - Google Patents

Description

  The present invention relates to a serial communication system, and more particularly to a serial communication system between a numerical control device and a servo amplifier or IO connected to the numerical control device.

  In numerical control of motors such as servo motors, servo control is performed in order to realize high-speed, high-precision control by drawing out the inherent performance of servo motors and amplifiers that control servo motors. The parameter is adjusted to an optimum value. The numerical control device and the control device, servo amplifier, and the like are connected by a serial communication path.

  FIG. 13 is a diagram showing a manner of connection through a serial communication path between a conventional numerical control device and a control device or servo amplifier. A numerical control device 210 includes a CPU 212, a first serial communication circuit 214, and a second serial communication circuit 216, and includes a CPU 212, a first serial communication circuit 214, and a second serial communication circuit. 216 are connected to each other by an internal bus 222.

  Servo amplifiers (290a, 290b) and a control device 270 are provided outside the numerical controller 210. The control device 270 includes a second serial communication circuit 272 for serial communication. Further, the first serial communication circuit 214 in the numerical controller 210 and the servo amplifier 290a, and the servo amplifier 290a and the servo amplifier 290b are connected by a first serial communication path 282, and numerical control is performed. A second serial communication path 284 is connected between the second serial communication circuit 216 in the apparatus 210 and the second serial communication circuit 272 in the control device 270.

  Here, a second serial connection between the numerical controller 210 and each servo amplifier 290, between the first serial communication path 282 connecting the servo amplifiers, and between the numerical controller 210 and the control device 270 is performed. The serial communication is different from the serial communication path 284, and the communication speed is also different. Therefore, it may not be possible to connect each connected device to an incompatible connector.

  Further, as a problem related to data transmission, there is a technique disclosed in Patent Document 1 as a technique for transmitting data of different sizes in a predetermined data transmission path. In Patent Document 1, in asynchronous Ethernet (registered trademark), when transmitting asynchronous data, the size of the asynchronous data to be transmitted and the size of the empty transmission space of the asynchronous frame portion included in the transmission frame are described. In comparison, when the size of asynchronous data is larger than the size of the transmission space, a technique has been disclosed in which the asynchronous data is divided and transmitted in accordance with the size of the transmission space.

JP 2005-304030 A

  In the prior art shown in FIG. 13, it is necessary to prepare a large number of connectors in the numerical controller in order to cope with different serial communications. For this reason, connectors that are not used may occur depending on the specifications of the machine on which the numerical control device is mounted. If there are a large number of such connectors, a large number of infrequently used connectors will be provided, resulting in waste. There is.

  Therefore, an object of the present invention is to provide a serial communication system that can reduce the necessity of providing a connector that is less frequently used in a numerical control device that uses a serial communication system.

In the invention according to claim 1 of the present application, the first serial communication circuit in the numerical controller that transmits and receives data in the first communication cycle, and the data in the second communication cycle different from the first communication cycle. In a serial communication system that performs serial communication between the numerical control device and the control device, between the numerical control device and the control device. A relay unit for performing serial communication is connected, the numerical controller and the relay unit are connected by a first serial communication path, and the relay unit and the control device are connected by a second serial communication path. The numerical controller converts the serial signal output from the second serial communication circuit in the numerical controller into parallel data, and converts the converted data into the first signal in the numerical controller. First serial input to Al communication circuit - and parallel conversion circuit, a parallel data first serial communication circuit in the numerical controller output, serial receiving via the first serial communication line the parallel data obtained by converting the signal is converted back into a serial signal, the first parallel to enter the serial signal said converted into second serial communication circuit in the numerical controller - a serial conversion circuit, said relay The unit includes a first serial communication circuit in the relay unit connected to the first serial communication path of the numerical controller, and a serial signal output from the control device and received via the second serial communication path was converted into parallel data, a second serial inputs the data the conversion to the first serial communication circuit in the relay unit - parallel converter And road, a parallel data first serial communication circuit in the relay unit output, converts again the parallel data obtained by converting the serial signal received from the first serial communication path in a serial signal, the conversion second parallel you output a serial signal to the control device via the second serial communication path - a serial conversion circuit, wherein the control device includes a second serial communication circuit in the control device A serial communication system is provided in which the numerical controller performs serial communication with the control device via the second serial communication path.

  In the invention according to claim 1, it is possible to reduce the number of connectors for serial communication at different speeds from the main body of the numerical control device, and it is possible to reduce the cost and reduce the size. Further, since the second serial communication circuit for sending a signal to the second serial communication path can be used as it is in the prior art, a simple configuration can be taken and the cost can be reduced. .

In the invention according to claim 2 of the present application, one or more units are connected in the first serial communication path, and the numerical controller communicates with each unit at a constant communication cycle, and the relay unit and performing a numerical control device serial - parallel conversion and parallel - cycle of serial conversion, characterized in that an integer fraction of one interval of the communication cycle in the first serial communication, according to claim 1 A communication system is provided.

  In the invention according to claim 2, since the cycle of serial-parallel conversion and parallel-serial conversion performed by the relay unit and the numerical control device is set to 1 / integer of the communication cycle interval in the first serial communication. Thus, it is possible to optimize the communication speed performed between the serial communication at different speeds.

In the invention according to claim 3 of the present application, the second serial communication path is composed of a plurality of signals, and the plurality of signals are communicated between the numerical controller and the relay unit via the first serial communication path, respectively. A communication system according to claim 1 or 2 is provided.
In the invention according to claim 3, since the second serial communication path is composed of a plurality of signals, a plurality of signals from the control device can be processed and transmitted to the first serial communication path. .

In the invention according to claim 4 of the present application, the communication unit according to any one of claims 1 to 3, wherein the relay unit includes a plurality of second serial communication path connectors and connector selection means. Provided.
In the invention according to claim 4, since the relay unit includes a plurality of second serial communication path connectors and connector selection means, even if a large number of serial communications are provided, the relay unit can select and communicate. Can be performed.

  According to the present invention, it is possible to provide a serial communication system that can reduce the necessity of providing a connector that is less frequently used in a numerical control device that uses a serial communication system.

It is the figure which showed the connection aspect between the numerical control apparatus in 1st Embodiment, a relay unit, and control equipment. It is the figure which showed the flow of the signal at the time of the transmission of the signal from a numerical controller. It is the figure which showed each signal at the time of transmission of the signal from a numerical controller. It is the figure which showed the operation | movement at the time of reception of the relay unit when data is transmitted from a numerical controller. It is the figure which showed each signal at the time of reception of the relay unit at the time of data being transmitted from the numerical controller. It is the figure which showed the operation | movement at the time of transmission of a relay unit when data is output from the control apparatus. It is the figure which showed each signal at the time of transmission of a relay unit at the time of data being output from the control apparatus. It is the figure which showed the operation | movement at the time of reception of the data in a numerical controller. It is the figure which showed each signal at the time of reception of the data in a numerical control apparatus. It is the figure which showed the operation | movement at the time of transmission of the relay unit at the time of data being output from the control apparatus in 2nd Embodiment. It is the figure which showed each signal of the relay unit at the time of data being output from the control apparatus in 2nd Embodiment. It is the figure which showed the relationship between the relay unit and control apparatus in 3rd Embodiment. It is the figure which showed the aspect of the connection by the serial communication path between the conventional numerical control apparatus and a control apparatus or a servo amplifier.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a connection mode between the numerical control device of this embodiment, a relay unit, and a control device.
The numerical controller 10 includes a CPU 12, a first serial communication circuit 14, a second serial communication circuit 16, a serial-parallel conversion circuit (S → P) 18, and a parallel-serial conversion circuit (P → S). ) 20 is provided. Further, the CPU 12, the first serial communication circuit 14, and the second serial communication circuit 16 are connected to each other by an internal bus 22. Further, the signal transmitted from the second serial communication circuit 16 is converted into parallel data by the serial-parallel conversion circuit 18 and then input to the first serial communication circuit 14. The signal transmitted from the circuit 14 is converted into serial data by the parallel-serial conversion circuit 20 and then input to the second serial communication circuit 16.

  The first serial communication circuit 14 is connected to the outside via the first serial communication path 82, and is daisy chained to the first serial communication path 82 from UNIT # 0 to UNIT # 5. Connected with. The numerical control device 10 and UNIT # 0 to UNIT # 5 communicate with each other at a constant period. Here, UNIT # 5 is a relay unit 50 connected to a control device 70, which will be described later, through a second serial communication path 84.

  Inside the relay unit 50, a first serial communication circuit 54, a parallel-serial conversion circuit (P → S) 58, and a serial-parallel conversion circuit (S → P) 60 are provided. The signal transmitted from the first serial communication circuit 54 is converted into serial data by the parallel-serial conversion circuit 58 and then input to the control device 70 via the second serial communication path 84. The signal transmitted from the control device 70 passes through the second serial communication path 84, is converted into parallel data by the serial-parallel converter 60, and is then input to the first serial communication circuit 54.

Next, based on FIG.2 and FIG.3, the operation | movement at the time of the transmission of the signal from a numerical control apparatus in this embodiment is demonstrated. FIG. 2 is a diagram showing a signal flow when a signal is transmitted from the numerical control device, and FIG. 3 is a diagram showing each signal at that time.
The serial data THX_2 output from the second serial communication circuit 16 in the numerical control device 10 is 1-bit data, and is sampled at a constant period by the serial-parallel conversion circuit 18 to obtain 8-bit parallel data TXDH_2. Become. The parallel data TXDH_2 is input to the first serial communication circuit 14 and transmitted to the relay unit 50 via each unit 90. The sampling interval at this time is a value obtained by dividing the period of the first serial communication by the number of bits of data transmitted to the relay unit 50 (8 in FIG. 2). In this embodiment, the number of bits of data transmitted to the relay unit 50 is 8, but this value can be changed as appropriate.

  Each signal will be described with reference to FIG. Reference numeral 302 denotes a sampling period. As described above, the sampling interval is set to 8 in this embodiment. Reference numeral 304 denotes a transmission signal output from the second serial communication circuit 16 and is composed of an on state and an off state. Reference numeral 306 denotes a sampling point and a value at the sampling point, and takes a value of 1 or 0 depending on the on / off state at each point.

  308 is 8-bit data TXDH_2 after sampling. The data at the sampling point 306 is 8-bit data for each sampling interval. “11100000” arranged from the lower bits is 07h, and “00111111” is FCh. It is configured as follows. Reference numeral 310 denotes a first serial communication cycle. Reference numeral 312 denotes data transmitted as TXDH_1 in the first serial communication path 82. The TXDH_1 data 312 is configured for each data transmission destination unit, and the TXDH_2 data 308 is stored in UNIT # 5 serving as a relay unit as a transmission destination. As a result, the sampled data TXDH_2 is transmitted to the relay unit 50.

Next, the operation at the time of reception of the relay unit 50 when data is transmitted from the numerical controller 10 will be described based on FIGS. 4 and 5. FIG. 4 is a diagram illustrating a signal flow when the relay unit 50 receives a signal, and FIG. 5 is a diagram illustrating each signal at that time.
The TXDH_1 data transmitted through the first serial communication path 82 is input to the first serial communication circuit 54 in the relay unit 50, and converted into parallel data RXDS_2 by the first serial communication circuit 54. The parallel data RXDS_2 is input to the parallel-serial conversion circuit 58 and converted into serial data RXS_2. The bit rate of the serial data RXS_2 is a value obtained by dividing the communication period of the first serial communication by the number of bits of data transmitted from the numerical controller 20 to the relay unit 50 (8 in FIG. 4). . In this embodiment, the number of bits of data transmitted to the relay unit 50 is 8, but this value can be changed as appropriate.

The serial data RXS_2 output from the parallel-serial conversion circuit 58 is transmitted to the control device 70 via the second serial communication path 84.
The control device incorporates a second serial communication circuit (not shown) inside, and performs various controls by reproducing the data transmitted by the numerical controller 10 from the serial data RXS_2.
As shown in FIG. 5, the first serial communication is performed by the reverse procedure when the transmission signal of the second serial communication shown in FIG. 3 is used as the data to be transmitted through the first serial communication path. The reception signal RXS_2 of the second serial communication is reproduced from the transmission signal TXDH_1.

  Next, an operation at the time of transmission of the relay unit 50 when data is output from the control device 70 will be described based on FIGS. 6 and 7. The serial data TXS_2 output from the control device 70 via the second serial communication path 84 is 1-bit data, and is sampled at a constant period by the serial-parallel conversion circuit 60, whereby 8-bit parallel data TXDS_2. It becomes. The parallel data TXDS_2 is input to the first serial communication circuit 54 and transmitted to the numerical controller 10 via each unit 90. The sampling interval at this time is a value obtained by dividing the period of the first serial communication by the number of bits of data transmitted from the relay unit 50 to the numerical controller 10 (8 in FIG. 6). In this embodiment, the number of bits of data transmitted to the relay unit 50 is 8, but this value can be changed as appropriate.

  Each signal will be described with reference to FIG. Reference numeral 322 denotes a sampling period. As already described, the sampling interval is set to 8 in the present embodiment. Reference numeral 324 denotes a transmission signal output from the control device 70, and is composed of an on state and an off state. Reference numeral 326 denotes a sampling point and a value at the sampling point, and takes a value of 1 or 0 depending on the on / off state at each point.

  328 is 8-bit data TXDS_2 after sampling. The data at the sampling point 326 is 8-bit data for each sampling interval. “11111000” arranged from the lower bits is F8h, and “00000011” is 03h. It is configured as follows. Reference numeral 330 denotes a first serial communication cycle. Reference numeral 332 denotes data transmitted as RXDH_1 in the first serial communication path 82. The TXDH_1 data 312 is divided into data transmission destination units, and the TXDS_2 data 328 is the data generated by the UNIT # 5 serving as a relay unit, and the data of the UNIT # 5 in the data. Each is stored in a position. Thereby, the sampled data RXDH_2 is transmitted to the numerical controller 10 as data created by the relay unit 50.

Next, the operation at the time of data reception in the numerical controller 10 will be described with reference to FIGS. FIG. 8 is a diagram showing a signal flow at the time of signal reception in the numerical control apparatus 10, and FIG. 9 is a diagram showing each signal at that time.
RXDH_1 data transmitted through the first serial communication path 82 is input to the first serial communication circuit 14 in the numerical controller 10 and converted into parallel data RXDH_2 by the first serial communication circuit 14. The parallel data RXDH_2 is input to the parallel-serial conversion circuit 20 and converted into serial data RXH_2. The bit rate of the serial data RXH_2 is a value obtained by dividing the communication cycle of the first serial communication by the number of bits of data transmitted from the numerical control device 10 to the relay unit 50 (8 in FIG. 8). . In this embodiment, the number of bits of data transmitted to the relay unit 50 is 8, but this value can be changed as appropriate.

The serial data RXH_2 output from the parallel-serial conversion circuit 18 is sent to the second serial communication circuit 16 and is used for control of the control device 70 as serial data from the control device 70.
As shown in FIG. 9, the first serial communication is performed by the reverse procedure when the transmission signal of the second serial communication shown in FIG. 7 is used as the data to be transmitted through the first serial communication path. The reception signal RXH_2 of the second serial communication is reproduced from the transmission signal RXDH_1.

(Second Embodiment)
In the present embodiment, the second serial communication path is composed of a plurality of signals. In serial communication, there are cases in which not only signals for transmitting data as in RS-232C but also a plurality of signals such as signals used for control. In this embodiment, the second serial communication path is composed of two communication paths.

  Based on FIG.10 and FIG.11, the operation | movement at the time of transmission of the relay unit 50 when data is output from the control apparatus 70 is demonstrated. 1-bit serial data TXS_2 is output from the control device 70 via the second serial communication path 86, and 1-bit serial data TXS_3 is output via the second serial communication path 88. The serial data TXS_2 and the serial data TXS_3 are sampled at a constant cycle by the serial-parallel conversion circuit 60, thereby becoming 8-bit parallel data TXDS_2 and parallel data TXDS_3, respectively. The parallel data TXDS_2 and the parallel data TXDS_3 are input to the first serial communication circuit 54 and transmitted to the numerical controller 10 via each unit 90. The sampling interval at this time is a value obtained by dividing the period of the first serial communication by the number of bits of data transmitted from the relay unit 50 to the numerical control device 10 (8 in FIG. 10). In this embodiment, the number of bits of data transmitted to the relay unit 50 is 8, but this value can be changed as appropriate.

  Each signal will be described with reference to FIG. Reference numeral 342 denotes a sampling period. As already described, the sampling interval is set to 8 in this embodiment. Reference numeral 344 denotes a transmission signal TXS_2 output from the control device 70, and includes an on state and an off state. Reference numeral 346 denotes a sampling point and a value at the sampling point, and takes a value of 1 or 0 depending on the on / off state at each point.

  Reference numeral 348 denotes 8-bit data TXDS_2 after sampling. Data at the sampling point 346 is converted into 8-bit data for each sampling interval. It is configured as follows. Similarly to the transmission signal TXS_2 (344) of the second serial communication, the transmission signal TXS_3 (354) of the second serial communication is sampled and becomes TXDS_3 data (358).

Reference numeral 360 denotes a first serial communication cycle. Reference numeral 362 denotes data transmitted as RXDH_1 in the first serial communication path 82, and the TXDS_2 data 348 and TXDS_3 data 358 are the data created by UNIT # 5 serving as a relay unit. It is stored in the position of UNIT # 5. Thereby, the sampled data RXDH_2 is transmitted to the numerical controller 10 as data created by the relay unit 50.
The difference between the present embodiment and the first embodiment is that the data transmitted and received on the first serial communication path 82 between the numerical controller 10 and the relay unit 50 is an integral multiple of one line, The number of signals converted by the serial-parallel conversion circuit and the parallel-serial conversion circuit is increased.

  In the present embodiment, the plurality of serial communication paths from the control device are all configured as the same serial communication path as the second serial communication path (86, 88). The relay unit 50 may be provided with a corresponding parallel-serial conversion circuit so as to transmit a signal to the first serial communication circuit 54.

(Third embodiment)
Numerous serial communications, such as communication with RS-232C, RS-485, and IO unit, exist in the numerical control device, but these serial communications have different electrical interfaces and require a circuit corresponding to the interface. Become. Therefore, a plurality of second serial communication path connectors and a circuit corresponding to the interface are mounted on the relay unit, and a connector selection means such as a selector is provided between the plurality of connectors and the serial-parallel conversion circuit or parallel-serial conversion circuit. Thus, the relay unit can support a plurality of serial communications. As an example of the connector selection means, a switch may be provided in the relay unit, or a selection signal may be input from the numerical control device via the first serial communication path.

  FIG. 12 is a diagram illustrating a relationship between the relay unit and the control device according to the present embodiment. A description of the same configuration as in the first embodiment will be omitted. The relay unit 50 includes a plurality of connectors, a connector 1 (110a), a connector 2 (110b), a connector 3 (110c),..., A connector n (110n), and the control device 1 (110a) is connected to the connector 1 (110a). RS-232C, which is 70a), RS-485, which is control device 2 (70b), and IO unit, which is control device 3 (70c), are connected to connector 2 (110b) and connector 3 (110c). Further, the connector 110 is configured to select one of the connectors 110 by the selector 100. As the selector 100 for selecting the connector 110, a method of providing a switch in the relay unit 50 or inputting a selection signal from the communication control device can be considered. As a means for operating the selector 100, it is possible to use a means such as providing a switch in the relay unit 50 or notifying the numerical control device by serial communication.

  In the present embodiment, the plurality of serial communication paths from the control device are all configured as the same serial communication path as the second serial communication path, but in the relay unit 50 as different serial communication paths. Each of the parallel-serial conversion circuits may be provided, and the selector 100 may be configured to transmit a signal to the corresponding parallel-serial conversion circuit.

  In the embodiment of the present invention, the second serial communication circuit 16 used in the prior art is used as it is, and the serial-parallel conversion circuit 18 and the parallel-serial conversion circuit 20 are provided inside the numerical controller 10. The data is converted into data applicable to the first serial communication circuit, but the second serial communication circuit, the serial-parallel conversion circuit, and the parallel-serial conversion circuit are integrated into a single circuit. Is also possible. With such a configuration, the circuit configuration in the numerical control device can be simplified.

10 Numerical control device 12 CPU
14 first serial communication circuit 16 second serial communication circuit 18 serial-parallel conversion circuit 20 parallel-serial conversion circuit 22 internal bus 50 relay unit 54 first serial communication circuit 58 parallel-serial conversion circuit 60 serial -Parallel conversion circuit 70 Control device 82 First serial communication path 84 Second serial communication path 90 Unit 100 Selector 110 Connector 210 Numerical control device 212 CPU
214 First serial communication circuit 216 Second serial communication circuit 222 Internal bus 270 Control device 272 Second serial communication circuit 282 First serial communication path 284 Second serial communication path 290 Servo amplifier

Claims (4)

A first serial communication circuit in the numerical controller that transmits and receives data in a first communication cycle; and
A second serial communication circuit in the numerical controller that transmits and receives data in a second communication cycle different from the first communication cycle,
In a serial communication system that performs serial communication between a numerical controller and a control device,
A relay unit that performs serial communication between the numerical controller and the control device is disposed,
Connecting the numerical controller and the relay unit via a first serial communication path;
Connecting the relay unit and the control device by a second serial communication path;
The numerical controller is
A serial signal output from the second serial communication circuit in the numerical control device is converted into parallel data, and the converted data is input to the first serial communication circuit in the numerical control device. A conversion circuit;
The parallel data output from the first serial communication circuit in the numerical control device, wherein the parallel data obtained by converting the serial signal received via the first serial communication path is converted again into the serial signal , and the conversion is performed. the first parallel to enter a serial signal to a second serial communication circuit in the numerical controller - a serial conversion circuit,
The relay unit is
A first serial communication circuit in the relay unit connected to the first serial communication path of the numerical control device;
A second serial signal that is output from the control device and that is received via the second serial communication path is converted into parallel data, and the converted data is input to the first serial communication circuit in the relay unit. A parallel conversion circuit;
Parallel data output from the first serial communication circuit in the relay unit , the parallel data obtained by converting the serial signal received from the first serial communication path is converted again into a serial signal, and the converted serial signal second parallel you output to the control device via the second serial communication path - a serial conversion circuit,
The control device includes a second serial communication circuit in the control device,
A serial communication system, wherein the numerical control device performs serial communication with the control device via the second serial communication path. In the first serial communication path, one or more units are connected, and the numerical controller communicates with each unit at a constant communication cycle, and serial-parallel conversion performed by the relay unit and the numerical controller 2. The communication system according to claim 1, wherein a period of the parallel-serial conversion is an integer of an interval of the communication period in the first serial communication.   The second serial communication path includes a plurality of signals, and the plurality of signals are respectively communicated between the numerical control device and the relay unit via the first serial communication path. Communications system. The relay unit includes a plurality of second serial communication path connectors, connector selection means,
The communication system according to any one of claims 1 to 3.