JP2008029161A - Serial communication device for controlling motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a serial communication device for controlling a motor achieving efficient serial communication. <P>SOLUTION: Motor driving devices 402-403 are each provided with communication I/F sections 409, 410 for performing communication with a high-order device and a low-order device, an access control unit 412 and a line setter 411. When a control command signal is transmitted from a high-order control device 401 to each of motors, the line setter sets a line of both the communication I/F sections and a line between the communication I/F section of high-order device side and the access control unit, and inputs the control command signal into the access control unit of each motor driving device. When data are transmitted from each motor driving device to the high-order control device, the line setter of each motor driving device positioned on the high-order device side connects a line of both the communication I/F sections to transmit the data to the high-order control device. In such a configuration, wiring efficiency is improved and efficient serial communication is achieved. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a serial communication device for motor control, and more particularly to a serial communication device for motor control for connecting a host control device (host control device) and a motor drive device to be controlled. .

  In recent years, connecting a host control device and a plurality of motor drive devices by serial communication, and giving an operation command to the motor via this serial communication has been widely performed for the purpose of reducing wiring and increasing functionality. Became. As an example of this, there is one in which Ethernet (registered trademark) or the like is applied to the physical layer of serial communication.

  FIG. 8 is a block diagram showing an example of the configuration of a conventional motor control serial communication device. The host control device 101 functioning as a master device is connected to a hub 102 serving as a network relay device via a communication cable 106 and a communication connector 109. The hub 102 is connected via a communication cable 106 and a communication connector 109 to motor drive devices 103 to 105 that drive the servo motor. The host control apparatus 101 includes an access control unit 107 that encodes / decodes transmission / reception data into / from a frame format, a communication I / F unit 108 that exchanges data, and a communication connector 109. Similarly, the motor driving devices 103 to 105 also include the same access control unit 107, communication I / F unit 108, and communication connector 109.

  Normally, a large number of these motor drive devices are arranged. However, in order to simplify the explanation, FIG. 8 shows an example in which there are three motor drive devices. As a whole, the host controller 101 and all of the motor drive devices 103 to 105 are connected to the hub 102 by communication cables 106 having independent paths for transmission and reception.

  In this configuration, master-slave communication is generally performed in which the motor driving devices 103 to 105 return responses to command transmission from the host control device 101. In FIG. 8, the host control device 101 corresponds to a master device, and the motor drive devices 103 to 105 correspond to slave devices. The command data transmitted from the host control device 101 is transmitted to the motor drive devices 103 to 105 via the hub 102, and the response data from the motor drive devices 103 to 105 is also transmitted to the host control device 101 via the hub 102. Is transmitted. The host control device 101 sequentially executes transmission / reception with the next motor driving device 104 when transmission / reception with one motor driving device 103 is completed, and transmission / reception with all motor driving devices 103 to 105 is completed. At this point, one communication cycle is completed. Real-time communication is realized by repeatedly executing this communication cycle.

  Further, FIG. 9 is a block diagram showing another configuration example of the motor control serial communication device as shown in Patent Document 1. FIG. The host controller 201 shown in FIG. 9 includes a first communication IC 202 that performs a set of transmission / reception communication control, a transmission terminal as the transmission terminal of the first communication IC 202, and a reception terminal as the reception terminal of the first communication IC 202. A first communication connector 203 connected thereto is provided. The motor driving device 204 includes a second communication IC 205 that performs a transmission / reception set of communication control, a second communication connector 206 whose reception terminal is connected to the reception terminal of the second communication IC 205, and a transmission terminal that is a second communication terminal. The transmission terminal of the communication IC 205 includes a third communication connector 207 whose reception terminal is connected to the transmission terminal of the second communication connector 206.

In the connection between the host control device 201 and the motor drive device 204 disposed in the forefront stage, the first communication connector 203 and the first communication cable 208 having the independent paths for transmission and reception are used. 2 communication connectors 206 are connected. Further, in the connection between the motor drive devices 204, the third communication connector 207 provided in one motor drive device 204 and the second communication connector provided in the other motor drive device 204 using the first communication cable 208 are used. 206 is connected. In the motor drive device 204 arranged at the last stage, the second communication cable 209 connecting the transmission terminal and the reception terminal is connected to the third communication connector 207, and by these configurations, the host control device 201 and each motor drive are connected. The device 204 is daisy chained.
JP 2003-189654 A

  However, the conventional example shown in FIG. 8 is a so-called star wiring in which the hub 102 is arranged at the center of the transmission path. As an actual arrangement of the devices, the host controller 101 and the motor driving device are arranged radially around the hub 102. Installation of 103 to 105 tends to be avoided because space efficiency is deteriorated. Therefore, it is normal to arrange the host control device 101 and the motor drive devices 103 to 105 in FIG. 8 side by side. In this case, there is a problem that the wiring efficiency is low because a place where the communication cables 106 are bundled, and the advantage of the reduced wiring, which is a major purpose of connection by serial communication, cannot be obtained sufficiently. Another problem is that the presence of the hub 102 increases the cost of the entire system.

Further, in the conventional example shown in Patent Document 1, in order to solve the above problem, the communication path arranged inside the motor driving device and the path of the communication cable are combined to form a loop-shaped communication path as a whole. However, there are the following problems.
(1) When a communication cable is disconnected in a certain section, all communication with the host controller is stopped and the section where the communication cable is disconnected cannot be specified. It is necessary to check every section.
(2) Since the communication connector and the communication path arranged in the motor drive device are relayed in multiple stages, multiple reflection occurs, which is not suitable for high-speed communication.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a motor control serial communication device capable of performing efficient serial communication.

The present invention
A host controller that generates control command signals for a plurality of motors and a motor drive device that drives each motor based on the control command signals from the host controller, and the host controller and each motor driver are serially connected. A serial communication device for motor control that is connected and serially transmits and receives data via a communication I / F unit,
Each of the motor drive devices has a first communication I / F unit for communicating with a higher-level device and a second communication I / F unit for communicating with a lower-level device, and an access for transmitting and receiving data. A line setting unit for setting a line between the control unit, the first communication I / F unit, the second communication I / F unit, and the access control unit;
When the control command signal is transmitted from the host controller to each motor, the line setting unit is configured to connect the line between the first communication I / F unit and the access control unit, and the first and second communication I / Fs. When connecting the lines between the units, allowing the control command signal to be input to the access control unit of each motor drive device, and transmitting the data from each motor drive device to the host control device, each motor located on the host device side The line setting unit of the drive device connects the line between the first and second communication I / F units and transmits the data to the host controller.

  According to the present invention, the motor drive device is provided with a communication I / F unit for communicating with the higher-level device and a communication I / F unit for communicating with the lower-level device, and access control is performed by the line setting unit. Since the line between the communication unit and both communication I / F units is set to a line corresponding to the communication mode, a relay hub is not required, the wiring efficiency is improved, and efficient serial communication is possible.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

  FIG. 1 is a block diagram of an embodiment of a serial communication device for motor control according to the present invention, and shows a signal flow during downlink data transmission from a host control device 401 to motor drive devices 402 to 404. In order to simplify the description, the case where there are three motor driving devices is shown as an example, but more motor driving devices can be connected. Each motor driving device 402 to 404 is connected to a motor (not shown), and each motor driving device receives command data (control command signal) transmitted from the host control device 401 by the access control unit 412. The data is received and output to the motor, and data such as the position, speed, and current value of the motor is taken into the access control unit 412 and transmitted to the host controller 401 or another motor drive device.

  The host control device 401 includes an access control unit 406 that encodes / decodes transmission / reception data into / from a frame format, a communication I / F unit 407 that communicates with the motor driving devices 402 to 404 and exchanges data, and a communication connector 408. Yes.

  Each motor driving device 402 to 404 transmits / receives data to / from a higher-level communication I / F unit 409 that communicates with a higher-level device and exchanges data, and a communication I / F unit 410 that communicates with a lower-level device and exchanges data. An access control unit 412 that encodes / decodes data in a frame format, line settings for the terminal side interfaces of the higher-level communication I / F unit 409 and the lower-level communication I / F unit 410, and both communication I / F units 409 and 410; A line setting unit 411 for setting a line between the access control units 412 and two communication ports 408 are provided.

  The line setting unit 411 of each of the motor drive devices 402 to 404 includes line setting switches 414 to 416. The switches 414 to 416 are described as two-point switches connected to either the point A or the point B, but may be switches having intermediate points not connected to the points A and B. In addition, the motor driving devices 402 to 404 transmit the cable disconnection detection signal 413 detected by the lower communication I / F unit 410 to the access control unit 412.

  The upper communication port 408 of the motor drive device 402 is connected to the communication port 408 of the upper control device 401 via the communication cable 405, and the lower communication port 408 is connected to the upper port of the motor drive device 403 via the communication cable 405. Side communication port 408. The lower communication port 408 of the motor driving device 403 is connected to the upper communication port 408 of the motor driving device 404 via the communication cable 405. Since the motor drive device is not provided on the lower side of the motor drive device 404, the lower-side communication port 408 is empty.

  FIG. 2 is a diagram showing the temporal arrangement of data on the transmission path of the motor control serial communication device. The transmission timing data SYN is used for synchronization to give transmission timing from the host control device 401 to the motor drive devices 402 to 404. It is data of. RSP1 to RSP3 are data transmitted from the motor drive devices 402 to 404 to the host control device 401. CMD is transmission data from the host control device 401 to the motor drive devices 402 to 404. Further, DD is downlink data when communication is performed between the motor drive devices, and UD is uplink data when communication is performed between the motor drive devices. The period from one transmission timing data SYN to the next transmission timing data SYN is one communication cycle.

  In the above configuration, when data is transmitted from the host controller 401 to the motor drive devices 402 to 404, as shown in FIG. 1, the switch 414 of the line setting unit 411 provided in the motor drive devices 402 to 404 is provided. The switches 415 and 416 are all set to the A side, and the transmission path shown thick in FIG. 1 is formed. In this state, the host control device 401 transmits transmission timing data SYN shown in FIG. 2 to all the motor drive devices 402 to 404.

  By receiving the transmission timing data SYN from the host controller 401, the motor driving devices 402 to 404 synchronize the internal timer of the own station with the host controller 401. When the internal timer reaches a value set in advance in the own station, the motor driving devices 402 to 404 send motor position data, motor speed data, motor current data, alarm status, etc. of the servo amplifier and spindle amplifier of the own station. The included motor data is transmitted to the host controller 401.

  For example, FIG. 3 illustrates a state in which the motor driving device 403 transmits data of the motor driven by the motor driving device to the host control device 401. For data transmission, the switch 415 of the line setting unit 411 of the motor driving device 403 is set to the B side, the upper communication I / F unit 409 and the access control unit 412 are connected, and the upper motor drive Communication I / F units 409 and 410 of the device 402 are connected via a switch 415. 3 is formed, and the data of the motor driven by this motor drive device can be transmitted from the access control unit 412 of the motor drive device 403 to the host control device 401. .

  In the above, the example in which the motor driving device 403 transmits the motor data to the host control device 401 has been shown. However, when the motor driving device 402 or 404 transmits the motor data, as described above, The switch 415 of the line setting unit 411 of the motor driving device to be set is set to the B side, and the other switches are set to the A side. Since the data transmitted from the motor driving devices 402 to 404 corresponds to RSP1 to RSP3 at the timing of FIG. 2, the switch 415 may be set to the B side at that timing.

  When the motor driving devices 402 to 404 complete the data transmission to the host control device 401, the switches 414 to 416 of the line setting units are returned to the state shown in FIG.

  After receiving the data regarding each motor from the motor driving devices 402 to 404, the host controller 401 thereafter transmits the operation command data (data CMD shown in FIG. 2) for the servo amplifier and the spindle amplifier to the thick line transmission path shown in FIG. Accordingly, the data is transmitted to the respective motor driving devices 402 to 404. Each motor driving device takes only the command data for its own station into the access control unit 412 and drives the motor of its own station according to the command data. Thus, motor control is realized by performing the same communication between the host control device 401 and the motor drive devices 402 to 404 in a cycle of one communication cycle.

  FIG. 4 illustrates an example where a communication cable is disconnected, for example, a communication cable 405 between the motor driving device 403 and the motor driving device 404 is disconnected.

  Due to this disconnection, the idle signal that is constantly sent from the higher-level communication I / F unit 409 that exchanges data with the higher-level control device of the motor drive device 404 does not reach the motor drive device 403. For this reason, the communication cable 405 between the motor driving device 404 and the motor driving device 403 is disconnected in the lower-level communication I / F unit 410 that exchanges data with the lower-level device of the motor driving device 403 (indicated by a cross in FIG. 4). And the information is sent to the access control unit 412 as a cable disconnection detection signal 413 as shown by a bold line.

  The access control unit 412 of the motor driving device 403 transmits the cable disconnection detection signal 413 to the host control device 401 as an alarm status of the local station data (status transmission data RSP2 shown in FIG. 2). Therefore, the line setting unit 411 sets the switch 415 to the B side. As a result, the host controller 401 receives the disconnection occurrence status from the motor driving device 403, thereby generating a disconnection in the communication cable 405 connected to the lower side device of the motor driving device 403, and the disconnection. It can be recognized from the host controller how many motor drive devices are disconnected.

  5 and 6 show the signal flow when communication is performed between the motor driving devices 402 to 404, and the frame format of communication data (downstream data DD and upstream data UD in FIG. 2) between the motor driving devices. An example is shown in FIG.

  For downlink data transmission, as shown in FIG. 5, the line setting unit 411 in the motor driving devices 402 to 404 is set so that the switch 414 is set to the A side, the switch 415 is set to the A side, and the switch 416 is set to the B side. Thus, a transmission path indicated by a thick line is formed. In this state, the host control device 401 transmits downlink data DD to the motor drive device 402. In the motor driving device 402, the downlink data DD is captured by the access control unit 412. When the motor drive device 402 communicates with other motor drive devices 403 and 404, the access control unit 412 sends the address to the motor drive device 403 or the motor drive device in the local data area 902 of the frame format 901 shown in FIG. Write data addressed to 404 and regenerate the frame signal. Then, the motor drive device 402 transmits a frame signal to the motor drive device 403 and, as shown in FIG. 6, the switch 414 of the line setting unit 411 of the motor drive device 402 is set to the B side, and the switch 415 is set to the A side. The switch 416 is set to the B side.

  The motor driving device 403 also performs the same operation as the motor driving device 402, receives the regenerated frame signal (DD), and if there is data addressed to itself from the motor driving device 402, the data Is read. At the same time, the data addressed to the other motor drive device to be communicated is written in the data area 903 of the own station, and the frame signal is regenerated. The motor driving device 403 transmits a frame signal to the motor driving device 404, and as shown in FIG. 6, the switch 414 of the line setting unit 411 of the motor driving device 403 is set to the B side, and the switch 415 is set to the A side. The switch 416 is set to the B side.

  The motor driving device 404 at the last stage performs the same operation as the motor driving devices 402 and 403, and when there is data addressed to the own station from other motor driving devices 402 and 403, the data is read and In the station data area 904, data addressed to another motor drive device to be communicated is written, and a frame signal is regenerated. Then, as shown in FIG. 6, the switch 414 of the line setting unit 411 of the motor driving device 404 is set to the A side, the switch 415 is set to the B side, and the switch 416 is set to the A side.

  As described above, when the switches of the line setting unit 411 in the motor driving devices 402 to 404 are switched, the transmission path shown in FIG.

  When the processing of the own station is completed, the motor drive device 404 outputs the regenerated downlink data DD as the uplink data UD as described above. As shown in FIG. 6, the upstream data UD output from the motor driving device 404 is transmitted in a bus form with the motor driving device 403, the motor driving device 402, and the host controller 401. At this time, if there is data addressed to the own station from the upstream data, the motor driving device 403 and the motor driving device 402 can fetch the data via the access control unit 412 of each motor driving device.

  As described above, communication among the three parties of the motor drive device 402, the motor drive device 403, and the motor drive device 404 can be secured, and the host control device 401 communicates between the motor drive devices 402 to 404. All the contents can be grasped from the upstream data UD.

  In the above embodiment, the internal configuration of the line setting unit 411 is described by the switches 414 to 416. However, it may be realized by a digital circuit instead of the switch. Although the communication interface is described as Ethernet (registered trademark), the communication interface can be realized as optical communication.

In the present invention,
(1) The motor driving devices 402 to 404 are each provided with a communication I / F unit 409 and a communication I / F unit 410 on the upper device side and the lower device side, and the communication I / F unit 409 and the communication I / F Since the line setting unit 411 for controlling the line setting of the terminal side interface of the F unit 410 is provided, a hub is not necessary and wiring efficiency can be improved.

  (2) Since the lower side communication I / F unit 410 of the motor driving devices 402 to 404 can monitor the input signal and notify the higher level control device 401 of the information as an alarm status, the communication cable 405 on the network can be used. Even when a disconnection occurs, it is possible to automatically specify the section where the disconnection occurs, and it becomes unnecessary to check the disconnection portion of the communication cable 405 by a human at the time of failure.

  (3) At the time of downlink data transmission, the line setting unit 411 sets a line in a daisy chain so that the access control unit 412 can write data to the motor drive unit communication dedicated frame, and at the time of uplink data transmission Since the line setting unit 411 sets a line in the form of a bus and the access control unit 412 can read data, data can be exchanged between a plurality of motor drive devices.

  (4) Since the communication I / F units 409 and 410 are provided for each transmission path and regeneratively relayed, the communication quality is stable even when relaying in multiple stages.

  Etc. are obtained.

It is a block diagram which shows the structural example at the time of the downlink data transmission from the high-order control apparatus 401 to the motor drive units 402-404. It is the signal diagram which showed the time arrangement | positioning of the data on a transmission line. It is a block diagram which shows the example at the time of the uplink data transmission from a motor drive unit to the high-order control apparatus 401. It is a block diagram which shows the example of the state which a disconnection generate | occur | produced in the communication cable. It is a block diagram which shows the example at the time of the downlink data transmission at the time of performing communication between the motor drive units 402-404. It is a block diagram which shows the example at the time of uplink data transmission at the time of performing communication between the motor drive units 402-404. It is explanatory drawing which shows an example of the frame format of the downlink data DD of FIG. 2, and the uplink data UD. It is a block diagram which shows the 1st structural example of the conventional serial communication apparatus for motor control. It is a block diagram which shows the 2nd structural example of the conventional serial communication apparatus for motor control.

Explanation of symbols

401 High-level control device 406 Access control unit 407 Communication I / F unit 402, 403, 404 Motor drive device 409 Communication I / F unit 410 Communication I / F unit 411 Line setting unit 412 Access control unit 414, 415, 416 switch

Claims (3)

A host controller that generates control command signals for a plurality of motors and a motor drive device that drives each motor based on the control command signals from the host controller, and the host controller and each motor driver are serially connected. A serial communication device for motor control that is connected and serially transmits and receives data via a communication I / F unit,
Each of the motor drive devices has a first communication I / F unit for communicating with a higher-level device and a second communication I / F unit for communicating with a lower-level device, and an access for transmitting and receiving data. A line setting unit for setting a line between the control unit, the first communication I / F unit, the second communication I / F unit, and the access control unit;
When the control command signal is transmitted from the host controller to each motor, the line setting unit is configured to connect the line between the first communication I / F unit and the access control unit, and the first and second communication I / Fs. When connecting the lines between the units, allowing the control command signal to be input to the access control unit of each motor drive device, and transmitting the data from each motor drive device to the host control device, each motor located on the host device side A serial communication device for motor control, wherein a line setting unit of a driving device connects a line between the first and second communication I / F units and transmits the data to a host control device.   The motor driving device detects disconnection on the lower device side based on a signal input from the lower device to the second communication I / F unit, and transmits the information to the upper control device. Item 2. A serial communication device for motor control according to Item 1.   A data area for each motor drive device is provided in the data to be transmitted / received, and at the time of data transmission / reception, each motor drive device writes data for other motor drive devices in the data area and for the local station written in the data area. The motor control serial communication device according to claim 1, wherein data is exchanged between the motor driving devices.

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