Control device and control system

Abstract

The purpose of the present invention is to suppress the occurrence of malfunctions and malfunctions in an encoder via a communication line when the encoder is detached from and attached to a control device. A control device (2) controls a motor (4) on the basis of a detection signal from an encoder (3) that detects the operating position of the motor (4). A control device (2) is provided with a communication unit (22), a pull-up resistor (R1), a first power source (26), a first switch (SW1), and a control unit (27). The communication unit (22) transmits and receives the detection signal to and from the encoder (3) via the communication line (L2). The pull-up resistor (R1) is connected to the communication line (L2). A first switch (SW1) is provided in a first circuit (L7) that connects a first power source (26) and a pull-up resistor (R1), and turns on and off the first circuit (L7). The control unit (27) controls the first switch (SW1).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a control device and a control system, and more particularly to a control device that controls a motor based on a detection signal of an encoder that detects a position of movement of the motor, and a control system that includes the control device. BACKGROUND

[0002] The substrate work machine described in Patent Literature 1 includes a multi-axis rotation servo amplifier (control device), an encoder, and a motor. The encoder detects a rotation angle of the motor. The multi-axis rotation servo amplifier is capable of communicating with the encoder via a multiplex communication device. The multi-axis rotation servo amplifier controls the motor based on a detection signal of the encoder received via the multiplex communication device.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: International Publication No. 2017 / 179156 SUMMARY

[0006] In the substrate work machine described in Patent Literature 1, in a case where a communication line of the multiplex communication device is connected to a power supply via a pull-up resistor, at the time of attachment of the encoder with respect to the control device, a surge current of the power supply flows to the encoder via the pull-up resistor and the communication line, and a failure or a defect sometimes occurs in the encoder. In addition, at the time of detachment of the encoder with respect to the control device, if the encoder is detached from the control device in a state where a voltage is applied to the communication line, a failure or a defect sometimes occurs in the encoder.

[0007] An object of the present disclosure is to provide a control device and a control system that can suppress a failure or a defect in an encoder via a communication line at the time of attachment and at the time of detachment of the encoder with respect to a control device.

[0008] A control device according to an aspect of the present disclosure is a control device that controls a motor based on a detection signal of an encoder that detects a position of movement of the motor. The control device includes a communication section, a pull-up resistor, a first power supply, a first switch, and a control section. The communication section transmits and receives the detection signal with the encoder via a communication line. The pull-up resistor is connected to the communication line. The first switch is provided in a first circuit that connects the first power supply and the pull-up resistor, and turns on and off the first circuit. The control section controls the first switch.

[0009] A control system according to another aspect of the present disclosure includes the control device, the encoder, and the motor.

[0010] According to the control device and the control system of the present disclosure, it is possible to suppress the effects of malfunction, defects, and the like of the encoder via the communication line at the time of disassembly and at the time of assembly of the encoder with respect to the control device. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a configuration diagram of the control system to which the embodiment relates.

[0012] Figure 2 is a configuration diagram of the control system to which the modification example 1 relates.

[0013] Figure 3 is a configuration diagram of the control system to which the modification example 2 relates.

[0014] Figure 4 is a flowchart illustrating a first action example of the control section to which the modification example 2 relates.

[0015] Figure 5 is a flowchart illustrating a second action example of the control section to which the modification example 2 relates.

[0016] Figure 6 is a configuration diagram of the control system to which the modification example 3 relates.

[0017] Figure 7 is a configuration diagram of the control system to which the modification example 4 relates.

[0018] Figure 8 is a partial enlarged view of Figure 7 , and is a configuration diagram illustrating a connection state of the connector.

[0019] Figure 9 is a configuration diagram illustrating a disconnection state of the connector in the control system to which the modification example 4 relates. DETAILED DESCRIPTION

[0020] (1) Embodiment

[0021] Hereinafter, the control device and the control system to which the embodiment relates will be described with reference to the drawings.

[0022] (1-1) Outline of Control Device

[0023] Figure 1 is a configuration diagram of the control system 1 to which the present embodiment relates. As Figure 1As shown, the control device 2 according to this embodiment controls the motor 4 based on the detection signal of the encoder 3 that detects the operating position of the motor 4. Here, the motor 4 is, for example, a servo motor used in semiconductor manufacturing equipment or production robots. However, the motor 4 is not limited to servo motors used in semiconductor manufacturing equipment or production robots. The control device 2 includes a communication unit 22, a pull-up resistor R1, a first power supply (e.g., a pull-up power supply 26), a first switch SW1, and a control unit 27. The communication unit 22 is, for example, a communication element with circuitry, capable of transmitting and receiving detection signals with the encoder 3 via a communication line L2. The pull-up resistor R1, the terminating resistor R2, and the pull-down resistor R3 are electrically connected to the communication line L2. The first switch SW1 is provided in a first circuit (e.g., circuit L7) that connects the first power supply (pull-up power supply 26) and the pull-up resistor R1, and turns the first circuit (circuit L7) on and off. The control unit 27 controls the first switch SW1.

[0024] According to this structure, the encoder 3 can be installed and removed from the control device 2 while the first circuit (circuit L7) is disconnected by the first switch SW1. This prevents malfunctions or defects in the encoder 3 caused by the communication line L2 during installation and removal from the control device 2. More specifically, it prevents inrush current from flowing from the first power supply (pull-up power supply 26) to the encoder 3 through the communication line L2 during installation from the control device 2, thus preventing malfunctions or defects in the encoder 3. It also prevents malfunctions or defects in the encoder 3 caused by a sudden disconnection of the communication line L2 (forced removal of the communication line L2) during removal from the control device 2.

[0025] Furthermore, the control system 1 according to this embodiment includes a control device 2, an encoder 3, and a motor 4. Based on this structure, a control system 1 including the control device 2 can be provided.

[0026] (1-2) Detailed description of the control system

[0027] like Figure 1 As shown, the control system 1 includes a control device 2 (also called a servo amplifier), an encoder 3, a motor 4, and a main power supply 5.

[0028] In this control system 1, the encoder 3 detects the rotational position (operating position) of the motor 4, and the control device 2 controls the motor 4 based on the detection result of the encoder 3. Such a control system 1 is suitable for controlling servo motors, such as those used in semiconductor manufacturing equipment or production robots, which function as motors 4.

[0029] (1-2-1) Main power supply

[0030] The main power supply 5 is an alternating-current power supply such as a commercial power supply. As shown in FIG. 1, the main power supply 5 supplies a power supply voltage to the control device 2, the encoder 3, and the motor 4. In the present embodiment, the power supply voltage is supplied from the main power supply 5 to the control device 2, and the power supply voltage is supplied from the control device 2 to the encoder 3 and the motor 4. The main power supply 5 is connected to a power supply input terminal T1 of the control device 2 via a main power supply switch SW0. Figure 1

[0031] (1-2-2) Control Device

[0032] The control device 2 controls the motor 4 on the basis of the rotational position of the motor 4 detected by the encoder 3. As shown in FIG. 2, the control device 2 includes a plurality of external terminals (the power supply input terminal T1, a power supply output terminal T2, communication terminals T3, T4, power supply terminals T5 to T7), an encoder power supply circuit 21, a communication section 22, a motor power supply circuit 23, an inverter 24, a PWM (Pulse Width Modulation) signal generation section 25, a power supply for pull-up 26, a pull-up resistor R1, a terminal resistor R2, a pull-down resistor R3, a first switch SW1, a second switch SW2, first to third short-circuit switches SW3 to SW5, and a control section 27. Figure 1

[0033] The power supply input terminal T1 is a terminal that inputs a voltage (an alternating-current voltage) from the main power supply 5. The power supply input terminal T1 is connected to the main power supply 5 via the main power supply switch SW0.

[0034] The power supply output terminal T2 is a terminal for outputting a voltage (a direct-current voltage) generated by the encoder power supply circuit 21 to the encoder 3. The power supply output terminal T2 is connected to a power supply input terminal T8 of the encoder 3 via a power supply cable L12.

[0035] In addition, the power supply cable L12 and the circuits L11, L13 described later constitute a power supply line L1 that connects the encoder power supply circuit 21 and a power supply circuit 31 in the encoder 3.

[0036] The communication terminals T3, T4 are terminals for communicatively connecting with the encoder 3. The communication terminals T3, T4 are connected to communication terminals T9, T10 of the encoder 3 via communication cables L22, L32.

[0037] In addition, the communication cable L22 and the circuits L21, L23 described later constitute one of two communication lines L2, L3 that connect the communication section 22 and the communication section 33 in the encoder 3. Further, the communication cable L32 and the circuits L31, L33 described later constitute the other of the two communication lines L2, L3.

[0038] ​​The power supply terminals T5 to T7 are terminals for outputting the 3-phase alternating voltage generated by the motor power supply circuit 23 to the motor 4. The power supply terminals T5 to T7 are connected to the power supply terminals T11, T12, T13 of the motor 4 via the power supply cables L42, L52, L62.

[0039] In addition, the power supply cable L42 and the circuit L41 described later constitute a U-phase power supply line L4 that connects the inverter 24 and the U-phase power supply terminal T11 of the motor. Further, the power supply cable L52 and the circuit L51 described later constitute a V-phase power supply line L5 that connects the inverter 24 and the V-phase power supply terminal T12 of the motor. The power supply cable L62 and the circuit L61 described later constitute a W-phase power supply line L6 that connects the inverter 24 and the W-phase power supply terminal T13 of the motor.

[0040] The encoder power supply circuit 21 generates a power supply voltage (direct current voltage) for the encoder based on the power supply voltage (alternating voltage) of the main power supply 5. The encoder power supply circuit 21, for example, has an alternating / direct current conversion section and a voltage conversion section. The alternating / direct current conversion section converts the power supply voltage (alternating voltage) of the main power supply 5 into a direct current voltage. The voltage conversion section converts the direct current voltage obtained by the conversion of the alternating / direct current conversion section into a direct current voltage having a given voltage value (for example, 5 V).

[0041] The encoder power supply circuit 21 has an input section 21a and an output section 21b. The input section 21a is a portion that inputs the power supply voltage of the main power supply 5 input to the power supply input terminal T1 to the encoder power supply circuit 21, and is connected to the power supply input terminal T1. The output section 21b is a portion that outputs the direct current voltage generated by the encoder power supply circuit 21 from the encoder power supply circuit 21, and is connected to the power supply output terminal T2 via the circuit L11. The second switch SW2 is provided in the circuit L11.

[0042] The second switch SW2 is provided in the circuit L11, and turns on and off the circuit L11 based on a control signal from the control section 27. Thereby, the supply and stop of the power supply voltage from the encoder power supply circuit 21 to the encoder 3 are switched.

[0043] The communication section 22 performs data communication between the communication section 33 of the encoder 3 described later based on a control signal from the control section 27. The communication section 22, for example, performs 2-wire communication using 2 communication lines L2, L3 between the communication section 33 of the encoder 3. The communication section 22 receives the rotational position information transmitted from the communication section 33 of the encoder 3, or transmits the control signal to the communication section 33 of the encoder 3. The above-described rotational position information is information of the rotational position of the motor 4 detected by the encoder 3.

[0044] The communication section 22 has a transmission mode and a reception mode. The transmission mode is an operation mode in which the communication section 22 transmits transmission data (for example, a control signal) to the communication section 33 of the encoder 3 via the communication lines L2, L3. The reception mode is an operation mode in which the communication section 22 receives reception data (for example, rotation position information) from the communication section 33 of the encoder 3 via the communication lines L2, L3. The operation mode of the communication section 22 is switched to the transmission mode or the reception mode in accordance with a control signal of the control section 27.

[0045] The communication section 22 has two signal input / output sections 22b, 22c. The two signal input / output sections 22b, 22c are portions that input / output data (the above-mentioned control signal and rotation position information) for data communication, and are connected to the communication terminals T3, T4 via the circuits L21, L31, respectively.

[0046] The pull-up power supply 26 is a direct-current power supply (for example, 5 V) for pulling up the circuit L21 (that is, a portion within the control device 2 of the communication line L2). The pull-up power supply 26 is generated, for example, in accordance with a main power supply 5 input to a power supply input terminal T1.

[0047] The pull-up resistor R1, the terminal resistor R2, and the pull-down resistor R3 are connected in series between the pull-up power supply 26 and a ground. The pull-up resistor R1, the terminal resistor R2, and the pull-down resistor R3 are arranged in this order from the pull-up power supply 26 toward the ground. The circuit L21 is connected to a connection point between the pull-up resistor R1 and the terminal resistor R2. The circuit L31 is connected to a connection point between the terminal resistor R2 and the pull-down resistor R3. The circuit L7 that connects the pull-up power supply 26 and the pull-up resistor R1 is provided with the first switch SW1. The conduction and the non-conduction of the circuit L7 are switched by switching the conduction and the non-conduction of the first switch SW1, and the effectiveness and the ineffectiveness of the pull-up resistor R1 of the communication line L2 are switched by the switching of the conduction and the non-conduction. The input voltage of the signal input / output section 22b of the communication section 22 is pulled up by the effectiveness of the pull-up resistor R1. The input voltage of the signal input / output section 22c of the communication section 22 is pulled down by the pull-down resistor R3.

[0048] The first switch SW1 is provided to the circuit L7, and switches the conduction and the non-conduction of the circuit L7 on the basis of a control signal from the control section 27. Thereby, the effectiveness and the ineffectiveness of the pull-up of the voltage of the circuit L21 (that is, the input voltage of the signal input / output section 22b of the communication section 22) are switched.

[0049] The motor power supply circuit 23 generates a power supply voltage (direct current voltage) for the motor based on the power supply voltage of the main power supply 5. The motor power supply circuit 23, for example, has an AC / DC conversion section and a voltage conversion section. The AC / DC conversion section converts the power supply voltage (alternating current voltage) of the main power supply 5 into a direct current voltage. The voltage conversion section converts the direct current voltage obtained by the conversion of the AC / DC conversion section into a direct current voltage having a given voltage value.

[0050] The inverter 24 converts the direct current voltage generated by the motor power supply circuit 23 into a 3-phase alternating current voltage, and supplies the 3-phase alternating current voltage obtained by the conversion to the motor 4. The inverter 24, for example, has six transistors. The six transistors are composed of three groups of two transistors connected in series. The three groups are connected in parallel to each other. Further, the direct current voltage generated by the motor power supply circuit 23 is applied in parallel to the three groups. The connection points of the two transistors of the three groups are connected to the three supply terminals T5 to T7 via the circuits L41, L51, L61, respectively, and are connected to the three supply terminals T11, T12, T13 of the motor 4 via the supply cables L42, L52, L62, respectively.

[0051] Between the circuits L41, L51, L61 and the ground, the first short-circuit switch SW3, the second short-circuit switch SW4, and the third short-circuit switch SW5 are provided, respectively.

[0052] The first short-circuit switch SW3, the second short-circuit switch SW4, and the third short-circuit switch SW5 constitute a dynamic brake for stopping the motor 4. The first short-circuit switch SW3 is provided in a branch circuit connecting the U-phase supply line L4 (more specifically, the circuit L41) and the ground, and switches the conduction and the cutoff of the branch circuit based on a control signal from the control section 27. The second short-circuit switch SW4 is provided in a branch circuit connecting the V-phase supply line L5 (more specifically, the circuit L51) and the ground, and switches the conduction and the cutoff of the branch circuit based on a control signal from the control section 27. The third short-circuit switch SW5 is provided in a branch circuit connecting the W-phase supply line L6 (more specifically, the circuit L61) and the ground, and switches the conduction and the cutoff of the branch circuit based on a control signal from the control section 27. By making the first short-circuit switch SW3, the second short-circuit switch SW4, and the third short-circuit switch SW5 conductive, the discharge time of the motor 4 can be shortened, and thus the motor 4 can be stopped more quickly.

[0053] In the present embodiment, however, at least one of the three supply lines L4 to L6 is provided with a short-circuit switch.

[0054] The PWM signal generation unit 25 performs PWM (Pulse Width Modulation) control on the six transistors of the inverter 24 based on the control signal from the control unit 27. Through this control, the inverter 24 converts the DC voltage from the motor power supply circuit 23 into a three-phase AC voltage, switching the supply and stopping of the converted three-phase AC voltage to the motor 4. Furthermore, through the above control, the inverter 24 causes the rotational speed of the motor 4 to change.

[0055] The control unit 27 controls the controlled objects (e.g., the first switch SW1, the second switch SW2, the communication unit 22, and the first short-circuit switches SW3 to SW5) by outputting control signals to each of them. More specifically, the control unit 27 controls the switching of the first switch SW1 on and off according to the control signals, thereby controlling the switching of the circuit L7 on and off. This controls the activation and deactivation of the pull-up of the input voltage of the signal input / output unit 22b of the communication unit 22. Furthermore, the control unit 27 controls the switching of the second switch SW2 on and off according to the control signals, thereby controlling the switching of the circuit L11 (i.e., the power line L1) on and off. This controls the supply and deactivation of the power supply voltage from the encoder power circuit 21 to the encoder 3 power circuit 31. Additionally, the control unit 27 switches the operating mode of the communication unit 22 to either a transmitting mode or a receiving mode according to the control signals. This switches the operating mode of the communication unit 22 to either a transmitting mode or a receiving mode. Furthermore, the control unit 27 controls the switching of the first short-circuit switch SW3 to the third short-circuit switch SW5 according to the control signal, thereby controlling the switching of the power supply lines L4 to L6 to ground. This controls the operation and non-operation switching of the dynamic braking of the motor 4.

[0056] (1-2-3) Encoder

[0057] like Figure 1 As shown, encoder 3 detects the rotational position (operating position) of motor 4. In this embodiment, motor 4 is a rotary motor, therefore encoder 3 detects the rotational position of motor 4. However, if motor 4 is a linear motor that operates linearly, encoder 3 detects the moving position of the motor.

[0058] The encoder 3 has a power input terminal T8, communication terminals T9 and T10, a power supply circuit 31, a detection circuit 32, a communication unit 33, a pull-up resistor R4, a terminating resistor R5, and a pull-down resistor R6.

[0059] The power input terminal T8 is a terminal that inputs a voltage (direct current voltage) from the encoder power supply circuit 21. The power input terminal T8 is connected to the power supply circuit 31 through the circuit L13. Further, the power input terminal T8 is connected to the power supply output terminal T2 of the control device 2 via the power supply cable L12.

[0060] The communication terminals T9, T10 are terminals for communicatively connecting with the control device 2. The communication terminals T9, T10 are connected to the communication terminals T3, T4 of the control device 2 via the communication cables L22, L32.

[0061] The power supply circuit 31 steps down a direct current voltage (for example, 5 V) supplied from the encoder power supply circuit 21 of the control device 2 to generate a power supply voltage (for example, 3 V) for the internal circuit (for example, the detection circuit 32 and the communication section 33) of the encoder 3.

[0062] The detection circuit 32 operates using the power supply voltage supplied from the power supply circuit 31 to detect the rotational position of the motor 4. The detection circuit 32 detects the rotational position (rotational angle) of the motor, for example, by detecting the rotational position (rotational angle) of a rotor fixed to the rotational shaft of the motor 4.

[0063] The communication section 33 is, for example, a communication element having a circuit, and performs data communication with the communication section 22 of the control device 2. As described above, the communication section 33 performs two-wire communication using two communication lines L2, L3 between the communication section 22. The communication section 33 transmits the detection result of the detection circuit 32 (rotational position information relating to the rotational position of the motor 4) to the communication section 22, or receives a control signal for the encoder 3 from the communication section 22. The communication section 33 has two signal input / output sections 33b, 33c. The two signal input / output sections 33b, 33c are portions that input and output data (the control signal and the rotational position information described above) for data communication, and are connected to the communication terminals T9, T10 through the circuits L23, L33, respectively.

[0064] The pull-up resistor R4, the terminal resistor R5, and the pull-down resistor R6 are connected in series between the circuit L13 and the ground. The pull-up resistor R4, the terminal resistor R5, and the pull-down resistor R6 are arranged in this order from the circuit L13 toward the ground. The circuit L23 is connected to the connection point between the pull-up resistor R4 and the terminal resistor R5. Thus, the input voltage of the signal input / output section 33b of the communication section 33 is pulled up. The circuit L33 is connected to the connection point between the terminal resistor R5 and the pull-down resistor R6. Thus, the input voltage of the signal input / output section 33c of the communication section 33 is pulled down.

[0065] (1-2-4) Motor

[0066] The motor 4 is, for example, a 3-phase alternating-current rotary servo motor that operates by a 3-phase alternating-current voltage supplied from the inverter 24 of the control device 2. The motor 4 is, for example, a servo motor used for a semiconductor manufacturing device or a production robot. In addition, the motor 4 is not limited to a servo motor used for a semiconductor manufacturing device or a production robot. The motor 4 has three power supply terminals T11, T12, T13 to which the 3-phase alternating-current voltage supplied from the inverter 24 of the control device 2 is input. The three power supply terminals T11, T12, T13 are connected to the three power supply terminals T5, T6, T7 of the control device 2 via three power supply cables L42, L52, L62, respectively. In addition, the motor 4 can also be a linear motor that linearly performs reciprocating operation.

[0067] (1-2-5) Features of the configuration of the control system

[0068] In the control device 2, the first switch SW1 is provided in a circuit L7 that connects the pull-up power supply 26 and the pull-up resistor R1. Therefore, the mounting and the dismounting of the encoder 3 with respect to the control device 2 can be performed in a state in which the circuit L7 is cut off by the first switch SW1, that is, in a state in which the pull-up of the circuit L21 (that is, the portion of the communication line L2 inside the control device 2) is made ineffective. Thus, it is possible to suppress the occurrence of a failure or a defect in the encoder 3 via the communication line L2 at the time of the mounting and the dismounting of the encoder 3 with respect to the control device 2. In more detail, it is possible to suppress the occurrence of a failure or a defect in the encoder 3 due to a surge current flowing from the pull-up power supply 26 to the encoder 3 through the communication line L2 at the time of the mounting of the encoder 3 with respect to the control device 2, or to suppress the occurrence of a failure or a defect in the encoder 3 due to a sudden cut-off of the communication line L2 (for example, a forcible unplugging of the communication line L2) at the time of the dismounting of the encoder 3 with respect to the control device 2.

[0069] (1-3) Main Effects

[0070] As described above, the control device 2 according to the embodiment controls the motor 4 on the basis of a detection signal of the encoder 3 that detects the operation position of the motor 4. The control device 2 includes the communication section 22, the pull-up resistor R1, the pull-up power supply 26 (first power supply), the first switch SW1, and the control section 27. The communication section 22 can transmit and receive the detection signal with the encoder 3 via the communication line L2. The pull-up resistor R1 is connected to the communication line L2. The first switch SW1 is provided in a circuit L7 (first circuit) that connects the pull-up power supply 26 and the pull-up resistor R1, and turns on and off the circuit L7. The control section 27 controls the first switch SW1.

[0071] According to this structure, it is possible to perform the attachment and detachment of the encoder 3 with respect to the control device 2 in a state in which the circuit L7 (first circuit) is cut off by the first switch SW1 (i.e., in a state in which the pull-up of the circuit L7 is made ineffective). Thereby, it is possible to suppress the occurrence of a failure or a malfunction in the encoder 3 via the communication line L2 at the time of the attachment and detachment of the encoder 3 with respect to the control device 2 (effects). More specifically, it is possible to suppress the occurrence of a failure or a malfunction in the encoder 3 due to the flow of a surge current from the pull-up power supply 26 (first power supply) to the encoder 3 via the communication line L2 at the time of the attachment of the encoder 3 with respect to the control device 2, or to suppress the occurrence of a failure or a malfunction in the encoder 3 due to the sudden cut-off of the communication line L2 (e.g., the forcible unplugging of the communication line L2) at the time of the detachment of the encoder 3 with respect to the control device 2.

[0072] Further, the pull-up power supply 26 (first power supply) is a power supply that is independent of the encoder power supply circuit 21 that supplies a power supply voltage to the encoder 3. According to this structure, in a structure in which the pull-up power supply 26 is a power supply that is independent of the encoder power supply circuit 21, the above-described effects can be achieved.

[0073] Further, the control system 1 according to the present embodiment is provided with the control device 2, the encoder 3, and the motor 4. According to this structure, it is possible to provide the control system 1 provided with the above-described control device 2.

[0074] (2) Modification

[0075] Hereinafter, a modification of the above-described embodiment will be described. In the following description, the same reference numerals are assigned to the same parts as those of the above-described embodiment, and the description thereof will be omitted, and only different parts will be described. Further, a combination of the above-described embodiment and the following modification can also be implemented.

[0076] (2-1) Modification 1

[0077] Figure 2 is a block diagram of the control system 1 according to Modification 1. In the control device 2 according to the above-described embodiment, the encoder power supply circuit 21 and the pull-up power supply 26 are independent structures. However, as shown in Figure 2 , the pull-up power supply 26 can be omitted, and the encoder power supply circuit 21 can be used as the pull-up power supply as well.

[0078] More specifically, as shown in Figure 2As shown, in the control device 2 according to the modification example 1, the pull-up power supply 26 and the second switch SW2 are omitted from the control device 2 according to the embodiment. Further, in the control device 2 according to the modification example 1, the circuit L11 connects the encoder power supply circuit 21 and the power supply output terminal T2 as in the embodiment. In the modification example 1, the first switch SW1 is provided to the circuit L11 to switch on and off the circuit L11. As in the embodiment, the circuit L7 connects the pull-up resistor R1 and one end of the first switch SW1 (the end on the encoder 3 side in the modification example 1).

[0079] In the control device 2 according to the modification example 1, the encoder power supply circuit 21 (the first power supply) is connected to the pull-up resistor R1 through the first circuit (i.e., the circuit composed of the circuits L11 and L7). Further, the first switch SW1 is provided to the first power supply (more specifically, the circuit L11) to switch on and off the circuit L11. By the switching on and off, the pull-up resistor R1 is switched between being active and being inactive.

[0080] Further, in the control device 2 according to the modification example 1, the encoder power supply circuit 21 supplies the power supply voltage to the encoder 3 via the power supply line L1 as in the embodiment. In the modification example 1, a part of the power supply line L1 (the circuit L11) is shared with the first power supply. Further, the first switch SW1 is provided to the power supply line L1 (more specifically, the circuit L11) to switch on and off the power supply line L1. By the switching on and off, the supply and stop of the power supply voltage from the encoder power supply circuit 21 to the encoder 3 are switched.

[0081] Further, in the control device 2 according to the modification example 1, the control section 27 is configured as in the control section 27 of the embodiment except that the function of controlling the second switch SW2 is omitted.

[0082] As such, in the modification example 1, the first switch SW1 has both the functions of switching the supply and stop of the power supply voltage from the encoder power supply circuit 21 to the encoder 3 and switching the pull-up resistor R1 between being active and being inactive.

[0083] According to the modification example 1, the encoder power supply circuit 21 functions as the encoder power supply circuit and also as the pull-up power supply. Further, by the first switch SW1, the switching on and off of the first circuit (the circuit composed of the circuits L11 and L7) and the switching on and off of the power supply line L1 (the circuit composed of the circuits L11, L13, and the power supply line cable L12) are performed. As a result, the number of components can be reduced.

[0084] Further, the mounting and dismounting of the encoder 3 with respect to the control device 2 can be performed in a state where the power supply line L1 is cut off by the first switch SW1. Thus, it is possible to suppress a failure or a malfunction of the encoder 3 due to a rush current flowing from the encoder power supply circuit 21 to the encoder 3 through the power supply line L1 at the time of mounting of the encoder 3 with respect to the control device 2, or to suppress a failure or a malfunction of the encoder 3 due to a sudden cut-off of the power supply line L1 (e.g., forcible unplugging of the power supply line L1) at the time of dismounting of the encoder 3 with respect to the control device 2.

[0085] (2-2) Modification 2

[0086] (2-2-1) Configuration Explanation

[0087] Figure 3 is a configuration diagram of the control system 1 to which Modification 2 is applied. As Figure 3 indicated, in the control device 2 to which Modification 2 is applied, the control section 27 controls the control objects (e.g., the first switch SW1, the second switch SW2, the communication section 22, and the first to third short-circuit switches SW3 to SW5) based on a trigger signal input from the external device 7, like in the control device 2 to which the above embodiment is applied.

[0088] More specifically, the control device 2 to which Modification 2 is applied further includes a signal input terminal T14 as an external terminal.

[0089] The signal input terminal T14 is connected to the signal input section 27b of the control section 27. The signal input terminal T14 is connected to the external device 7 via a signal cable L9.

[0090] The external device 7 is, for example, a PLC (Programmable Logic Controller) or an amplifier, or the like. The external device 7 outputs a trigger signal to the signal input terminal T14 of the control device 2 via the signal cable L9, for example, in accordance with an operation of an operator. The trigger signal is a signal that instructs the control section 27 to start execution of a predetermined process (e.g., a series of processes for a plurality of control objects) for the above control objects. The external device 7 outputs different kinds of trigger signals (e.g., the first to third trigger signals described later) in accordance with the contents of the operation of the operator.

[0091] In the control device 2 to which Modification 2 is applied, the control section 27 is configured identically to the control section 27 of the above embodiment, except for the point that the control section 27 controls the above control objects based on the trigger signal input to the signal input terminal T14.

[0092] (2-2-2) Action Explanation

[0093] Next, the operation of the control section 27 will be described.

[0094] (2-2-2-1) First Action Example of Control Section 27

[0095] Figure 4 is a flowchart illustrating a first action example of the control section 27 involved in the modification example 2. In the case where the encoder 3 is detached from the control device 2, the operator operates the external device 7 so that the first trigger signal is output from the external device 7. Then, the control section 27 in the control device 2, if the first trigger signal from the external device 7 is acquired via the signal input terminal T14, executes a series of processes of the steps S1 to S4 shown in Figure 4

[0096] In more detail, as shown in Figure 4 , the control section 27, if the first trigger signal is acquired (S1), first switches the operation mode of the communication section 22 to the reception mode (S2). Then, the control section 27 next switches the first switch SW1 from ON to OFF (S3). Thereby, the circuit L7 is cut off, and the pull-up resistor R1 in the control device 2 becomes ineffective. Further, by the above-mentioned cut-off of the circuit L7, the supply current from the pull-up power supply 26 is suppressed from flowing to the encoder 3 through the communication line L2, the pull-up resistor R4, and the circuit L13. Then, the control section 27 finally switches the second switch SW2 from ON to OFF (S4). Thereby, the supply voltage from the encoder power supply circuit 21 is stopped from being supplied to the encoder 3 through the power supply line L1.

[0097] As such, in the case where the encoder 3 is detached from the control device 2, the second switch SW2 is switched to OFF after the first switch SW1 is switched to OFF. Thereby, in the OFF state of the second switch SW2 (i.e., the OFF state of the supply of the power to the encoder 3), the supply of the supply current from the pull-up power supply 26 to the power supply circuit 31 in the encoder 3 through the communication line L2, the pull-up resistor R4, and the circuit L13 is stopped, so that the unstable operation of the encoder 3 can be suppressed.

[0098] Further, in the case where the encoder 3 is detached from the control device 2, as described above, after the operation mode of the communication section 22 is switched to the reception mode, the first switch SW1 is switched from ON to OFF, and then the second switch SW2 is switched from OFF to ON. Thereby, the case (i.e., the non-preferred case) where the communication section 22 of the control device 2 becomes the transmission mode so as to apply the voltage to the communication line L2 in the OFF state of the second switch SW2 (i.e., the OFF state of the supply of the power to the encoder 3) can be suppressed.

[0099] (2-2-2-2) Second Action Example of Control Section 27​

[0100] Figure 5 is a flowchart illustrating a second example of operation of the control section 27 involved in the modification example 2. In the case where the control device 2 is installed with the encoder 3, the operator operates the external device 7 so that the second trigger signal is output from the external device 7. Then, the control section 27 in the control device 2, if the second trigger signal from the external device 7 is acquired via the signal input terminal T14, executes a series of processes of the steps Sll-S14 illustrated in FIG. 9 with respect to the communication section 22, the first switch SWl, and the second switch SW2. Figure 5

[0101] In more detail, as illustrated in FIG. 9, if the control section 27 acquires the second trigger signal (Sll), the second switch SW2 is first switched from off to on (Sl2). Thereby, the power supply voltage from the encoder power supply circuit 21 is supplied to the encoder 3 through the power supply line Ll. Then, the control section 27 switches the first switch SWl from off to on (Sl3). Thereby, the circuit L7 is turned on, so that the pull-up resistor Rl in the control device 2 becomes active. Then, the control section 27 switches the operation mode of the communication section 22 to the transmission mode or the reception mode (Sl4). Figure 5

[0102] As such, in the case where the control device 2 is installed with the encoder 3, the first switch SWl is switched to on after the second switch SW2 is switched to on. Thereby, since the case where the power supply current from the pull-up power supply 26 is supplied to the power supply circuit 31 in the encoder 3 through the communication line L2, the pull-up resistor R4, and the circuit L13 in the off state of the second switch SW2 (i.e., the off state of the power supply to the encoder 3) is stopped, the encoder 3 can be inhibited from performing unstable operation.

[0103] Further, in the case where the control device 2 is installed with the encoder 3, as described above, the second switch SW2 is switched to on, and then the operation mode of the communication section 22 is switched to the reception mode or the transmission mode after the first switch SWl is switched to on. Thereby, the case where the communication section 22 of the control device 2 becomes the transmission mode to apply a voltage to the communication line L2 in the off state of the power supply to the encoder 3 (i.e., the off state of the second switch SW2) (i.e., the non-preferred case) can be inhibited.

[0104] In addition, in the present embodiment, the case where the control section 27 performs both the switching of the on and off of each of the first switch SWl and the second switch SW2 and the switching of the operation mode of the communication section 22 is exemplified. However, the control section 27 can omit the switching of the operation mode of the communication section 22 and perform only the switching of the on and off of the first switch SWl and the second switch SW2. ​​

[0105] (2-2-2-3) Third Action Example of Control Section

[0106] In the case where the motor 4 is detached from the control device 2, the operator operates the external device 7 so that the third trigger signal is output from the external device 7. Then, the control section 27 in the control device 2, if the third trigger signal from the external device 7 is acquired via the signal input terminal T14, executes the following processing with respect to the first to third short-circuit switches SW3 to SW5.

[0107] More specifically, the control section 27, if the third trigger signal is acquired, switches the first to third short-circuit switches SW3 to SW5 from off to on. Thereby, the electric energy in the motor 4 is discharged to the ground via the first to third short-circuit switches SW3 to SW5. By this discharge, the discharge of the motor 4 is completed in a short time. Then, after the discharge of the motor 4 is completed (i.e., after a given time elapses from the start of the discharge), the motor 4 is detached from the control device 2.

[0108] As such, in the case where the motor 4 is to be detached from the control device 2, the first to third short-circuit switches SW3 to SW5 are set to on immediately before this, so that the dynamic braking is applied to the motor 4. Thereby, the discharge time of the motor 4 is shortened, so that the time taken for the detachment of the motor 4 from the control device 2 can be shortened. This is particularly effective for the structure in which the encoder 3 and the motor 4 are integrated. In this case, immediately before the encoder 3 and the motor 4 are to be detached from the control device 2, the control section 27 acquires the first trigger signal and the third trigger signal from the external device 7.

[0109] (2-3) Modified Example 3

[0110] Figure 6 is a block diagram of the control system 1 to which the modified example 3 relates.

[0111] In the control device 2 to which the modified example 2 relates, the control section 27 controls the control objects (e.g., the first and second switches SW1 and SW2, the first to third short-circuit switches SW3 to SW5, and the communication section 22) based on the trigger signals from the external device 7. In contrast, in the control device 2 to which the modified example 3 relates, as shown in Figure 6 , the control section 27 controls the above control objects based on the trigger signal from the trigger button 8 (operation section) provided in the control device 2. Note that the trigger button 8 is an example of the operation section which receives the operation from the operator. As the above operation section, not only the button-type operation section like the trigger button 8 but also other operation sections can be used.

[0112] More specifically, in the control device 2 according to the modification 3, the control device 2 is configured similarly to the control device 2 according to the modification 2 except that the trigger button 8 is provided instead of the signal input terminal T14.

[0113] The trigger button 8 includes a plurality of buttons corresponding one-to-one to mutually different kinds of trigger signals (e.g., the first to third trigger signals according to the modification 2). If the plurality of buttons are selectively subjected to a pressing operation by an operator, a corresponding kind of trigger signal is output to the control section 27. The trigger button 8 is disposed, for example, on a surface of a housing of the control device 2.

[0114] In the control device 2 according to the modification 3, if the control section 27 acquires various trigger signals (e.g., the first to third trigger signals according to the modification 2) from the trigger button 8, the control section 27 performs processing corresponding to the various trigger signals on the above-described control objects, as in the first to third operation examples of the control section according to the modification 2.

[0115] According to the modification 3, the control objects can be controlled by an input operation to the trigger button 8 (operation section).

[0116] (2-4) Modification 4

[0117] (2-4-1) Configuration Explanation

[0118] Figure 7 is a configuration diagram of the control system according to the modification 4.

[0119] In the modification 2, the control section 27 of the control device 2 controls the control objects (e.g., the first switch SW1, the second switch SW2, the first to third short-circuit switches SW3 to SW5, and the communication section 22) based on the trigger signal from the external device 7. In contrast, in the modification 4, as shown in Figure 7 the control device 2 and the encoder 3 are detachably connected via the first connector 9 and the second connector 10, and the control section 27 of the control device 2 controls the above-described control objects based on a trigger signal output in response to attachment and detachment of the first connector 9 and the second connector 10.

[0120] More specifically, as shown in Figure 7As shown, the control device 2 of the modification example 4 omits the signal input terminal T14 from the control device 2 of the modification example 2. In addition, the control device 2 of the modification example 4 has the first connector 9 in place of the power supply output terminal T2 and the communication terminals T3, T4 from the control device 2 of the modification example 2. In addition, one end of each of the power supply cable L12 and the communication cables L22, L32 is connected to the second connector 10. In addition, the control device 2 of the modification example 4 further has the detection section 11 that detects attachment and detachment of the first connector 9 and the second connector 10 from the control device 2 of the modification example 2.

[0121] The first connector 9 is, for example, a male connector. The first connector 9 is connected to the control device 2. In more detail, the first connector 9 is arranged to be exposed to the outside from the surface of the housing of the control device 2. Figure 8 Figure 7 is a partial enlarged view, and is a structural view that shows the state of connection of the connector. As shown in Figure 8 The first connector 9 has a first connector housing 91, a power supply output terminal M2 that is male, a pair of communication terminals M3, M4 that are male, and a pair of first terminals M5, M6 that are male.

[0122] The power supply output terminal M2, the pair of communication terminals M3, M4, and the pair of first terminals M5, M6 are arranged to be housed in the first connector housing 91. The power supply output terminal M2 is connected to one end of the circuit L11, and is connected to the output section of the encoder power supply circuit 21 via the circuit L11. The pair of communication terminals M3, M4 are respectively connected to one end of the circuits L21, L31, and are connected to the signal input / output sections 22b, 22c of the communication section 22 via the circuits L21, L31. One of the pair of first terminals M5, M6 is connected to the signal input section 27a of the control section 27 via the circuit L8, and the other of the pair of first terminals M6 is grounded.

[0123] The signal input section 27a of the control section 27 is connected to the second power supply 28 (voltage Vcc) via the resistor R7, and is connected to the one of the first terminals M5. That is, the second power supply 28 is connected to the signal input section 27a of the control section 27 and the one of the first terminals M5 via the resistor R7.

[0124] ​The detection section 11 detects attachment and detachment (connection and disconnection) of the first connector 9 and the second connector 10, and outputs the first level signal or the second level signal as a trigger signal to the signal input section 27a of the control section 27 in accordance with the connection and disconnection. That is, the detection section 11 changes the voltage input to the signal input section 27a of the control section 27 in accordance with the attachment and detachment of the first connector 9 and the second connector 10. The first level signal is a signal indicating that the first connector 9 and the second connector 10 are disconnected, and is, for example, an H (High) level signal. The second level signal is a signal indicating that the first connector 9 and the second connector 10 are connected, and is, for example, an L (Low) level signal.

[0125] The detection section 11 is configured by a pair of first terminals M5, M6, the second power supply 28, and a resistor R7. The pair of first terminals M5, M6 are connected to and disconnected from a pair of second terminals M11, M12 of the second connector 10 in accordance with the connection and disconnection of the first connector 9 and the second connector 10. In this way, the pair of first terminals M5, M6 are connected to and disconnected from the pair of second terminals M11, M12 that are short-circuited to each other, and thus the pair of first terminals M5, M6 are turned on and off. If the pair of first terminals M5, M6 are turned off, the voltage Vcc of the second power supply 28 is input to the signal input section 27a of the control section 27 as the first level signal (H level signal). Further, if the pair of first terminals M5, M6 are turned on, the signal input section 27a of the control section 27 is connected to the ground, and the ground potential is input to the signal input section 27a of the control section 27 as the second level signal (L level signal).

[0126] The control section 27 of the modified example 4 is configured identically to the control section 27 of the modified example 2 except that the control section 27 controls the above-described control object based on the trigger signal (first level signal or second level signal) input from the detection section 11.

[0127] The second connector 10 is connected to the encoder 3 via the power supply cable L12 and the communication cables L22, L32. The second connector 10 is a female connector that is attachable and detachable to the male first connector 9. As shown in FIG. 2, the second connector 10 has a second connector housing 101, a power input terminal M8 that is a female terminal, a pair of communication terminals M9, M10 that are female terminals, and a pair of second terminals M11, M12 that are female terminals. Figure 8

[0128] The power input terminal M8, the pair of communication terminals M9, M10, and the pair of second terminals M11, M12 are disposed by being housed in the second connector housing 101.

[0129] ​The power input terminal M8 is a female terminal that is detachably connected to the male power output terminal M2 of the first connector 9. The power input terminal M8 is connected to one end of the power cable L12, and is connected to the power circuit 31 of the encoder 3 via the power cable L12 and the circuit L13. The pair of communication terminals M9, M10 correspond one-to-one to the pair of communication terminals M3, M4 of the first connector 9, and are female terminals that are detachably connected to the corresponding communication terminals. The pair of communication terminals M9, M10 are connected to one end of the communication cables L22, L32, respectively, and are connected to the communication section 33 of the encoder 3 via the communication cables L22, L32 and the circuits L23, L33. The pair of second terminals M11, M12 correspond one-to-one to the pair of first terminals M5, M6 of the first connector 9, and are female terminals that are detachably connected to the corresponding first terminals. That is, the second terminal M11 corresponds to the first terminal M5, and the second terminal M12 corresponds to the first terminal M6. The pair of second terminals M11, M12 are short-circuited to each other.

[0130] (2-4-2) Explanation of the operation of the detection section

[0131] The operation of the detection section 11 when the first connector 9 and the second connector 10 are connected and when they are separated, and when the detection section 11 outputs a trigger signal (first trigger signal or second trigger signal) to the signal input section 27a of the control section 27 will be explained.

[0132] (2-4-2-1) Operation when the first connector and the second connector are separated

[0133] Figure 9 is a structural diagram showing the state of the connectors when the second connector 10 is separated from the first connector 9 in the control system according to the modification 4.

[0134] As shown in Figure 9 , when the first connector 9 and the second connector 10 are separated, the first connector housing 91 of the first connector 9 and the second connector housing 101 of the second connector 10 are separated from each other. As a result, the power output terminal M2, the pair of communication terminals M3, M4, and the pair of first terminals M5, M6 in the first connector 9 are separated from the power input terminal M8, the pair of communication terminals M9, M10, and the pair of second terminals M11, M12 in the second connector 10, respectively. By the pair of first terminals M5, M6 being separated from the pair of second terminals M11, M12 at this time, the input voltage to the signal input section 27a of the control section 27 is pulled up to the voltage Vcc of the second power supply 28. As a result, the voltage Vcc of the second power supply 28 is input to the signal input section 27a of the control section 27 as a first level signal (trigger signal).

[0135] In addition, if the control unit 27 receives the first level signal (trigger signal), it controls the first switch SW1, the second switch SW2 and the communication unit 22 as described in the first operation example of the control unit in Modified Example 2, or controls the first short-circuit switch SW3 to the third short-circuit switch SW5 as described in the third operation example of the control unit in Modified Example 2, and applies dynamic braking to the motor 4.

[0136] like Figure 8 As shown, if the first connector 9 and the second connector 10 are connected, the first connector housing 91 of the first connector 9 and the second connector housing 101 of the second connector 10 are interconnected. Thus, the power output terminal M2, the pair of communication terminals M3 and M4, and the pair of first terminals M5 and M6 in the first connector 9 are respectively connected to the power input terminal M8, the pair of communication terminals M9 and M10, and the pair of second terminals M11 and M12 in the second connector 10. Through this connection between the pair of first terminals M5 and M6 and the pair of second terminals M11 and M12, the signal input section 27a of the control unit 27 is connected to ground via the circuit L8, the pair of first terminals M5 and M6, and the pair of second terminals M11 and M12. Therefore, the ground potential is input to the signal input section 27a of the control unit 27 as a second-level signal (trigger signal).

[0137] Furthermore, if the control unit 27 receives the second level signal (trigger signal), it controls the first switch SW1, the second switch SW2, and the communication unit 22, as described in the second operation example of the control unit in Modified Example 2.

[0138] (2-4-3) Effect of variation example 4

[0139] According to Modification 4, the controlled object (e.g., the first switch SW1, the second switch SW2, the first short-circuit switch SW3 to the third short-circuit switch SW5, and the communication unit 22) can be automatically controlled by attaching and detaching the first connector 9 and the second connector 10 (i.e., attaching and detaching the control device 2 and the encoder 3). Furthermore, the detection unit 11 can be configured with a simple structure.

[0140] (3) Method

[0141] Based on the above-described embodiments and variations, this disclosure includes the following methods.

[0142] The first mode relates to a control device (2) that controls a motor (4) based on a detection signal of an encoder (3) that detects a movement position of the motor (4). The control device (2) includes a communication section (22), a pull-up resistor (R1), a first power supply (26; 21), a first switch (SW1), and a control section (27). The communication section (22) transmits and receives the detection signal to and from the encoder (3) via a communication line (L2). The pull-up resistor (R1) is connected to the communication line (L2). The first switch (SW1) is provided in a first circuit (L7; L11, L7) that connects the first power supply (26; 21) and the pull-up resistor (R1), and turns on and off the first circuit (L7; L11, L7). The control section (27) controls the first switch (SW1).

[0143] According to this structure, the mounting and dismounting of the encoder (3) with respect to the control device (2) can be performed in a state where the first circuit (L7; L11, L7) is turned off by the first switch (SW1). Thus, it is possible to suppress a failure or a malfunction of the encoder (3) via the communication line (L2) at the time of dismounting and mounting of the encoder (3) with respect to the control device (2). More specifically, it is possible to suppress a failure or a malfunction of the encoder (3) due to a surge current flowing from the first power supply (26; 21) to the encoder (3) via the communication line (L2) at the time of mounting of the encoder (3) with respect to the control device (2), or to suppress a failure or a malfunction of the encoder (3) due to a sudden turn-off (e.g., forcible pull-out) of the communication line (L2) at the time of dismounting of the encoder (3) with respect to the control device (2).

[0144] In the control device (2) of the second mode, in the first mode, the first power supply (21) is an encoder power supply circuit (21) that supplies a power supply voltage to the encoder (3) via a power supply line (L1). The first switch (SW1) is provided in the power supply line (L1) to turn on and off the power supply line (L1).

[0145] According to this structure, the first power supply (21) can be used as both a pull-up power supply and the encoder power supply circuit (21). Further, the turning on and off of the first circuit (circuit composed of the circuits L11 and L7) and the turning on and off of the power supply line (L1) can be performed by the first switch (SW1). As a result, the number of components can be reduced. Further, the mounting and dismounting of the encoder (3) with respect to the control device (2) can be performed in a state where the power supply line (L1) is turned off by the first switch (SW1).

[0146] In the control device (2) according to the third aspect, in the first aspect, the first power supply (26) is a pull-up power supply (26) that is independent of an encoder power supply circuit (21) that supplies an encoder (3) with a power supply voltage.

[0147] According to this structure, the effect of the first aspect can be achieved in a structure in which the first power supply (26) is a pull-up power supply (26) that is independent of the encoder power supply circuit (21).

[0148] The control device (2) according to the fourth aspect further includes the encoder power supply circuit (21) and a second switch (SW2) in the control device (2) according to the third aspect. The second switch (SW2) turns on and off a power supply line (L1) that connects the encoder power supply circuit (21) and the encoder (3). The control section (27) further controls the second switch (SW2).

[0149] According to this structure, the encoder (3) can be attached to and detached from the control device (2) in a state in which the power supply line (L1) is turned off by the second switch (SW2).

[0150] The control device (2) according to the fifth aspect further includes the second switch (SW2) in the control device (2) according to the fourth aspect. In a case in which the encoder (3) is detached from the control device (2), the control section (27) turns off the power supply line (L1) by the second switch (SW2) after turning off the first circuit (L7) by the first switch (SW1).

[0151] According to this structure, it is possible to suppress a failure or a defect of the encoder (3) in a case in which the encoder (3) is detached from the control device (2).

[0152] The control device (2) according to the sixth aspect further includes the first switch (SW1) in the control device (2) according to the fourth or fifth aspect. In a case in which the encoder (3) is attached to the control device (2), the control section (27) turns on the first circuit (L7) by the first switch (SW1) after turning on the power supply line (L1) by the second switch (SW2).

[0153] According to this structure, it is possible to suppress a failure or a defect of the encoder (3) in a case in which the encoder (3) is attached to the control device (2).

[0154] The control device (2) according to the seventh aspect further includes the communication section (22) in the control device (2) according to the fifth aspect. In a case in which the encoder (3) is detached from the control device (2), the control section (27) turns off the first circuit (L7) by the first switch (SW1) after switching the communication section (22) to the reception mode.

[0155] According to this structure, in the case of detaching the encoder (3) from the control device (2), it is possible to suppress the application of voltage to the communication line (L2) by the transmission mode of the communication section (22) in a state where the power supply line (L1) is cut off by the second switch (SW2) and thus the power supply to the encoder (3) is cut off. Thus, it is possible to suppress the malfunction or the bad condition of the encoder (3).

[0156] In the control device (2) according to the eighth aspect, the communication section (22) is capable of switching between the transmission mode and the reception mode in the sixth aspect. In the case of attaching the encoder (3) to the control device (2), the control section (27) switches the communication section (22) to the transmission mode or the reception mode after turning on the first circuit (L7) by the first switch (SW1).

[0157] According to this structure, in the case of attaching the encoder (3) to the control device (2), it is possible to suppress the application of voltage to the communication line (L2) by the transmission mode of the communication section (22) in a state where the power supply line (L1) is cut off by the second switch (SW2) and thus the power supply to the encoder (3) is cut off. Thus, it is possible to suppress the malfunction or the bad condition of the encoder (3).

[0158] In the control device (2) according to the ninth aspect, the control section (27) controls the first switch (SW1), the second switch (SW2), and the switching of the transmission mode or the reception mode of the communication section (22) based on the trigger signal from the external device (7) in any one of the fourth to eighth aspects.

[0159] According to this structure, it is possible to control the first switch (SW1), the second switch (SW2), and the switching of the transmission mode or the reception mode of the communication section (22) based on the trigger signal from the external device (7). Thus, it is possible to control the first switch (SW1) by remote operation.

[0160] The control device (2) according to the tenth aspect further includes an operation section (8) that receives an operation for outputting a trigger signal in any one of the fourth to eighth aspects. The control section (27) controls the first switch (SW1), the second switch (SW2), and the switching of the transmission mode or the reception mode of the communication section (22) based on the trigger signal from the operation section (8).

[0161] According to this structure, it is possible to control the first switch (SW1), the second switch (SW2), and the switching of the transmission mode or the reception mode of the communication section (22) by the input operation to the operation section (8).

[0162] The 11th aspect relates to the control device (2) in any one of the first to eighth aspects, further including a first connector (9) and a detection section (11). The first connector (9) is detachably connected to a second connector (10) connected to the encoder (3). The detection section (11) detects attachment and detachment of the first connector (9) to and from the second connector (10). The control section (27) controls the first switch (SW1) based on a detection result of the detection section (11).

[0163] According to this structure, the first switch (SW1) can be automatically controlled by attachment and detachment of the first connector (9) to and from the second connector (10) (i.e., attachment and detachment of the control device (2) to and from the encoder (3)).

[0164] In the control device (2) of the twelfth aspect, in the eleventh aspect, the second connector (10) has a pair of second terminals (M11, M12) that are short-circuited to each other. The detection section (11) has a pair of first terminals (M5, M6) and a second power supply (28). The pair of first terminals (M5, M6) is provided to the first connector (9) and is detachably connected to the pair of second terminals (M11, M12) by connection of the first connector (9) to the second connector (10). The second power supply (28) is connected to one of the pair of first terminals (M5, M6) and a signal input section (27a) of the control section (27) via a resistor (R7). The other of the pair of first terminals (M5, M6) is connected to a ground. The detection section (11) changes an input voltage to the signal input section (27a) of the control section (27) according to attachment and detachment of the first connector (9) to and from the second connector (10).

[0165] According to this structure, the detection section (11) can be configured by a simple structure.

[0166] In the control device (2) of the thirteenth aspect, in the ninth or tenth aspect, the motor (4) is a 3-phase AC motor. The control device (2) includes an inverter (24) and at least one short-circuit switch (SW3 to SW5). The inverter (24) supplies 3-phase AC current to the motor (4) via three power supply lines (L4 to L6). The at least one short-circuit switch (SW3 to SW5) is provided to at least one of the three power supply lines (L4 to L6) and is turned on and off between the provided power supply line and a ground. The control section (27) controls the short-circuit switch (SW3 to SW5) based on a trigger signal.

[0167] According to this structure, the short-circuiting switch (SW3 to SW5) constitutes a dynamic brake of the motor (4). Thus, a dynamic brake can be applied to the motor (4) by a trigger signal from the external device (7) or the operation section (8). As a result, the discharge time of the motor (4) is shortened, and thus the time taken for the motor (4) to be detached from the control device (2) can be shortened. This is particularly effective for a structure in which the encoder (3) and the motor (4) are integrated.

[0168] The control system (1) according to the fourteenth aspect includes the control device (2) according to any one of the first to thirteenth aspects, the encoder (3), and the motor (4).

[0169] According to this structure, the control system (1) including the control device (2) can be provided.

[0170] Industrial Applicability

[0171] According to the control device and the control system of the present disclosure, it is possible to suppress a failure or a defect of the encoder via the communication line at the time of detachment and the time of attachment of the encoder with respect to the control device. Thus, the control device and the control system of the present disclosure are industrially useful.

[0172] Explanation of Reference Signs

[0173] 1 Control system

[0174] 2 Control device

[0175] 3 Encoder

[0176] 4 Motor

[0177] 7 External device

[0178] 8 Trigger button

[0179] 9 First connector

[0180] 10 Second connector

[0181] 11 Detection section

[0182] 26 Pull-up power supply (first power supply)

[0183] 21 Encoder power supply circuit (first power supply)

[0184] 22 Communication section

[0185] 24 Inverter

[0186] 27 Control section

[0187] 27a, 27b Signal input section

[0188] 33 Communication section

[0189] L1 power supply line

[0190] L2, L3 communication line

[0191] L4 to L6 power supply line

[0192] L7, L8, L11, L13, L21, L23, L31, L33, L41, L51, L61 circuit

[0193] M5, M6 first terminal

[0194] M11, M12 second terminal

[0195] R1, R4 pull-up resistor

[0196] R2, R5 terminal resistor

[0197] R3, R6 pull-down resistor

[0198] R7 resistor

[0199] SW1 first switch

[0200] SW2 second switch

[0201] SW3 first short-circuiting switch

[0202] SW4 second short-circuiting switch

[0203] SW5 third short-circuiting switch

Claims

1. A control device that controls a motor based on a detection signal of an encoder that detects a movement position of the motor, the control device including: a communication section that transmits and receives the detection signal to and from the encoder via a communication line; a pull-up resistor connected to the communication line; a first power supply; a first switch provided in a first circuit that connects the first power supply and the pull-up resistor, and that turns on and off the first circuit; and a control section that controls the first switch.

2. The control device according to claim 1, wherein the first power supply is an encoder power supply circuit that supplies a power supply voltage to the encoder via a power supply line, the first switch is provided in the power supply line to turn on and off the power supply line.

3. The control device according to claim 1, wherein the first power supply is a power supply for pull-up that is independent of an encoder power supply circuit that supplies a power supply voltage to the encoder.

4. The control device according to claim 3, wherein the control device further includes: the encoder power supply circuit; and a second switch that turns on and off a power supply line that connects the encoder power supply circuit and the encoder, the control section further controls the second switch.

5. The control device according to claim 4, wherein in a case where the encoder is detached from the control device, the control section turns off the first circuit by the first switch after turning off the power supply line by the second switch.

6. The control device according to claim 4 or 5, wherein in a case where the encoder is attached to the control device, the control section turns on the first circuit by the first switch after turning on the power supply line by the second switch.

7. The control device according to claim 5, wherein the communication section is capable of switching between a transmission mode and a reception mode, in a case where the encoder is detached from the control device, the control section turns off the first circuit by the first switch after switching the communication section to the reception mode.

8. The control device according to claim 6, wherein the communication section is capable of switching between a transmission mode and a reception mode, in a case where the encoder is attached to the control device, the control section switches the communication section to the transmission mode or the reception mode after turning on the first circuit by the first switch.

9. The control device according to any one of claims 4 to 8, wherein the control section controls the first switch, the second switch, and the switching of the transmission mode or the reception mode of the communication section based on a trigger signal from an external device.

10. The control device according to any one of claims 4 to 8, wherein the control device further includes an operation section that receives an operation for outputting a trigger signal, the control section controls the first switch, the second switch, and the switching of the transmission mode or the reception mode of the communication section based on the trigger signal from the operation section.

11. The control device according to any one of claims 1 to 8, wherein the control device includes: a first connector that is detachably connected to a second connector of the encoder; and a detection section that detects detachment of the first connector from the second connector, and the control section controls the first switch based on a detection result of the detection section.

12. The control device according to claim 11, wherein the second connector has a pair of second terminals that are short-circuited to each other, the detection section includes: a pair of first terminals that are provided to the first connector and are detachably connected to the pair of second terminals by connection of the first connector to the second connector; and a second power supply that is connected to one of the pair of first terminals and a signal input section of the control section via a resistor, the other of the pair of first terminals is connected to a ground, and the detection section changes an input voltage to the signal input section of the control section according to detachment of the first connector from the second connector.

13. The control device according to claim 9 or 10, wherein the motor is a 3-phase AC motor, the control device includes: an inverter that supplies 3-phase AC current to the motor via 3 power supply lines; and at least one short-circuit switch that is provided to at least one of the 3 power supply lines and that conducts and interrupts between the provided power supply line and a ground, and the control section controls the short-circuit switch based on the trigger signal.

14. A control system including: the control device according to any one of claims 1 to 13; the encoder; and the motor. ​ ​

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