CN108372504B - Control device - Google Patents

Abstract

The present invention relates to a control device capable of limiting a function of an emergency stop when an operation panel is detached and stably performing control of a load. The control device includes a connection portion for detachably connecting an operation panel having a normally closed first contact for stopping an operation of a load, and an instruction portion for instructing disengagement of the operation panel, and controls the load by an instruction from the operation panel. The connecting portion includes a first terminal for connection to the first contact and a second terminal for connection to a signal line for detecting a connection state of the operation panel. The control device does not restrict the operation of the load when the operation panel is in the disconnected state and the instruction section instructs the operation panel to be disconnected. The control device limits the operation of the load when the operation panel is in the connection state and the instruction of the instruction part to the operation panel is given.

Description

Control device

Technical Field

The present invention relates to a control device for controlling an operation of a load.

Background

The following control devices are well known: the operation of a load including a power source, a display device, and the like is controlled by operating a detachable operation panel. The control device sometimes has the following functions: when an operation panel of an emergency stop switch having a B contact is disengaged, the power source is brought to an emergency stop. Japanese patent laid-open No. 1993-42493 discloses a robot control device capable of disabling an emergency stop of a robot when an operation panel is detached. In this robot control device, when the operation panel is detached in a state where the attachment/detachment switch is turned off, the robot is urgently stopped, and when the operation panel is detached in a state where the attachment/detachment switch is turned on, the urgent stop of the robot is invalidated.

In the robot control device, the emergency stop is invalidated even if the operation panel is in the attached state during a period from the turning on of the attachment/detachment switch to the disengagement of the operation panel. When the user turns on the emergency stop switch during this period, the robot control device cannot perform emergency stop of the robot. Therefore, the robot control device may not stably perform the control of the robot.

Disclosure of Invention

The invention aims to provide a control device which can limit the function of emergency stop when an operation panel is separated and can stably execute the control of a load.

A control device according to claim 1 is a control device including a connection portion configured to detachably connect an operation panel having a normally closed first contact for stopping an operation of a load, and an instruction portion configured to instruct detachment of the operation panel, the control device being configured to control the load by an instruction from the operation panel, the connection portion including a first terminal configured to be connected to the first contact and a second terminal configured to be connected to a signal line configured to detect a connection state of the operation panel, the control device including: a first control unit that stops an operation of the load when the operation panel is in an unconnected state without a disconnection instruction from the instruction unit to the operation panel, or when an operation of the first contact is detected via the first terminal when the operation panel is in a connected state without a disconnection instruction from the instruction unit to the operation panel; a second control unit that does not restrict the operation of the load when the operation panel is in an unconnected state in response to a disconnection instruction from the instruction unit to the operation panel; and a third control unit that restricts an operation of the load when the instruction unit instructs the operation panel to be disconnected and the operation panel is in the connected state.

The control device does not restrict the operation of the load when the operation panel is in the disconnected state and the instruction section instructs the operation panel to be disconnected. Therefore, even if the operation panel is not connected, the user can continue to operate the load by the control device. The control device limits the operation of the load when the operation panel is in the connection state and the instruction of the instruction part to the operation panel is given. In this case, when the control device restricts the operation of the load, it is possible to suppress the occurrence of an event that becomes a factor for stopping the load. Therefore, when the instruction section instructs the operation panel to disengage, the control device can control the load in a stable state even if the load stop function is disabled.

The control device according to claim 2 may further include a first switching unit that switches between enabling and disabling the operation of the first contact, wherein the first switching unit enables the operation of the first contact before the third control unit restricts the operation of the load, and the first switching unit disables the operation of the first contact after the third control unit restricts the operation of the load. The control device enables the operation of the first contact point until the operation of the load is limited. Therefore, the control device can stop the load according to the operation of the first contact. After the control device limits the operation of the load, the operation of the first contact is invalidated. The control device can disable the stop function of the load according to the operation of the first contact in a state where the operation of the load is restricted.

In the control device according to claim 3, the first switching unit may disable the operation of the first contact until a predetermined time elapses after the third control unit restricts the operation of the load, and the first switching unit may enable the operation of the first contact after the predetermined time elapses. In this case, the control device can limit the period during which the stop function of the load according to the operation of the first contact is disabled.

The control device according to claim 4 to 6 may further include: a limiting unit that limits an operation of the load; and a second switching unit that switches whether the limiting unit is to be enabled or disabled, wherein the second control unit does not limit the operation of the load when the limiting unit is disabled by the second switching unit, and the third control unit limits the operation of the load when the limiting unit is enabled by the second switching unit. In this case, the control device can easily switch between the case of limiting the operation of the load and the case of not limiting the operation of the load by the limiting unit.

The control device according to claim 7 or 8 may be configured such that the first switching unit switches between enabling and disabling a bypass circuit that bypasses the first contact, thereby switching between enabling and disabling the operation of the first contact. In this case, the first switching unit can easily switch whether the operation of the first contact is to be enabled or disabled by the bypass circuit.

The control device according to claim 9 may be configured such that the second terminal includes a first side connection terminal and a second side connection terminal, and the connection state of the operation panel can be detected by the first side connection terminal when a first distance is provided between the connection portion and the operation panel, the first terminal is connected to the first contact when a second distance shorter than the first distance is provided between the connection portion and the operation panel, and the connection state of the operation panel can be detected by the second side connection terminal when a third distance shorter than the second distance is provided between the connection portion and the operation panel. In this case, the control device can limit the period during which the operation of the first contact is disabled to a period during which the operation panel is connected to the connection portion.

The control device according to claim 10 may be configured such that the second control unit enables a plurality of operation commands to the load, and the third control unit disables at least one of the plurality of operation commands. In this case, the control device can suppress the occurrence of an event that causes an emergency stop by controlling the operation of the load by the third control unit. Therefore, the control device can safely control the load.

Drawings

Fig. 1 is a block diagram of a control device 1A.

Fig. 2 is a diagram showing a connection relationship between the first contact 71, the second contact 81, and the indicator 2.

Fig. 3 is a diagram of an operation mode of the control device 1A.

Fig. 4 is a flowchart of the first main process.

Fig. 5 is a flowchart of the second main process.

Fig. 6 is a block diagram of the control device 1B.

Fig. 7 is a diagram of an operation mode of the control device 1B.

Fig. 8 is a block diagram of a modification of the control device 1B.

Fig. 9 is a block diagram of the control device 1C.

Fig. 10 is a diagram of the connection portion 3 and the connector 76.

Fig. 11 is a flowchart of the third main process.

Detailed Description

< first embodiment >

As shown in fig. 1 to 3, the control device 1A controls the operation of the load 9. A specific example of the load 9 is a motor. The motor includes a motor for rotating a tool of a machine tool, a motor for moving a workpiece, and the like. The load 9 is not limited to a motor, and may be, for example, a high-pressure turbine, a high-voltage device, a welding machine using high heat, a melting furnace, or the like. The user operates an operation panel 8 provided in the control device 1A, and controls the operation of the load 9 via the control device 1A. The control device 1A connects the operation panel 7A in a detachable manner. The user can operate the operation panel 7A connected to the control device 1A, and the operation of the load 9 is controlled by the control device 1A. The control device 1A includes an instruction unit 2, a connection unit 3, a first switching unit 4, a control unit 5, and an operation panel 8. The operation panel 7A includes a first contact 71 and a communication circuit 72.

The instruction unit 2 includes normally open switches 2A, 2B, and 2C. The switches 2A, 2B, and 2C are switched to any one of the on/off states in conjunction with each other. The switch 2A is connected to the first terminal 31A of the connection unit 3 via the switch 4A of the first switching unit 4. The switch 2B is connected to the first terminal 31B of the connection unit 3 via the switch 4B of the first switching unit 4. One end of the switch 2C is connected to the reference potential 10 of the control device 1A, and the other end is connected to the CPU51 and the state monitoring unit 52. When the user does not instruct the operation panel 7A to be detached, the user does not operate the instructing section 2. At this time, the switches 2A, 2B, and 2C of the indicating section 2 are in a non-conductive state. The switches 2A, 2B, and 2C are in the non-conduction state and are referred to as "the indicating section 2 is turned off". When the user instructs the operation panel 7A to disengage, the user operates the instructing section 2. At this time, switches 2A, 2B, and 2C of indicator 2 are turned on. The on state of the switches 2A, 2B, and 2C is referred to as "the indicating section 2 is turned on". The reason why the indicating unit 2 includes the switches 2A, 2B, and 2C is to accurately detect the state of the indicating unit 2 in a redundant manner.

The first switching unit 4 includes switches 4A and 4B. The switch 4A is interposed between the switch 2A and the first terminal 31A. The switch 4B is interposed between the switch 2B and the first terminal 31B. The switches 4A and 4B are switched to either conductive or non-conductive states in conjunction with each other in accordance with a control signal output from the state monitoring unit 52. The state in which the switches 4A and 4B are non-conductive is referred to as "the first switching unit 4 is turned off". Turning on the switches 4A and 4B is referred to as turning on the first switching unit 4.

The operation panel 8 is connected to the control device 1A so as not to be detachable. The operation panel 8 includes a second contact 81. The second contact 81 has normally closed switches 81A and 81B. The switches 81A and 81B are switched to either conductive or non-conductive states in conjunction with each other. When the user stops the operation of the load 9 without the control device 1A, the user does not operate the second contact 81. At this time, the switches 81A and 81B are turned on. When the user urgently stops the operation of the load 9 by the control device 1A, the user operates the second contact 81. At this time, the switches 81A and 81B are in a non-conductive state. The reason why the second contact 81 has the switches 81A, 81B is to accurately detect the state of the second contact 81 in a redundant manner.

Unlike the operation panel 8 described above, the operation panel 7A is detachably connected to the connection portion 3. The operation panel 7A includes a first contact 71 and a communication circuit 72.

The first contact 71 has normally closed switches 71A and 71B. The switches 71A and 71B are switched to either conductive or non-conductive states in conjunction with each other. When the user stops the operation of the load 9 without the control device 1A, the user does not operate the first contact 71. At this time, the switches 71A and 71B are turned on. When the user urgently stops the operation of the load 9 by the control device 1A, the user operates the first contact 71. At this time, the switches 71A and 71B are in a non-conductive state. The reason why the first contact 71 has the switches 71A, 71B is to accurately detect the state of the first contact 71 in a redundant manner.

The communication circuit 72 is an element for communicating with the control device 1A. The communication circuit 72 has an output terminal 72A and an input terminal 72B. The communication circuit 72 can output an operation command of the load 9 to the control device 1A via the output terminal 72A. The communication circuit 72 can detect a command output from the control device 1A via the input terminal 72B.

The connection portion 3 is a tool for detachably connecting the operation panel 7A. The connection portion 3 includes first terminals 31A and 31B (collectively referred to as first terminals 31), second terminals 32A and 32B (collectively referred to as second terminals 32), and third terminals 33A and 33B (collectively referred to as third terminals 33). A state in which the operation panel 7A is connected to the connection unit 3 is referred to as a "connected state", and a state in which the operation panel 7A is not connected to the connection unit 3 is referred to as an "unconnected state".

When the operation panel 7A is in the connected state, the first terminal 31A is connected to the switch 71A of the first contact 71 of the operation panel 7A. When the operation panel 7A is in the connected state, the first terminal 31B is connected to the switch 71B of the first contact 71 of the operation panel 7A. One end of each of the first terminals 31A and 31B is connected to the reference potential 10 of the control device 1A.

The second terminal 32 and the third terminal 33 are connected to the state monitoring unit 52. When the operation panel 7A is in the connected state, the second terminals 32A, 32B are connected to the reference potential 70 of the operation panel 7A via signal lines. Therefore, when the operation panel 7A is in the connected state, the reference potential 70 of the operation panel 7A is connected to the state monitoring unit 52. When the operation panel 7A is in the connected state, the third terminal 33A is connected to the output terminal 72A of the communication circuit 72. When the operation panel 7A is in the connected state, the third terminal 33B is connected to the input terminal 72B of the communication circuit 72. Therefore, when the operation panel 7A is in the connected state, the communication circuit 72 is connected to the state monitoring unit 52.

The control unit 5 includes a CPU51, a state monitoring unit 52, an emergency stop circuit 53, and a storage unit 54. The CPU51 controls the entire operation of the control device 1A. The CPU51 is connected to the state monitoring unit 52, the emergency stop circuit 53, the storage unit 54, the switch 2C, and the load 9. The CPU51 can detect on/off of the instruction section 2 by means of the switch 2C. When the operation panel 7A is in the connected state, the CPU51 can control the operation of the load 9 based on the operation command received from the operation panel 7A via the state monitoring unit 52. When the operation panel 7A is in the disconnected state, the CPU51 can control the operation of the load 9 in accordance with the operation command stored in the storage unit 54.

The state monitoring unit 52 is connected to the switch 2C and can detect on/off of the instruction unit 2. The state monitoring unit 52 is connected to the second terminal 32 and can detect the connection state of the operation panel 7A. That is, the state monitoring unit 52 determines that the operation panel 7A is in the connected state when the second terminal 32 is at the reference potential 70, and determines that the operation panel 7A is in the unconnected state when the second terminal 32 is not at the reference potential 70. The state monitoring unit 52 is connected to the third terminal 33 and can communicate with the operation panel 7A in the connected state. The state monitoring unit 52 transmits the operation command received from the operation panel 7A to the CPU 51. The state monitoring unit 52 is connected to the first switching unit 4. The state monitoring unit 52 can output a control signal to the first switching unit 4 to switch the first switching unit 4 on/off.

The emergency stop circuit 53 is connected to the second contact 81 of the operation panel 8, and can detect the conductive state of the second contact 81. When the operation panel 7A is in the connected state, the emergency stop circuit 53 is connected to the first contact 71 of the operation panel 7A, and the conductive state of the first contact 71 can be detected, which will be described in detail later. The emergency stop circuit 53 is connected to the load 9. The emergency stop circuit 53 can stop the supply of power to the load 9 in accordance with the states of the first contact 71 and the second contact 81, thereby emergency-stopping the operation of the load 9. The storage unit 54 stores a program executed by the CPU51 and a plurality of operation commands for controlling the load 9.

The connection relationship among the instructing unit 2, the first contact 71, the first switching unit 4, the second contact 81, and the emergency stop circuit 53 will be described with reference to fig. 2. When the operation panel 7A is in the connected state, the first contact 71 and the second contact 81 are connected in series, and the indicating section 2 and the first contact 71 are connected in parallel via the first switching section 4.

The connection relationship when the operation panel 7A is in the connected state will be described with reference to (a) to (d) of fig. 2. In any case of (a) turning on the indicating section 2 and turning off the first switching section 4, (b) turning off the indicating section 2 and turning on the first switching section 4, and (c) turning off the indicating section 2 and turning off the first switching section 4, that is, when at least one of the indicating section 2 and the first switching section 4 is turned off, the indicating section 2 and the first switching section 4 do not bypass the first contact 71. At this time, the first contact 71 and the second contact 81 are connected in series and interposed between the emergency stop circuit 53 and the reference potential 10. When the user does not operate the first contact 71 and the second contact 81, the first contact 71 and the second contact 81 are in a conductive state, and the emergency stop circuit 53 and the reference potential 10 are in a conductive state. Therefore, the emergency stop circuit 53 detects the reference potential 10. When the user operates at least one of the first contact 71 and the second contact 81, at least one of the first contact 71 and the second contact 81 operated by the user is in a non-conductive state, and the emergency stop circuit 53 and the reference potential 10 are in a non-conductive state. Therefore, the emergency stop circuit 53 does not detect the reference potential 10.

The emergency stop circuit 53 does not cause the operation of the load 9 to be stopped urgently when the reference potential 10 is detected, and causes the operation of the load 9 to be stopped urgently when the reference potential 10 is not detected. Therefore, when at least one of the instructing unit 2 and the first switching unit 4 is turned off ((a) to (c) of fig. 2), the operation of the first contact 71 and the second contact 81 is enabled to emergency stop the load 9, and the emergency stop circuit 53 emergency stops the operation of the load 9.

When the indicating section 2 is turned on and the first switching section 4 is turned on (d), the indicating section 2 and the first switching section 4 bypass the first contact 71. When the user does not operate the second contact 81, the emergency stop circuit 53 is connected to the reference potential 10 via the indicating section 2, the first switching section 4, and the second contact 81. Even if the user operates the first contact 71 and the first contact 71 becomes non-conductive, the emergency stop circuit 53 is connected to the reference potential 10 via the indicating section 2, the first switching section 4, and the second contact 81. The emergency stop circuit 53 cannot detect the operation of the first contact 71. When the user does not operate the second contact 81, the second contact 81 is in a conductive state, and the emergency stop circuit 53 detects the reference potential 10. When the user operates the second contact 81, the second contact 81 is in a non-conductive state, and the emergency stop circuit 53 does not detect the reference potential 10. Therefore, when the instructing unit 2 and the first switching unit 4 are turned on (fig. 2 (d)), the operation of the first contact 71 for emergency stop of the load 9 is disabled, and the emergency stop circuit 53 does not emergency stop the operation of the load 9. The emergency stop circuit 53 enables the operation of the second contact 81 to emergency stop the load 9, and thus the operation of the load 9 is emergency stopped.

As described above, the first switching unit 4 can switch whether to validate or invalidate the operation performed on the first contact 71 in the state where the instruction unit 2 is turned on.

The connection relationship when the operation panel 7A is in the unconnected state will be described with reference to (e) to (h) of fig. 2. When the operation panel 7A is in the unconnected state, the first terminal 31 is always in the non-conductive state. At this time, when any of the instruction section 2 is on, the first switching section 4 is off (e), the instruction section 2 is off, the first switching section 4 is on (f), and the instruction section 2 is off, and the first switching section 4 is off (g), that is, when at least one of the instruction section 2 and the first switching section 4 is off, the emergency stop circuit 53 and the reference potential 10 are always in a non-conductive state. Therefore, the emergency stop circuit 53 does not always detect the reference potential 10 regardless of the operation of the second contact 81. Therefore, when at least one of the instructing unit 2 and the first switching unit 4 is turned off (fig. 2 (e) to (g)), the emergency stop circuit 53 emergently stops the operation of the load 9.

When the indicating section 2 is turned on and the first switching section 4 is turned on (h), the indicating section 2 and the first switching section 4 bypass the first terminal 31. At this time, the emergency stop circuit 53 is connected to the reference potential 10 via the indicating unit 2, the first switching unit 4, and the second contact 81. When the user does not operate the second contact 81, the second contact 81 is in a conductive state, and the emergency stop circuit 53 detects the reference potential 10. When the user operates the second contact 81, the second contact 81 is in a non-conductive state, and the emergency stop circuit 53 does not detect the reference potential 10. Therefore, when the instructing unit 2 and the first switching unit 4 are turned on ((h) of fig. 2), the operation of the second contact 81 is enabled, and the emergency stop circuit 53 emergently stops the operation of the load 9.

< operation mode >

An operation mode when the control device 1A controls the operation of the load 9 will be described with reference to fig. 3. The CPU51 drives the operation panel in an operation mode according to the presence or absence of a disconnection instruction from the instruction unit 2 to the operation panel 7A and the connection/disconnection of the operation panel 7A, and controls the operation of the load 9. When the user instructs the operation panel 7A to disengage, the user operates the instructing unit 2. At this time, the indicating section 2 is turned on. When the user does not instruct the operation panel 7A to be detached, the user does not operate the instructing section 2. At this time, the indicating section 2 is turned off. Therefore, the CPU51 controls the operation of the load 9 by driving in an operation mode according to the on/off state of the instruction unit 2 and the connected/disconnected state of the operation panel 7A.

The CPU51 regulates the operation of the load 9 when the instruction unit 2 is turned on (there is an instruction to disconnect the operation panel 7A) and the operation panel 7A is in the connected state (see fig. 2 (a) and (d)). That is, the CPU51 invalidates at least a part of the plurality of operation commands of the load 9 received from the communication circuit 72 of the operation panel 7A via the third terminal 33. The operation mode of the control device 1A at this time is referred to as a restricted mode.

The CPU51 does not restrict the operation of the load 9 when the instruction unit 2 is off (no instruction to detach the operation panel 7A is given) and the operation panel 7A is in the connected state (see fig. 2 (b) and (c)). That is, the CPU51 validates all of the plurality of operation commands of the load 9 received from the communication circuit 72 of the operation panel 7A via the third terminal 33. The operation mode of the control device 1A at this time is referred to as a normal mode.

The CPU51 does not restrict the operation of the load 9 when the instruction unit 2 is turned on (there is an instruction to disconnect the operation panel 7A) and the operation panel 7A is in the unconnected state (see fig. 2 (e) and (h)). That is, the CPU51 validates all of the plurality of operation commands of the load 9 stored in the storage unit 54. The operation mode of the control device 1A at this time is the normal mode.

When the instruction unit 2 is turned off (no instruction to detach the operation panel 7A is given) and the operation panel 7A is in the unconnected state (see (f) and (g) of fig. 2), the CPU51 causes the emergency stop circuit 53 to emergency-stop the operation of the load 9. The operation mode of the control device 1A at this time is referred to as an emergency stop mode. When the operation of the control device 1A is changed to the emergency stop mode, the operation is not returned to the other operation modes (normal mode and restricted mode).

< first Main treatment >

The first main process executed by the CPU51 is explained with reference to fig. 4. The CPU51 executes the program stored in the storage unit 54 to repeatedly execute the first main process at a predetermined cycle (for example, 1ms cycle).

The CPU51 determines whether or not the instruction section 2 is on using the switch 2C (S11). When determining that the instruction unit 2 is on (there is a disengagement instruction of the operation panel 7A) (S11: "yes") (see (a), (d), and (h) of fig. 2), the CPU51 advances the process to S13. When the indicator 2 is off (S11: no) and the operation panel 7A is in the unconnected state (S23: no), the CPU51 drives in the emergency stop mode in S27 described later, which will be described in detail later. As described above, the operation mode of the control device 1A is not returned from the emergency stop mode to the normal mode. Therefore, in S21 described later, the first switching unit 4 is not turned off, and thus the state in fig. 2 (e) is not obtained.

The CPU51 communicates with the state monitoring unit 52, and acquires information indicating the connected/disconnected state of the operation panel 7A detected by the state monitoring unit 52. The CPU51 determines whether the operation panel 7A is in the connected state based on the acquired information (S13). When determining that the operation panel 7A is in the connected state (S13: yes) (see (a) and (d) of fig. 2), the CPU51 drives in the restriction mode to restrict the operation of the load 9 (S15). The CPU51 advances the process to S19. The CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning on the first switching unit 4 from the state monitoring unit 52 (S19). At this time, the first switching unit 4 is turned on (see fig. 2 (d)). The indicating section 2 and the first switching section 4 bypass the first contact 71, and therefore the operation of the first contact 71 is invalidated. Therefore, even if the user operates the first contact 71 to urgently stop the operation of the load 9, the emergency stop circuit 53 does not urgently stop the operation of the load 9. The CPU51 ends the first main process.

When determining that the operation panel 7A is not connected (S13: "no") (see fig. 2 (h)), the CPU51 drives in the normal mode without restricting the operation of the load 9 (S17). At this time, operation panel 7A is changed from the connected state (S13: YES) to the unconnected state (S13: NO) in the state where indicator 2 is on (S11: YES), and thus first switching section 4 is on in S19. Therefore, the state shown in fig. 2 (e) is not obtained, and therefore the emergency stop circuit 53 can emergency stop the load 9 when the user operates the second contact 81. The CPU51 advances the process to S19.

The CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning on the first switching unit 4 from the state monitoring unit 52 (S19). At this time, the first switching unit 4 is turned on (see fig. 2 (h)). The CPU51 ends the first main process.

When determining that the instruction unit 2 is in the off state (no instruction to disengage the operation panel 7A is issued) (S11: "no"), the CPU51 advances the process to S21 (see fig. 2 (b), (c), (f), and (g)). The CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning off the first switching unit 4 from the state monitoring unit 52 (S21). At this time, the first switching unit 4 is turned off (see (c) and (g) of fig. 2). The CPU51 communicates with the state monitoring unit 52, and acquires information indicating the connected/disconnected state of the operation panel 7A detected by the state monitoring unit 52. The CPU51 determines whether the operation panel 7A is in the connected state based on the acquired information (S23). When determining that the operation panel 7A is in the connected state (S23: yes) (see fig. 2 (c)), the CPU51 drives in the normal mode without limiting the operation of the load 9 (S25). At this time, the indicating section 2 and the first switching section 4 do not bypass the first contact 71, and therefore, the operation of the first contact 71 is effective. Therefore, when the user operates the first contact 71 to urgently stop the operation of the load 9, the emergency stop circuit 53 urgently stops the operation of the load 9. The CPU51 ends the first main process.

When determining that the operation panel 7A is in the unconnected state (S23: no) (see fig. 2 (g)), the CPU51 drives in the emergency stop mode. At this time, the emergency stop circuit 53 emergently stops the operation of the load 9 (S27). The CPU51 ends the first main process.

< actions and effects of the first embodiment >

When the instruction section 2 issues an instruction to disconnect the operation panel 7A (S11: yes) and the operation panel 7A is in the disconnected state (S13: no), the CPU51 of the control device 1A drives the operation panel in the normal mode and does not restrict the operation of the load 9 (S17). At this time, all the operation commands of the load 9 are valid. The CPU51 can bypass the first terminal 31 by the instructing unit 2 and the first switching unit 4 by turning on the first switching unit 4 (S19). Therefore, even if the operation panel 7A is in the disconnected state, the emergency stop function of the emergency stop circuit 53 is disabled, and the user can continue to operate the load 9 by using the control device 1A.

When the operation panel 7A is in the connected state (S13: yes) in response to the instruction of the instruction unit 2 to disengage the operation panel 7A (S11: yes), the CPU51 drives in the restricted mode to restrict the operation of the load 9 (S15). At this time, at least a part of the operation command of the load 9 is invalidated, and therefore, occurrence of an event which becomes a factor for stopping the load 9 can be suppressed. Therefore, when the instruction section 2 issues an instruction to disengage the operation panel 7A, the control device 1A can control the load 9 in a stable state.

After driving in the restricted mode (S15), the CPU51 turns on the first switching unit 4(S19) to bypass the first contact 71 ((d) of fig. 2). At this time, the operation of the first contact 71 is invalidated, and the emergency stop circuit 53 does not emergency-stop the operation of the load 9 even if the user operates the first contact 71. When the operation panel 7A is changed from the connected state to the unconnected state while being driven in the restricted mode, the first terminal 31 is in the non-conductive state. However, since the first switching unit 4 is turned on to bypass the first terminal 31 ((h) of fig. 2), the emergency stop circuit 53 does not detect the non-conductive state of the first terminal 31. Therefore, even if the operation panel 7A is disengaged during the driving in the restricted mode, the emergency stop circuit 53 does not emergency-stop the operation of the load 9. Therefore, when the control device 1A is driven in the restricted mode, even if the user operates the first contact 71 of the operation panel 7A or the operation panel 7A is disengaged, the operation of the load 9 is not stopped urgently.

While the CPU51 is driven in the restricted mode and the operation of the load 9 is restricted (S15), the first switch 4 is turned off (S21) to disable the bypass of the first contact 71 (fig. 2 a), thereby enabling the operation of the first contact 71. Therefore, the emergency stop circuit 53 can stop the load 9 in accordance with the operation of the first contact 71 until the operation of the load 9 is limited (S15). After the CPU51 drives in the restricted mode to restrict the operation of the load 9 (S15), the first switch 4 is turned on (S19) to bypass the first contact 71 (fig. 2 (d)), thereby invalidating the operation of the first contact 71. Therefore, the control device 1A can disable the stop function of the load 9 according to the operation of the first contact 71 in a state where the operation of the load 9 is restricted.

When the instruction section 2 does not give an instruction to disengage the operation panel 7A (S11: no), the CPU51 turns off the first switching section 4(S21) and does not bypass the first contact 71 ((c) of fig. 2). At this time, the operation of the first contact 71 is effective. Therefore, when the operation panel 7A is driven in the normal mode while being in the connected state (S25), the emergency stop circuit 53 can emergency-stop the operation of the load 9 in accordance with the operation of the first contact 71. When the operation panel 7A is changed from the connected state to the disconnected state while operating in the normal mode, the first terminal 31 is in the non-conductive state. Since the first switching unit 4 is turned off and the first terminal 31 is not bypassed ((g) of fig. 2), the emergency stop circuit 53 detects a non-conductive state of the first terminal 31. Therefore, when the operation is performed in the normal mode, the emergency stop circuit 53 can emergency-stop the operation of the load 9 in response to the disengagement of the operation panel 7A.

When the user instructs the operation panel 7A to be detached by the instruction unit 2, the first switching unit 4 can easily switch between the state of bypassing the first contact 71 and the state of not bypassing the first contact 71 by turning on/off the switch.

< second embodiment >

The second embodiment is different from the first embodiment in the following respects: the CPU51 executes the second main processing instead of the first main processing. In the second main process, the period during which the first switching unit 4 is turned off is different from that in the first main process. The configuration of the control device 1A is the same as that of the first embodiment.

< second Main treatment >

The second main process executed by the CPU51 is explained with reference to fig. 5. The same processes as those of the first main process are denoted by the same reference numerals and the description is simplified. The CPU51 determines whether the instruction section 2 is on (S11). When determining that the instruction section 2 is on (there is a disengagement instruction of the operation panel 7A) (S11: yes), the CPU51 determines whether or not the operation panel 7A is in the connected state (S13). When determining that the operation panel 7A is not connected (S13: no), the CPU51 drives the operation panel in the normal mode without limiting the operation of the load 9 (S17). The CPU51 sets 0 to the timer stored in the storage unit 54 and resets it (S37). The CPU51 turns on the first switching unit 4(S19, see fig. 2 (h)).

After the prescribed period has elapsed, the CPU51 restarts the second main process. The following are exemplified: indicator 2 is turned on (S11: YES), and operation panel 7A is changed from the unconnected state to the connected state (S13: YES). At this time, the CPU51 drives the load 9 in the restricted mode (S15). The CPU51 increments the timer stored in the storage unit 54 by 1 to update the timer (S31). The CPU51 determines whether or not the value of the timer is greater than a predetermined threshold value, and determines whether or not a predetermined time has elapsed since the reset of the timer (S33). When determining that the predetermined time has not elapsed (S33: no), the CPU51 advances the process to S19. The CPU51 turns on the first switching unit 4(S19, fig. 2 (d)). The CPU51 ends the second main process. The CPU51 repeats the second main processing. When determining that the predetermined time has elapsed (S33: "YES"), CPU51 turns off first switching unit 4(S35, FIG. 2 (a)). The CPU51 ends the second main process.

When determining that the instruction unit 2 is off (S11: NO), the CPU51 drives the vehicle in the normal mode or the emergency stop mode (S25, S27). The CPU51 sets 0 to the timer to reset it (S39).

< action and Effect of the second embodiment >

The CPU51 monitors whether or not a predetermined time has elapsed since the start of driving in the restricted mode by using a timer (S33). Until the predetermined time elapses (S33: NO), the CPU51 turns on the first switching unit 4(S19) to bypass the first contact 71 ((d) of FIG. 2). At this time, the operation of the first contact 71 is disabled. Therefore, even if the user operates the first contact 71 until the predetermined time elapses after the start of the regulation mode, the emergency stop circuit 53 does not emergency-stop the operation of the load 9. After a predetermined time has elapsed (S33: "YES"), the CPU51 turns off the first switching unit 4(S35) without bypassing the first contact 71 (FIG. 2 (a)). At this time, the operation of the first contact 71 is effective. Therefore, when the user operates the first contact 71 after a predetermined time has elapsed from the start of the restricted mode, the emergency stop circuit 53 emergently stops the operation of the load 9. Therefore, the control device 1A can limit the period during which the emergency stop function is deactivated by bypassing the first contact 71 when driving in the restricted mode.

< third embodiment >

A control device 1B and an operation panel 7B according to a third embodiment will be described with reference to fig. 6 and 7. The control device 1B differs from the first embodiment in the following respects: the control device 1B further includes a second switching unit 6, and the control unit 5 further includes a regulating unit 55. The operation plate 7B is different from the first embodiment in the following respects: the operation plate 7B also has a third contact 73.

< operation panel 7B >

As shown in fig. 6, the operation panel 7B includes third contacts 73. The third contact 73 has normally open switches 73A and 73B. The switches 73A and 73B are switched to either conductive or non-conductive states in conjunction with each other. When the user makes the restriction unit 55 described later effective to restrict the operation of the load 9, the user does not operate the third contact 73. At this time, the switches 73A and 73B are in a non-conductive state. When the user invalidates the restriction of the operation of the load 9 by the restriction unit 55, the user operates the third contact 73. At this time, the switches 73A and 73B are in the on state. The reason why the third contact 73 has the switches 73A, 73B is to accurately detect the conductive state/non-conductive state of the third contact 73 in a redundant manner.

< control device 1B >

The connection portion 3 further includes fourth terminals 34A and 34B (collectively referred to as fourth terminals 34). When the operation panel 7B is in the connected state, the fourth terminal 34A is connected to the switch 73A of the third contact 73. When the operation panel 7B is in the connected state, the fourth terminal 34B is connected to the switch 73B of the third contact 73. One end of the fourth terminal 34A is connected to a switch 6A described later, and one end of the fourth terminal 34B is connected to a switch 6B described later. The other ends of the fourth terminals 34A and 34B are connected to the reference potential 10 of the control device 1B.

The second switching unit 6 is used for switching between enabling and disabling the limitation of the operation of the load 9 by the limiting unit 55 to be described later. The second switching unit 6 includes switches 6A and 6B. The switch 6A is interposed between the fourth terminal 34A of the connection portion 3 and a regulation portion 55 described later. The switch 6B is interposed between the fourth terminal 34B of the connection portion 3 and the restriction portion 55. The switches 6A and 6B are switched to either conductive or non-conductive states in conjunction with each other in accordance with a control signal output from the state monitoring unit 52. The state in which the switches 6A and 6B are non-conductive is referred to as "the second switching unit 6 is off". The switches 6A and 6B are turned on, which is referred to as "the second switching unit 6 is turned on".

The limiting unit 55 limits the operation of the load 9 according to the state of the input terminal. The input terminal of the limiter 55 is connected to the second switching unit 6. When the operation panel 7B is in the connected state, the regulating portion 55 is connected to the third contact 73 via the second switching portion 6. When the user operates the third contact 73 in a state where the second switching unit 6 is turned on, the input terminal of the limiting unit 55 detects the reference potential 10. At this time, the restriction unit 55 is ineffective to restrict the operation of the load 9. When the second switching unit 6 is turned off or when the user does not operate the third contact 73 in a state where the second switching unit 6 is turned on, the input terminal of the limiting unit 55 does not detect the reference potential 10. At this time, the restriction unit 55 is effective to restrict the operation of the load 9.

When the user disengages the operation panel 7B from the control device 1B, one end and the other end of the fourth terminal 34A and one end and the other end of the fourth terminal 34B are short-circuited by short-circuit lines, not shown. Therefore, when the operation panel 7B is in the unconnected state and the second switching unit 6 is turned on, the limiting unit 55 detects the reference potential 10. At this time, the restriction unit 55 is ineffective to restrict the operation of the load 9. When the operation panel 7B is in the disconnected state and the second switching unit 6 is turned off, the reference potential 10 is not detected by the limiting unit 55. At this time, the restriction unit 55 is effective to restrict the operation of the load 9.

< operation mode >

An operation mode when the control device 1B controls the operation of the load 9 will be described with reference to fig. 7. Descriptions of the same contents as those of the first embodiment will be omitted.

When the instruction unit 2 is turned on (there is a disconnection instruction of the operation panel 7B) and the operation panel 7B is in the connected state (S11: "yes", S13: "yes", refer to fig. 4), the CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning off the second switching unit 6 from the state monitoring unit 52. The restriction portion 55 is effective to restrict the operation of the load 9 regardless of the operation of the third contact 73. Therefore, the control device 1B drives in the restricted mode (S15, see fig. 4).

When the instruction section 2 is turned off (no instruction to detach the operation panel 7B is given) and the operation panel 7B is in the connected state (S11: "no", S23: "yes", refer to fig. 4), the CPU51 communicates with the state monitoring section 52, and outputs a control signal for turning on the second switching section 6 from the state monitoring section 52. When the user operates the third contact 73 of the operation panel 7B, the restriction portion 55 invalidates the restriction of the operation of the load 9. Therefore, the control device 1B performs driving in the normal mode (S25, see fig. 4). When the user does not operate the third contact 73 of the operation panel 7B, the restriction portion 55 is effective to restrict the operation of the load 9. Therefore, the control device 1B drives in the restricted mode (S25, see fig. 4).

When the instruction unit 2 is turned on (there is a disconnection instruction of the operation panel 7B) and the operation panel 7B is in the unconnected state (S11: "yes", S13: "no", refer to fig. 4), the CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning on the second switching unit 6 from the state monitoring unit 52. Since the user short-circuits the fourth terminal 34 by a short-circuit line, not shown, the restriction unit 55 does not effectively restrict the operation of the load 9. Therefore, the control device 1B performs driving in the normal mode (S17, see fig. 4). When the instruction unit 2 is turned off (no instruction to disengage the operation panel 7B is given) and the operation panel 7B is in the unconnected state (S11: "no", S23: "no", refer to fig. 4), the emergency stop circuit 53 emergently stops the operation of the load 9 (emergency stop mode) (S27, refer to fig. 4).

< action and Effect of the third embodiment >

As described above, the control device 1B includes the limiting unit 55 that limits the operation of the load 9, and the second switching unit 6 that switches whether the limiting unit 55 enables or disables the limitation of the operation of the load 9. The CPU51 turns off the second switching unit 6 when the instruction unit 2 is on (there is a disengagement instruction of the operation panel 7B) and the operation panel 7B is in the connected state. At this time, since the restriction unit 55 is effective to restrict the operation of the load 9, the control device 1B is driven in the restriction mode. The CPU51 turns on the second switching unit 6 when the instruction unit 2 is off (there is no instruction to disengage the operation panel 7B) and the operation panel 7B is in the connected state. At this time, the user operates the third contact 73 of the operation panel 7B, so that the restriction unit 55 cancels the restriction of the operation of the load 9, and the control device 1B is driven in the normal mode. Therefore, the control device 1B can easily switch between the case of limiting the operation of the load 9 and the case of not limiting the operation of the load 9 by the limiting unit 55 and the second switching unit 6.

< modification of the third embodiment >

As shown in fig. 8, the instruction unit 2 of the control device 1B may further include switches 2D and 2E. At this time, the switch 2D is connected in parallel to the fourth terminal 34A, and the switch 2E is connected in parallel to the fourth terminal 34B. The fourth terminal 34A is opened when the switch 2D is in a non-conductive state, and the fourth terminal 34A is short-circuited when the switch 2D is in a conductive state. The fourth terminal 34B is opened when the switch 2E is in a non-conductive state, and the fourth terminal 34B is short-circuited when the switch 2E is in a conductive state. The switches 2D and 2E are switched to any one of the on/off states in conjunction with the other switches 2A, 2B, and 2C of the instruction unit 2. When the indicating section 2 is off, the switches 2D and 2E are in a non-conductive state. When the instruction unit 2 is turned on, the switches 2D and 2E are turned on.

When the instruction unit 2 is turned on (there is a disconnection instruction of the operation panel 7B) and the operation panel 7B is in the unconnected state (S11: "yes", S13: "no", refer to fig. 4), the CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning on the second switching unit 6 from the state monitoring unit 52. Since the indicator 2 is turned on, the fourth terminal 34 is short-circuited by the switches 2D and 2E. Therefore, the restriction unit 55 is ineffective to restrict the operation of the load 9. Therefore, the control device 1B performs driving in the normal mode (S17, see fig. 4).

When the instruction unit 2 is turned on (there is a disconnection instruction of the operation panel 7B) and the operation panel 7B is in the connected state (S11: "yes", S13: "yes", refer to fig. 4), the CPU51 communicates with the state monitoring unit 52, and outputs a control signal for turning off the second switching unit 6 from the state monitoring unit 52. Therefore, even if the fourth terminal 34 is short-circuited by the switches 2D and 2E, the limiter 55 effectively limits the operation of the load 9. Therefore, the control device 1B drives in the restricted mode (S15, see fig. 4).

< fourth embodiment >

A control device 1C and an operation panel 7C according to a fourth embodiment will be described with reference to fig. 9 to 11. The control device 1C differs from the first embodiment in the following respects: the indicating section 2 does not have the switch 2C; the second terminal 32 of the connection portion 3 has a first terminal 321 and a second terminal 322.

< control device 1C >

As shown in fig. 9, the indicating section 2 of the control device 1C includes short-circuited switches 2A and 2B. Since the switches 2A and 2B are always on, the indicating section 2 is always on. The indicating unit 2 does not include the switch 2C of the control device 1A. The second terminal 32 of the connection portion 3 has a first terminal 321 and a second terminal 322. When the operation panel 7C is in the connected state, the one-side terminal 321 and the other-side terminal 322 are connected to the reference potential 70 of the operation panel 7C. The one terminal 321 and the other terminal 322 are connected to the state monitoring unit 52. The state monitoring unit 52 can determine whether or not the operation panel 7C is in the connected state by the one terminal 321 and the other terminal 322.

< operation panel 7C >

As shown in fig. 10, the operation panel 7C has a connector 76 for connection with the connection portion 3 of the control device 1C. The connector 76 has a connection terminal 761 for connection with the first terminal 31, a connection terminal 771 for connection with the one-side terminal 321, and a connection terminal 772 for connection with the other-side terminal 322. A connection terminal for connection with the third terminal 33 is omitted. As shown in fig. 9, the connection terminal 761 is connected to the first contact 71 of the operation panel 7C. The connection terminals 771 and 772 are connected to the reference potential 70 of the operation panel 7C.

As shown in fig. 10, the connection terminals 761, 771, and 772 have different lengths, respectively, the connection terminal 771 being the longest and the connection terminal 772 being the shortest. Therefore, when the connector 76 is connected to the connection unit 3 of the control device 1C in order to set the operation panel 7C to the connected state, timings at which the connection terminals 761, 771, 772 are connected to the connection unit 3 are different. That is, when the distance between the control device 1C and the operation panel 7C is a predetermined first distance, the connection terminal 771 is connected to the one terminal 321. When the distance between the operation panel 7C and the control device 1C is a predetermined second distance shorter than the first distance, the connection terminal 761 is connected to the first terminal 31. When the distance between the operation panel 7C and the control device 1C is a predetermined third distance shorter than the second distance, the connection terminal 772 is connected to the other terminal 322.

Therefore, when the distance between the operation panel 7C and the control device 1C is the first distance, the state monitoring unit 52 can detect whether or not the operation panel 7C is in the connected state based on whether or not the reference potential 70 is detected via the one terminal 321. When the distance between the operation panel 7C and the control device 1C is the second distance, the emergency stop circuit 53 can detect whether the user operates the first contact 71 via the first terminal 31. When the distance between the operation panel 7C and the control device 1C is the third distance, the state monitoring unit 52 can detect whether or not the operation panel 7C is in the connected state based on whether or not the reference potential 70 is detected via the other terminal 322. The state monitoring unit 52 detects the reference potential 70 through the first terminal 321 and the second terminal 322, which are referred to as "the first terminal 321 is turned on" and "the second terminal 322 is turned on", respectively. The case where the state monitoring unit 52 does not detect the reference potential 70 via the one terminal 321 and the other terminal 322 is referred to as "one terminal 321 is off" and "the other terminal 322 is off", respectively.

< third Main treatment >

The third main process executed by the CPU51 is explained with reference to fig. 11. The description of the same processing as the second main processing is simplified. The CPU51 communicates with the state monitoring unit 52, and acquires the state of the other side terminal 322 detected by the state monitoring unit 52. The CPU51 determines whether the other side terminal 322 is off based on the acquired information (S51). When the CPU51 determines that the other side terminal 322 is off (S51: YES), the process proceeds to S53. At this time, the distance between the operation panel 7C and the control device 1C is larger than the third distance.

The CPU51 communicates with the state monitoring unit 52, and acquires the state of the one terminal 321 detected by the state monitoring unit 52. The CPU51 determines whether or not the one terminal 321 is on based on the acquired information (S53). When the CPU51 determines that the one terminal 321 is on (S53: yes), the process proceeds to S55. At this time, the distance between the operation panel 7C and the control device 1C is smaller than the first distance. Therefore, the connection terminal 761 of the operation plate 7C is connected to the first terminal 31, and thus the operation plate 7C is in a connected state. The CPU51 drives in the restricted mode (S55).

The CPU51 increments the timer stored in the storage unit 54 by 1 to update the timer (S57). The CPU51 determines whether or not a predetermined time has elapsed since the timer was reset by determining whether or not the value of the timer is greater than a predetermined threshold value (S59). When determining that the predetermined time has not elapsed (S59: no), the CPU51 advances the process to S69. The CPU51 turns on the first switching section 4 (S69). Since the indicating section 2 is always on, the indicating section 2 and the first switching section 4 bypass the first terminal 31. Therefore, the emergency stop circuit 53 does not detect an operation to bring the operation panel 7C into the unconnected state. The CPU51 ends the third main process.

When CPU51 determines that the predetermined time has elapsed (S59: yes), first switching unit 4 is turned off (S61). At this time, the indicating section 2 and the first switching section 4 do not bypass the first terminal 31. Therefore, the emergency stop circuit 53 can detect an operation to bring the operation panel 7C into the unconnected state and emergency stop the driving of the load 9 in accordance with the operation. Since the state where the other terminal 322 is off and the one terminal 321 is on continues for a predetermined time, there is a possibility that the connection between the connector 76 and the connection unit 3 is insufficient. The CPU51 notifies the user of the connection abnormality of the connector 76 (S63). The CPU51 ends the third main process.

When the CPU51 determines that the one terminal 321 is off (S53: no), the process proceeds to S65. At this time, the distance between the operation panel 7C and the control device 1C is larger than the first distance. Therefore, the connection terminal 761 of the operation plate 7C is not connected to the first terminal 31, and the operation plate 7C is in an unconnected state. The CPU51 performs driving in the normal mode (S65). The CPU51 sets 0 to the timer to initialize it (S67). The CPU51 turns on the first switching section 4 (S69). Since the indicating section 2 is always on, the indicating section 2 and the first switching section 4 bypass the first terminal 31. Therefore, the emergency stop circuit 53 does not detect an operation to bring the operation panel 7C into the unconnected state. The CPU51 ends the third main process.

When the CPU51 determines that the other side terminal 322 is on (S51: NO), it turns off the first switch 4 (S71). At this time, the distance between the operation panel 7C and the control device 1C is smaller than the third distance. Therefore, the connection terminal 761 of the operation plate 7C is connected to the first terminal 31, and thus the operation plate 7C is in a connected state. The CPU51 determines whether the one terminal 321 is on (S73). When the CPU51 determines that the one terminal 321 is on (S73: "YES"), it drives in the normal mode (S75). The CPU51 advances the process to S79. When the CPU51 determines that the one terminal 321 is off (S73: "no"), the other terminal 322 is on and the one terminal 321 is off, and therefore, there is a possibility that: deformation of the connector 76 with respect to the connection portion 3, bending of the pin of the connection portion 3, contact failure due to adhesion, and the like occur. The CPU51 notifies the user of the connection abnormality of the connector 76 (S77). The CPU51 advances the process to S79. The CPU51 sets 0 to the timer stored in the storage unit 54 and initializes the timer (S79). The CPU51 ends the third main process.

< action and Effect of the fourth embodiment >

In the control device 1C, when the connector 76 of the operation panel 7C is brought close to the connection portion 3 and connected thereto, the first terminal 321 is first connected, the first contact 71 is connected to the first terminal 31, and the second terminal 322 is connected. Therefore, while the one terminal 321 is on and the other terminal 322 is off, the CPU51 turns on the first switching unit 4 to bypass the first contact 71, and invalidates the operation of the first contact 71. When the one terminal 321 and the other terminal 322 are on, the CPU51 turns off the first switching unit 4 so as not to bypass the first contact 71, and thereby, the operation of the first contact 71 is enabled. At this time, the CPU51 can limit the period in which the first contact 71 is bypassed by the instructing unit 2 and the first switching unit 4 to the period in which the connector 76 is connected to the connection unit 3. Therefore, the control device 1C can minimize the period during which the operation of the first contact 71 is disabled.

< modification example >

The present invention is not limited to the above-described embodiments. The control unit 5 may be configured by an integrated device of the CPU51, the state monitoring unit 52, the emergency stop circuit 53, and the storage unit 54. The first contact 71, the second contact 81, the indicating section 2, the first switching section 4, and the second switching section 6 may have one switch. The indicating unit 2 is not limited to the normally open switch, and may be a normally closed switch. The indicator 2 may be a terminal that switches between a short-circuit state and a non-short-circuit state, instead of a switch. Operation plates 7A, 7B, and 7C may have short-circuit terminals for turning on indicator 2 when connected to connector 3. At this time, the indication unit 2 may be turned on when the operation panels 7A, 7B, and 7C are in the connected state.

Instead of urgently stopping the operation of the load 9, the emergency stop circuit 53 may output a control signal to the CPU 51. The CPU51 may display notification information on a display unit, not shown, when detecting the control signal output from the emergency stop circuit 53. The case where the first to third main processes are realized by performing processing based on a program by the CPU51 is not limited. The first to third main processes may be executed by hardware using a logic circuit or the like. The operation control device 1A, 1B, or 1C is not limited to the case where a part of the plurality of operation commands is invalidated when operating in the restricted mode. For example, when the control devices 1A, 1B, and 1C operate in the restricted mode, all the operations for controlling the operation of the load 9 performed on the operation panels 7A, 7B, and 7C may be invalidated.

The control devices 1A, 1B, and 1C may not have the operation panel 8. The user may operate the first contact 71 of the operation panels 7A, 7B, and 7C to urgently stop the operation of the load 9. The control devices 1A, 1B, and 1C may not have the first switching unit 4. At this time, the first contact 71 may be bypassed by turning on the indicator 2. The operation panels 7A, 7B, and 7C may not have the communication circuit 72. In the fourth embodiment, the second terminals 32A of the second terminals 32 of the first embodiment may be used as one-side terminals, and the second terminals 32B may be used as the other-side terminals.

Claims (8)

1. A control device provided with a connecting portion for detachably connecting an operation panel having a normally closed first contact for stopping an operation of a load, and an instruction portion for instructing detachment of the operation panel, the control device controlling the load by an instruction from the operation panel, the control device being characterized in that,

the connecting portion includes a first terminal for connecting to the first contact and a second terminal for connecting to a signal line for detecting a connection state of the operation panel,

the control device is provided with:

a first control unit that stops an operation of the load when the operation panel is in an unconnected state without a disconnection instruction from the instruction unit to the operation panel, or when an operation of the first contact is detected via the first terminal when the operation panel is in a connected state without a disconnection instruction from the instruction unit to the operation panel;

a second control unit that does not restrict the operation of the load when the operation panel is in an unconnected state in response to a disconnection instruction from the instruction unit to the operation panel;

a third control unit that restricts an operation of the load when the instruction unit instructs the operation panel to be disconnected and the operation panel is in the connected state; and

a first switching section for switching whether to validate or invalidate operation on the first contact,

the first switching unit enables the operation of the first contact point before the third control unit restricts the operation of the load, and disables the operation of the first contact point after the third control unit restricts the operation of the load.

2. The control device according to claim 1,

the first switching unit disables the operation of the first contact until a predetermined time elapses after the third control unit restricts the operation of the load, and enables the operation of the first contact after the predetermined time elapses.

3. The control device according to claim 1, comprising:

a limiting unit that limits an operation of the load; and

a second switching section for switching whether to validate or invalidate the limiting section,

the third control unit restricts the operation of the load by activating the restriction unit by the second switching unit.

4. The control device according to claim 2,

a limiting unit that limits an operation of the load; and

a second switching section for switching whether to validate or invalidate the limiting section,

the third control unit restricts the operation of the load by activating the restriction unit by the second switching unit.

5. The control device according to claim 1,

the first switching unit switches whether to enable or disable a bypass circuit that bypasses the first contact, thereby switching whether to enable or disable an operation on the first contact.

6. The control device according to claim 2,

the first switching unit switches whether to enable or disable a bypass circuit that bypasses the first contact, thereby switching whether to enable or disable an operation on the first contact.

7. The control device according to any one of claims 1 to 6,

the second terminal includes a one-side connection terminal and another-side connection terminal,

the connection state of the operation panel can be detected by the one-side connection terminal when the connection portion is a first distance from the operation panel,

the first terminal is connected to the first contact when a second distance shorter than the first distance is provided between the connection portion and the operation panel,

when the connection portion and the operation panel are at a third distance shorter than the second distance, the connection state of the operation panel can be detected by the other-side connection terminal.

8. The control device according to any one of claims 1 to 6,

the second control unit validates a plurality of operation commands to the load,

the third control unit invalidates at least one of the plurality of operation commands.

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