JP5254968B2 - Control device - Google Patents

Description

  The present invention relates to a control device for safely controlling the operation of a machine or device.

  In general, in the field of factory automation (FA), a safety controller (safety PLC: "programmable logic controller") is used to safely control the operation of industrial robot systems, general-purpose machine tools, semiconductor manufacturing equipment, etc. What is called is put into practical use.

  The safety controller consists of an input unit that receives ON / OFF signals from switches and sensors, an output unit that outputs control signals to devices such as servo motors, hydraulic cylinders, actuators such as solenoid valves, and relays, And a CPU unit that performs arithmetic processing in accordance with a stored control program based on an input from the input unit and controls the output unit.

  In such a safety controller, for example, when a safety sensor such as a light curtain detects a person entering the work area of a machine or apparatus, a detection signal from the safety sensor is input to the input unit. The CPU unit receives this input signal and controls the output unit so as to output, for example, a drive stop signal to the operating actuator based on a predetermined control program. In this way, the operating equipment is stopped urgently to ensure the safety of the operator.

  The control program in the safety controller is generally created by the user or manufacturer of the safety controller as described in paragraph [0004] of Japanese Patent Application Laid-Open No. 2004-299797. The control program is stored in the safety controller by, for example, downloading a program created using a personal computer or the like to the memory of the safety controller.

  However, the creation of a control program stored in the safety controller is very laborious and requires specialized knowledge, and if the user of the safety controller has to create the control program, the burden on the user is excessive. Become.

  Therefore, in paragraph [0014] of Japanese Patent Application Laid-Open No. 2004-297997, the safety controller can be configured by simply setting which type of switch is connected to which external input terminal without creating a control program. The point which enables the setting of is described.

  On the other hand, in Japanese Patent Application Laid-Open No. 2005-115698, in a safety controller including first and second CPUs, a setting input for one CPU is logically inverted with respect to the other CPU, whereby both CPUs are provided. In this example, it is unnecessary to repeat the setting operation with the same contents.

  In the case of Japanese Patent Application Laid-Open No. 2004-297997, as described in paragraph [0033] of the same document, it is necessary to set the safety controller by connecting a personal computer to the safety controller and inputting a key from the personal computer. Yes, the burden on users of safety controllers is still large.

  In the case of Japanese Patent Laid-Open No. 2005-115698, setting input is input to each of the first and second CPUs, and the burden on the CPU is large.

  The present invention has been made in view of such a conventional situation, and a problem to be solved by the present invention is to provide a control device that can easily perform setting and reduce the burden on the user. Further, the present invention attempts to improve the reliability of the CPU by distributing the load on the CPU in such a control device. Furthermore, the present invention can perform desired safety control simply by connecting the input unit to an input device such as a safety switch and connecting the output unit to an external control target device, and control that can reduce the burden on the user. Trying to provide a device.

The control device according to the present invention includes an input unit to which a safety input is input, an output unit that outputs a safety control output to an external device, and a plurality of safety control logics stored in the arithmetic processing unit. A setting switch for selecting and setting a desired safety control logic, an arithmetic processing unit for controlling the output unit according to the safety control logic set by the setting switch based on the safety input input to the input unit , A display unit configured to display setting information set by a user using a setting switch, and the arithmetic processing unit includes a first arithmetic processing unit to which the setting switch is connected and a second arithmetic processing to which the display unit is connected. Each of the first and second arithmetic processing units performs arithmetic processing according to the safety control logic set by the setting switch, Based on the case results and controls the output unit.

According to the present invention, a plurality of safety control logics are stored in advance in the arithmetic processing unit, and when the user sets the safety control logic, the user selects a desired safety control logic from the plurality of safety control logics. It is only necessary to select and turn on the setting switch of the corresponding control device. Thereby, it is not necessary to create a safety control logic (that is, without a program), the control device can be easily set, and the burden on the user can be reduced. In addition, it is possible to perform desired control after setting the control device by simply connecting the input unit of the control device to an input device such as a safety switch and connecting the output unit to an external control target device. The burden on the user can be reduced.

Also, one of the first and second arithmetic processing unit configured to improve reliability of the result, the setting input from the setting switch only is input to the first arithmetic processing unit, a second arithmetic processing not input to the section, the display output to the table radical 113 can be done just by the second arithmetic processing unit does not perform the first processing unit. Thereby, the load on the arithmetic processing unit can be distributed, and the reliability of the entire arithmetic processing unit can be further improved. Furthermore, since the respective calculation results of the first and second calculation processing units are collated, it is possible to perform processing with higher safety.

  The second arithmetic processing unit is preferably connected to a memory for storing previous previous setting information set by the setting switch. Then, the first arithmetic processing unit transmits the new setting information newly set by the setting switch to the second arithmetic processing unit, and the second arithmetic processing unit stores it in the memory of the second arithmetic processing unit. The old setting information that has been set is transmitted to the first arithmetic processing unit. In each of the first and second calculation processing units, the new setting information set by the setting switch is compared with the old setting information. When the new setting information is different from the old setting information, the second calculation processing is performed. Is displaying an alarm on the display.

  In this case, when the new setting information set by the setting switch is different from the old setting information, the display unit displays an alarm, so that the user's attention can be drawn at the time of setting.

  Preferably, the control device further includes an approval switch for validating the setting information set by the user with the setting switch as the confirmation information, and the approval switch is turned on when the display unit displays an alarm. As a result, the old setting information is reset and the new setting information is validated as confirmed information.

  In this case, only when the user turns on the approval switch, the new setting information set by the user is validated as the confirmation information, so that incorrect settings due to user setting mistakes or setting switch operation mistakes may occur in advance. Can be prevented.

In the present invention, the input unit has a plurality of safety input terminals to which a plurality of safety inputs are input and a non-safety input terminal to which a start input is input , and each safety input is provided between the input unit and the output unit. A logic circuit for outputting a safety control output based on each safety input input to the terminal from the output unit is connected . The logic circuit inputs each safety input that is input to each safety input terminal and outputs the logical product of these, and the output from the AND circuit is input and held, and input to the non-safety input terminal And a holding circuit that outputs the held safety input to the output unit using the start input as a trigger input.

In this case, since the logic circuit that controls the output unit includes an AND circuit that outputs the logical product of each safety input input to each safety input terminal, all safety inputs are turned on ( For example, when the contacts of all safety input devices are closed, all non-contact safety switches are on, and all light curtains are unshielded), the output from the logic circuit is turned on and the safety control output from the output section Is turned on, and the external device remains in operation. Next, if any safety input is turned off from this state (for example, any safety input device contact is open, any non-contact safety switch is off, any light curtain is blocked) The output from the logic circuit is turned off, the safety control output from the output unit is turned off, and the external device is stopped.

In this case, the control unit can be connected to an input device (safety device) such as a safety switch or an emergency stop switch, and the output unit can be connected to an external control target device. Since it can be performed, the burden on the user can be reduced.

In this case , when a direct-opening device such as an emergency stop switch or safety switch is used as an input device connected to the input unit, it is used as an external control target machine for various machines such as machine tools and robots. A highly versatile device can be realized. In addition, when a NO (Normal Open) / NC (Normal Close) contact device such as a non-contact safety switch is used as the input device, a device suitable for a semiconductor manufacturing apparatus, a food packaging machine, or the like can be realized. Further, when a semiconductor output device such as a safety light curtain or a safety laser scanner is used as an input device, a control device suitable for a device having an opening such as a transfer line to a robot can be realized.

In the present invention, the input unit includes a first safety input terminal to which a mode select input for switching between the normal operation mode and the teaching mode is input, a second safety input terminal to which a safety input from the teaching device is input, the third safety input terminal to which the safety input from the switch is input, and, first, first second start input is input, and having a second non-safety input terminal, a first safety input terminal The first AND circuit that outputs the logical product of the inputs from the teach mode input from the first safety input and the safety input from the second safety input terminal, and the normal operation mode input and the third safety input from the first safety input terminal. A second AND circuit that outputs a logical product of these inputs with the safety input from the input terminal as an input, and an output from the first AND circuit is input and held. Using the first start input input to the first non-safety input terminal as a trigger input, the first holding circuit that outputs the held safety input and the output from the second AND circuit are input and this And a second holding circuit for outputting the held safety input using the second start input input to the second non-safety input terminal as a trigger input, and the first and second holding circuits An OR circuit that outputs the logical sum of these outputs as inputs, and an output unit that receives the output from the OR circuit and outputs a safety control output based on the input to an external device. ing.

In this case, the first safety input terminal is switched to the normal operation mode, when the first safety input terminal normal operation mode input is entered, the normal operation mode input and a third safety from safety input terminal The input is input to the second AND circuit, and the output of the second AND circuit is turned on. The ON output of the second AND circuit is input and held in the second holding circuit, and is output to the OR circuit using the second start input as a trigger input. As a result, the output from the OR circuit is turned on, the safety control output from the output unit is turned on, and the operating state of the external device is maintained. At this time, since the teaching mode input is off, the output of the first AND circuit remains off even if the teaching device such as the enable switch is operated, and the teaching device function is disabled. Yes.

  Next, when the first safety input terminal is switched to the teach mode and the teach mode input is input to the first safety input terminal, the teach mode input is input to the first AND circuit. In this state, when the operator operates the teaching device, the output of the first AND circuit is turned on, this on output is inputted and held in the first holding circuit, and the first start input is used as a trigger input. Output to the OR circuit. Thereby, since the output of the OR circuit is turned on, the operator can teach an external device using the teaching device. At this time, since the normal operation mode input is off, even if the safety input from the third safety input terminal is on, the output of the second AND circuit is off, and the third safety input Safety input from the input terminal is disabled.

Thus, the first for carrying out the first safety input terminals a mode select input for switching the normal operation mode and the teaching mode is entered, the control according to the mode, the second AND circuit and Since a logic circuit composed of an OR circuit is provided, appropriate control can be performed according to each of the normal operation mode and the teach mode. Further, in this case, desired control can be performed simply by connecting the input unit of the control device to an input device such as a safety switch or an emergency stop switch and connecting the output unit to an external control target device. Therefore, the burden on the user can be reduced.

In the present invention , the input unit receives safety input from an emergency stop safety input terminal to which an emergency stop switch is connected and a plurality of first safety switches provided corresponding to external first devices. A first safety input terminal, a second safety input terminal to which safety inputs from a plurality of second safety switches provided corresponding to the external second device are input, and first to second with 3 start input and a first to third non-safety input terminal of which is input, a first aND circuit which outputs the logical product of the plurality of safety input from the first safety input terminal as an input A second AND circuit that outputs a logical product of these inputs from a plurality of safety inputs from the second safety input terminal, holds the safety input from the safety input terminal for emergency stop, and The number input to the safety input terminal A first holding circuit that outputs the held safety input as a trigger input, and an output from the first AND circuit as an input, and holds this as a second or third non-safety input A second holding circuit that outputs the held safety input using the second or third start input input to the terminal as a trigger input, and an output from the second AND circuit as an input and holding this , A third holding circuit that outputs the held safety input using the second start input inputted to the second non-safety input terminal as a trigger input, and each output from the first and second holding circuits The third AND circuit that outputs the logical product of these inputs, the output from the first holding circuit or the output from the third AND circuit, and each output from the third holding circuit And a fourth AND circuit which outputs the logical product as an output unit, first safety control output outside the first output from the third AND circuit based on the inputted and the input a first output unit for outputting to the device, a second outputting second safety control output the output from the fourth aND circuit is based on the input and the input to the external of the second device Output section.

In this case, when the output from the output and the third holding circuit from the first holding circuit for the fourth AND circuit is input, it is turned on safety inputs from the emergency stop safety input terminal In this state, when the safety input from the first safety input terminal provided corresponding to the first external device is turned off, the output of the first AND circuit is turned off, and the second holding circuit As a result, the output of the third AND circuit is turned off. As a result, the safety control output from the first output unit is turned off, and the operation of the external first device is stopped. At this time, if the safety input from the second safety input terminal on the side of the external second device is in the on state, the output of the second AND circuit is turned on, and the output from the third holding circuit is The output is turned on, and this on output is input to the fourth AND circuit. At this time, since the safety input from the safety input terminal for emergency stop is on, the output of the first holding circuit is also on, and this on output is input to the fourth AND circuit. The output from the AND circuit 4 is turned on. Thereby, the safety control output from the second output unit is turned on, and the operation of the external second device is maintained.

  On the contrary, when the safety input from the emergency stop safety input terminal is turned on, the safety input from the second safety input terminal provided corresponding to the second external device is turned off. The output of the second AND circuit is turned off, the output of the third holding circuit is turned off, and the output of the fourth AND circuit is turned off. As a result, the safety control output from the second output unit is turned off, and the operation of the external second device is stopped. At this time, if the safety input from the first safety input terminal on the external first device side is in the on state, the output of the first AND circuit is turned on, and the output from the second holding circuit is The output is turned on, and this on output is input to the third AND circuit. At this time, since the safety input from the safety input terminal for emergency stop is on, the output of the first holding circuit is on, and this on output is input to the third AND circuit. The output from the AND circuit 3 is turned on. Thereby, the safety control output from the first output unit is turned on, and the operation of the external first device is maintained.

  Next, when the safety input from the first and second safety input terminals is turned on and the emergency stop switch is pressed and the safety input from the safety input terminal for emergency stop is turned off, The input to the first holding circuit is turned off, and the output of the first holding circuit is turned off. This off output is input to the third and fourth AND circuits, and therefore both the outputs of both AND circuits are turned off. As a result, the outputs of the first and second output units are both turned off, and the operation of the external first and second devices is stopped.

  In this case, if the safety input from the first safety input terminal is turned off, the operation of the external first device is stopped, and if the safety input from the second safety input terminal is turned off, the external input Since the operation of the second device is stopped, safe operation control of the external first and second devices can be performed independently. Moreover, in this case, the input unit of the control device is connected to an input device such as a safety switch or an emergency stop switch, and the output unit is connected to the external first and second control target devices. Since the control can be performed, the burden on the user can be reduced.

Further, when the output from the output and the third holding circuit from the third AND circuit against fourth and- circuit is inputted, the safety inputs from the emergency stop safety input terminal is turned on In this state, when the safety input from the first safety input terminal provided corresponding to the first external device is turned off, the output of the first AND circuit is turned off, and the second holding circuit As a result, the output of the third AND circuit is turned off. As a result, the safety control output from the first output unit is turned off, and the operation of the external first device is stopped. At this time, since the OFF output of the third AND circuit is input to the fourth AND circuit, the output of the fourth AND circuit is also turned OFF, and the safety control output from the second output unit is output. It is turned off and the operation of the external second device is also stopped.

  On the contrary, when the safety input from the emergency stop safety input terminal is turned on, the safety input from the second safety input terminal provided corresponding to the second external device is turned off. The output of the second AND circuit is turned off, the output of the third holding circuit is turned off, and the output of the fourth AND circuit is turned off. As a result, the safety control output from the second output unit is turned off, and the operation of the external second device is stopped. At this time, if the safety input from the first safety input terminal on the external first device side is in the on state, the output of the first AND circuit is turned on, and the output from the second holding circuit is The output is turned on, and this on output is input to the third AND circuit. At this time, since the safety input from the safety input terminal for emergency stop is on, the output of the first holding circuit is also on, and this on output is input to the third AND circuit. The output from the AND circuit 3 is turned on. Thereby, the safety control output from the first output unit is turned on, and the operation of the external first device is maintained.

  Next, when the safety input from the first and second safety input terminals is turned on and the emergency stop switch is pressed and the safety input from the safety input terminal for emergency stop is turned off, The input to the first holding circuit is turned off, and the output of the first holding circuit is turned off. This off output is input to the third AND circuit, and therefore the output of the third AND circuit is turned off. Further, the OFF output of the third AND circuit is input to the fourth AND circuit, and therefore the output of the fourth AND circuit is also turned OFF. As a result, the outputs of the first and second output units are both turned off, and the operation of the external first and second devices is stopped.

  In this case, if the safety input from the first safety input terminal is turned off, the operation of both the first and second external devices is stopped. It is possible to perform safe driving control of both the first and second devices. Moreover, in this case, the input unit of the control device is connected to an input device such as a safety switch or an emergency stop switch, and the output unit is connected to the external first and second control target devices. Since the control can be performed, the burden on the user can be reduced.

  As described above, according to the control device of the present invention, a plurality of safety control logics are stored in the arithmetic processing unit in advance, and a setting switch for the user to select and set a desired safety control logic is provided. Therefore, when the user sets the safety control logic, the user only has to select a desired safety control logic from among the plurality of safety control logics and turn on the setting switch of the corresponding control device. In this way, the control device can be easily set, and the burden on the user can be reduced. Also, in this case, simply connect the input unit of the control device to an input device such as a safety switch or emergency stop switch and connect the output unit to an external control target device. Can reduce the burden on the user.

  Further, according to the control device according to the present invention, the logic circuit for outputting the safety control output based on the plurality of safety inputs input to the input unit to the external device from the output unit is provided. Since the desired safety control can be performed simply by connecting the unit to an input device such as a safety switch or emergency stop switch and connecting the output unit to an external control target device, the burden on the user can be reduced.

It is a front view of the safety controller by one Example of this invention, Comprising: The state which closed the protective cover is shown. It is a front view of the safety controller by one Example of this invention, Comprising: The state which opened the protective cover is shown. It is a block block diagram of the said safety controller. It is a partial detail view of the block configuration diagram. It is a flowchart which shows the setting procedure of the said safety controller. It is a block diagram which shows the circuit structure for implement | achieving a 1st safety control logic (logic pattern 1). It is a block diagram which shows the circuit structure for solenoid control. It is a block diagram which shows the circuit structure for implement | achieving a 2nd safety control logic (logic pattern 2). It is a block diagram which shows the circuit structure for implement | achieving a 3rd safety control logic (logic pattern 3). It is a block diagram which shows the circuit structure for implement | achieving a 4th safety control logic (logic pattern 4). It is a top view which shows an example of the layout of a muting sensor and a safety light curtain. It is a top view which shows an example of the layout of a muting sensor and a safety light curtain. It is a block diagram which shows the circuit structure for implement | achieving the 5th safety control logic (logic pattern 5). It is a figure which shows the opening / closing state of each door switch with progress of the opening / closing operation | movement of a safety door. It is a figure which shows the opening / closing state of each door switch with progress of the opening / closing operation | movement of a safety door. It is a figure which shows the opening / closing state of each door switch with progress of the opening / closing operation | movement of a safety door. It is a block diagram which shows the circuit structure for implement | achieving the 6th safety control logic (logic pattern 6). It is a block diagram which shows the circuit structure for solenoid control at the time of normal operation mode. It is a block diagram which shows the circuit structure for solenoid control at the time of teach mode. It is a block diagram which shows the circuit structure for implement | achieving the 7th safety control logic (logic pattern 7). It is a block diagram which shows the circuit structure for implement | achieving the 8th safety control logic (logic pattern 8). It is a block diagram which shows the state by which the expansion unit was connected to the safety controller. It is a block diagram of the expansion unit for input circuits. It is a block diagram of the expansion unit for output circuits. It is a block diagram of the communication unit as an expansion unit. It is a block diagram of a program expansion unit. It is a block diagram of the safety controller which has a safety explosion-proof function. It is a block diagram of the expansion unit for input circuits which has a safety explosion-proof function.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIGS. 1 to 5 are diagrams for explaining a safety controller (safety PLC: “programmable logic controller”) as a control device according to an embodiment of the present invention. 1 and 2 are front views of a safety controller according to the present embodiment, in which FIG. 1 shows a state in which a protective cover is closed, FIG. 2 shows a state in which the protective cover is opened, FIG. 3 is a block diagram of the safety controller, FIG. 4 is a partial detail view of FIG. 3, and FIG. 5 is a flowchart showing a setting procedure of the safety controller.

  As shown in FIGS. 1 and 2, the safety controller 1 includes an input connector portion 2 to which an external input device such as a sensor or a switch is connected, and an output connected to an external device that is an output control target. Pattern setting switch for the user to select and set a desired logic pattern from a plurality of (in this case, 8) logic patterns (safety control programs) stored in the connector unit 3 and the safety controller 4, a timer setting switch 5 for selecting and setting an off-delay timer value that is a delay time during an off operation, an approval switch 6 for enabling a setting condition set by the user, and a logic pattern setting switch 4. A protective cover 7 that can be opened and closed so as to cover the timer setting switch 5 and the approval switch 6. Eteiru.

  Here, eight logic pattern setting switches 4 are provided, each corresponding to each of the eight logic patterns described above. Further, in the example shown in FIG. 2, the logic pattern setting switch 4 and the timer setting switch 5 are both configured from dip switches, but other switches (for example, a touch panel, etc.) may be employed. The protective cover 7 is locked in the closed position by a lock hole 71 provided in the upper part of the safety controller.

  The safety controller 1 further includes 7-segment LED displays 8 and 9 and LED indicators 10 and 11 as display units. The LED display 8 is for displaying a logic pattern set by the logic pattern setting switch 4, and the LED display 9 is for displaying an error. These LED displays 8 and 9 may be composed of an LCD or a CRT. The LED display 10 is for displaying the timer value set by the timer setting switch 5, and the LED display 11 is for displaying the input / output state.

  As shown in FIG. 3, the safety controller 1 has an arithmetic processing circuit 50 that is an arithmetic processing unit. The arithmetic processing circuit 50 is connected to an input circuit 51 and a non-safety input circuit 52 as input units, and an output circuit 53 and a non-safety output circuit 54 as output units. Further, a power supply circuit 55 for applying a power supply voltage to the arithmetic processing circuit 50, the input circuit 51, the output circuit 53, and the non-safety output circuit 54 is provided.

  The input circuit 51 is a circuit to which an input signal from an external input device such as an emergency stop switch, a safety switch, a light curtain, a muting sensor, or an enable switch is input. The non-safety input circuit 52 is a circuit to which an input signal from a start switch, a start sensor, or the like is input. The input circuit 51 is a circuit that processes the input of an emergency stop switch, a safety switch, a light curtain, an enable switch, etc. by duplication, and the non-safety input circuit 52 simply inputs without performing the duplication processing. Circuit. The output circuit 53 and the non-safety output circuit 54 are circuits for outputting a control signal to an external machine such as an industrial robot or a machine tool. Specifically, devices such as servo motors, hydraulic cylinders, actuators such as solenoid valves, relays, and the like are the targets of safety output control. Note that the output circuit 53 is a circuit that processes the output (PLC output) in a duplex manner for an output control target that requires a certain level of safety, and the non-safety output circuit 54 performs such processing. This circuit simply outputs the PLC output without performing the above.

  A program interface (I / F) circuit 56 and a user interface (I / F) circuit 57 are further connected to the arithmetic processing circuit 50 of the safety controller 1. The program I / F circuit 56 is a circuit for a manufacturer that provides a safety controller to create a logic pattern that is a safety control program. For example, a personal computer or the like can be connected to the program I / F circuit 56. Before shipping the safety controller to the factory, the manufacturer creates some general-purpose logic patterns that can be used for various applications on a personal computer, and these logic patterns are passed through the program I / F circuit 56 to the safety controller. Download to memory. The user I / F circuit 57 includes the above-described logic pattern setting switch 4, timer setting switch 5, approval switch 6, LED displays 8 and 9, and LED indicators 10 and 11.

  As shown in FIG. 4, the arithmetic processing circuit 50 includes a first arithmetic processing device (first arithmetic processing unit) 50A and a second arithmetic processing device (second arithmetic processing unit) 50B. ing. Each of the first and second arithmetic processing devices 50A and 50B is mainly composed of a CPU, and is configured to be able to communicate with each other via a communication port.

  A logic pattern setting switch 4, a timer setting switch 5, and an approval switch 6 are connected to the first arithmetic processing unit 50A. LED displays 8 and 9 and LED indicators 10 and 11 are connected to the second arithmetic processing unit 50B. A ROM 70 is connected to the second arithmetic processing unit 50B. The ROM 70 stores setting information set by the logic pattern setting switch 4 and the timer setting switch 5.

  Next, the setting procedure of the safety controller 1 configured as described above will be described with reference to the flowchart of FIG. 5 showing a safety control program setting routine. In the figure, the left side shows the processing of the first arithmetic processing unit 50A, and the right side shows the processing of the second arithmetic processing unit 50B.

  When the safety control program setting routine is started, first, in step S1 of FIG. 5, the first arithmetic processing unit 50A reads setting information performed by the user using the logic pattern setting switch 4 and the timer setting switch 5.

  Next, in step S2, the first arithmetic processing unit 50A transmits the setting information read in step S1 to the second arithmetic processing unit 50B. In step T1, second arithmetic processing unit 50B receives the setting information transmitted from first arithmetic processing unit 50A.

  In step T2, the second arithmetic processing unit 50B reads the previous old setting information stored in the ROM 70, and transmits the old setting information to the first arithmetic processing unit 50A. In step S3, first arithmetic processing unit 50A receives the old setting information transmitted from second arithmetic processing unit 50B.

  In step S4, the first arithmetic processing unit 50A compares the setting information read in step S1 with the previous setting information set last time, and determines whether or not both data (information) match. .

  If it is determined in step S4 that the two data match, the safety control program setting routine ends. In this case, the process proceeds to a safety control program execution routine described later, and when the first arithmetic processing unit 50A outputs a control signal to an external machine, the output is continued without being stopped.

  If it is determined in step S4 that the two data do not match, the safety control program setting routine proceeds to step S5. In step S5, when the first arithmetic processing unit 50A outputs a control signal to an external machine, the output is stopped.

  Next, in step S6, it is determined whether or not the approval switch 6 is turned on. If the approval switch 6 is not turned on, the safety control program setting routine returns to the beginning, and the processing of steps S1 to S6 is repeated.

  If it is determined in step S6 that the approval switch 6 is turned on, the process proceeds to step S7. In step S7, the setting information read in step S1 is transmitted as confirmation information to the second arithmetic processing unit 50B. After the process in step S7, the safety control program setting routine ends. In this case, the process proceeds to a safety control program execution routine, which will be described later, and a control signal is output to an external machine based on the newly set data. That is, according to the logic pattern newly set by the user with the logic pattern setting switch 4, the control signal is output from the first arithmetic processing unit 50A, and the external machine is controlled.

  On the other hand, in step T3, the second arithmetic processing unit 50B compares the setting data received in step T1 with the previously set data, and determines whether or not both data match.

  If it is determined in step T3 that the two data match, the process proceeds to step T4. In step T4, the setting data is lit and displayed on the LED display 8. For example, when the logic pattern number set by the user with the logic pattern setting switch 4 is 1, “1” is lit on the LED display 8. After the process in step T4, the safety control program setting routine ends. In this case, the process proceeds to a safety control program execution routine described later, and when the second arithmetic processing unit 50B outputs a control signal to an external machine, the output is continued without being stopped.

  If it is determined in step T3 that the two data do not match, the safety control program setting routine proceeds to step T5. In step T5, when the second arithmetic processing unit 50B outputs a control signal to an external machine, the output is stopped.

  Next, in step T6, the setting data is displayed blinking on the LED display 8 (that is, an alarm display). For example, when the logic pattern number set by the user with the logic pattern setting switch 4 is 2, “2” blinks on the LED display 8.

  Next, in step T7, it is determined whether or not the approval switch 6 is turned on. If the approval switch 6 is not turned on, the safety control program setting routine returns to the beginning, and the processes of steps T1 to T7 are repeated.

If it is determined in step T7 that the approval switch 6 is turned on, the process proceeds to step T8. In step T8, the confirmation information transmitted from the first arithmetic processing device 50A is received, and the setting information received in step T1 is transmitted to the first arithmetic processing device 50A as confirmation information. The first arithmetic processing unit 50A receives this transmission data in step S7. After the process in step T8, the safety control program setting routine ends. In this case, the process proceeds to a safety control program execution routine, which will be described later, and a control signal is output to an external machine based on the newly set data. That is, according to the logic pattern newly set by the user with the logic pattern setting switch 4, a control signal is output from the second arithmetic processing unit 50B, and the external machine is controlled.

Next, the safety control program execution routine will be described.
In this routine, the same input signals input from the input circuits 51 and 52 are input to the first arithmetic processing device 50A and the second arithmetic processing device 50B. Each of the first and second arithmetic processing devices 50A and 50B executes a safety control program corresponding to the setting information, and performs arithmetic processing on the input signal. And each arithmetic processing unit outputs each arithmetic result to the other arithmetic processing unit, and collates its own arithmetic result with the other arithmetic result. When the collation results of the first arithmetic processing unit 50A and the second arithmetic processing unit 50B match, the arithmetic processing circuit 50 controls the output circuits 53 and 54 based on the arithmetic result. To do. If the collation result of at least one of the first and second arithmetic processing units 50A and 50B does not match, the arithmetic processing unit 50 does not output a control signal to an external machine. The output circuits 53 and 54 are controlled.

  Thus, in the safety control program execution routine, the arithmetic processing circuit 50 functions as a dual system using the first arithmetic processing circuit 50A and the second arithmetic processing circuit 50B in order to improve the reliability of the arithmetic result. The input signals input from the input circuits 51 and 52 are subjected to arithmetic processing according to the safety control program set by the setting switch, and the output circuits 53 and 54 are controlled based on the collation result of the two arithmetic results. To do.

  As described above, according to this embodiment, a plurality of logic patterns for controlling an external machine are stored in advance in an arithmetic processing circuit, and a logic for a user to select and set a desired logic pattern. Since the pattern setting switch is provided, when setting a logic pattern, the user selects a desired logic pattern from a plurality of logic patterns and only turns on the logic pattern setting switch of the corresponding safety controller. It's okay. In this way, the safety controller can be set easily and the burden on the user can be reduced.

  In addition, according to the present embodiment, since the approval switch for enabling the setting information set by the user with the logic pattern setting switch as valid information is provided, the approval switch is set after the user sets the logic pattern with the setting switch. By turning on, the setting information set by the user is validated as confirmed information. Accordingly, it is possible to prevent an erroneous setting due to a user setting error or a setting switch operation error.

  Furthermore, according to the present embodiment, the setting input from the logic pattern setting switch is input only to the first arithmetic processing unit, not input to the second arithmetic processing unit, and is displayed on the display unit. The output is performed only by the second arithmetic processing unit, not the first arithmetic processing unit. Thereby, the load of the arithmetic processing circuit can be distributed, and the reliability of the entire arithmetic processing circuit is improved.

  Next, details of each of a plurality (eight in this example) of safety control logic (logic patterns) stored in the memory of the safety controller 1 will be described with reference to the block diagrams of FIGS. In these drawings, the same reference numerals indicate the same or corresponding parts.

<Logic pattern 1>
FIG. 6 is a block diagram showing a circuit configuration for realizing the first safety control logic (logic pattern 1), and FIG. 7 is a block diagram showing a circuit configuration for solenoid control. As shown in FIG. 6, the input circuit 51 (FIG. 3) of the safety controller 1 has safety inputs 1 to 6 from a plurality of (6 in this example) direct opening devices such as emergency stop switches and safety switches. Have a total of 12 (that is, 6 × 2) safety input terminals that are input in duplicate. The non-safety input circuit 52 of the safety controller 1 has non-safety input terminals to which the non-safety inputs from the start inputs 1 and 2 and the external device monitors 1 and 2 are inputted. The external device monitors 1 and 2 are for monitoring the control target device of the safety controller 1 and are connected to NC contacts such as a contactor and a safety relay.

  Six safety inputs 1 to 6 are input to the AND circuit 100. The AND circuit 100 is a logic circuit for outputting a logical product of these six safety inputs 1 to 6. The output S1 of the AND circuit 100 is input to the self-holding circuit 101. On the other hand, the start inputs 1 and 2 are input to the OR circuit 102. The OR circuit 102 is a logic circuit for outputting a logical sum of the start inputs 1 and 2. The output of the OR circuit 102 is input to the trigger terminal of the self-holding circuit 101. The self-holding circuit 101 temporarily holds the ON input S1 from the AND circuit 100, and uses the start inputs 1 and 2 input to the trigger terminal as a trigger input, and the held ON input S1 with an off-delay timer at the subsequent stage. This is a circuit for outputting to the safety output circuits 103 and 104. Further, non-safety inputs from the external device monitors 1 and 2 are inputted to the EDM terminals of the safety output circuits 103 and 104.

  The safety output circuits 103 and 104 are circuits for holding the outputs of the self-holding circuit 101 as safety control outputs 1 and 2 respectively after holding the output of the self-holding circuit 101 for a predetermined time set by an off-delay timer. Safety control outputs 1 and 2 are both duplicated and output.

  The outputs Y0 and Y1 of the safety control output 1 and the output S1 of the AND circuit 100 are inverted and input to the solenoid control AND circuit 105 as shown in FIG. The solenoid control AND circuit 105 is a circuit for outputting a logical product of the inverting input of the outputs Y0 and Y1 of the safety control output 1 and the inverting input of the output S1 of the AND circuit 100. The output SL1 of the solenoid control AND circuit 105 is input to a solenoid for releasing the lock state of the safety door provided in the external control target device.

  Similarly, the outputs Y2 and Y3 of the safety control output 2 and the output S1 of the AND circuit 100 are inverted and input to the solenoid control AND circuit 106, as shown in FIG. The solenoid control AND circuit 106 is a circuit for outputting a logical product of the inverting inputs of the outputs Y2 and Y3 of the safety control output 1 and the inverting input of the output S1 of the AND circuit 100. The output SL2 of the solenoid control AND circuit 106 is input to a solenoid for releasing the lock state of the safety door provided in the external control target device.

  In such a logic pattern 1, when the contacts of all the directly open devices are closed and all the safety inputs 1 to 6 are turned on, the output S1 of the AND circuit 100 is turned on, and the output S1 is self- Input to the holding circuit 101. In this state, when one of the start inputs 1 and 2 is turned on, the output of the OR circuit 102 is turned on, and this is input to the trigger terminal of the self-holding circuit 101, thereby being held in the self-holding circuit 101. The safety input S1 is output to the safety output circuits 103 and 104. As a result, the safety outputs 1 and 2 from the safety output circuits 103 and 104 are turned on, and the operating state of the external controlled machine is maintained.

  At this time, the output SL1 of the solenoid control AND circuit 105 to which the respective inverting inputs of the safety output 1 (that is, Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are input is turned off. The solenoid keeps the safety door locked. Similarly, the output SL2 of the solenoid control AND circuit 106 to which the inverted inputs of the output 2 of the safety output circuit 104 (that is, Y2 and Y3) and the output S1 of the AND circuit 100 are input is turned off, and the solenoid is safe. Keep the door locked.

  Next, when the contact of any safety input device is opened from this state, the output S1 of the AND circuit 100 is turned off, and the off output S1 is input to the safety output circuits 103 and 104 via the self-holding circuit 101. The The safety output circuits 103 and 104 turn off the safety outputs 1 and 2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the external controlled machine is stopped.

  At this time, the output SL1 of the AND circuit 105 for solenoid control to which the respective inverting inputs of the safety output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are input is turned on, and the solenoid Is driven, and the solenoid releases the locked state of the safety door. Similarly, the output SL2 of the solenoid control AND circuit 106 to which the respective inverting inputs of the safety output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input is turned on to drive the solenoid. The solenoid then unlocks the safety door.

  In this case, simply connect the safety inputs 1 to 6 of the safety controller 1 to a directly open device such as an emergency stop switch or safety switch, and connect the safety outputs 1 and 2 to an external control target device. Can reduce the burden on the user. In this case, the output from the solenoid control AND circuit is turned on only when the safety control output from the safety output circuit is OFF and the output from the AND circuit is OFF, so that the solenoid is driven. The safety door is unlocked, but in other cases, the output from the solenoid control AND circuit is turned off, and the safety door is locked. Thereby, the locked state of the safety door is not released during operation of the external device, and the safety of the operator is ensured. Furthermore, in this case, a highly versatile safety control device that can be applied to various machines such as machine tools and robots can be realized as an external control target machine.

<Logic pattern 2>
FIG. 8 is a block diagram showing a circuit configuration for realizing the second safety control logic (logic pattern 2). This circuit configuration is similar to that of the logic pattern 1 of FIG. 6, but here, as the safety inputs 1 to 4, for example, NO from an NO / NC contact device such as a non-contact safety switch for a movable door. This is different from Logic Pattern 1 in that / NC input is duplicated and input. Further, as the safety inputs 5 and 6, safety inputs from directly open devices such as emergency stop switches and safety switches are duplicated and input. Six safety inputs 1 to 6 are input to the AND circuit 100.

  In such a logic pattern 2, when the ON conditions of all NO / NC contact devices are satisfied and the contacts of the open circuit devices are closed and all the safety inputs 1 to 6 are turned on, the AND circuit The output S1 of 100 is turned on, and the output S1 is input to the self-holding circuit 101. In this state, when one of the start inputs 1 and 2 is turned on, the output of the OR circuit 102 is turned on, and this is input to the trigger terminal of the self-holding circuit 101, thereby being held in the self-holding circuit 101. The safety input S1 is output to the safety output circuits 103 and 104. As a result, the safety outputs 1 and 2 from the safety output circuits 103 and 104 are turned on, and the operating state of the external controlled machine is maintained.

  At this time, similarly to the case of the logic pattern 1, as shown in FIG. 7, the respective inverting inputs of the output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are controlled by solenoid control. In this case, the output SL1 of the solenoid control AND circuit 105 is turned off, and the solenoid maintains the safety door locked state. Similarly, the inverting inputs of the output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input to the solenoid control AND circuit 106. At this time, the solenoid control AND circuit 106 The output SL2 is turned off, and the solenoid keeps the safety door locked.

  Next, from this state, when the safety inputs 1 to 6 from any NO / NC contact device or directly open circuit device are turned off, the output S1 of the AND circuit 100 is turned off, and the output S1 To the safety output circuits 103 and 104. The safety output circuits 103 and 104 turn off the safety outputs 1 and 2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the external controlled machine is stopped.

  At this time, the output SL1 of the AND circuit 105 for solenoid control to which the respective inverting inputs of the safety output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are input is turned on, and the solenoid Is driven, and the solenoid releases the locked state of the safety door. Similarly, the output SL2 of the solenoid control AND circuit 106 to which the respective inverting inputs of the safety output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input is turned on to drive the solenoid. The solenoid then unlocks the safety door.

  In this case, the safety inputs 1 to 6 of the safety controller 1 are connected to NO / NC contact devices such as non-contact safety switches and directly open devices such as emergency stop switches and safety switches, and safety outputs 1 and 2 are connected. Since desired control can be performed only by connecting to an external control target device, the burden on the user can be reduced. In this case, a safety control device suitable for a machine such as a semiconductor manufacturing apparatus or a food packaging machine can be realized as an external control target machine.

<Logic pattern 3>
FIG. 9 is a block diagram showing a circuit configuration for realizing the third safety control logic (logic pattern 3). This circuit configuration is similar to that of the logic pattern 1 of FIG. 6, but here, as the safety inputs 1 and 2, for example, inputs from semiconductor input devices such as safety light curtains and safety laser scanners are duplicated. This is different from the logic pattern 1 in that it is input. Further, as the safety inputs 3 to 6, the safety inputs from the direct opening devices such as the emergency stop switch and the safety switch are duplicated and input. Six safety inputs 1 to 6 are input to the AND circuit 100.

  In such a logic pattern 3, all the safety inputs 1 and 2 from all the semiconductor input devices are turned on (for example, the safety light curtain is not shielded), and the contacts of all the directly open devices are closed. When all the safety inputs 1 to 6 are turned on, the output S1 of the AND circuit 100 is turned on, and the output S1 is input to the self-holding circuit 101. In this state, when one of the start inputs 1 and 2 is turned on, the output of the OR circuit 102 is turned on, and this is input to the trigger terminal of the self-holding circuit 101, thereby being held in the self-holding circuit 101. The safety input S1 is output to the safety output circuits 103 and 104. As a result, the safety outputs 1 and 2 from the safety output circuits 103 and 104 are turned on, and the operating state of the external controlled machine is maintained.

  At this time, similarly to the case of the logic pattern 1, as shown in FIG. 7, the respective inverting inputs of the output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are controlled by solenoid control. In this case, the output SL1 of the solenoid control AND circuit 105 is turned off, and the solenoid maintains the safety door locked state. Similarly, the inverting inputs of the output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input to the solenoid control AND circuit 106. At this time, the solenoid control AND circuit 106 The output SL2 is turned off, and the solenoid keeps the safety door locked.

  Next, when the safety inputs 1 and 2 from any of the semiconductor input devices are turned off from this state (for example, the safety light curtain is shielded), or the safety inputs 3 to 6 from the open circuit device are turned off, The output S1 of the circuit 100 is turned off, and the output S1 is input to the safety output circuits 103 and 104 via the self-holding circuit 101. The safety output circuits 103 and 104 turn off the safety outputs Y1 and Y2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the external controlled machine is stopped.

  At this time, the output SL1 of the AND circuit 105 for solenoid control to which the respective inverting inputs of the safety output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are input is turned on, and the solenoid Is driven, and the solenoid releases the locked state of the safety door. Similarly, the output SL2 of the solenoid control AND circuit 106 to which the respective inverting inputs of the safety output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input is turned on to drive the solenoid. The solenoid then unlocks the safety door.

  In this case, the safety inputs 1 to 6 of the safety controller 1 are connected to semiconductor input devices such as safety light curtains and safety laser scanners, and directly open devices such as emergency stop switches and safety switches, and safety outputs 1 and Since desired control can be performed simply by connecting 2 to an external device to be controlled, the burden on the user can be reduced. In this case, a safety control device suitable for an apparatus having an opening, such as a transfer line to a robot, can be realized as an external control target machine.

<Logic pattern 4>
FIG. 10 is a block diagram showing a circuit configuration for realizing the fourth safety control logic (logic pattern 4). This circuit configuration is similar to that of the logic pattern 3 in FIG. 9, but here, in addition to the safety inputs 1 and 2, the muting inputs 1 and 2 to which the input from the muting sensor is input are provided. It is different from the logic pattern 3 in that it is provided. As the safety inputs 1 and 2, as with the logic pattern 3, inputs from semiconductor input devices such as a safety light curtain and a safety laser scanner are duplicated and input. As the safety inputs 3 and 4, similarly to the logic patterns 1, 2, and 3, safety inputs from directly open devices such as emergency stop switches and safety switches are duplicated and input.

  The safety input 1 and the muting input 1 are input to the muting circuit 110. Similarly, the safety input 2 and the muting input 2 are input to the muting circuit 111. The muting circuits 110 and 111 are circuits for adding a muting function to the safety inputs 1 and 2. Here, the “muting function” means that the safety function of the safety input device (for example, the safety light curtain) is temporarily reserved when the muting sensor reacts (that is, the safety light curtain OFF signal is temporarily set). Disable it). The outputs of the muting circuits 110 and 111 and the safety inputs 3 and 4 are input to the AND circuit 100.

  10A and 10B are plan views showing an example of the layout of the muting sensor and the safety light curtain. As shown in these drawings, a conveyor 211 is disposed through an opening 210 a formed in the partition wall 210. The workpiece W placed on the conveyor 211 is conveyed by the conveyor 211 in the direction of the arrow from the safety area on the left side of the partition wall 210 toward the danger area on the right side. A machine tool, a robot, or the like that is a control target machine is arranged in the dangerous area.

  Muting sensors 200 and 201 are provided on both sides of the conveyor 211. The muting sensor 200 includes a light projecting unit 200a provided in the safe area and a light receiving unit 200b provided in the dangerous area. Similarly, the muting sensor 201 is provided with the light projecting unit 200b provided in the safe area. It is comprised from the light part 201a and the light-receiving part 201b provided in the dangerous area. In the muting sensors 200 and 201, the respective light beams L1 and L2 intersect each other in an X shape. Safety light curtains 202 are provided on both sides of the opening 210a of the partition wall 210. The safety light curtain 202 includes a light projecting unit 202a and a light receiving unit 202b. Also, a muting lamp 203 is provided in the vicinity of the partition wall 210 to notify the operator that the muting state is present.

  In this logic pattern 4, when safety inputs 1 and 2 from all semiconductor input devices are turned on (for example, the safety light curtain 202 is not shielded as shown in FIG. 10A), muting is performed. The outputs from the circuits 110 and 111 are both turned on. At this time, when all the contacts of all the directly open devices are closed and the safety inputs 3 and 4 are turned on, the output S1 of the AND circuit 100 is turned on, and the output S1 is input to the self-holding circuit 101. The In this state, when one of the start inputs 1 and 2 is turned on, the output of the OR circuit 102 is turned on, and this is input to the trigger terminal of the self-holding circuit 101, thereby being held in the self-holding circuit 101. The safety input S1 is output to the safety output circuits 103 and 104. As a result, the safety outputs 1 and 2 from the safety output circuits 103 and 104 are turned on, and the operating state of the external controlled machine is maintained.

  At this time, similarly to the case of the logic pattern 1, as shown in FIG. 7, the respective inverting inputs of the output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are controlled by solenoid control. In this case, the output SL1 of the solenoid control AND circuit 105 is turned off, and the solenoid maintains the safety door locked state. Similarly, the inverting inputs of the output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input to the solenoid control AND circuit 106. At this time, the solenoid control AND circuit 106 The output SL2 is turned off, and the solenoid keeps the safety door locked.

  Next, the work W is carried in by the conveyor 211, and the light beams L1 and L2 of the muting sensors 200 and 201 are shielded (see FIG. 10B). When the safety inputs 1 and 2 are turned off by blocking the light beam L3 of the light curtain 202 (see the same figure), the outputs from the muting circuits 110 and 111 are both turned on and muting is performed. Transition to the state. At this time, if all the contacts of all the directly open devices are closed and the safety inputs 3 and 4 are turned on, the output S1 of the AND circuit 100 is turned on, and the output S1 is input to the self-holding circuit 101. Then, using the input of the start input 1 or 2 as a trigger input, the input S1 held in the self-holding circuit 101 is input to the safety output circuits 103 and 104. As a result, the safety outputs 1 and 2 from the safety output circuits 103 and 104 are turned on, and the operating state of the external controlled machine is maintained. Thereby, the productivity of the machine can be improved. In this muting state, the muting lamp 203 is turned on by outputting the muting lamp output to the muting lamp 203, and thus the controlled machine is in the muting state. Can be notified to the operator.

  In this case, the muting sensors 200 and 201 detect the workpiece W at the same time so that the muting inputs 1 and 2 are simultaneously input, or one of the muting sensors 200 and 201 is detected. After the muting input from is input, the muting state can be changed only when the muting input from the other muting sensor is input within a predetermined time (for example, within 0.5 seconds). By controlling, safer control can be performed.

  Also, when the light rays L1 and L2 of the muting sensors 200 and 201 are not shielded by the entrance of a person and the light rays L3 of the safety light curtain 202 are shielded, muting inputs 1 and 2 are input. Without fail, safety inputs 1 and 2 are turned off. At this time, the outputs from the muting circuits 110 and 111 are both turned off. At this time, the output S1 of the AND circuit 100 is turned off, and the output S1 is supplied to the safety output circuits 103 and 104 via the self-holding circuit 101. Is input. The safety output circuits 103 and 104 turn off the safety outputs 1 and 2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the external controlled machine is stopped. In this way, the safety of the machine is ensured.

  At this time, the output SL1 of the AND circuit 105 for solenoid control to which the respective inverting inputs of the safety output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are input is turned on, and the solenoid Is driven, and the solenoid releases the locked state of the safety door. Similarly, the output SL2 of the solenoid control AND circuit 106 to which the respective inverting inputs of the safety output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input is turned on to drive the solenoid. The solenoid then unlocks the safety door.

  In this case, when a work is brought into an external control target machine (for example, a machine tool or a robot), the safety light is detected by both the input device such as a safety light curtain and the muting sensor detecting the work. While temporarily disabling input devices such as curtains to maintain the machine's operating status, the muting sensor is not detected by the muting sensor, but only the safety light curtain detects the entry of people. Stop. Thereby, the productivity of the machine can be improved. In this case, the safety inputs 1 and 2 of the safety controller 1 are connected to a semiconductor input device such as a safety light curtain and a safety laser scanner, the muting inputs 1 and 2 are connected to a muting sensor, and the safety input 3 4 can be connected to a directly open device such as an emergency stop switch or safety switch, and the safety outputs 1 and 2 can be connected to an external device to be controlled. Can be reduced. In this case, a safety control device suitable for an apparatus having an opening, such as a transfer line to a robot, can be realized as an external control target machine.

<Logic pattern 5>
FIG. 11 is a block diagram showing a circuit configuration for realizing the fifth safety control logic (logic pattern 5). This circuit configuration is similar to that of the logic pattern 1 of FIG. 6, but here, inputs from a safety device having a dual interlocking operation mechanism such as a safety switch are input as safety inputs 1 to 6, for example. This is different from the logic pattern 1. In this case, the monitoring time (mismatch monitoring time) of the two input states of the duplex input is set to “∞ (infinite)”. That is, in this case, the mismatch time monitoring of the two input states of the duplex input is not performed.

  11A to 11C are schematic views showing an example in which a door switch is provided on a safety door installed in a work area of a robot as an external control target machine. As shown in these drawings, first and second door switches 221 and 222 are provided on the upper side and the lower side of the end portion of the safety door 220 as safety devices having a dual interlocking operation mechanism, respectively. The outputs of the door switches 221 and 222 are input to the safety input 2 (FIG. 11) as a duplex input, for example. Although not shown, the safety door 220 is provided with a solenoid for locking and unlocking.

  In this logic pattern 5, when the contacts of all safety devices including the door switches 221 and 222 are closed (see FIG. 11A) and all the safety inputs 1 to 6 are turned on, the AND circuit 100 The output S1 is turned on, and the output S1 is input to the self-holding circuit 101. In this state, when one of the start inputs 1 and 2 is turned on, the output of the OR circuit 102 is turned on, and this is input to the trigger terminal of the self-holding circuit 101, thereby being held in the self-holding circuit 101. The safety input S1 is output to the safety output circuits 103 and 104. As a result, the safety outputs 1 and 2 from the safety output circuits 103 and 104 are turned on, and the operating state of the robot is maintained.

  At this time, similarly to the case of the logic pattern 1, as shown in FIG. 7, the respective inverting inputs of the output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are controlled by solenoid control. In this case, the output SL1 of the solenoid control AND circuit 105 is turned off, and the solenoid maintains the locked state of the safety door 220. Similarly, the inverting inputs of the output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input to the solenoid control AND circuit 106. At this time, the solenoid control AND circuit 106 The output SL2 is turned off, and the solenoid maintains the locked state of the safety door 220.

Next, from this state, as shown in FIG. 11B, when the operator P tries to open the safety door 220, only the first door switch 221 is in the “open” state, and the second door Assume that the switch 222 is maintained in the “closed” state. At this time, one of the safety input 2 from the first door switch 221 is turned off, the other safety input 2 from the second door switch 222 to be interlocked therewith remains on. However, in this case, the monitoring time (mismatch monitoring time) of the input states of these two redundant interlocking safety inputs 2 is set to “∞ (infinite)”, and the mismatching times of the input states of the two redundant interlocking safety inputs 2 are set. There is no monitoring. Therefore, the safety input 2 is turned off and input to the AND circuit 100, and the output S1 of the AND circuit 100 is turned off. The output S1 is input to the safety output circuits 103 and 104 via the self-holding circuit 101. The safety output circuits 103 and 104 turn off the safety outputs 1 and 2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the robot is stopped.

  At this time, the output SL1 of the AND circuit 105 for solenoid control to which the respective inverting inputs of the safety output 1 (Y0, Y1) of the safety output circuit 103 and the output S1 of the AND circuit 100 are input is turned on, and the solenoid Is driven, and the solenoid releases the locked state of the safety door 221. Similarly, the output SL2 of the solenoid control AND circuit 106 to which the respective inverting inputs of the safety output 2 (Y2, Y3) of the safety output circuit 104 and the output S1 of the AND circuit 100 are input is turned on to drive the solenoid. Then, the solenoid releases the locked state of the safety door 221.

  Next, as shown in FIG. 11C, when the operator P further opens the safety door 220, the second door switch 222 also shifts to the “open” state. At this time, the safety input 2 from the second door switch 222 is also turned off, but the output S1 of the AND circuit 100 remains off, and the robot maintains the operation stop state.

  In this case, if the contact of one door switch is turned off, the robot immediately stops without waiting for the contact of the other door switch to be turned off. In this case, since the robot stops without being affected by the speed at which the safety door 220 is opened, the safety performance of the apparatus can be improved.

  In this case, the safety inputs 1 to 6 of the safety controller 1 are connected to a safety device having a dual interlocking operation mechanism, and the safety outputs 1 and 2 are connected to an external control target device. Can reduce the burden on the user. In this case, a safety control device suitable for a machine such as a machine tool having a safety door or a robot can be realized as an external control target machine.

<Logic pattern 6>
FIG. 12 is a block diagram showing a circuit configuration for realizing the sixth safety control logic (logic pattern 6), and FIGS. 13 and 14 are block diagrams showing a circuit configuration for solenoid control. It is. This logic pattern is a logic configured to be able to switch between a normal operation mode and a maintenance mode (teach mode).

  As shown in FIG. 12, the safety input 1 receives an input (mode select input) from a device having a mode selection function such as a mode select switch. Safety input 2 is input from a teaching device such as an enable switch or teaching pendant. Safety inputs 3 and 4 are input with safety inputs from directly open devices such as safety switches, and safety inputs 5 and 6 are input with safety inputs from directly open devices such as emergency stop switches. .

  The teach mode input and the safety input 2 of the safety input 1 are input to the AND circuit 110. The AND circuit 110 is a circuit that outputs a logical product of the teach mode input and the safety input 2. The normal operation mode input and the safety inputs 3 and 4 of the safety input 1 are input to the AND circuit 111. The AND circuit 111 is a circuit that outputs a logical product of the normal operation mode input and the safety inputs 3 and 4. The safety inputs 5 and 6 are input to the AND circuit 112. The AND circuit 112 is a circuit that outputs a logical product of the safety inputs 5 and 6.

  The output of the AND circuit 110 is input to the self-holding circuit 113, the output S1 of the AND circuit 111 is input to the self-holding circuit 114, and the output S2 of the AND circuit 112 is input to the self-holding circuit 115. A start input 1 is input to the trigger terminal of the self-holding circuit 113, and a start input 2 is input to each trigger terminal of the self-holding circuits 114 and 115. Each output from the self-holding circuits 113 and 114 is input to an OR circuit 116, and the OR circuit 116 is a circuit that outputs a logical sum of these inputs. The output of the OR circuit 116 and the output of the self-holding circuit 115 are input to the AND circuit 117. The AND circuit 117 is a circuit that outputs a logical product of the output of the OR circuit 116 and the output of the self-holding circuit 115. The output of the AND circuit 117 is input to the safety output circuits 118 and 119. Non-safety inputs from the external device monitors 1 and 2 are input to the EDM terminals of the safety output circuits 118 and 119.

  As shown in FIG. 13, the safety output 1 (Y0, Y1) of the safety output circuit 118 and the outputs S1, S2 of the AND circuits 111, 112 are inverted in the normal operation mode, respectively, and are used for solenoid control AND circuits. 120 is input. The solenoid control AND circuit 120 is a circuit for outputting a logical product of the inverting input of the safety output 1 (Y0, Y1) and the inverting inputs of the outputs S1 and S2 of the AND circuits 111 and 112. The output SL1 of the solenoid control AND circuit 120 is input to a solenoid for releasing the lock state of the safety door provided in the external control target device.

  Similarly, the safety output 2 (Y2, Y3) of the safety output circuit 119 and the outputs S1, S2 of the AND circuits 111, 112 are inverted and solenoid controlled in the normal operation mode, as shown in FIG. Is input to the AND circuit 121. The solenoid control AND circuit 121 is a circuit for outputting a logical product of the inverting input of the safety output 2 (Y2, Y3) and the inverting inputs of the outputs S1 and S2 of the AND circuits 111 and 112. The output SL2 of the solenoid control AND circuit 121 is input to a solenoid for releasing the lock state of the safety door provided in the external control target device.

  Further, as shown in FIG. 14, the safety output 1 (Y0, Y1) of the safety output circuit 118 is inverted into the output SL1 in the teach mode, and the output SL1 is an external control target device. Is input to the solenoid for releasing the lock state of the safety door provided in the. Similarly, as shown in FIG. 14, the safety outputs 2 (Y2, Y3) of the safety output circuit 119 are inverted to become the output SL2 in the teach mode, and the output SL2 is externally controlled. It is input to the solenoid for releasing the lock state of the safety door provided in the target device.

  In this logic pattern 6, when the normal operation mode is selected by the mode select switch, the normal operation mode input is input to the safety input 1. At this time, since the teaching mode input is off, the output of the AND circuit 110 remains off even if a teaching device such as an enable switch is operated, and the function of the teaching device is disabled. At this time, when the safety inputs 3 to 6 are turned on, the outputs S1 and S2 of the AND circuits 111 and 112 are turned on, the output S1 is input to the self-holding circuit 114, and the output S2 is the self-holding circuit. 115 is input.

  When the start inputs 1 and 2 are turned on from this state, the start input 1 is input to the trigger terminal of the self-holding circuit 113, and the start input 2 is input to the trigger terminals of the self-holding circuits 114 and 115. As a result, the safety input S1 held in the self-holding circuit 114 is output to the OR circuit 116. At this time, since the output of the self-holding circuit 113 remains off, the output of the OR circuit 116 is turned on, and this is input to the AND circuit 117. On the other hand, the safety input S2 held in the self-holding circuit 115 is input to the AND circuit 117. As a result, the output from the AND circuit 117 is turned on and input to the safety output circuits 118 and 119. As a result, the safety outputs 1 and 2 from the safety output circuits 118 and 119 are turned on, and the operating state of the external controlled machine is maintained.

  At this time, as shown in FIG. 13, the output 1 (Y0, Y1) of the safety output circuit 118 and the inverted inputs of the outputs S1, S2 of the AND circuits 111, 112 are input to the AND circuit 120 for solenoid control. The output SL1 is turned off, and the solenoid keeps the safety door locked. Similarly, the output SL2 of the solenoid control AND circuit 121 to which the output 2 (Y2, Y3) of the safety output circuit 119 and the inverted inputs of the outputs S1 and S2 of the AND circuits 111 and 112 are input is turned off. The solenoid keeps the safety door locked.

  Next, when the contact of any safety input device is opened from this state, for example, when the safety inputs 3 and 4 are turned off, the output S1 of the AND circuit 111 is turned off and the output of the OR circuit 116 is also turned off. Become. As a result, the output from the AND circuit 111 is turned off, and the safety output circuits 118 and 119 turn off the safety outputs 1 and 2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the external controlled machine is stopped.

  At this time, the output SL1 of the solenoid control AND circuit 120 to which the inverted inputs of the output 1 (Y0, Y1) of the safety output circuit 118 and the output S1 of the AND circuit 111 are input is turned on, and the solenoid is driven. The solenoid will unlock the safety door. Similarly, the output SL2 of the solenoid control AND circuit 121 to which the inverted inputs of the output 2 (Y2, Y3) of the safety output circuit 119 and the output S1 of the AND circuit 111 are input is turned on to drive the solenoid. The solenoid will unlock the safety door.

  Further, when the contact of any safety input device is opened in the solenoid locked state, for example, when the safety inputs 5 and 6 are turned off, the output S2 of the AND circuit 112 is turned off, and By being input to the circuit 117, the output of the AND circuit 117 is turned off, and the safety output circuits 118 and 119 turn off the safety outputs 1 and 2 after a predetermined time set by the off-delay timer has elapsed. Thereby, the operation of the external controlled machine is stopped.

  At this time, the output SL1 of the solenoid control AND circuit 120 to which the inverted inputs of the output 1 (Y0, Y1) of the safety output circuit 118 and the output S2 of the AND circuit 112 are input is turned on, and the solenoid is driven. The solenoid will unlock the safety door. Similarly, the output SL2 of the solenoid control AND circuit 121 to which the inverted inputs of the output 2 (Y2, Y3) of the safety output circuit 119 and the output S2 of the AND circuit 112 are input is turned on, and the solenoid is driven. The solenoid will unlock the safety door.

  If the emergency stop switch is pressed while the machine is operating and the safety inputs 5 and 6 are turned off, the output S2 of the AND circuit 112 is turned off and the output of the self-holding circuit 115 is turned off. Thus, the output of the AND circuit 117 is turned off. The output of the AND circuit 117 is input to the safety output circuits 118 and 119. For this reason, the safety outputs 1 and 2 are turned off after the set time of the off-delay timer, and the operation of the external controlled machine is stopped. The

  Next, when the teach mode is selected with the mode select switch, the teach mode input is input to the safety input 1. At this time, since the normal operation mode input is off, the output S1 of the AND circuit 111 is off even when the safety inputs 3 and 4 are on. That is, in this case, the safety inputs 3 and 4 are invalidated. If the safety inputs 5 and 6 are turned on, the output S2 of the AND circuit 112 is turned on. When the start input 2 is inputted, the self-holding circuit 115 sends the held input S2 to the AND circuit 117. Output.

  On the other hand, when the teaching device such as the enable switch is off, the safety input 2 is off and the output of the AND circuit 110 is off. This OFF output is input to the OR circuit 116. On the other hand, the output S1 of the AND circuit 111 is also OFF, and this OFF output S1 is input to the OR circuit 116. As a result, the output of the OR circuit 116 is turned off. This OFF output is input to the AND circuit 117. As a result, the output of the AND circuit 117 is turned off, and the outputs of the safety output circuits 118 and 119 are turned off.

  At this time, as shown in FIG. 14, the outputs 1 (Y0, Y1) and 2 (Y2, Y3) of the safety output circuits 118, 119 are inverted and the outputs SL1, SL2 are turned on, so that the solenoid is turned on. Driven. Thereby, since the locked state of the safety door is released, the operator can enter the danger area by opening the safety door.

  Next, when the operator operates the teaching device, the safety input 2 is turned on, the output of the AND circuit 110 is turned on, and this on output is input to the self-holding circuit 113. The self-holding circuit 113 outputs the held input from the AND circuit 110 to the OR circuit 116 when the start input 1 is input to the trigger terminal. As a result, the output of the OR circuit 116 is turned on, and this ON output is input to the AND circuit 117. On the other hand, since the ON output from the self-holding circuit 115 is input to the AND circuit 117, the output of the AND circuit 117 is turned ON. As a result, safety outputs 1 and 2 are output from the safety output circuits 118 and 119, and the operator can operate the teaching device to teach the control target device.

  During this teaching, as shown in FIG. 14, the inverted output of output 1 (Y0, Y1) is used as the safety output of the solenoid, and the inverted output of output 2 (Y2, Y3) is used as the safety output of the solenoid. Yes. That is, in the teach mode, the safety door is locked and the safety is ensured by turning off the output to the solenoid.

  In this case, the safety inputs 1 to 6 of the safety controller 1 are connected to teaching devices such as enable switches, devices with mode selection functions, directly open devices such as emergency stop switches and safety switches, and safety outputs 1 and 2 Since desired control can be performed only by connecting to an external control target device, the burden on the user can be reduced. In this case, a highly versatile safety control device that can be applied to various machines such as machine tools and robots can be realized as an external control target machine.

<Logic pattern 7>
FIG. 15 is a block diagram showing a circuit configuration for realizing the seventh safety control logic (logic pattern 7). This logic pattern is suitable logic when, for example, the first and second robots as two devices to be controlled arranged in parallel must not be stopped simultaneously or when it is not necessary to stop them simultaneously.

  The safety input 1 is input with a safety input from an emergency stop switch for stopping the first and second robots simultaneously. The safety inputs 2 and 3 are duplicated from the first and second safety switches (for example, safety guard open / close detection switches) as direct opening devices provided corresponding to the danger area of the first robot. Has been entered. The safety inputs 4 and 5 are safety inputs from third and fourth safety switches (for example, safety guard opening / closing detection switches) as direct opening devices provided corresponding to the dangerous area of the second robot. Is duplicated and input.

  The input S1 from the safety input 1 is input to the self-holding circuit 122, and the output of the self-holding circuit 122 is input to the subsequent AND circuit 127. Each input from the safety inputs 2 and 3 is input to the AND circuit 120, and the AND circuit 120 outputs a logical product of the safety inputs 2 and 3. The output S2 of the AND circuit 120 is input to the self-holding circuit 123, and the output of the self-holding circuit 123 is input to the subsequent AND circuit 127. The AND circuit 127 outputs a logical product of the outputs of the self-holding circuits 122 and 123. Each input from the safety inputs 4 and 5 is input to the AND circuit 121, and the AND circuit 121 outputs a logical product of the safety inputs 4 and 5. The output S3 of the AND circuit 121 is input to the self-holding circuit 124, and the output of the self-holding circuit 124 is input to the subsequent AND circuit 128. The output of the self-holding circuit 122 is also input to the AND circuit 128. The AND circuit 128 outputs a logical product of the outputs of the self-holding circuits 122 and 124.

  A start input 1 is input to the trigger terminal of the self-holding circuit 122. Further, start inputs 2 and 3 are input to the OR circuit 125, and start inputs 2 and 4 are input to the OR circuit 126. The output of the OR circuit 125 is input to the trigger terminal of the self-holding circuit 123, and the output of the OR circuit 126 is input to the trigger terminal of the self-holding circuit 124. The output of the AND circuit 127 is input to the safety output circuit 129, and the output of the AND circuit 128 is input to the safety output circuit 130. The safety output circuit 129 outputs a safety control output 1 to the first robot, and the safety output circuit 130 outputs a safety control output 2 to the second robot.

  In this logic pattern 7, when the safety input 1 is turned on, the safety guard on the first robot side is opened and the safety input 2 or 3 from the first or second safety switch is turned off. The output S2 of the circuit 120 is turned off, the output of the self-holding circuit 123 is turned off, and the output of the AND circuit 127 is turned off. As a result, the safety output 1 from the safety output circuit 129 is turned off after the set time of the off-delay timer, and the operation of the first robot is stopped. At this time, if the safety inputs 4 and 5 from the safety switch on the second robot side are in the on state, the output S3 of the AND circuit 121 is on, and the self-holding circuit is input by the input of the start input 2 or 4 The output from 124 is turned on and input to the AND circuit 128. At this time, the input of the start input 1 also turns on the output of the self-holding circuit 122, which is input to the AND circuit 128, and the output from the AND circuit 128 is turned on. Thereby, the safety output 2 from the safety output circuit 130 is turned on, and the operation of the second robot is maintained.

  On the contrary, when the safety input on the second robot side is opened and the safety input 4 or 5 from the third or fourth safety switch is turned off with the safety input 1 turned on, the AND circuit The output S3 of 121 is turned off, the output of the self-holding circuit 124 is turned off, and the output of the AND circuit 128 is turned off. As a result, the safety output 2 from the safety output circuit 130 is turned off after the set time of the off-delay timer, and the operation of the second robot is stopped. At this time, if the safety inputs 2 and 3 from the safety switch on the first robot side are in the on state, the output S2 of the AND circuit 120 is on, and the self-holding circuit is input by the input of the start input 2 or 3 The output from 123 is turned on and input to the AND circuit 127. At this time, the input of the start input 1 also turns on the output of the self-holding circuit 122, which is input to the AND circuit 127, and the output from the AND circuit 127 is turned on. Thereby, the safety output 1 from the safety output circuit 129 is turned on, and the operation of the first robot is maintained.

  Next, when the safety input 2, 3, 4, and 5 are turned on and the emergency stop switch is pressed and the safety input 1 is turned off, the input S 1 to the self-holding circuit 122 is turned off. Thus, the output of the self-holding circuit 122 is turned off. The output of the self-holding circuit 122 is input to the AND circuits 127 and 128. For this reason, both the outputs of the AND circuits 127 and 128 are turned off. As a result, the outputs of both safety output circuits 129 and 130 are turned off after the set time of the off-delay timer, and the operations of the first and second robots are stopped.

  In this case, the safety input 1 of the safety controller 1 is connected to the emergency stop switch, the safety inputs 2 and 3 are connected to a directly open device such as a safety switch on the first robot side, and the safety inputs 4 and 5 are connected. A desired control can be performed by connecting the safety output 1 directly to the first robot and connecting the safety output 2 to the second robot as well as connecting directly to the open circuit device such as a safety switch on the second robot side. Can reduce the burden on the user.

<Logic pattern 8>
FIG. 16 is a block diagram showing a circuit configuration for realizing the eighth safety control logic (logic pattern 8). The logic pattern 8 is similar to the logic pattern 7 except that the output of the self-holding circuit 122 is not input to the AND circuit 128 and the output of the AND circuit 127 is input to the AND circuit 128. This is different from the logic pattern 7.

  In the logic pattern 8, when the safety input 1 is turned on and the safety guard on the first robot side is opened and the safety input 2 or 3 from the first or second safety switch is turned off, The output S2 of the circuit 120 is turned off, the output of the self-holding circuit 123 is turned off, and the output of the AND circuit 127 is turned off. As a result, the safety output 1 from the safety output circuit 129 is turned off after the set time of the off-delay timer, and the operation of the first robot is stopped. At this time, the off output of the AND circuit 127 is input to the AND circuit 128, and therefore the output of the AND circuit 128 is also turned off. As a result, the safety output 2 from the safety output circuit 130 is also turned off after the off-delay timer setting time, and the operation of the second robot is also stopped.

  On the contrary, when the safety input on the second robot side is opened and the safety input 4 or 5 from the third or fourth safety switch is turned off with the safety input 1 turned on, the AND circuit The output S3 of 121 is turned off, the output of the self-holding circuit 124 is turned off, and the output of the AND circuit 128 is turned off. As a result, the safety output 2 from the safety output circuit 130 is turned off after the set time of the off-delay timer, and the operation of the second robot is stopped. At this time, if the safety inputs 2 and 3 from the safety switch on the first robot side are in the on state, the output S2 of the AND circuit 120 is on, and the self-holding circuit is input by the input of the start input 2 or 3 The output from 123 is turned on and input to the AND circuit 127. At this time, the output of the self-holding circuit 122 is also turned on by the input of the start input 1, and this on output is inputted to the AND circuit 127, and the output from the AND circuit 127 is turned on. Thereby, the safety output 1 from the safety output circuit 129 is turned on, and the operation of the first robot is maintained.

  Next, when the safety input 2, 3, 4, and 5 are turned on and the emergency stop switch is pressed and the safety input 1 is turned off, the input S 1 to the self-holding circuit 122 is turned off. Thus, the output of the self-holding circuit 122 is turned off. The off output of the self-holding circuit 122 is input to the AND circuit 127, and therefore the output of the AND circuit 127 is turned off. The off output of the AND circuit 127 is input to the AND circuit 128. Therefore, the output of the AND circuit 128 is also turned off. As a result, the outputs of both safety output circuits 129 and 130 are turned off after the set time of the off-delay timer, and the operations of the first and second robots are stopped.

  In this case, the safety input 1 of the safety controller 1 is connected to the emergency stop switch, the safety inputs 2 and 3 are connected to a directly open device such as a safety switch on the first robot side, and the safety inputs 4 and 5 are connected. A desired control can be performed by connecting the safety output 1 directly to the first robot and connecting the safety output 2 to the second robot as well as connecting directly to the open circuit device such as a safety switch on the second robot side. Can reduce the burden on the user.

  Needless to say, the application of the present invention is not limited to the above-described eight types of logic patterns. The safety controller according to the present invention can rewrite a built-in program via a program I / F circuit, and can construct various logic patterns corresponding to various applications for a user who uses the safety controller. Moreover, the number of logic patterns limited to eight can be increased by connecting the expansion units described below to the safety controller.

  Next, the above-described safety controller may have an expansion (expansion) function, and such a safety controller will be described with reference to each block of FIGS. In each figure, the same reference numerals as those in the above-described embodiments indicate the same or corresponding parts.

FIG. 17 is a block diagram in which the expansion unit 1 </ b> A is connected to the safety controller 1. Safety controller 1 has an enhanced interface (I / F) circuit 58, likewise, extension unit 1A has an enhanced interface (I / F) circuits 58A ₁ and 58A _2. Safety controller 1 and expansion unit 1A is connected via the expansion interface circuit 58, 58a _1. The extension interface circuit 58 is connected to the arithmetic processing circuit 50. Expansion interface (I / F) circuits 58A ₁ and 58A _2, together are serially connected using the serial bus, and is parallel connected with the parallel bus. An arithmetic processing circuit 50A is bus-connected to these serial bus and parallel bus. The extension unit 1 </ b> A has substantially the same configuration as the safety controller 1 and has the same input / output function as the safety controller 1. A serial interface (I / F) circuit 59 is further connected to the arithmetic processing circuit 50A of the expansion unit 1A.

Although not shown, the expansion unit 1A, other extension unit via the extension interface 58A ₂ is connectable. Communication between the arithmetic processing circuit 50 and the extended interface circuit 58, communication between the extended interface circuits 58A ₁ and 58A ₂ , and communication between the arithmetic processing circuit 50A and the extended interface circuits 58A ₁ and 58A ₂ are performed by CRC (Cyclic Redundancy). The security is ensured by using (Check: cyclic redundancy check) or adding a sequence number to the data.

FIG. 18 is a block diagram of the input circuit expansion unit 1B. This expansion unit 1B is specialized for the input function and is not equipped with an output circuit. In this case as well, a safety controller or other extension unit can be connected via the extension interface circuits 58B ₁ and 58B ₂ as in the extension unit 1A of FIG.

FIG. 19 is a block diagram of the output circuit extension unit 1C. This expansion unit 1C is specialized for the output function and is not equipped with an input circuit. The output from the output circuit 53C includes not only a semiconductor output but also a relay output. Also in this case, similarly to the extension unit 1A of FIG. 17, a safety controller or other extension unit can be connected via the extension interface circuits 58C ₁ and 58C ₂ .

FIG. 20 is a block diagram of a communication unit 1D as an expansion unit. In this case, by changing the arithmetic processing circuit 50D and the serial interface circuit 59, safe wired communication, non-secure wired communication, safe wireless communication, non-safe wireless communication, and the like can be configured. In this case as well, a safety controller or another extension unit can be connected via the extension interface circuits 58D ₁ and 58D ₂ as in the extension unit 1A of FIG.

FIG. 21 is a block diagram of the program expansion unit 1E. In the safety controller 1 described above, the logic (program) for safety control is limited to eight patterns, but the program expansion unit 1E can be expanded to an infinite number of programs. In this case as well, a safety controller or another extension unit can be connected via the extension interface circuits 58E ₁ and 58E ₂ as in the extension unit 1A of FIG.

  Next, the safety controller described above may have an intrinsically safe explosion-proof function. Such a safety controller will be described with reference to the block diagrams of FIGS. 22 and 23. In each figure, the same reference numerals as those in the above-described embodiments indicate the same or corresponding parts.

  In the safety controller 1 ′ shown in FIG. 22, a safety input circuit 61 corresponding to an intrinsically safe explosion-proof input is connected to the safety input circuit 51 ′, and an input circuit 62 and an output circuit 63 corresponding to an intrinsically safe explosion-proof are respectively non-safety. The input circuit 52 ′ and the non-safety output circuit 59 ′ are respectively connected. A power supply voltage from the intrinsically safe explosion-proof power supply circuit 60 is applied to the safety input circuit 61.

  The intrinsically safe explosion-proof power supply circuit 60 has a voltage limiting circuit composed of a Zener diode ZD or a thyristor. The intrinsically safe explosion-proof safety input circuit 61 and the intrinsically safe explosion-proof compatible input circuit 62 are composed of resistors for limiting current, a semiconductor current limiting circuit R, and the like. The safety input circuit 61, the input circuit 62, and the output circuit 63 are insulated from the safety input circuit 51 ′, the non-safety input circuit 52 ′, and the non-safety output circuit 59 ′, respectively, such as a photocoupler PC and a transformer. Insulated by the element. This configuration limits the voltage and current to the safety controller input circuit, so you can use safety devices such as emergency stop switches and safety switches installed in locations where there is a risk of explosion. become able to. Since the input circuit is mounted on a dedicated board, it is possible to cope with explosion-proof only by switching the board.

  FIG. 23 is a block diagram of the input circuit expansion unit 1'B corresponding to the intrinsically safe explosion-proof input. The expansion unit 1'B is mainly specialized for the input function and is not equipped with an output circuit. In this case, an explosion-proof function can be realized even for an extended input. Also in this case, as in the safety controller 1 of FIG. 11, an intrinsically safe explosion-proof power circuit 60B, an intrinsically safe explosion-proof safety input circuit 61B, an intrinsically safe explosion-proof input circuit 62B and an output circuit 63B are provided. ing.

  Note that, by appropriately using the above-described non-explosion-proof input circuit and the intrinsically safe explosion-proof input circuit, it is possible to construct a safety circuit optimal for a system in which a safety controller is used.

  Moreover, you may make it the structure which a safety controller produces | generates and supplies the signal for driving the apparatus which outputs a safety input. For example, as a device for outputting a safety input, a direct opening / closing device such as an emergency stop switch or a safety switch has a signal (for example, a pulse signal) given to the first contact when the first and second contacts are closed. Through the second contact as a safety input. When a safety control logic that uses a safety input from a direct opening / closing device is selected by incorporating a signal generation circuit that generates and outputs this signal into the safety controller, the arithmetic processing circuit 50 generates a signal based on the safety control logic. The generation circuit may be controlled to generate and output a signal. In this way, the safety controller generates and supplies a signal for driving the device that outputs the safety input, so that the device that outputs the safety input can be appropriately driven.

  Furthermore, the safety controller not only controls the external device to stop the machine, but also controls the approach of a person to the machine. That is, the safety controller stops the machine by turning off the safety outputs 1 and 2, and then outputs a signal (an ON signal of the outputs SL 1 and 2) for allowing a person to approach the machine, Release the safety door lock. This allows a person to open the safety door and approach the machine after the machine has stopped. In this way, a person can be brought close to the stopped machine, and safety can be ensured. As described above, the signal for allowing the person to approach the machine is given to the indicator lamp that displays that the person may approach the machine, as well as the solenoid of the safety switch. May be.

  As described above, the control device according to the present invention is useful as a safety control device for various machines such as machine tools and robots. In particular, the user only has to select a built-in logic pattern without creating a program. Therefore, it is suitable as a user-friendly safety controller.

JP 2004-297997 A JP 2005-115698 A

Claims (6)

A control device for safely controlling the operation of external equipment,
An input unit to which a safety input is input;
An output unit for outputting a safety control output to an external device;
A setting switch for the user to select and set a desired safety control logic from among a plurality of safety control logics stored in an arithmetic processing unit to be described later,
Based on the safety input input to the input unit, an arithmetic processing unit that controls the output unit according to the safety control logic set by the setting switch;
A display unit for displaying setting information set by the user using the setting switch;
The arithmetic processing unit is configured to include a first arithmetic processing unit to which the setting switch is connected and a second arithmetic processing unit to which the display unit is connected. Each of the arithmetic processing units performs arithmetic processing according to the safety control logic set by the setting switch, and controls the output unit based on a collation result of both arithmetic results.
A control device characterized by that . In claim 1,
The first arithmetic processing unit transmits new setting information newly set by the setting switch to the second arithmetic processing unit,
The second arithmetic processing unit is connected to a memory that stores previous previous setting information set by the setting switch, and the old setting stored in the memory of the second arithmetic processing unit While transmitting information to the first arithmetic processing unit,
In each of the first and second arithmetic processing units, the new setting information set by the setting switch is compared with the old setting information, and when the new setting information is different from the old setting information, The second arithmetic processing unit is displaying an alarm on the display unit,
A control device characterized by that. In claim 2,
An approval switch for validating the setting information set by the user with the setting switch as confirmed information;
When the display unit displays the alarm, when the approval switch is turned on, the old setting information is reset and the new setting information is validated as finalized information.
A control device characterized by that. In any of claims 1 to 3,
The input unit has a plurality of safety input terminals to which a plurality of safety inputs are input, and a non-safety input terminal to which a start input is input,
Between the input unit and the output unit, a logic circuit for outputting the safety control output based on each safety input input to each safety input terminal from the output unit is connected,
The logic circuit is
An AND circuit that outputs the logical product of each safety input input to each safety input terminal; and
An output from the AND circuit is inputted and held, and a holding circuit that outputs the held safety input to the output unit using the start input inputted to the non-safety input terminal as a trigger input; Composed of,
A control device characterized by that. In any of claims 1 to 3,
The input unit includes a first safety input terminal to which a mode select input for switching between a normal operation mode and a teaching mode is input, a second safety input terminal to which a safety input from a teaching device is input, and a safety switch A third safety input terminal to which a safety input from is input, and first and second non-safety input terminals to which first and second start inputs are input,
A first AND circuit that outputs a logical product of the teach mode input from the first safety input terminal and the safety input from the second safety input terminal as inputs, and a normal from the first safety input terminal A second AND circuit that outputs a logical product of the operation mode input and the safety input from the third safety input terminal as inputs; and
An output from the first AND circuit is inputted and held, and the held safety input is set by using the first start input inputted to the first non-safety input terminal as a trigger input. A first holding circuit for outputting and an output from the second AND circuit are inputted and held, and the second start input inputted to the second non-safety input terminal is used as a trigger input. A second holding circuit for outputting the held safety input;
An OR circuit that receives the outputs from the first and second holding circuits as inputs and outputs a logical sum of these outputs ;
The output unit receives an output from the OR circuit and outputs a safety control output based on the input to an external device.
A control device characterized by that. In any of claims 1 to 3,
The input unit has a safety input terminal for emergency stop to which an emergency stop switch is connected and a safety input from a plurality of first safety switches provided corresponding to the first external device. A safety input terminal, a second safety input terminal to which safety inputs from a plurality of second safety switches provided corresponding to the external second device are input, and first to third start inputs And first to third non-safety input terminals to which
A first AND circuit that outputs a logical product of a plurality of safety inputs from the first safety input terminal as an input, and a logical product of the first AND circuit that outputs a logical product of the safety inputs from the second safety input terminal as inputs. A second AND circuit that outputs
The safety input from the emergency stop safety input terminal is held, and the held safety input is output using the first start input inputted to the first non-safety input terminal as a trigger input. 1 holding circuit and holding the output from the first AND circuit as an input and triggering the second or third start input inputted to the second or third non-safety input terminal A second holding circuit that outputs the held safety input as an input, and an output from the second AND circuit as an input to hold this, and input to the second non-safety input terminal A third holding circuit for outputting the held safety input using the second start input as a trigger input;
A third AND circuit that outputs the logical product of the outputs from the first and second holding circuits, and an output from the first holding circuit or an output from the third AND circuit; And a fourth AND circuit that outputs the logical product of the outputs from the third holding circuit as inputs.
The output unit receives an output from the third AND circuit, and outputs a first safety control output based on the input to an external first device; and And an output from the AND circuit of 4 and a second output unit that outputs a second safety control output based on the input to an external second device,
A control device characterized by that.

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