JP2023033795A - Safety control device - Google Patents

Abstract

To provide a safety control device that reduces the user's burden of creating a control program, and can cope with various specifications with different types and combinations of safety input devices.SOLUTION: In a safety control device, a safety control logic is built in advance to safely control a target device, and an arithmetic processing unit executes control on the target device according to the safety control logic. In such a safety control device, a determination processing unit determines types of safety input devices connected to an input unit according to the safety control logic, based on input signals input from the safety input devices to the input unit. Then, the arithmetic processing unit executes control following the safety control logic on the target device depending on the type of the safety input device determined by the determination processing unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a safety control device for safely controlling target equipment.

In the field of FA (Factory Automation) technology, while operations such as manufacturing and inspection in the production process are automated by equipment such as industrial robots, machine tools, and manufacturing equipment, there are various dangers associated with such automation. (e.g. workers entering dangerous areas) may occur. For this reason, in the field of FA technology, it is important to avoid dangers that may occur with automation. A controller is essential.

Specifically, a safety control device is a device that safely controls a target device based on an input signal from a safety input device such as an emergency stop switch or a safety light curtain. As an example, when an emergency stop switch is pressed or a person is detected by the safety light curtain, the safety controller immediately stops the target equipment based on the input signals received from those safety input devices. In such a safety control device, the control of the target equipment is realized by hardware by means of circuits including relay switches, etc., and by software by causing a processing device such as a CPU to execute a control program. There are things that are done. As the latter safety control device, a safety PLC (Programmable Logic Controller) that takes in and executes a control program created by the user has been conventionally used.

Japanese Patent No. 5254968

However, according to the safety PLC described above, since the user can create the control program by himself/herself, it is possible to perform safety control suitable for the user's specifications. become.

Therefore, for example, in Patent Document 1, as a safety control device, a plurality of control programs prepared in advance by the supplier are stored in the safety control device, and the user can select and use them. is proposed. According to such a safety control device, the user only needs to select a control program, so the user's burden of creating a control program is reduced. On the other hand, the inventors have found that such a safety control device has the following problems.

In the control program, even if the basic logic for safely controlling the target device (hereinafter referred to as "safety control logic") is the same, if the type of safety input device is different, the safety input device The process for determining operating conditions will be different. Therefore, if the types of safety input devices (emergency stop switches, safety light curtains, etc.) and their combinations are different, a corresponding control program is required. In addition, the number of types and combinations of safety input devices is enormous, and the number of control programs corresponding to them is also enormous. However, there is a limit to the number of control programs that the supplier can prepare. For this reason, even if there is a control program prepared in advance that can be used according to the user's specifications for safety control logic, the type of safety input device that can be handled by that control program is determined by the user. If it is different from what he wants to use, the user cannot use the control program, and therefore cannot use the safety control device itself. In other words, the number of control programs that can be prepared by the supplier is limited, so the safety control device of Patent Document 1 is limited in its ability to handle specifications with different types and combinations of safety input devices.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a safety control device that reduces the user's burden of creating a control program and that is capable of supporting various specifications with different types and combinations of safety input devices. .

A safety control device according to the present invention is a safety control device that safely controls a target device based on an input signal from a safety input device, and includes an input unit, an output unit, a safety control logic, an arithmetic processing unit, Prepare. A safety input device is connected to the input section, and a target device is connected to the output section. The safety control logic is preconfigured logic for safely controlling the target device. The arithmetic processing unit executes control on the target device according to the safety control logic. In such a configuration, the safety control device further includes a determination processing section. The determination processing unit determines the type of safety input device connected to the input unit according to the safety control logic based on the input signal input from the safety input device to the input unit. Then, the arithmetic processing unit executes control according to the safety control logic on the target device according to the type of the safety input device determined by the determination processing unit.

According to the safety control device, the type of safety input device connected to the input unit is automatically determined, and control according to the safety control logic is executed for the target device according to the type determined there. . Therefore, even with the same safety control logic, it is possible to support various specifications with different types and combinations of safety input devices.

The safety control device may further include a determination processing section. Here, the determination processing unit determines the operating state of the safety input device connected to the input unit according to the type of the safety input device determined by the determination processing unit. Then, the arithmetic processing unit performs control according to the safety control logic on the target device according to the operating state of the safety input device determined by the determination processing unit.

According to the above configuration, the type of safety input device connected to the input unit is automatically determined, and the operating state of the safety input device is automatically determined according to the type, and the determined operating state is determined. Accordingly, control according to the safety control logic is performed on the target device. Therefore, even with the same safety control logic, it is possible to support various specifications with different types and combinations of safety input devices.

In addition, the safety control device is provided with safety control logic in advance, and the type and operating state of the safety input device connected to the input section are automatically discriminated and determined according to the safety control logic. Therefore, it is not necessary for the user to create a series of control programs for executing those controls, and the user's burden of creating such a control program is reduced.

The safety control device may further include a determination condition. Here, the determination condition is a condition used for comparison with the input signal from the safety input device in order to determine the operating state of the safety input device, and differs for each type of safety input device. In such a configuration, the determination processing unit selects a determination condition corresponding to the type of safety input device determined by the determination processing unit from among the determination conditions, and compares the determination condition with the input signal to determine the input signal. It may determine the operating state of safety input devices connected to the unit.

According to the above configuration, since the determination condition corresponding to the type of safety input device determined by the determination processing unit is selected, the operating state of the safety input device can be accurately determined according to the type of the safety input device. becomes possible to do.

The safety control device may further include a display unit that displays the type of the safety input device determined by the determination processing unit, and a confirmation operation unit that is used to determine the type displayed on the display unit. good. In such a configuration, the determination processing unit is connected to the input unit by selecting and using the determination condition corresponding to the type from among the determination conditions when the type is confirmed by the confirmation operation unit. may determine the operational status of safety input devices that are

According to the above configuration, the user can confirm whether or not the safety control device correctly recognizes the type of safety input device to be used according to the user's specifications by checking the display unit. Then, it is confirmed on the display that the type of safety input device is correctly recognized by the safety control device. Under the correct recognition of the type of input device, the operating state of the safety input device will be correctly determined. Therefore, erroneous control of the target device, which may occur due to erroneous connection of the safety input device by the user or erroneous recognition of the type by the safety control device, is prevented.

The safety control device may include a plurality of safety control logics, and may further include a logic setting operation section used for selecting any one of the plurality of safety control logics. In addition, the input section may be provided with a plurality of terminals for connecting safety input devices, among which the terminals to be used for connecting the safety input devices to the input section are specified in advance for each safety control logic. may be associated with each other. In such a configuration, when any safety control logic is selected by the logic setting operation unit, the determination processing unit uses the input signal input to the terminal associated with that safety control logic. , the type of safety input device connected to the terminal may be determined.

According to the above configuration, the number of safety control logic options increases, and whatever safety control logic is selected, it becomes possible to support various specifications with different types and combinations of safety input devices. .

The safety input device may be a device configured such that an input signal from the safety input device is duplicated into a first input signal and a second input signal. In this case, in the safety control device, the determination processing unit determines whether the type of the safety input device connected to the input unit is satisfied by the first input signal and the second input signal input from the safety input device to the input unit. You may discriminate by the difference of the existing conditions.

In the above configuration, the fact that the safety input device is duplicated is used to determine the type of the safety input device. That is, since the safety input device is duplicated, it is possible to use two signals (first input signal and second input signal) to determine the type of the safety input device. By using two signals in this way, the number of discriminable types can be increased by the number of conditions that the two signals can satisfy.

ADVANTAGE OF THE INVENTION According to this invention, while reducing a user's burden of creating a control program, it becomes possible to respond to various specifications with which the kind and combination of safety input devices differ.

1 is a block diagram showing the configuration of a safety control device according to an embodiment; FIG. 1 is a front view of a safety control device according to an embodiment; FIG. It is the conceptual diagram which showed the structure of the duplexed safety input device for every kind. 4 is a conceptual diagram showing determination conditions used in the embodiment; FIG. 4 is a flow chart showing safety control processing executed in the present embodiment;

[1] Configuration of Safety Control Device FIG. 1 is a block diagram showing the configuration of the safety control device according to the embodiment. The safety control device of this embodiment is a device that safely controls the target device 102 based on the input signal Sp from the safety input device 101 . Here, the target device 102 is a device automated by FA technology, such as an industrial robot, a machine tool, and a manufacturing device. In addition, the safety input device 101 detects the occurrence of an emergency related to the target device 102 such as an emergency stop switch, safety switch NO/NC, safety light curtain, etc. It is a device that notifies with a signal (input signal Sp). In this embodiment, the input signal Sp from the safety input device 101 and the target All of the output signals Sq to the device 102 are duplicated. The details of duplication will be described later.

As shown in FIG. 1 , the safety control device includes an input section 1 , an output section 2 , a storage section 3 , an operation section 4 , a display section 5 and a control section 6 . Further, FIG. 2 is a front view of the safety control device, and in this embodiment, the input unit 1, the output unit 2, the operation unit 4, and the display unit 5 are collectively provided on the front of the safety control device. there is In addition, these parts are not limited to being collectively provided on one surface, and may be separately provided on different surfaces. The configuration of each unit will be specifically described below.

[1-1] Input Unit The input unit 1 is a portion (interface) to which the safety input device 101 is connected, and the input unit 1 is provided with a plurality of terminals G for connecting the safety input device 101. . The input unit 1 may be provided with another terminal for connecting an input device other than the safety input device 101, such as a start switch or a monitor.

In the present embodiment, the input unit 1 is configured to allow connection of the redundant safety input device 101 . Specifically, the input unit 1 is provided with two drive terminals Gd1 and Gd2 and two receive terminals Gr1 and Gr2 corresponding to these terminals, respectively. 101 are connected (hereinafter referred to as "terminal group Mg"). Further, the input section 1 is provided with a plurality of such terminal groups Mg.

From the two drive terminals Gd1 and Gd2 in each terminal group Mg, a first reference signal St1 and a second reference signal St2, which serve as criteria for judgment (discrimination and judgment) in discrimination processing and judgment processing, which will be described later, are respectively transmitted. output. Also, the first input signal Sp1 and the second input signal Sp2 from the safety input device 101 connected to these terminals are input to the receive terminals Gr1 and Gr2 in each terminal group Mg, respectively. Here, the first input signal Sp1 and the second input signal Sp2 are the duplicated input signal Sp from the safety input device 101 . More specifically, it is as follows.

The duplexed safety input device 101 can be classified into three types as follows. 3A to 3C are conceptual diagrams showing the configuration of the redundant safety input device 101 for each type. In FIG. 3A, the safety input device 101 has two normally closed contacts SA1 and SA2 (NC contacts), and their opening and closing operations are interlocked with the movements of the operators (buttons, switches, etc.) (including the case where the timing shifts and operates). When connecting to the input section 1, both ends of the normally closed contact SA1 are connected to the drive terminal Gd1 and the receive terminal Gr1, and both ends of the normally closed contact SA2 are connected to the drive terminal Gd2 and the receive terminal Gr2.

When the normally closed contact SA1 is closed, the first reference signal St1 output from the drive terminal Gd1 is directly input to the receive terminal Gr1 as the first input signal Sp1 from the safety input device 101. be. Therefore, as the first reference signal St1, when a signal with a constant voltage level of H (high) level (eg, 24 V) (hereinafter referred to as "H level signal") is output from the drive terminal Gd1, The signal is directly input to the receive terminal Gr1 as the first input signal Sp1. Further, when a signal having a constant voltage level (eg, 0 V) and having a constant voltage level (hereinafter referred to as "L level signal") is output from the drive terminal Gd1 as the first reference signal St1, The signal is directly input to the receive terminal Gr1 as the first input signal Sp1. On the other hand, when the normally closed contact SA1 is opened, the first reference signal St1 output from the drive terminal Gd1 is cut off by the normally closed contact SA1. , an L-level signal is input to the receive terminal Gr1 as the first input signal Sp1.

Similarly, when the normally closed contact SA2 is closed, the second reference signal St2 output from the drive terminal Gd2 is directly input to the receive terminal Gr2 as the second input signal Sp2 from the safety input device 101. be done. Therefore, when an H-level signal is output from the drive terminal Gd2 as the second reference signal St2, the signal is directly input to the receive terminal Gr2 as the second input signal Sp2. Also, when an L-level signal is output from the drive terminal Gd2 as the second reference signal St2, the signal is directly input to the receive terminal Gr2 as the second input signal Sp2. On the other hand, when the normally closed contact SA2 is opened, the second reference signal St2 output from the drive terminal Gd2 is cut off by the normally closed contact SA2. , an L-level signal is input to the receive terminal Gr2 as the second input signal Sp2.

Such a configuration of FIG. 3A is applied to a safety input device 101 such as an emergency stop switch. Below, this type of safety input device 101 is referred to as "first safety input device 101A". A case where both the normally closed contacts SA1 and SA2 are in a closed state is defined as a case where the operating state of the first safety input device 101A is in a "normal state", and at least one of the normally closed contacts SA1 and SA2 is in a "normal state". The case where the open state is assumed is the case where the operating state of the first safety input device 101A becomes "abnormal state".

In FIG. 3B, the safety input device 101 has a normally open contact SB1 (NO contact) and a normally closed contact SB2 (NC contact), and their opening and closing operations are interlocked with the movement of an operator (such as an actuator). is configured to operate in the opposite direction. When connecting to the input section 1, both ends of the normally open contact SB1 are connected to the drive terminal Gd1 and the receive terminal Gr1, and both ends of the normally closed contact SB2 are connected to the drive terminal Gd2 and the receive terminal Gr2.

When the normally open contact SB1 is open and the normally closed contact SB2 is closed, the first reference signal St1 output from the drive terminal Gd1 is interrupted by the normally open contact SB1. Regardless of whether the 1-reference signal St1 is an H level signal or an L level signal, an L level signal is input to the receive terminal Gr1 as the first input signal Sp1. On the other hand, the second reference signal St2 output from the drive terminal Gd2 is directly input to the receive terminal Gr2 as the second input signal Sp2. Therefore, when an H-level signal is output from the drive terminal Gd2 as the second reference signal St2, the signal is directly input to the receive terminal Gr2 as the second input signal Sp2. Also, when an L-level signal is output from the drive terminal Gd2 as the second reference signal St2, the signal is directly input to the receive terminal Gr2 as the second input signal Sp2.

On the other hand, when the normally open contact SB1 is closed and the normally closed contact SB2 is open, the first reference signal St1 output from the drive terminal Gd1 is directly output from the safety input device 101. It is input to the receive terminal Gr1 as the first input signal Sp1. Therefore, when an H-level signal is output from the drive terminal Gd1 as the first reference signal St1, the signal is directly input to the receive terminal Gr1 as the first input signal Sp1. When an L level signal is output from the drive terminal Gd1 as the first reference signal St1, the signal is directly input to the receive terminal Gr1 as the first input signal Sp1. On the other hand, since the second reference signal St2 output from the drive terminal Gd2 is cut off by the normally closed contact SB2, regardless of whether the second reference signal St2 is an H level signal or an L level signal, the receive terminal Gr2 , an L-level signal is input as the second input signal Sp2.

Such a configuration of FIG. 3B is applied to safety input devices 101 such as safety switches NO/NC. Below, this type of safety input device 101 is referred to as a "second safety input device 101B". A case where the normally open contact SB1 is in the open state and the normally closed contact SB2 is in the closed state is assumed to be the "normal state" of the second safety input device 101B, and the normally open contact SB1 is closed. It is assumed that the operating state of the second safety input device 101B is "abnormal state" when the normally closed contact SB2 is opened while the state is changed.

In FIG. 3C, the safety input device 101 includes two sensor elements SC1 and SC2 that output an H level signal when not detected and an L level signal when detected. are configured to perform the same operation with respect to the same detected object (person, etc.). Further, when connecting to the input section 1, there is no connection to the drive terminals Gd1 and Gd2, and only the receive terminals Gr1 and Gr2 are connected to the sensor elements SC1 and SC2, respectively. It is connected via a control circuit (not shown) that outputs a corresponding signal.

Then, when the sensor element SC1 is in the non-detection state, an H level signal is input to the receive terminal Gr1 as the first input signal Sp1 from the safety input device 101. FIG. On the other hand, when the sensor element SC1 is in the detection state, an L level signal is input to the receive terminal Gr1 as the first input signal Sp1. Similarly, when sensor element SC2 is in a non-detection state, a signal of H level is input to receive terminal Gr2 as second input signal Sp2 from safety input device 101 . On the other hand, when the sensor element SC2 is in the detection state, an L level signal is input to the receive terminal Gr2 as the second input signal Sp2.

Such a configuration of FIG. 3C is applied to a safety input device 101 such as a safety light curtain. Below, this type of safety input device 101 is referred to as "third safety input device 101C". Further, a case where neither of the sensor elements SC1 and SC2 is in a detected state is defined as a case where the operating state of the third safety input device 101C is in a "normal state", and at least one of the sensor elements SC1 and SC2 is detected. It is assumed that the operation state of the third safety input device 101C becomes "abnormal state".

Here, when the third safety input device 101C is connected to the input unit 1, the third safety input device is configured so that it can be checked whether the signal is normally output from the device. At 101C, the output circuit is controlled to periodically output an off-check pulse (L level pulse).

[1-2] Output Unit The output unit 2 is a portion (interface) to which the target device 102 is connected, and the output unit 2 is provided with a plurality of terminals H for connecting the target device 102 . In this embodiment, the output section 2 is configured such that the output signal Sq to the target device 102 connected to the output section 2 is duplicated. Specifically, two output terminals H1 and H2 are provided in the output unit 2, and one group (hereinafter referred to as "terminal group Mh") to which one target device 102 is connected is formed by these two terminals. ) is configured. Further, the output section 2 is provided with a plurality of such terminal groups Mh. The two output terminals H1 and H2 in each terminal group Mh output the same control signal for safely controlling the target device 102 connected to the terminal group Mh.

[1-3] Storage Unit The storage unit 3 is a memory such as a ROM or a RAM, and various information necessary for safety control is stored in the storage unit 3 . In this embodiment, the storage unit 3 stores determination conditions, determination conditions, safety control logic, and default settings as information necessary for safety control. Specifically, it is as follows.

<Discrimination condition>
The determination condition is to determine the type of safety input device 101 that is duplicated (that is, which one of the first safety input device 101A, the second safety input device 101B, and the third safety input device 101C). It is a condition used for comparison with the input signal Sp (the first input signal Sp1 and the second input signal Sp2) from the input device 101, and is used in the determination processing described later.

FIG. 4 is a conceptual diagram showing determination conditions used in this embodiment. In this embodiment, the determination process is executed after the user confirms that the operating state of the safety input device 101 is in the "normal state", and the determination condition can be used in such determination process. is defined as Specifically, it is as follows. Depending on the type of the safety input device 101, the determination process may be executed while the user temporarily changes the operating state of the safety input device 101 to an "abnormal state." , a discrimination condition will be defined for use in such a discrimination process.

In the first safety input device 101A (see FIG. 3A), when the operating state is the “normal state”, both the normally closed contacts SA1 and SA2 are closed, so the first input signal Sp1 and the second The two input signals Sp2 match the first reference signal St1 and the second reference signal St2, respectively. Therefore, when the same H level signal is output as the first reference signal St1 and the second reference signal St2 (when St1=St2=H level), the voltages of the first input signal Sp1 and the second input signal Sp2 are All the levels become H level (see FIG. 4). Further, when the same L level signal is output as the first reference signal St1 and the second reference signal St2 (when St1=St2=L level), the voltages of the first input signal Sp1 and the second input signal Sp2 are All the levels become L level (see FIG. 4).

In the second safety input device 101B (see FIG. 3B), when the operating state is the "normal state", the normally open contact SB1 is open and the normally closed contact SB2 is closed. The 1 input signal Sp1 becomes an L level signal, and the second input signal Sp2 matches the second reference signal St2. Therefore, when the same H level signal is output as the first reference signal St1 and the second reference signal St2 (when St1=St2=H level), the voltage level of the first input signal Sp1 becomes L level. , and the voltage level of the second input signal Sp2 becomes H level (see FIG. 4). Further, when the same L level signal is output as the first reference signal St1 and the second reference signal St2 (when St1=St2=L level), the voltages of the first input signal Sp1 and the second input signal Sp2 are All the levels become L level (see FIG. 4).

In the third safety input device 101C (see FIG. 3C), when the operating state is the “normal state”, both the sensor elements SC1 and SC2 are in the undetected state. Both of the two input signals Sp2 are H level signals except for the off-check pulse portion. Therefore, when the same H level signal is output as the first reference signal St1 and the second reference signal St2 (St1=St2=H level) or when the same L level signal is output (St1=St2= L level), regardless of what those signals are, the voltage levels of both the first input signal Sp1 and the second input signal Sp2 are equal to the off-check pulse. becomes H level (see FIG. 4).

In this way, when the operating state is the "normal state", the conditions (first The combination of the expected values of the input signal Sp1 and the second input signal Sp2 (specifically, the combination of the voltage levels appearing in the first input signal Sp1 and the second input signal Sp2) differs depending on the type of the safety input device 101 concerned. become valuable. Therefore, in the present embodiment, the above conditions that are satisfied when the operation state is the "normal state" for each type of safety input device 101 are used as determination conditions (see FIG. 4).

<Judgment conditions>
The determination condition is the input signal Sp from the safety input device 101 (the first input signal Sp1 and the This is a condition used for comparison with the second input signal Sp2), and is used in the determination process to be described later. Judgment conditions differ for each type of safety input device 101 described above (see FIGS. 3A to 3C), and storage unit 3 stores conditions corresponding to each type. Specifically, it is as follows.

In the first safety input device 101A, as described above, when both the normally closed contacts SA1 and SA2 are in the closed state, the operating state is the "normal state." Therefore, regarding the operation state of the first safety input device 101A, when the first input signal Sp1 and the second input signal Sp2 respectively match the first reference signal St1 and the second reference signal St2, it is in a "normal state". It can be determined that there is Therefore, the judgment condition for judging the operation state of the first safety input device 101A is that the first input signal Sp1 and the second input signal Sp2 match the first reference signal St1 and the second reference signal St2, respectively. is used, and if the condition is met, it is determined to be in a "normal state", and if the condition is not met, it is determined to be in an "abnormal state".

In the second safety input device 101B, as described above, the operating state is the "normal state" when the normally open contact SB1 is open and the normally closed contact SB2 is closed. Therefore, regarding the operating state of the second safety input device 101B, when the first input signal Sp1 is an L level signal and the second input signal Sp2 matches the second reference signal St2, "normal state”. Therefore, the determination conditions for determining the operating state of the second safety input device 101B are that the first input signal Sp1 is an L level signal and the second input signal Sp2 matches the second reference signal St2. If the condition is met, the condition is determined to be "normal", and if the condition is not met, the condition is determined to be "abnormal".

In the third safety input device 101C, as described above, the operating state is the "normal state" when both the sensor elements SC1 and SC2 are in the undetected state. Therefore, regarding the operation state of the third safety input device 101C, when the voltage levels of the first input signal Sp1 and the voltage level of the second input signal Sp2 are both H level (in this embodiment, the off-check pulse portion is excluded). H level) can be judged to be in a “normal state”. Therefore, as a judgment condition for judging the operation state of the third safety input device 101C, the condition that the voltage levels of the first input signal Sp1 and the second input signal Sp2 are both H level is used. If the condition is met, it is determined to be in a "normal state", and if it is not met, it is determined to be in an "abnormal state".

<Safety control logic>
The safety control logic is a pre-established logic for safely controlling the target device 102, and how the target device 102 is controlled according to the operating state (normal state or abnormal state) of the safety input device 101. is programmed. That is, the safety control logic is a portion of the control program executed by the safety control device that is executed after the judgment processing, and does not include the judgment processing and the judgment processing. In this embodiment, a plurality of such safety control logics are prepared corresponding to various specifications and stored in the storage unit 3 . Further, for each safety control logic, among the plurality of terminal groups Mg provided in the input unit 1, a terminal group Mg to be used for connecting the safety input device 101 in the safety control logic is associated in advance. there is

<Default settings>
In the default setting, the types of safety input devices 101 that can be used in the safety control logic are set in advance for each safety control logic. Specifically, the default setting is such that determination conditions corresponding to the types of safety input devices 101 that can be used in the safety control logic are associated in advance with each safety control logic. More specifically, the default setting includes information for identifying a plurality of terminal groups Mg provided in the input unit 1 (numbers of various terminals included in each terminal group Mg, etc.) and information for each safety control logic. , and judgment conditions according to the types of safety input devices 101 that can be connected to those terminal groups Mg are associated in advance on a one-to-one basis.

[1-4] Operation Unit The operation unit 4 includes a logic setting operation unit 41, a timer setting operation unit 42, and a confirmation operation unit 43 (see FIG. 2). Here, the logic setting operation section 41 is used to select any one of the plurality of safety control logics stored in the storage section 3 . In this embodiment, the logic setting operation unit 41 is composed of eight setting switches, and the on/off arrangement of the eight setting switches (on when the knob of the setting switch is moved up, and when the knob is moved down). off when moved), the safety control logic is selected.

The timer setting operation unit 42 operates the target device 102 after the safety input device 101 connected to the input unit 1 is operated (specifically, when the operating state of the safety input device 101 is determined in the determination process). is used to set the time difference (hereinafter referred to as "off-delay time") until the output of the output signal Sq to is executed. In this embodiment, the timer setting operation unit 42 is composed of eight setting switches provided separately from the eight setting switches that constitute the logic setting operation unit 41 (see FIG. 2). are associated with eight values prepared in advance as settable off-delay times. When any one of the eight setting switches is turned on (on when the knob of the setting switch is moved up, and off when the knob of the setting switch is moved down), the setting switch is turned on. is set as the off-delay time.

The confirmation operation unit 43 confirms the safety control logic selected by the logic setting operation unit 41, confirms the off-delay time set by the timer setting operation unit 42, and confirms the safety input devices displayed on the display unit 5, which will be described later. It is used for determining the type of 101 and the like. In this embodiment, the confirmation operation section 43 is composed of one button (see FIG. 2).

[1-5] Display Section The display section 5 includes a logic state display section 51, an error state display section 52, a timer state display section 53, and an input/output state display section 54 (see FIG. 2). . Here, the logic state display section 51 displays the safety control logic number selected by the logic setting operation section 41 . The error state display unit 52 displays an abnormality (monitoring abnormality, wiring abnormality, circuit abnormality, power supply abnormality, etc.) occurring in the safety control device with an error number associated with the abnormality. The timer state display section 53 displays the off-delay time set by the timer setting operation section 42 . In this embodiment, the timer state display unit 53 is composed of LEDs corresponding to the settable off-delay times one-to-one, and the off-delay times that have been set are displayed by lighting the LEDs. . The input/output state display unit 54 displays the type of the safety input device 101 determined by determination processing described later. In the present embodiment, the input/output state display section 54 is composed of LEDs corresponding to all the receive terminals Gr1 and Gr2 one-to-one, and the colors of light emitted by the LEDs (for example, three colors of red, yellow, and green) ) displays the type of the safety input device 101 connected to each receive terminal (that is, which one of the first safety input device 101A, the second safety input device 101B, and the third safety input device 101C). . Furthermore, the input/output state display unit 54 has LEDs corresponding to all the output terminals H1 and H2 on a one-to-one basis, and the lighting of the LEDs indicates the output state of the safety control device.

[1-6] Control Unit The control unit 6 is a processing device such as a CPU. Then, when any safety control logic has already been selected by the logic setting operation unit 41 when the safety control device is powered on, or when the state is changed to another safety control logic , when the safety control logic is confirmed by the operation of the confirmation operation unit 43, the control unit 6 executes the safety control process for the target device 102 in the "default mode" described below.

In the "default mode", the control unit 6 uses the determination condition associated with the established safety control logic by default (that is, the determination condition associated with the above-described default setting) to control the input unit 1 to determine the operation state of all the safety input devices 101 connected to (determination processing). Then, the control unit 6 determines the operation states of all the safety input devices 101, and executes control according to the safety control logic on the target devices 102 according to the operation states (computation processing ).

On the other hand, if none of the safety control logics is selected by the logic setting operation unit 41 when the safety control device is powered on, the control unit 6 performs safety control processing for the target device 102 as follows. Run in "modifiable mode" as described in . In this embodiment, the control unit 6 has all eight setting switches of the logic setting operation unit 41 turned off, and all eight setting switches of the timer setting operation unit 42 are turned off. In this case, safety control processing is executed in "modifiable mode". In addition, regardless of the states of the eight setting switches of the timer setting operation unit 42, the control unit 6 sets the safety control process to "changeable" when all the eight setting switches of the logic setting operation unit 41 are turned off. It may be appropriately changed to one that performs processing such as executing in "mode".

In the "changeable mode", the control unit 6 accepts selection of safety control logic in the logic setting operation unit 41, setting of off-delay time in the timer setting operation unit 42, and confirmation by operation of the confirmation operation unit 43. , the type of the safety input device 101 can be changed from that associated with the received safety control logic by default. Then, the control unit 6 discriminates all of the types of the safety input devices 101 connected to the input unit 1 that have been changed and those that remain default (determination processing). After that, the control unit 6 determines the operating states of all the safety input devices 101 connected to the input unit 1 using determination conditions corresponding to the types of the determined safety input devices 101 (determination processing). Then, the control unit 6 determines the operation states of all the safety input devices 101, and executes control according to the safety control logic on the target devices 102 according to the operation states (computation processing ).

In the present embodiment, the determination processing, determination processing, and arithmetic processing described above are executed by a determination processing unit 61, a determination processing unit 62, and an arithmetic processing unit 63, respectively, which are configured in the control unit 6 (see FIG. 1). ). Specifically, these processing units are composed of software by causing a processing device (such as a CPU), which is the control unit 6, to execute a main program. Such a main program is stored in the storage unit 3. Saved. Note that the above processing unit may be configured by hardware by constructing the control unit 6 with a circuit in the safety control device.

Details of the safety control processing (including determination processing, determination processing, and arithmetic processing) executed by the safety control device will be described below.

[2] Safety Control Processing Executed by Safety Control Device FIG. 5 is a flowchart showing safety control processing executed in this embodiment. This safety control process is started when the safety control device is powered on.

When the safety control process is started, the control unit 6 of the safety control device determines whether the safety control process should be executed in the default mode or the changeable mode. It is determined whether or not the safety control logic has already been selected in the logic setting operation unit 41 when the power is turned on (step S100).

Specifically, when at least one of the eight setting switches of the logic setting operation unit 41 is set to ON (a state in which the knob of the setting switch is moved upward), the eight setting switches at that time Since the safety control logic corresponding to the ON/OFF arrangement of the two setting switches has been selected by the logic setting operation unit 41, the control unit 6 determines "selected (Yes)" in step S100. can be determined.

On the other hand, when all eight setting switches of the logic setting operation section 41 are set to OFF (the knob of the setting switch is moved downward), any safety control logic is selected by the logic setting operation section 41. Therefore, the control unit 6 can determine "not selected (No)" in step S100. In this embodiment, the control unit 6 has all eight setting switches of the logic setting operation unit 41 turned off, and all eight setting switches of the timer setting operation unit 42 are turned off. In this case, it is determined that "not selected (No)" in step S100. Note that regardless of the state of the eight setting switches of the timer setting operation unit 42, the control unit 6, when all the eight setting switches of the logic setting operation unit 41 are turned off, "selected It may be appropriately changed to a process such as determining that "there is no (No)".

Then, when the control unit 6 determines that "it is selected (Yes)" in step S100, it determines that the safety control process should be executed in the "default mode" based on the determination, and step S101. Execute the process from On the other hand, if it is determined that "not selected (No)" in step S100, it is determined that the safety control process should be executed in the "changeable mode" based on that determination, and the process from step S111 is performed. Execute. Specifically, it is as follows.

<Default mode>
In the default mode, the control unit 6 first determines whether or not the safety control logic selected by the logic setting operation unit 41 has been confirmed by the operation of the confirmation operation unit 43 (step S101). In this embodiment, the control unit 6 sets the safety control logic selected by the logic setting operation unit 41 and the off-delay time set by the timer setting operation unit 42 by operating the confirmation operation unit 43. At the same time, it is determined whether or not they have been confirmed.

Then, the control unit 6 repeatedly executes step S101 until it can be determined that "it has been decided (Yes)" in step S101. At this time, the user can confirm whether or not the desired safety control logic is correctly selected by confirming the number displayed on the logic state display section 51 . Further, the user can confirm whether or not the desired off-delay time is correctly set by confirming which LED is lit on the timer state display section 53 . Furthermore, the user may change the safety control logic selected by the logic setting operation unit 41 to another safety control logic before confirming it, or change the off-delay time set by the timer setting operation unit 42. It may be confirmed after changing to another off-delay time.

If the control unit 6 can determine that it is "confirmed (Yes)" in step S101, the control unit 6 refers to the default setting stored in the storage unit 3 to set the safety control logic to the confirmed safety control logic by default. The associated determination condition is read out from the storage unit 3 (step S102). Specifically, the control unit 6 reads the determination condition associated with each terminal group Mg together with information for identifying the terminal group Mg. Thereby, the control unit 6 can determine the operating state of the safety input device 101 connected to each terminal group Mg using the determination condition corresponding to the terminal group Mg.

Next, the control unit 6 starts outputting the first reference signal St1 and the second reference signal St2 from the drive terminals Gd1 and Gd2 in each terminal group Mg in order to start determining the operating state of the safety input device 101. (step S103). Specifically, the control unit 6 determines the operating state of the first safety input device 101A or the second safety input device 101B among the determination conditions read in step S102. Output of the first reference signal St1 and the second reference signal St2 from the drive terminals Gd1 and Gd2 in the terminal group Mg corresponding to the conditions is started. On the other hand, the third safety input device 101C outputs signals according to its operating state as the first input signal Sp1 and the second input signal Sp2 regardless of the presence or absence of the first reference signal St1 and the second reference signal St2. Therefore, in relation to the determination condition for determining the operation state of the third safety input device 101C among the determination conditions read in step S102, the control unit 6 determines whether the drive in the terminal group Mg to which the determination condition corresponds. The terminals Gd1 and Gd2 may or may not output the first reference signal St1 and the second reference signal St2.

In this manner, the first input signal Sp1 and the second input signal Sp2 from the safety input device 101 connected to the terminal group Mg are input to the receive terminals Gr1 and Gr2 in each terminal group Mg. become.

Then, using the determination conditions read in step S102, the control unit 6 converts the first input signal Sp1 and the second input signal Sp2 input to the receive terminals Gr1 and Gr2 in each terminal group Mg to the corresponding terminal group Mg. By comparing with the determination condition corresponding to Mg, the operating state (normal state or abnormal state) of the safety input device 101 connected to the terminal group Mg is determined (step S104). In this way, the control section 6 determines the operating states of all safety input devices 101 connected to the input section 1 .

After that, the control unit 6 performs control on the target device 102 according to the safety control logic according to the operating state of the safety input device 101 determined in step S104 (step S105). Specifically, when the control unit 6 determines that at least one of the operating states of the safety input device 101 is in an "abnormal state", it is necessary to stop the target device 102 according to the safety control logic. In this case, a signal for emergency stopping of the target device 102 is duplicated as the output signal Sq and output from the output section 2 (output terminals H1 and H2). At this time, the control unit 6 outputs the output signal Sq from the output unit 2 at a timing considering the off-delay time set by the timer setting operation unit 42 . As an example, when the off-delay time is set to 0 seconds, the control unit 6 outputs the output signal Sq from the output unit 2 immediately after determining that the "abnormal state" is established in step S104. As another example, when the off-delay time is set to 1 second, the control unit 6 outputs the output signal Sq to the output unit 1 second after determining that the "abnormal state" exists in step S104. Output from 2.

Then, the control unit 6 safely controls the target device 102 by repeatedly executing the processing from step S104 until it can be determined that the power supply to the safety control device has been cut off (Yes) in step S106. do.

According to such safety control processing in the default mode, the types of safety input devices 101 that can be connected to each terminal group Mg are limited to those set by default. Only by selecting a logic, it becomes possible to execute control on the target device 102 according to the safety control logic. On the other hand, even if the safety control logic is the same, some users may want to use a different type of safety input device 101 from the default in their own specifications. Therefore, in the safety control device of this embodiment, the safety control process can be executed in a changeable mode described below so that the user can change the type of the safety input device 101 .

<Changeable mode>
In the changeable mode, the user selects the safety control logic using the logic setting operation unit 41, and sets the type of the safety input device 101 used in the selected safety control logic according to his/her specifications. can be changed from what is mapped by default to . Specifically, it is as follows.

First, the control unit 6 determines whether or not any safety control logic has been selected by the logic setting operation unit 41 and the selected safety control logic has been confirmed by the operation of the confirmation operation unit 43 (step S111). At this time, the user can confirm whether or not the desired safety control logic is correctly selected by confirming the number displayed on the logic state display section 51 . In the present embodiment, the user sets the off-delay time using the timer setting operation unit 42 and confirms which LED is lit using the timer state display unit 53 to determine the desired off-delay time. You can check if it is set correctly. Therefore, in the present embodiment, in step S111, the control unit 6 determines whether the safety control logic selected by the logic setting operation unit 41 and the off-delay time set by the timer setting operation unit 42 are confirmed by the confirmation operation. It is determined whether or not they have been confirmed simultaneously by the operation of the unit 43 . Then, the control unit 6 repeatedly executes step S111 until it can be determined that "it has been decided (Yes)" in step S111.

If the control unit 6 can determine that it is "confirmed (Yes)" in step S111, the control unit 6 determines the type of the safety input device 101 connected to the input unit 1 according to the confirmed safety control logic. (Step S112). That is, the control unit 6 determines the type of the safety input device 101 connected to the input unit 1 by the user according to his/her own specifications.

Specifically, the control unit 6 temporarily outputs the first reference signal St1 and the second reference signal St2 from the drive terminals Gd1 and Gd2 in each terminal group Mg in order to determine the type of the safety input device 101. Output. In this embodiment, the control unit 6 generates a pulse signal whose voltage changes periodically (for example, every 10 ms) between an H level (for example, 24 V) and an L level (for example, 0 V) as the first reference signal St1. As the second reference signal St2, the same pulse signal as the first reference signal St1 is output. The first reference signal St1 and the second reference signal St2 that are output for determining the type are the same as the first reference signal St1 and the second reference signal St2 that are output for determining the operating state in step S103. They may be the same or different.

As a result, the receive terminals Gr1 and Gr2 in each terminal group Mg receive the safety input device 101 as the first input signal Sp1 and the second input signal Sp2 from the safety input device 101 connected to the terminal group Mg. A signal corresponding to the type of is input. Specifically, it is as follows (see FIG. 4).

When the first safety input device 101A is connected, the pulse signals, which are the first reference signal St1 and the second reference signal St2, are directly applied to the receive terminals Gr1 and Gr2 as the first input signal Sp1 and the second input signal Sp2. are entered respectively. Therefore, the voltage levels (Sp1, Sp2) of the first input signal Sp1 and the second input signal Sp2 become (Sp1, Sp2)=(H, H) with respect to the H level portion of the pulse signal, and will appear in a combination of (Sp1, Sp2)=(L, L) for the L level portion of .

When the second safety input device 101B is connected, an L level signal is always input to the receive terminal Gr1 as the first input signal Sp1 with respect to the pulse signal that is the first reference signal St1, and the second reference signal The pulse signal St2 is directly input to the receive terminal Gr2 as the second input signal Sp2. Therefore, the voltage levels (Sp1, Sp2) of the first input signal Sp1 and the second input signal Sp2 become (Sp1, Sp2)=(L, H) with respect to the H level portion of the pulse signal, and will appear in a combination of (Sp1, Sp2)=(L, L) for the L level portion of .

When the third safety input device 101C is connected, regardless of the pulse signals that are the first reference signal St1 and the second reference signal St2, the H level signal is the first input signal Sp1 and the second input signal Sp2 is input to receive terminals Gr1 and Gr2, respectively. Therefore, the voltage levels (Sp1, Sp2) of the first input signal Sp1 and the second input signal Sp2 are (Sp1, Sp2)=(H, H) for both the H level and L level portions of the pulse signal. It will appear in a combination of

If a safety input device 101 of a type other than these is connected, or if any of the above safety input devices 101 is connected, it may be malfunctioning (contact failure, etc.), or the power may not be turned on. If the operating state is "abnormal", the voltage levels (Sp1, Sp2) of the first input signal Sp1 and the second input signal Sp2 appear in combinations other than the above.

Therefore, the control unit 6 uses the determination conditions (see FIG. 4) stored in the storage unit 3 to control the first input signal Sp1 and the second input signal Sp1 input to the receive terminals Gr1 and Gr2 in each terminal group Mg. The type of the safety input device 101 connected to the terminal group Mg is determined by judging which of the three types the combination of voltage levels appearing in the input signal Sp2 matches the discrimination condition corresponding to the type. determine. At this time, if the control unit 6 determines that none of the determination conditions corresponding to the three types is met, the control unit 6 determines whether the type of the safety input device 101 is other than the three types, or the three types. Although one of the three types is connected, it is determined that there is a failure (contact failure, etc.), the power is not turned on, or the operating state is "abnormal".

Here, when the third safety input device 101C is connected to the input unit 1, the first input signal Sp1 and the second input signal Sp2 periodically include off-check pulses as described above. Therefore, depending on the timing for determining the type of the safety input device 101, the off-check pulse may be used for determination. However, although the off-check pulse is a signal from the third safety input device 101C, it does not meet the determination condition corresponding to the third safety input device 101C. Therefore, depending on the timing of determining the type, a situation may arise in which the type cannot be determined accurately.

Therefore, in the present embodiment, the control unit 6 controls the H level and L level of the pulse signals, which are the first reference signal St1 and the second reference signal St2, so that the type of the safety input device 101 can be accurately determined. A voltage level for a predetermined period (for example, 100 periods) is compared with the determination condition, with a portion in which the level appears one time in succession as one period. Then, when there is a determination condition that matches a predetermined ratio (for example, 90%) or more as a result of the comparison, the control unit 6 determines the type of the safety input device 101 based on the determination condition.

As described above, in this embodiment, the fact that the safety input device 101 is duplicated is used to determine the type of the safety input device 101 . That is, since the safety input device 101 is duplicated, it is possible to use two signals (the first input signal Sp1 and the second input signal Sp2) to determine the type of the safety input device 101. By using two signals in this way, it is possible to increase the number of types that can be distinguished by the number of conditions that the two signals can satisfy (in this embodiment, the number of combinations of voltage levels). . In this embodiment, three types of safety input devices 101 (that is, first safety input device 101A, second safety input device 101B, and third safety input device 101C) can be distinguished.

Then, the control unit 6 displays the type of the safety input device 101 determined in step S112 on the input/output state display unit 54 (step S113). Specifically, the control unit 6 causes the LEDs corresponding to the receive terminals Gr1 and Gr2 in each terminal group Mg to indicate the type of the safety input device 101 connected to the terminal group Mg (the type determined in step S112). to emit light in the corresponding color. On the other hand, in step S112, the control unit 6 determines that the combination of voltage levels appearing in the first input signal Sp1 and the second input signal Sp2 does not match any of the determination conditions corresponding to the three types (that is, three If it is determined that the error occurred in a combination other than the combination that appears in one type, in step S113, an error number indicating that fact may be displayed on the error state display section 52. FIG. Note that the control unit 6 uses another means (for example, a method of turning on the corresponding LEDs in the input/output state display unit 54 while changing the color in order) instead of displaying the error number. You can let me know.

As a result, the user can confirm whether or not the safety control device correctly recognizes the type of safety input device 101 to be used according to the specifications of the user by confirming the color of light emitted from the LED and the error number. can. Then, when the user can confirm that the type of the safety input device 101 is correctly recognized, the user operates the confirmation operation unit 43 to confirm the safety input device 101 displayed on the input/output state display unit 54. Determine the type of On the other hand, if the user can confirm that the safety input device 101 is not correctly recognized, correct the type of the safety input device 101 and the connection error until the user can confirm that the safety input device 101 has been correctly recognized by the light emission color of the LED. can do. At this time, the correction of the error may require a restart of the safety control device.

Therefore, the control unit 6 determines whether or not the type of the safety input device 101 determined in step S112 has been determined (step S114). repeats the process of Then, when the control unit 6 can determine that "it has been confirmed (Yes)" in step S114, the control unit 6 proceeds to the next step S115.

In step S115, the control unit 6 selects the determination condition corresponding to the type of the safety input device 101 determined in step S112 from among the determination conditions stored in the storage unit 3, and stores the determination condition in the storage unit 3. read from Specifically, the control unit 6 selects, for each terminal group Mg, a determination condition corresponding to the type of the safety input device 101 connected to the terminal group Mg (the type determined in step S112), and Conditions are read out from the storage unit 3 . This enables the control unit 6 to determine the operating state of the safety input device 101 connected to each terminal group Mg using the determination condition corresponding to the type of the safety input device 101 .

Next, the control unit 6 proceeds to step S103 in order to start determining the operating state of the safety input device 101, and detects the first reference signal St1 and the second reference signal from the drive terminals Gd1 and Gd2 in each terminal group Mg. Output of the signal St2 is started. Specifically, the control unit 6 determines the operating state of the first safety input device 101A or the second safety input device 101B among the determination conditions read in step S115. Output of the first reference signal St1 and the second reference signal St2 from the drive terminals Gd1 and Gd2 in the terminal group Mg corresponding to the conditions is started. On the other hand, the third safety input device 101C outputs signals according to its operating state as the first input signal Sp1 and the second input signal Sp2 regardless of the presence or absence of the first reference signal St1 and the second reference signal St2. Therefore, in relation to the determination condition for determining the operation state of the third safety input device 101C among the determination conditions read in step S102, the control unit 6 determines whether the drive in the terminal group Mg to which the determination condition corresponds. The terminals Gd1 and Gd2 may or may not output the first reference signal St1 and the second reference signal St2.

In this manner, the first input signal Sp1 and the second input signal Sp2 from the safety input device 101 connected to the terminal group Mg are input to the receive terminals Gr1 and Gr2 in each terminal group Mg. become.

Then, the control unit 6 proceeds to step S104, and uses the determination condition read out in step S115 to determine the first input signal Sp1 and the second input signal input to the receive terminals Gr1 and Gr2 in each terminal group Mg. By comparing Sp2 with the determination condition corresponding to the terminal group Mg, the operating state (normal state or abnormal state) of the safety input device 101 connected to the terminal group Mg is determined. In this way, the control section 6 determines the operating states of all safety input devices 101 connected to the input section 1 .

According to such determination processing, the determination condition corresponding to the type of safety input device 101 determined in step S112 (determination processing) is selected. Accurate determination can be made according to the type of Further, in the present embodiment, it is confirmed by the input/output state display unit 54 that the type of the safety input device 101 is correctly recognized by the safety control device, and the judgment processing is executed when the correctly recognized one is confirmed. Therefore, the operating state of the safety input device 101 can be determined correctly under the correct recognition of the type of the safety input device 101 . Therefore, erroneous control of the target device 102 that may occur due to erroneous connection of the safety input device 101 by the user or erroneous recognition of the type by the safety control device is prevented.

After that, as in the case of the default mode, the control unit 6 executes control on the target device 102 according to the safety control logic according to the operating state of the safety input device 101 determined in step S104 (step S105). ). Then, the control unit 6 safely controls the target device 102 by repeatedly executing the processing from step S104 until it can be determined that the power supply to the safety control device has been cut off (Yes) in step S106. do.

According to such safety control processing in the changeable mode, the type of the safety input device 101 connected to the input unit 1 is automatically determined, and the operating state of the safety input device 101 is changed according to the type. It is determined automatically, and control according to the safety control logic is executed for the target device 102 according to the determined operating state. Therefore, even with the same safety control logic, it is possible to support various specifications with different types and combinations of the safety input devices 101 .

In addition, in the safety control device of the present embodiment, a plurality of safety control logics are provided in advance in a selectable manner, and the type of safety input device 101 connected to the input unit 1 according to the selected safety control logic and the operating state is automatically discriminated and determined. Therefore, it is not necessary for the user to create a series of control programs for executing those controls, and the user's burden of creating such a control program is reduced. In addition, as the number of safety control logic options increases, whatever safety control logic is selected can accommodate various specifications with different types and combinations of the safety input devices 101 .

[3] Modification [3-1] First Modification In the above-described safety control device, the determination process is performed based on the input signal Sp input from the safety input device 101 to the input unit 1. can be discriminated, it is not limited to the case of discriminating the type using the discrimination conditions described above (that is, the case of discriminating by the difference in the conditions satisfied by the first input signal Sp1 and the second input signal Sp2). It may be appropriately changed to one that can be determined by the method of.

In the determination process, voltages are applied to the drive terminals Gd1 and Gd2 to output the first reference signal St1 and the second reference signal St2 from these terminals, respectively, and the voltages of the receive terminals Gr1 and Gr2 are measured. , the first input signal Sp1 and the second input signal Sp2 input to those terminals may be acquired. Then, the type may be determined using the voltages measured at the receive terminals Gr1 and Gr2.

Further, in the determination process, by applying a current to the drive terminals Gd1 and Gd2, the first reference signal St1 and the second reference signal St2 are output from these terminals, respectively, and the voltages of the receive terminals Gr1 and Gr2 are measured. , the first input signal Sp1 and the second input signal Sp2 input to those terminals may be acquired. Then, using the current applied to the drive terminals Gd1 and Gd2 and the voltage measured at the receive terminals Gr1 and Gr2, the resistance value between the drive terminal and the receive terminal is obtained, and the type is determined based on the resistance value. may be performed.

[3-2] Second Modification The safety control process (see FIG. 5) executed by the safety control device described above is set by the logic setting operation section 41 or the timer setting operation section 42 during execution of the safety control process. It may be changed as appropriate such that, when the on/off state of the switch is changed, the process proceeds to step S101 and executes the process in the default mode.

[3-3] Third Modified Example In the safety control device described above, the determination process is performed to determine the operating state of the safety input device 101 connected to the input unit 1. If the operation state can be determined using the above-described determination conditions (that is, when the operation state is determined by comparing the first input signal Sp1 and the second input signal Sp2 with the determination conditions ) may be appropriately changed to a method that can be determined by another method.

[3-4] Fourth Modification The safety control device described above does not incorporate the default mode into the safety control process (that is, the safety control process is executed only in the changeable mode). good.

[3-5] Fifth Modified Example Even if the safety input device 101 is not duplicated, the type of the safety input device 101 can be determined based on the input signal Sp from the safety input device 101. can apply the above-described safety control processing in the changeable mode to a safety control device that can connect such a safety input device 101 that is not duplicated.

Further, the safety control device described above may be appropriately changed to one in which the output signal Sq from the output unit 2 to the target device 102 is not duplicated.

[3-6] Sixth Modification In the safety control device described above, various processing units (determination processing unit 61, determination processing unit 62, and arithmetic processing unit 63) are duplicated so that the target device 102 can be safely controlled. It may be changed as appropriate.

The description of the above-described embodiments should be considered illustrative in all respects and not restrictive. The scope of the invention is indicated by the claims rather than the above-described embodiments. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and range of equivalents of the claims.

Further, from the above-described embodiment and modifications, the object of the invention is not limited to the safety control device, but the elements (control unit 6, etc.) constituting it, the control method, the program, etc. may be individually extracted. , some of which may be partially extracted.

1 Input section 2 Output section 3 Storage section 4 Operation section 5 Display section 6 Control section G, H Terminal 41 Logic setting operation section 42 Timer setting operation section 43 Confirmation operation section 51 Logic state display section 52 Error state display section 53 Timer state display Unit 54 Input/output state display unit 61 Judgment processing unit 62 Judgment processing unit 63 Arithmetic processing unit H1, H2 Output terminals Mg, Mh Terminal group Sp Input signal Sq Output signal 101 Safety input device 101A First safety input device 101B Second safety input Device 101C Third safety input device 102 Target device Gd1, Gd2 Drive terminals Gr1, Gr2 Receive terminals SA1, SA2 Normally closed contact SB1 Normally open contact SB2 Normally closed contacts SC1, SC2 Sensor element Sp1 First input signal Sp2 Second input signal St1 First reference signal St2 Second reference signal

Claims (6)

A safety control device that safely controls a target device based on an input signal from a safety input device,
an input unit to which the safety input device is connected;
an output unit to which the target device is connected;
Safety control logic pre-built to safely control the target device;
an arithmetic processing unit that executes control on the target device according to the safety control logic;
with
Further comprising a determination processing unit that determines the type of the safety input device connected to the input unit according to the safety control logic based on the input signal input from the safety input device to the input unit,
The safety control device, wherein the arithmetic processing unit performs control on the target device according to the safety control logic in accordance with the type of the safety input device determined by the determination processing unit. A determination processing unit that determines the operating state of the safety input device connected to the input unit according to the type of the safety input device determined by the determination processing unit,
2. The safety according to claim 1, wherein the arithmetic processing unit controls the target device according to the safety control logic according to the operating state of the safety input device determined by the determination processing unit. Control device. a condition used for comparison with the input signal from the safety input device to determine the operating state of the safety input device, and a determination condition that differs for each type of the safety input device;
The determination processing unit selects a determination condition corresponding to the type of the safety input device determined by the determination processing unit from among the determination conditions, and compares the determination condition with the input signal to determine the input 3. The safety control device according to claim 2, which determines the operation state of the safety input device connected to the unit. a display unit that displays the type of the safety input device determined by the determination processing unit;
a confirmation operation unit used to confirm the type displayed on the display unit;
further comprising
The determination processing unit is connected to the input unit by selecting and using the determination condition corresponding to the type from the determination conditions when the type is confirmed by the confirmation operation unit. 4. The safety control device according to claim 3, wherein the operating state of the safety input device is determined. A plurality of the safety control logics are provided, and a logic setting operation unit used for selecting any one of the plurality of safety control logics is further provided,
The input section is provided with a plurality of terminals for connecting the safety input device, and the terminal to be used for connecting the safety input device to the input section is specified for each safety control logic. are pre-associated,
When any safety control logic is selected by the logic setting operation unit, the determination processing unit uses the input signal input to the terminal associated with the safety control logic to determine the terminal The safety control device according to any one of claims 1 to 4, wherein the type of said safety input device connected to is discriminated. The safety input device is a device configured such that the input signal from the safety input device is duplicated into a first input signal and a second input signal,
The determination processing unit determines the type of the safety input device connected to the input unit according to the conditions that the first input signal and the second input signal input from the safety input device to the input unit satisfy. The safety control device according to any one of claims 1 to 5, which discriminates by difference.

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