JP4816961B2 - Safety remote I / O terminal - Google Patents

Description

  The present invention relates to a safety remote I / O terminal connected to a safety programmable controller (hereinafter referred to as a safety PLC) via a network.

  Safety PLCs have a high level of safety and reliability in their control by incorporating a safety self-diagnosis function in addition to logic operation functions and input / output control functions similar to general PLCs. There is a function (fail-safe function) for forcibly performing safe control so that self-control does not lead to danger when an abnormality is detected by the self-diagnosis result.

  More specifically, the term “safety” as used herein means that standardized safety standards are included. Safety standards include, for example, IEC61508 and EN standards. IEC61508 (International Electrotechnical Commission on Functional Safety of Programmable Electronic Systems) defines the probability of dangerous failure per hour (Probability of Failure per Hour), and the SIL level (Safety Integrity) is defined by this probability. Level) is classified into four stages. Further, EN standards require that the risk level of a machine be evaluated and risk reduction measures be taken, and EN 954-1 specifies the safety categories. The safety PLC, the safety remote I / O terminal, and the like referred to in this specification correspond to any of these safety standards.

  A basic configuration diagram of such a safety PLC system is shown in FIG. As shown in the figure, this safety PLC system is configured by connecting a safety PLC 1 and a safety remote I / O terminal 2 via a network 4. The safety remote I / O terminal 2 is provided with input terminals (IN0 to INn) and output terminals (OUT0 to OUTn). The input device 5 and the output device 6 are connected to these input / output terminals. Here, as is well known to those skilled in the art, examples of the input device 5 include a safety emergency stop switch, a safety light curtain, a safety limit switch, and a safety door switch. Safety relays, safety contactors, etc.

  The ON / OFF state of the input device 5 is transmitted as input data to the safety PLC 1 side. On the safety PLC 1 side, output data is generated by executing a predetermined logic operation programmed in advance based on the received input data. The output data thus obtained is transmitted to the safety remote I / O terminal. On the safety remote I / O terminal 2 side, such output data is received and the state of the output terminals (OUT0 to OUTn) is controlled based on the output data thus received. Through such a series of data flows, the state of the output terminals (OUT0 to OUTn) is controlled.

That is, the ON / OFF state of the output terminals (OUT0 to OUTn) of the safety remote I / O terminal is uniquely determined by the contents of the output data transmitted from the safety PLC1. Therefore, in order to control the state of the output terminals (OUT0 to OUTn) of the safety remote I / O terminal 2, it is always necessary to create some arithmetic program on the safety PLC1 side, and accordingly, the safety PLC1 side There has been a problem that the calculation program of (2) has to be complicated (see Patent Document 1).
JP 2006-304463 A

  In order to solve the above-described problem, the safety remote I / O terminal 2 also arbitrarily incorporates an arithmetic program, and outputs output data generated based on the arithmetic program thus incorporated into the safety remote I / O terminal 2. It is conceivable to output from the output terminals (OUT0 to OUTn) of the / O terminal 2.

  However, if an arithmetic program is also incorporated into the safety remote I / O terminal 2 side and output data can be generated independently, how the output data thus obtained is output to the output terminals (OUT0 to OUTn). ) Should be output.

  That is, since the output terminals (OUT0 to OUTn) on the safety remote I / O terminal 2 side are uniquely associated with the operation program incorporated on the safety PLC 1 side, If the output data generated on the side is inadvertently output to its own output terminals (OUT0 to OUTn), output data conflicts between the safety PLC 1 side and the safety remote I / O terminal 2 side.

  In order to avoid such a competition, if an output terminal dedicated to the terminal side is added, the cost of the safety remote I / O terminal product is increased and the degree of freedom in selecting the output terminal is impaired.

  The present invention has been made paying attention to such conventional problems, and the object of the present invention is that any operation can be performed from the side of the safety remote I / O terminal without operating a calculation program of the safety PLC. Output data can be output, and the same output terminal can be shared between the safety PLC side and the safety remote I / O terminal without causing output data contention between the two. It is an object of the present invention to provide a new safety remote I / O terminal that does not cause an increase in cost due to the expansion.

  Other objects and operational effects of the present invention should be easily understood by those skilled in the art by referring to the following description of the specification.

  The above technical problem can be solved by a secure remote I / O terminal having the following configuration.

  That is, the safety remote I / O terminal includes a communication circuit for communicating with a safety PLC via a network, one or more external output terminals to which output devices are connected, and each external output terminal. Output circuit for sending output signals to output devices connected to the external output terminals, and output data storage for local output data for storing output data to be sent to each of the output circuits Means, output data storage means for communication-derived output data storing output data for each output terminal received from the safety PLC via the communication circuit, and for each output terminal generated inside itself or each Output data storage means for internally derived output data that stores output data common to the output terminals, and external output for each external output terminal Output function setting table storage means for rewritably storing an output function setting table in which child output functions are set, and setting contents of each external output terminal of the output function setting table stored in the output function setting table storage means When the setting content is an output function to output communication-derived output data, the communication-derived output data of the corresponding external output terminal stored in the output data storage means for communication-derived output data is output to the local Is stored in the storage location of the corresponding external output terminal of the output data storage means for use, and when the set content is an output function to output the internally derived output data, it is stored in the output data storage means for the internally derived output data The output data stored in the output data storage means for local output data is output from the corresponding external output terminal. Local output switching means for storing in the storage location of the output terminal, and output refresh means for sending each output data stored in the output data storage means for local output data to each of the output circuits of the corresponding external output terminals And.

  According to such a configuration, the output data for each output terminal received from the safety PLC via the communication circuit is output to the output data storage means for communication-derived output and each output terminal generated within itself. Output data common to each output terminal is stored in output data storage means for internally derived output data, but the output data is output data storage means for local output data by the action of the local output switching means The output data is not sent to the corresponding external output terminal via the output refresh means, while the output data to be stored in the output data storage means for local output data is determined by each external output. Since it is determined by the contents of the output function setting table for each terminal, the contents of this output function setting table match the desired control specifications. Allowed by setting appropriately, it is possible to selectively use a series of external output terminals and communication from the output data and the internal-derived output data. For this reason, the same output terminal can be arbitrarily shared between the safety PLC side and the safety remote I / O terminal side, so that an increase in cost due to the addition of a terminal block or the like can be avoided.

  Here, various data can be arbitrarily adopted as the internally derived output data. For example, if the output data for each output terminal obtained as the execution result of the logic operation arbitrarily programmed within itself is adopted as the internally derived output data, it is arbitrary even without operating the operation program on the safety PLC side. The output data obtained as a result of executing the logic operation can be output from its own arbitrary output terminal. For this reason, the safety quality can be improved by executing this with an internal logic operation for an application that is inappropriate for communication due to the necessity of high-speed response.

  Moreover, if the auxiliary output data common to each output terminal generated by the predetermined processing fixedly incorporated in the inside is adopted as the internally derived output data, the user does not set up a special arithmetic program, Desired auxiliary output data can be output from any external output terminal simply by specifying or selecting auxiliary output data.

  Various data can be adopted as such auxiliary output data. For example, if equivalent output data of any output terminal is adopted as such auxiliary output data, it can be used for an application in which the ON / OFF state of the contactor connected to the external output terminal is displayed on the notification lamp. . Moreover, if the inverted value output data of an arbitrary output terminal is adopted as auxiliary output data, it can be used for an application that provides an unlock signal for an electromagnetic lock safety door switch. Moreover, if the output data for blinking the lamp for the reset request is adopted as the auxiliary output data, it can be used for an application for returning after the safety emergency stop switch is activated. If the output data corresponding to the operation mode flag indicating whether or not the terminal is in operation is adopted as the auxiliary output data, the program on the safety PLC side required for the same output as the conventional one can be obtained. It becomes unnecessary. Furthermore, if the output data corresponding to the status flag indicating whether or not the terminal is in a normal state is adopted as the auxiliary output data, the robot side receives this signal by inputting such output data to the robot. It is possible to build an application that shifts to operation when ON and to stop when OFF.

  According to the present invention, it is possible to output the internally derived output data generated inside itself to any external output terminal without competing with the communication derived output data coming from the safety PLC side. Therefore, the usability of this type of safety remote I / O terminal can be greatly improved without increasing costs due to hardware modifications such as the addition of a terminal block.

  Hereinafter, a preferred embodiment of a safe remote I / O terminal according to the present invention will be described in detail with reference to the accompanying drawings.

  A schematic configuration diagram of a safety PLC system to which the present invention is applied is shown in FIG. As shown in the figure, this safety PLC system is a network of a safety PLC 1, a safety remote I / O terminal 2, and a program development support device 3 configured by incorporating predetermined tool software into a notebook personal computer. 4 is connected.

  As described above, the input device 5 and the output device 6 are connected to the safety PLC 1, and the input device 5 and the output device 6 are also connected to the safety remote I / O terminal 2. . Examples of these input devices include a safety emergency stop switch, a safety light curtain, a safety limit switch, and a safety door switch. Examples of the output device 6 include a safety relay and a safety contactor.

  Next, a block diagram showing the electrical hardware configuration of the safety remote I / O terminal 2 is shown in FIG. As shown in the figure, the safety remote I / O terminal 2 is connected to a communication circuit 204 for communicating with a safety PLC 1 (see FIG. 1) via a network 4 and an input device 5 is connected to the safety remote I / O terminal 2. Two or more external input terminals (IN0 to INn), one or more external output terminals (OUT0 to OUTn) to which the output device 6 is connected, and each external input terminal are provided for each external input. An input circuit 202 for inputting an input signal from the input device 5 connected to the terminal, and an output signal to the output device 6 provided for each external output terminal and connected to the external output terminal. An output circuit 203 for sending is provided.

  The display circuit 205 includes a lamp for displaying the operation status of the terminal and a numerical display. The setting circuit 206 includes a DIP switch used for setting a node address necessary for communication of the terminal. Consists of.

  The CPU 201 performs overall control of the entire terminal, and includes a microprocessor (MPU) 201a, a ROM 201b, and a RAM 201c. In the ROM 201b, in addition to various system programs for realizing the function as the terminal, various logic operation programs arbitrarily programmed on the user side and various auxiliary output data described later are generated. A fixed program is stored. A part of the ROM 201b is composed of a non-volatile rewritable recording medium such as a flash memory. In the ROM 201b, an output function setting table described later, a logic operation program arbitrarily created by the user, Arbitrary data that can be rewritten by the user is stored. The RAM 201c is used as a work area when the microprocessor (MPU) 201a executes various programs in the ROM 201b.

  Next, an explanatory diagram of an output function setting mode for each output terminal (OUT0 to OUTn) is shown in FIG. As shown in the figure, the ROM 201b described above is provided with a first storage area (M1), and an output function setting table TB is stored in the first storage area (M1). . This output function setting table TB is configured by setting the output function of the external output terminal for each of the external output terminals (OUT0 to OUTn).

  Here, as the output function, as shown in the figure, output data from the safety PLC (communication-derived output data), logic operation (obtained as an execution result of logic operation arbitrarily programmed within itself) Output data for each output terminal) and auxiliary output (output data generated by the selection process of the auxiliary output function fixedly incorporated in itself).

  As will be described in detail later, this auxiliary output data includes equivalence output data at any output terminal, inverted output data at any output terminal, output data for blinking the lamp for a reset request, the terminal Output data corresponding to an operation mode flag indicating whether or not the terminal is in operation, and output data corresponding to a status flag indicating whether or not the terminal is in a normal state.

  Next, FIG. 4 shows a memory map showing the configuration of the second to fifth storage areas developed in a predetermined area of the RAM 201c. As shown in the figure, the second storage area (M2), the third storage area (M3), the fourth storage area (M4), and the fifth storage area (M5) are provided in a predetermined area of the RAM 201c. ing.

  The second storage area (M2) functions as output data storage means for local output data for storing output data to be sent to each output circuit 203. As will be described later, the output data stored in the second storage area (M2) is sent to each output circuit of the corresponding external output terminal by executing the output refresh process.

  The third storage area (M3) functions as output data storage means for communication-derived output data that stores output data for each output terminal (OUT0 to OUTn) received from the safety PLC 1 via the communication circuit 204. It is.

  On the other hand, the fourth storage area (M4) and the fifth storage area (M5) are output for each output terminal (OUT0 to OUTn) generated inside the safety remote I / O terminal itself or all outputs. It functions as output data storage means for internally derived output data that stores output data common to the terminals (OUT0 to OUTn).

  The fourth storage area (M4) stores output data for each output terminal (OUT0 to OUTn) obtained as a result of executing a logic operation arbitrarily programmed within the safety remote I / O terminal itself. Functions as output data storage means derived from internal logic operations.

  The fifth storage area (M5) is common to all output terminals (OUT0 to OUTn) generated in the selection process of the auxiliary output function fixedly incorporated in the safety remote I / O terminal itself. It functions as an output data storage means derived from an auxiliary output calculation for storing auxiliary output data. Here, as auxiliary output data, equivalence output data of any output terminal, inverted output data of any output terminal, output data for blinking the lamp for a reset request, whether the terminal is in operation Output data corresponding to an operation mode flag indicating whether or not the terminal is in a normal state, and output data corresponding to a state flag indicating whether or not the terminal is in a normal state.

  Next, a general flowchart showing the processing of the safety remote I / O terminal is shown in FIG. As shown in the figure, when the process is started by turning on the power, the operation mode control process (step 101) is first executed to determine whether or not to change to each of a plurality of operation modes prepared in advance. The operation mode transition process is executed.

  In the illustrated example, the description is centered on the case where the RUN mode is selected as the operation mode. However, when another mode is selected, processing corresponding to that mode is executed. That is, in the group in the operation mode control process (step 101), there is a branch for shifting to the process of each mode depending on which mode the mode is, but this is omitted in the figure. .

  Subsequently, an I / O refresh process (step 102) is executed. In this I / O refresh processing, local input / output processing and local input / output terminal diagnosis processing are executed. The local input / output processing includes a local input storage area (not shown) and a local output storage area, that is, the second storage area (M2) in this example, the input device 5 and the output device. By exchanging data with each other, the latest external input state is taken into the storage area for local input, and the latest local output is transferred to the external output terminal via the corresponding output circuit 6. Send it out.

  In the local input / output terminal diagnosis process, by driving each of the new input / output stages incorporated in this type of safety remote I / O terminal, contact burn-in is performed on each of the input device 5 and the output device 6. Diagnosis processing is performed to determine whether there is a failure such as poor continuity.

  In the subsequent communication processing (step 103), the local output data stored in the second storage area (M2) is transmitted to the safety PLC1 by communicating with the safety PLC1 via the communication circuit 204, and from the safety PLC1. Received output data is received and stored in the third storage area (M3). In the case of the conventional safety remote I / O terminal, the output data from the safety PLC thus received is immediately sent to the corresponding external output terminal by the I / O refresh process (step 102) described above. As will be described later, in the case of the present invention, the output data thus received from the safety PLC is not necessarily sent to the external output terminal.

  In the subsequent logic operation processing (step 104), logic operation processing, equivalence data, inverted value data creation / update processing, reset request creation / update processing, and local output data creation processing are executed.

  In the logic operation processing, a logic operation program that is arbitrarily created by the user in advance and stored in the remote I / O terminal is executed, and output data for each output terminal (OUT0 to OUTn) obtained as a result of the execution is executed. The logic operation output data is generated and stored in the storage location of the corresponding external output terminal (OUT0 to OUTn) in the fourth storage area (M4). Thus, the output data corresponding to the logic operation execution result stored in the fourth storage area (M4) is transferred to the second storage area (M2) for local output data as necessary, and finally the corresponding Sent to the external output terminal.

  Further, in the process of creating / updating equivalence data and inversion value data, equivalence data and inversion value data relating to the corresponding output terminal are created / updated based on the contents of the output function setting table TB as will be described later.

  In the reset request creation / update process, output data for blinking the lamp for the reset request is created / updated by a process described later.

  Further, in the local output data creation process, as will be described in detail later, necessary data is obtained from the third storage area (M3), the fourth storage area (M4), and the fifth storage area (M5). Is transferred to the second storage area (M2) to finalize the local output data.

  In the subsequent self-diagnosis process (step 105), various hardware diagnosis processes of the remote I / O terminal are performed, and the diagnosis results are stored.

  If any serious abnormality occurs while repeating the above processing (steps 101 to 105) (YES in step 106), the operation is immediately stopped.

  Next, FIG. 6 shows a flowchart showing details of processing for setting an output function related to the output terminal n with respect to the output function setting table TB shown in FIG. When processing is started in the figure, the following processing is performed by decoding output function setting data sent from a program development support device (not shown) connected to the network (for example, reference numeral 3 in FIG. 1). Is executed. That is, if the decoded output function is to output the output data from the safety PLC (same as before), the contents of the corresponding output terminal of the output function setting table TB stored in the first storage area (M1). The predetermined code is stored as the output data from the safety PLC to be output (step 202).

  If the decoded output function content is determined as output data determined by the execution result of the logic operation program incorporated therein (step 201), the corresponding output terminal setting in the output function setting table TB is set. The content is a predetermined code stored as output data obtained as a result of the execution of the logic operation program (step 203).

  On the other hand, the content of the decoded output function is determined as an auxiliary output (step 201), and the content is the same as output terminal n, inverted with output terminal n, reset request, operation mode flag, or status flag. Is determined (step 204), the contents of the corresponding output terminal of the output function table TB are set to predetermined codes corresponding to such output data (steps 205, 206, 207, 208). 209).

  As described above, the contents of the output function setting table TB stored in the first storage area (M1) shown in FIG. 3 are transmitted from the program development support apparatus connected to the network or directly connected to the remote I / O terminal. It is possible to rewrite arbitrarily according to the setting data.

  As an example, FIG. 14 and FIG. 15 show screen explanatory diagrams (part 1 and part 2) when setting the operation mode flag.

  As is clear from these figures, a predetermined window is opened on the screen of the notebook personal computer constituting the program development support apparatus, and a setting parameter list 400 is displayed in the window. In this setting parameter list 400, the setting parameter and its value related to the output function are displayed for each output terminal. Therefore, the user selects a predetermined parameter by the cursor operation (see FIG. 14) and pull-down button 401. To display the parameter list 406, search for the required parameter value by operating the scroll bar 405, move the cursor 405 to the required parameter value, and operate the OK button 402. The necessary parameters and parameter values can be easily set for each output terminal.

  The output function setting data created in this way is sent to the remote I / O terminal via the network, so that the output function setting process for the output terminal n shown in FIG. 6 can be executed. is there.

  Next, a detailed flowchart of the process for determining the contents of the local output OUTm is shown in FIG. As shown in FIG. 4, it is assumed that the local output data is stored in the second storage area (M2), the output data from the safety PLC is stored in the third storage area (M3), and the fourth storage area (M4). Assume that the output data obtained by the internal logic operation is stored in the fifth storage area (M5) with auxiliary output data such as a reset request, an operation mode flag, and a status flag.

  In such a state, when the processing shown in FIG. 7 is started, the contents of the local output OUTm are sequentially determined for each output terminal number (m). That is, first, by referring to the contents of the output function setting table TB shown in FIG. 3, the set output function of each output terminal is determined, and corresponding processing (steps 303 to 309) is performed according to the determination result. Is executed, rewriting processing of output data at locations corresponding to the output terminals (OUT0 to OUTn) in the second storage area (M2) is executed.

  That is, when the setting content of the output function setting table TB is to output the output data from the safety PLC (step 302), the content of the local output OUTm is rewritten by the output data OUTm from the safety PLC (step 303). .

  If it is determined that the output function setting content is determined by the internal logic operation (step 302), the content of the local output OUTm is rewritten with the content of the logic operation output OUTm.

  If it is determined that the decoded setting content is the same value as the local output OUTn (step 302), the content of the local output OUTn is rewritten with the content of the local output OUTn.

  If it is determined that the output function of OUTm is the inverted value of OUTn, the contents of local output OUTm are rewritten as the inverted value of local output OUTn (step 306).

  If it is determined that the output function of OUTm is a reset request, the contents of local output OUTm are rewritten to a status data reset request (step 307).

  If it is determined that the output function of OUTm is an operation mode flag, the content of local output OUTm is rewritten as an operation mode flag of status data (step 308).

  Furthermore, if it is determined that the output function of OUTm is a status flag, the contents of local output OUTm are rewritten as status data status flags (step 309).

  The above process is repeated for the number of output points from m = 0 (step 311).

  As a result of executing the processing shown in the flowchart of FIG. 7, the contents of the local output data stored in the second storage area (M2) shown in FIG. 4 are the output function setting table shown in FIG. As a result of rewriting with the contents of the third storage area (M3), the fourth storage area (M4), and the fifth storage area (M5) according to the set contents of TB, in the general flowchart shown in FIG. When the refresh process (step 102) is executed, local output data stored in the second storage area (M2) is output to each of the actual external output terminals (OUT0 to OUTn).

  Therefore, according to the remote I / O terminal of the above embodiment, a predetermined operation is performed in a program development support apparatus (not shown), and the contents of the output function setting table TB shown in FIG. The external output terminals (OUT0 to OUTn) are shared, and for each terminal, output data derived from communication, output data derived from internal logic operation, output data equivalent to an arbitrary output terminal, inverted value of an arbitrary output terminal Output data, output data for reset request, output data corresponding to the operation mode flag, and output data corresponding to the status flag can be output arbitrarily, making this type of remote I / O terminal easier to use While this can be improved, the output terminal block itself can be used as it is. Because it can be used, those having the advantage of not causing a special cost increase.

  Next, an application suitable for each of the output functions described above will be described with reference to FIGS.

  FIGS. 8 and 9 are explanatory diagrams (No. 1 and No. 2) of the safety control application suitable for the “equivalent output function”. In FIG. 8, 81 is a lamp for notifying the worker of various information, 82 is a safety light curtain installed at the entrance of the safety fence, 83 is a robot as a danger source, 84 is an operator, 85 is a reset switch for returning from the emergency stop state, and 86 is an emergency stop switch.

  Assuming such a work site, usually, during operation of the robot 83 which is a danger source, the lamp 81 is turned on to notify that the robot 83 is in operation. In such a case, connection as shown in the connection diagram of FIG. 9A is performed on the external terminal block of the remote I / O terminal.

  That is, in brief, the contactor relays (KM1, KM2) are driven by outputting the output signals (OUT0, OUT1) to the terminals (23, 24). Duplexing processing is performed by interposing contacts (KM1, KM2) of the contactors (KM1, KM2) in series in the current path of the motor (M) that drives the robot. Further, the output signal (OUT2) is output to the terminal (25) to drive the lamp (L) (corresponding to the lamp 81 in FIG. 8).

  At this time, in the conventional method, the driving of the lamp (L) is performed via a logic operation program on the safety PLC 1 side. On the other hand, in the present invention, the output signal (OUT2) is output to the terminal (25) as an equivalent output by using the “equivalent output function” described above.

  Then, as shown in the timing chart of FIG. 9B, the output signal (OUT2) for driving the lamp (L) is the output signal (OUT0, OUT1) for driving the contactors (KM1, KM2). Turns on and off in sync with. At this time, for example, the output signal OUT2 is defined as the same value as the output signal OUT0. Thereby, the lighting operation of the lamp (L) can be realized without the control on the safety PLC 1 side.

  An explanatory diagram of a safety control application suitable for the “reset request output function” is shown in FIG. As described with reference to FIG. 8, this type of work site is provided with a lamp 81 for notifying the operator 84 of various situations. When the operation of the robot 83 is stopped by operating the emergency stop switch 86, the original state cannot be restored unless the reset switch 85 is operated for reasons of safety standards. At this time, in a state of waiting for the operation of the reset switch 85 so that the operator 84 does not forget to operate the reset switch 85, the lamp 81 is driven to blink by sending out a reset request signal which is an oscillation output.

  As shown in FIG. 10, for this blinking drive, a reset request signal that is an oscillation output of a predetermined frequency must be sent. Conventionally, this reset request signal has been generated by building a predetermined program on the safety PLC 1 side, but the processing has been complicated. On the other hand, in the present invention, for a certain period determined by the output of the emergency stop switch shown in FIG. 5A and the output of the reset switch shown in FIG. The oscillation output corresponding to the reset request can be generated as shown in FIG. 6 and this reset request can be output from an arbitrary external output terminal by setting it as the “reset request” in the output function setting table TB. . As a result, the reset request can be output from the remote I / O terminal side without passing through the safety PLC 1, and the lamp 81 can be driven to blink.

  FIGS. 11 and 12 are explanatory diagrams (No. 1 and No. 2) of the safety control application suitable for the “inverted output function”. In FIG. 11, 84 is an operator, 86 is an emergency stop switch, 87 is an electromagnetic lock safety door switch, 88 is a danger source, and 89 is a limit switch.

  The electromagnetic lock safety door switch automatically becomes a mechanical lock when the dedicated operation key is inserted, and the door cannot be opened. At this time, when a voltage is applied to the solenoid, the lock is released and the door can be opened. Therefore, for example, as shown in FIG. 12A, the contactor output is sent to the output signals (OUT0, OUT1), and the unlock signal of the electromagnetic lock safety door switch is output as the output signal (OUT2). Then, as shown in the time chart of FIG. 5B, when the lock release signal is acquired after the contactor output is turned OFF, the output signal (OUT2) of the remote I / O terminal By simply setting “inverted output”, the program on the safety PLC 1 side becomes unnecessary.

  An explanatory diagram of a safety control application suitable for the “status flag output function” is shown in FIG. As shown in FIG. 13, if an output signal corresponding to the status flag is sent from an arbitrary output terminal of the safety remote I / O terminal 2, an output signal corresponding to the status flag is output on the robot 7 side. Safety control can be realized by setting as an operating condition. According to such a configuration, in the conventional example shown in FIG. 4B, it corresponds to such a status flag to the robot 7 with a dedicated cable without intervening communication from the safety PLC 1 separately. What needed to deliver a signal eliminates the need for such a cable and improves usability.

  According to the present invention, it is possible to output the internally derived output data generated inside itself to any external output terminal without competing with the communication derived output data coming from the safety PLC side. Therefore, the usability of this type of safety remote I / O terminal can be greatly improved without increasing costs due to hardware modifications such as the addition of a terminal block.

1 is a schematic configuration diagram of a safety PLC system to which the present invention is applied. It is a block diagram which shows the electrical hardware constitutions of a safe remote I / O terminal. It is explanatory drawing of the output function setting aspect about each output terminal (OUT0-OUTn). It is a memory map which shows the structure of the 2nd-5th storage area. It is a general flowchart which shows the process of a safe remote I / O terminal. It is a detailed flowchart of the output function setting process regarding the output terminal n. It is a detailed flowchart of the process for determining the content of local output OUTm. It is explanatory drawing (the 1) of the safety control application suitable for "equivalent output function". It is explanatory drawing (the 2) of the safety control application suitable for "equivalent output function". It is explanatory drawing of the safety control application suitable for a "reset request output function". It is explanatory drawing (the 1) of the safety control application suitable for an "inversion output function". It is explanatory drawing (the 2) of the safety control application suitable for an "inversion output function". It is explanatory drawing of the safety control application suitable for a "status flag output function". FIG. 6 is a screen explanatory diagram (part 1) when an operation mode flag is set for output 2; FIG. 12 is a screen explanatory diagram (part 2) when an operation mode flag is set for output 2; It is a basic lineblock diagram of a safety PLC system.

Explanation of symbols

1 Safety PLC
2 Safety Remote I / O Terminal 3 Program Development Support Device 4 Network 5 Input Device 6 Output Device 7 Robot 81 Alarm Lamp 82 Safety Light Curtain 83 Robot 84 Worker 85 Reset Switch 86 Emergency Stop Switch 87 Electromagnetic Lock Safety Door Switch 88 Hazard Source 89 Limit switch 201 CPU
201a Microprocessor (MPU)
201b ROM
201c RAM
202 Input circuit 203 Output circuit 204 Communication circuit 205 Display circuit 206 Setting circuit 400 Parameter list 401 Pull-down button 402 OK button 403 Cancel button 404 Scroll bar 405 Cursor KM1, KM2 Contactor M Motor M1 First storage area M2 Second storage area M3 Second 3 storage area M4 4th storage area M5 5th storage area L Lamp OUT0-OUTn External output terminal TB Output function setting table

Claims (8)

A communication circuit for communicating with the safety PLC via the network;
One or more external output terminals each connected to an output device;
An output circuit that is provided for each external output terminal and sends an output signal to an output device connected to the external output terminal;
Output data storage means for local output data for storing output data to be sent to each of the output circuits;
Output data storage means for communication-derived output data for storing output data for each output terminal received from the safety PLC via the communication circuit via the communication circuit;
Output data storage means for internally derived output data for storing output data for each output terminal generated internally or common to each output terminal;
For each external output terminal, an output function setting table storage means for storing an rewritable output function setting table in which the output function of the external output terminal is set, and
Refer to the setting contents of each external output terminal of the output function setting table stored in the output function setting table storage means, and when the setting contents are output functions to output communication-derived output data, The communication-derived output data of the corresponding external output terminal stored in the output data storage means is stored in the storage location of the corresponding external output terminal of the output data storage means for local output data, while the setting contents are output from the internal When the output function is to output data, the internal origin output data of the relevant external output terminal stored in the output data storage means for internal origin output data is converted into the corresponding external of the output data storage means for local output data. Local output switching means for storing in the storage location of the output terminal;
An output refresh means for sending each output data stored in the output data storage means for the output data for the local to each of the output circuits of the corresponding external output terminals, and a safety remote I / O comprising: Terminal.   2. The safety remote I / O according to claim 1, wherein the internally derived output data is output data for each output terminal obtained as a result of execution of a logic operation arbitrarily programmed within itself. Terminal.   2. The safety remote I according to claim 1, wherein the internally derived output data is auxiliary output data common to each output terminal generated by a predetermined process fixedly incorporated therein. / O terminal.   4. The safety remote I / O terminal according to claim 3, wherein the auxiliary output data is equivalent output data of an arbitrary output terminal.   The safety remote I / O terminal according to claim 3, wherein the auxiliary output data is inverted value output data of an arbitrary output terminal.   4. The safety remote I / O terminal according to claim 3, wherein the auxiliary output data is output data for blinking a lamp for a reset request.   4. The safety remote I / O terminal according to claim 3, wherein the auxiliary output data is output data corresponding to an operation mode flag indicating whether or not the terminal is in operation.   4. The safety remote I / O terminal according to claim 3, wherein the auxiliary output data is output data corresponding to a status flag indicating whether or not the terminal is in a normal state.

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