JP4225925B2 - Digital controller - Google Patents

Description

  The present invention relates to a control device that performs control by outputting a control signal to a control target based on an input signal, and particularly controls the control target even when a failure occurs in an input / output unit of a digital signal or an analog signal. The present invention relates to a digital control device that can continue.

  FIG. 16 is a schematic diagram outlining the configuration of a control device 1 used for controlling plant equipment as an example of a conventional digital control device.

  According to FIG. 16, the control device 1 uses a control signal for the controller 2 to control a control target 3 such as a plant, based on a signal indicating a plant state (hereinafter referred to as a plant state signal) input to the controller 2 as a control means. And output to the plant 3 that is the control target. In addition, when the failure detection unit 4 that detects a failure of the control device 1 detects a failure, the failure detection unit 4 outputs the detected result to the man-machine interface device 5 as a display unit, and outputs the result to the man-machine interface device 5. indicate.

  The plant state signal input to the controller 2 has at least one of a digital signal and an analog signal, and is input to a digital signal input unit (DI) 6 and an analog signal input unit (AI) 7 as signal input means. The Of the plant state signals, digital signals are input from the digital signal input unit 6 and analog signals are input from the analog signal input unit 7.

  The digital signal input from the digital signal input unit 6 is input to the calculation unit 8 included in the controller 2 and is calculated by the control calculation unit 9 included in the calculation unit 8. The control arithmetic unit 9 outputs a digital signal resulting from the arithmetic processing from a digital signal output unit (DO) 10 as signal output means. The digital signal output from the digital signal output unit 10 is input to a control target such as a pump or a valve, for example, and operates the plant.

  The analog signal input from the analog signal input unit 7 is input to the calculation means 8 provided in the controller 2 and is calculated by the detector 11 and the subtractor 12 included in the calculation means 8. The detector 11 outputs a signal (ON) when the input analog signal is above a certain level or below a certain level. The digital signal output from the detector 11 is input to the control target via the digital signal output unit 10.

  The subtracter 12 subtracts an analog signal indicating the process state of the plant input from a preset set value and outputs the result. The analog signal output from the subtracter 12 is input to the adjustment control calculation unit 13 and is calculated by the adjustment control calculation unit 13. The analog signal output from the adjustment control calculation unit 13 is input to a control target such as a controller that monitors the opening of the valve, for example, via an analog signal output unit (AO) 14 as a signal output unit.

  On the other hand, since the controller 2 has one input / output unit for one input / output signal, the digital signal input unit 6, the analog signal input unit 7, the digital signal output unit 10 and the analog signal output unit 14 are abnormal. In this case, the signal input / output cannot be normally performed. Therefore, when a failure occurs, the failure detection means 4 in the controller 2 detects the failure by self-diagnosis such as data error detection, and outputs the detection result to the man-machine interface device 5 to notify the user of the occurrence of the failure. ing.

  Further, the failure recovery is performed by connecting the maintenance support device 15 capable of performing internal monitoring of the controller 2 to the controller 2, confirming the detailed information of the failure location, and performing the recovery work of the failed part. In some cases, a failure that cannot be detected by the failure detection means 4 may occur. In such a case, the failure may be confirmed based on the investigation result due to a change in the plant operation state or the like.

An example of the digital control device described above is disclosed in Japanese Patent Laid-Open No. 11-85251. (For example, refer to Patent Document 1).
JP-A-11-85251 (paragraph numbers [0001], [0008] to [0009], [0040], FIG. 1)

  However, since the controller 2 of the conventional control apparatus 1 performs only one point of input / output signals, the digital signal input unit 6, the analog signal input unit 7, the digital signal output unit 10, and the analog signal output unit 14 are used. If any of the above malfunctions, the signal cannot be input / output normally, and there is a possibility that it is difficult to continue the operation of the plant 3 to be controlled.

  Further, in the case of a failure at the end of each input / output unit, the failure detection means 4 cannot detect the failure, so no failure is output to the man-machine interface device 5 and it takes time to identify the failure location. It was. Furthermore, at the time of recovery of the fault location, if the fault location is the input / output unit, check the version of the replacement target (in this case the input / output unit) managed in the ledger and prepare a replacement. However, there may be a case where the version to be exchanged does not match the version on the ledger due to the problem of ledger management. If the prepared replacement target does not support the version of the failure part, it must be searched again for a replacement supported version, which may take time to recover.

  On the other hand, the control device 1 periodically checks (tests) the soundness in order to prevent failure. In periodic soundness confirmation tests, it is necessary to consider that other control panels, equipment, and field equipment will not be affected by erroneous signal output. For this reason, during the inspection in the soundness confirmation test, the plant operation as the control target is stopped, and each input / output of the digital signal input unit 6, the analog signal input unit 7, the digital signal output unit 10 and the analog signal output unit 14 is performed. It is necessary to fix the signal (ON or OFF in the case of a digital signal, and a fixed value by a voltage generator or the like in the case of an analog signal), and it is also possible that a work error occurs due to test preparation, testing, and recovery work.

  The present invention has been made to solve the above-described problems, and provides a digital control device capable of controlling a control target even when a failure occurs in a digital signal input / output unit and an analog signal input / output unit. Objective.

  Another object of the present invention is to provide a control device that shortens the recovery time of a fault location and reduces human work in periodic inspection.

In order to solve the above-described problems, a digital control device according to the present invention has a plurality of signal transmission systems, performs a calculation process on an input signal, and outputs a signal, and the control means output from the control means An output selection means for outputting one signal based on the output signal, and the control means includes a signal input means including a digital input section and an analog input section configured to be capable of inputting a plurality of identical signals, and an input An input selection means for outputting a plurality of received signals as one signal, an arithmetic means for performing an arithmetic processing on the input signal output from the input selection means, and a digital device configured to output a plurality of identical signals a signal output unit, and a signal output means comprising an analog signal output section, the 1-system digital signals are fed back output from the digital signal output of the signal output means Contact 2 system digital signal and the digital signal output from the arithmetic means are compared and output mismatch detection means for performing ON output in case of mismatch, and 1 system analog output from the analog signal output section of the signal output means and fed back When the signal and the 2-system analog signal are compared with the analog signal output from the arithmetic means, and at least one of the output deviation large detection means for performing the ON output when the deviation is larger than the allowable range, and the failure of the apparatus is detected A fault detection means for outputting a fault detection signal to the fault detection signal, a fault detection signal output from the fault detection means, a fault detection signal input from the fault detection means, and an output mismatch detection means and a large output deviation detection means. It is determined whether or not there are duplicate ON outputs from at least one. And a failure overlap determination means for blocking the ON output from at least one of the force discrepancy detecting means and the output deviation great detection means, the input selection means, a plurality of signals which are input in the case of digital signals, a logic operation A digital input selector that outputs a single digital signal, and when the input signal is an analog signal, the highest or lowest value of the multiple analog signals is alternatively selected to output a single signal. An analog input selection unit, and the output selection unit selects a digital output selection unit that performs a logical operation on a plurality of input digital signals and outputs a maximum value or a minimum value of the plurality of input analog signals. And an analog output selection unit that selects and outputs the data.

In order to solve the above-described problems, a digital control device according to the present invention has a plurality of signal transmission systems, performs a calculation process on an input signal, and outputs a signal, and the control means output from the control means based on the output signals, one output selecting means for outputting a signal, and display means for displaying the information outputted from the control means, signal transmission switching selection means for selecting switching the signal transmission system accepts external input A normal / test selection means for selecting whether the maintenance inspection test has not been conducted or not, a normal / test switching signal generation means for generating a switch switching signal for switching a signal path according to normal operation and testing, separate from normal the one signal transmission system control signal is transmitted in the time of the test time and the one signal transmission system and the normal operation test signal during the test by switching the signal path is transmitted in response to the operation Comprising a normal / test switch means for securing the another independent signal transmission system, wherein the control means includes a signal input means comprising a digital input and an analog input section having a plurality of identical signals are configured to be input An input selection unit that outputs a plurality of input signals as one signal, an arithmetic unit that performs an arithmetic processing on the input signal that is output from the input selection unit, and a plurality of identical signals can be output. A signal output means comprising a digital signal output section and an analog signal output section, and a test circuit for performing a maintenance inspection test of at least one of the signal input means and the signal output means , wherein the input selection means is input When a plurality of signals are digital signals, a digital input selection unit that performs a logical operation and outputs one digital signal, and a plurality of input signals are analog An analog input selection unit that alternatively selects the highest value or the lowest value of a plurality of analog signals and outputs one signal, and the output selection means includes a plurality of input digital signals A digital output selection unit that performs logical operation on the output and an analog output selection unit that alternatively selects and outputs the highest value or the lowest value of a plurality of input analog signals .

In order to solve the above-described problems, a digital control device according to the present invention has a plurality of signal transmission systems, performs a calculation process on an input signal, and outputs a signal, and the control means output from the control means Based on the output signal, output selection means for outputting one signal, display means for displaying information output from the control means, selection of whether or not a maintenance inspection test has been performed and selection of the signal transmission system Normal / test selection means to be performed, signal transmission system switching selection means for automatically switching and selecting the signal transmission system upon receiving a signal output from the normal / test selection means, during normal operation and during testing A normal / test switching signal generating means for generating a switch switching signal for switching the signal path according to the signal, and a signal for switching the signal path according to the normal operation and the test and transmitting the test signal during the test. A normal / test switching means for ensuring a transmission system and another signal transmission system that is independent of the one signal transmission system through which a control signal during normal operation is transmitted, and the control means includes a plurality of A signal input means comprising a digital input section and an analog input section configured to allow the same signal to be input; an input selection means for outputting a plurality of inputted signals as one signal; and output from the input selection means, A signal output means comprising: an arithmetic means for arithmetically processing an input signal; a digital signal output section configured to output a plurality of identical signals; and an analog signal output section; and the signal input means and the signal output means. A test circuit for performing at least one maintenance inspection test, and the input selection means performs a logical operation on one digital signal when the plurality of input signals are digital signals. And a digital input selection unit for selectively selecting the highest value or the lowest value of the plurality of analog signals and outputting one signal when the plurality of input signals are analog signals And the output selection means alternatively selects a digital output selection unit that performs a logical operation on a plurality of input digital signals and outputs a maximum value or a minimum value of the plurality of input analog signals. And an analog output selection unit for outputting.
Here, the test circuit means at least one of the test circuits of the digital test circuit and the analog test circuitry.

  According to the digital control device of the present invention, even if a failure occurs in the digital signal input unit, the analog signal input unit, the digital signal output unit, and the analog signal output unit, unlike the conventional digital control device, If the output unit is healthy, the plant equipment to be controlled can be operated in a safe direction.

  Further, at the time of carrying out the maintenance inspection test, it is possible to carry out the maintenance inspection test in the other signal transmission system while continuing the control of the control target in one signal transmission system.

  Furthermore, since the test results are stored in the memory built in the test circuit, the test results can be confirmed by outputting to the display unit or connecting to a maintenance support device and reading the memory, and maintenance performed regularly The labor required for the inspection test can be reduced.

  Hereinafter, a digital control device according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 schematically shows the configuration of a digital control apparatus 20 that uses plant equipment (including associated instruments) as a control target as an example of the digital control apparatus according to the first embodiment of the present invention. A schematic diagram is shown.

  According to FIG. 1, the digital control device 20 performs a logical operation or a control based on a controller 21 as a control unit that performs arithmetic processing on a plurality of input signals and outputs a signal, and a plurality of output signals output from the controller 21. Output selection means for selecting a signal and outputting one signal to the outside of the digital control device 20. In the following description, the case where the number of signals input to and output from the controller 21 is two will be described as an example.

  The controller 21 of the digital control device 20 includes a signal input unit that receives an input of a signal from the outside, and an input selection unit that outputs one signal by performing a logical operation or signal selection based on two signals input to the signal input unit. And an arithmetic means for arithmetically processing the input signal, and a signal output means for outputting the signal arithmetically processed by the arithmetic means to the outside of the controller 21.

  The signal input means of the controller 21 includes a digital signal input unit 25 for inputting a digital signal and an analog signal input unit 26 for inputting an analog signal. The digital signal input unit 25 and the analog signal input unit 26 are respectively Are configured in pairs. That is, two digital signal input sections (shown as DI1 and DI2 in the figure) 25 for one digital input signal, and two analog signal input sections 26 (AI1 in the figure) for one analog input signal. , AI2).

  Two identical signals obtained by branching one signal outside the digital control device 20 are inputted to the signal input means. When the input signal is a digital signal, one of the two digital signals is input to DI1 of the digital signal input unit 25 and the other is input to DI2 of the digital signal input unit 25. When the input signal is an analog signal, one of the two analog signals is input to AI1 of the analog signal input unit 26 and the other is input to AI2 of the analog signal input unit 26.

  The signals input to the digital signal input unit 25 (DI1 and DI2) are respectively output and input to the input selection means. Similarly to the signal input to the digital signal input unit 25, the signals input to the analog signal input unit 26 (AI1 and AI2) are also output and input to the input selection unit.

  When the two input signals are digital signals, the input selection means performs a logical operation to output one digital signal, and when the two input signals are analog signals, An analog input selection unit 29 is provided to select one of the high value or the low value of two analog signals and output one signal.

  The digital input selection unit 28 has an AND function 31 for performing a logical operation on a logical product (AND) of two input digital signals or an OR function 32 for performing a logical operation on a logical sum (OR). One digital signal is output by performing a logical operation on the two digital signals. In FIG. 1, the digital input selection unit 28 is shown as an example having an AND function 31, but which of the AND function 31 and the OR function 32 has to be calculated is either AND or OR. It is determined in consideration of whether the controlled object is safe.

  For example, when the input signal to the calculation means is ON and the output signal of the controller 21 is in a safe direction for preventing damage to the plant equipment to be controlled, any one of the input signals has malfunctioned / not malfunctioned. Even in this case, the digital input selection unit 28 having the OR function 32 is configured so as to perform a logical operation on the OR for which the input signal to the operation means is ON. On the contrary, when the safety direction is set to OFF, the AND function 31 is provided so as to perform a logical operation on an AND in which the input of the control calculation unit is OFF even when any one of the input signals malfunctions or malfunctions. The digital input selection unit 28 is configured.

  Although the digital input selection unit 28 has the AND function 31 or the OR function 32, the digital input selection unit 28 has both the AND function 31 and the OR function 32, and the digital input selection unit 28 has the AND function 31 and the OR function. One of the 32 may be configured to be selectively switchable later.

  The analog input selection unit 29 also selects a high-value selection function 34 or a low-value signal (three) for selecting a high-value signal (the highest-value signal in the case of three or more signals) of the two input signals. A low value selection function 35 for selecting the lowest signal in the case of the above signals is selected, and the high value or the low value of the two input signals are selected alternatively. In FIG. 1, the analog input selection unit 29 is shown as an example having a high value selection function 34, but whether the high value selection function 34 or the low value selection function 35 is provided is determined by the digital input selection unit 28. Similarly, it is determined in consideration of which one is selected as safer to control.

  For example, if the output signal of the controller 21 is in a safe direction when the input signal input to the analog input selection unit 29 is large, the analog input selection unit 29 having the high value selection function 34 is configured, and the analog input selection unit 29 When the output signal of the controller 21 is in a safe direction when the input signal input to is low, the analog input selection unit 29 having the low value selection function 35 is configured.

  As in the case of the digital input selection unit 28, the analog input selection unit 29 is configured to have both the high value selection function 34 and the low value selection function 35, and the analog input selection unit 29 is configured to have the high value selection function 34 and the low value selection function 35. One of the value selection functions 35 may be configured to be switchable afterwards.

  In the input selection means, the digital input selection unit 28 performs a logical operation on two input digital signals and outputs one digital signal. For the two input analog signals, the analog input selection unit 29 outputs one analog signal. The digital signal and the analog signal output from the input selection unit are input to the calculation unit.

  The calculation means detects and detects whether the digital signal output from the digital input selection unit 28 is processed and output, and the analog signal output from the analog input selection unit 29 is above or below a certain level. In this case, the detector 38 outputs a signal (digital signal), the subtractor 39 that subtracts the analog signal output from the analog input selection unit 29 from the preset setting value, and the analog signal of the subtractor 39. And an adjustment control calculation unit 40 that calculates the output and outputs an analog signal.

  The output signal output from the calculation means includes a digital signal output from the control calculation unit 37 and the detector 38 and an analog signal output from the adjustment control calculation unit 40. The output signals output from the control calculation unit 37, the detector 38, and the adjustment control calculation unit 40 are branched into two identical signals and then input to the signal output means.

  Similarly to the signal input means, the signal output means includes a digital signal output section 42 and an analog signal output section 43. The digital signal output section 42 and the analog signal output section 43 are configured in pairs. . That is, two digital signal output units (shown as DO1 and DO2 in the figure) 42 for one digital signal, and two analog signal input units 43 (AO1, in the figure) for one analog input signal. AO2) is provided.

  The digital signal output section 42 outputs two identical digital signals output from the control calculation section 37 and the detector 38 as calculation means and branched to the output selection means, one via DO1 and the other via DO2. The analog signal input unit 43 outputs two identical analog signals output from the adjustment control calculation unit 40 and branched to the output selection means, one through AO1 and the other through AO2.

  On the other hand, the output selection means alternatively selects the digital output selection unit 45 that performs logical operation on the two input digital signals and outputs them, and alternatively selects the high value or the low value of the two input analog signals. An analog output selection unit 46 for output. The functional configuration and processing content of the digital output selection unit 45 are the same as the processing content of the digital input selection unit 28, and the functional configuration and processing content of the analog output selection unit 46 are the same as the processing content of the analog input selection unit 29. Since it is the same, description is abbreviate | omitted here.

  According to the digital control device 20 configured as described above, the signal input means and the signal output means are made redundant, and the input control means and the output selection means for outputting one signal based on two input signals are provided. Even if a failure occurs in the digital signal input unit 25, the analog signal input unit 26, the digital signal output unit 42, and the analog signal output unit 43, one of the signal input / output units can be sound, unlike the conventional digital control device. For example, the plant equipment that is the control target can operate in a safe direction.

  In other words, in the case of the digital control device 20, since the plant equipment that is the control target can be controlled in a safe direction as long as the two signal input / output units do not fail at the same time, the digital control device 20 is a control target compared to the conventional digital control device. The probability that it is difficult to continue operation (operation) of plant equipment can be further reduced.

  The digital control device 20 includes a subtractor 39 and an adjustment control calculation unit 40 as a calculation unit of the controller 21, an analog signal output unit 43 as a signal output unit, and an analog output selection unit 46 as an output selection unit. However, it is not always necessary. That is, the pure digital control device 20 may be configured not to output any analog signal.

  Further, if it is assumed that there is no analog signal in the signal input to the controller 21 and all signals are input as digital signals, the digital signal input unit 25 is used as the signal input means, and the digital input selection unit 28 is used as the input selection means. The control unit 37 may be configured as the calculation unit, the controller 21 including the digital signal output unit 42 as the signal output unit, and the output selection unit including the digital output selection unit 45 may be configured. Absent.

  Further, according to FIG. 1, the digital input selection unit 28 has an AND function 31 and the digital output selection unit 45 has an OR function 32. However, the configuration is not limited to the example shown in FIG. Not. This is because, as described above, which of the AND function 31 and the OR function 32 is provided is determined in consideration of which function is selected as the operation to be controlled, which is safer. Further, the analog input selection unit 29 and the analog output selection unit 46 are not necessarily limited to the example illustrated in FIG. 1 for the same reason.

  Furthermore, according to FIG. 1, the number of digital signal input portions 25 of the signal input means is one pair of DI1 and DI2, but the example shown in FIG. 1 is merely an example, and the pair shown in FIG. It is not limited to. The same applies to the analog signal input unit 26, the digital signal output unit 42, and the analog signal output unit 43.

  Furthermore, the input signal is separated outside the digital control device 20 and then inputted to the digital control device 20, but the input signal may be separated not inside the digital control device 20 but inside. .

  On the other hand, according to FIG. 1, in the digital control device 20, the analog input selection unit 29 and the analog output selection unit 46 have the high value selection function 34 or the low value selection function 35, and the high value or low value of the two input signals. As shown in FIG. 2, instead of the analog input selection unit 29, an analog input selection unit 29A having an average value output function for outputting an average value of two input signals is selected as shown in FIG. Instead of the unit 46, a digital control device 20A including an analog output selection unit 46A having an average value output function for outputting an average value of two input signals may be configured.

  As shown in FIG. 2, in the case of the digital control apparatus 20A to which the analog input selection unit 29A or the analog output selection unit 46A that outputs an average value of two input signals is applied, one of the two input signals, which has a high value or a low value, is used. Compared with the digital control device 20 to which the analog input selection unit 29 or the analog output selection unit 46 to which the analog output selection unit 46 is applied is selected, one signal transmission system (for example, AI1 system) of the analog signal input unit 26 is signal-locked due to a failure. Alternatively, when there is a sudden change, the digital control device 20 may select an erroneous signal. However, since the digital control device 20A outputs an average value, the signal error is reduced and the degree of influence on the plant equipment to be controlled. Can be reduced.

  The digital control device 20A is configured to include the analog input selection unit 29A and the analog output selection unit 46A. However, the digital control device 20A does not necessarily include both, and either the analog input selection unit 29A or the analog output selection unit 46A. The structure provided with one side may be sufficient.

[Second Embodiment]
FIG. 3 schematically shows the configuration of a digital control device 20B in which plant objects (including accompanying instruments) are controlled as an example of the digital control device according to the second embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20B has one of two signal transmission systems (a signal transmission system on one side such as DI1 to DO1 and a signal transmission system on two sides such as DI2 to DO2) to the digital control device 20. It further includes a selection switch 50 as signal transmission system switching selection means for manually switching selection, and a display unit 51 as display means for displaying to the user as a man-machine interface, and a controller 21A instead of the controller 21. It differs in that it has.

  However, other points are not essentially different. Therefore, in the description of the digital control device 20B, portions that are not essentially different from the digital control device 20 are denoted by the same reference numerals and description thereof is omitted. Also, effects, modifications, and the like that are not essentially different from the digital control device 20 that has already been described are omitted.

  According to FIG. 3, the digital control device 20B includes a controller 21A, output selection means, a selection switch 50 for manually switching and selecting one of the two signal transmission systems, a display unit (man machine interface) 51, It comprises. Further, the controller 21A of the digital control device 20B detects a failure of the digital control device 20B in addition to the signal input means, calculation means, and signal output means included in the controller 21, and outputs a failure detection signal when detected. A detection means 53 is further provided.

  In the digital control device 20B, the selection switch 50 receives a switch input from the user, and inputs selection means (digital input selection unit 28 and analog input selection unit 29) and output selection means (digital output selection unit 45 and analog output selection unit). The signal transmission system 46) is manually switched between the one-side signal transmission system (hereinafter referred to as system 1) or the 2-side signal transmission system (hereinafter referred to as system 2).

  The display unit 51 serving as a man-machine interface and a display unit detects a failure by receiving a failure detection signal (digital signal) output from the failure detection unit 53 after detecting the failure from the controller 21A via the digital signal output unit 42. Display to the effect.

  According to the digital control device 20B configured as described above, the selection switch 50 for switching and selecting the 1-system and 2-system signal transmission systems and the display unit 51, which is a man-machine interface, are added to the digital control device 20. If the controller 21A is provided with the failure detection means 53 instead of the controller 21, and the input / output unit detects that one side of the system has failed, the user has detected the failure via the display unit 51. And the user can manually switch the selection switch 50 to select one of the sound systems.

  When the user selects and switches one of the sound systems, the sound signal transmission system selected by the selection switch 50 normally inputs and outputs a signal to the controller 21, so that the operation of the plant equipment to be controlled ( Operation) can be continued.

  According to FIG. 3, the digital control device 20B includes two selection switches 50, one of which is the signal transmission system of the input selection means (digital input selection unit 28 and analog input selection unit 29). The signal transmission system of the output selection means (digital output selection unit 45 and analog output selection unit 46) is switched to the first system and the second system, and the other is selected as shown in FIG. It is not limited.

  For example, the digital control device 20B is provided with one selection switch 50, and this selection switch 50 is configured to switch and select the signal transmission system of both the input selection means and the output selection means between the 1 system and the 2 system. Alternatively, the digital control device 20B includes four selection switches (first selection switch to fourth selection switch) 50, and the first selection switch 50 is digitally input using these four selection switches 50. The selection unit 28, the second selection switch 50 is the analog input selection unit 29, the third selection switch 50 is the digital output selection unit 45, and the fourth selection switch 50 is the signal transmission system of the analog output selection unit 46. It may be configured to switch between the system and the second system.

  The digital control device 20B does not necessarily have to include the display unit 51. For example, if the display device can display that a failure has been detected using an external device such as a display device (not shown), even if the display unit 51 is not provided, the signal transmission in which the user has failed. This is because the system can be known.

  Further, the digital control device 20B includes a controller 21A having a failure detection means 53 instead of the controller 21, but detects a failure using an external device, and the user knows the signal transmission system in which the failure has occurred. If possible, the controller 21 may be provided. This is because if the selection switch 50 is provided, the user can switch and select one of the sound systems, so that the operation (operation) of the plant equipment to be controlled can be continued.

[Third Embodiment]
FIG. 4 schematically shows the configuration of a digital control apparatus 20C in which plant objects (including associated instruments) are controlled as an example of the digital control apparatus according to the third embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20C is different from the digital control device 20B in that a selection switch 50A is provided in place of the selection switch 50, and a failure detection signal (1 or 2 failure detected by the failure detection means 53). However, the other points are not essentially different.

  Therefore, in the description of the digital control device 20C, portions that are not essentially different from the digital control device 20B are denoted by the same reference numerals and description thereof is omitted. Also, descriptions of effects, modifications, and the like that are not essentially different from the already described digital control devices 20, 20A, 20B are omitted.

  According to FIG. 4, the digital controller 20C includes a controller 21A, output selection means, a selection switch 50A as signal transmission system switching selection means for switching one of the two signal transmission systems, and display means. A display unit (man machine interface) 51 is provided. Further, a failure detection signal (digital signal) output from the failure detection means 53 provided in the controller 21A to the outside of the controller 21A via the digital signal output unit 42 is input to the selection switch 50A.

  When the selection switch 50A receives a failure detection signal (digital signal) from the failure detection means 53 via the digital signal output unit 42, the selection switch 50A automatically performs switching selection to the 1-system or 2-system based on the received failure detection signal. .

  More specifically, when the failure detection unit 53 detects a failure in the signal input unit of the first system, a failure detection signal (hereinafter referred to as a failure detection signal indicating that the failure detection unit 53 has detected a failure in the signal input unit of the first system. 1 system I / O failure detection signal and the 2 system side is also used as 2 system I / O failure detection signal). When receiving the signal, the selection switch 50A automatically switches and selects the signal transmission system to the second system side where no failure is detected.

  Conversely, when the failure detection means 53 detects a failure in the signal input unit of the second system, it receives the second system I / O failure detection signal output from the failure detection means 53, and the selection switch 50A transmits the signal. The system is automatically switched to the 1 system side where no failure is detected.

  According to the digital control apparatus 20C configured as described above, a failure detection signal output from the failure detection means 53 is received instead of the selection switch 50, and the signal transmission system is automatically switched to the 1 system or the 2 system. By providing the selection switch 50A, when the failure detection means 53 detects a failure of the signal input unit of the first system, the selection switch 50A automatically selects the other two systems and inputs the second system signal. When the failure of the part is detected, the selection switch 50A automatically selects the other one system, so that the signal is normally input to and output from the controller 21A. ) It is possible to continue.

[Fourth Embodiment]
FIG. 5 schematically shows the configuration of a digital control apparatus 20D that uses plant equipment (including associated instruments) as a control target as an example of the digital control apparatus according to the fourth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20D is different from the digital control device 20 in that it includes a controller 21B instead of the controller 21 and further includes a display unit 51, but the other points are not essentially different. . Therefore, in the description of the digital control device 20D, portions that are not essentially different from the digital control device 20 are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20C that have already been described are also omitted.

  Referring to FIG. 5, the digital control device 20D includes a controller 21B, a man-machine interface that displays information output from the controller 21B, a display unit 51 as display means, and output selection means.

  The controller 21B compares the signals of the 1-system and 2-system input to the digital signal input section 25 with respect to the controller 21 and outputs an ON mismatch when there is a mismatch, and the analog signal input section 26. The system further includes a large input deviation detecting means 56 that compares the signals of the first and second systems inputted to the output signal and performs ON output when the deviation is larger than the allowable range.

  The input mismatch detection means 55 of the controller 21B receives the signals output from DI1 and DI2 of the digital signal input section 25, and receives the digital signal output from DI1 (1-system digital signal) and the digital output from DI2. The signal (2 system digital signal) is compared. Then, when both signals do not match, ON output is performed. The digital signal output from the input mismatch detection means 55 is input to the display unit 51 via the digital signal output unit 42 and displays that the 1-system and 2-system digital signals do not match.

  Further, the large input deviation detecting means 56 receives the signals output from the AI1 and AI2 of the analog signal input unit 26, and outputs the analog signal output from the AI1 (system 1 analog signal) and the analog output from the DI2. The signal (2 system analog signal) is compared. When the deviation between both signals is larger than the set allowable range, ON output is performed. The analog signal output from the large input deviation detection means 56 is input to the display unit 51 via the analog signal output unit 43, and displays that the deviation between the 1-system and 2-system analog signals exceeds the allowable range. To do.

  According to the digital control device 20D configured as described above, the controller 21B includes the input mismatch detection means 55 and the large input deviation detection means 56, so that the mismatch between the 1-system and 2-system digital signals and the 1-system and 2-system It is possible to monitor whether or not the deviation of the analog signal is within an allowable range.

  Considering that the possibility that DI1 and DI2 or AI1 and AI2 fail at the same time in the digital signal input unit 25 and the analog signal input unit 26 is very low, there is a mismatch between the first and second digital signals and the first and second systems. It is possible to monitor whether or not the deviation of the analog signal of system 2 is within the allowable range. If the input mismatch or the deviation exceeds the allowable range, either DO1 and DO2 or AO1 and AO2 are abnormal. It can be detected that

  In addition, the fact that any one of DO1 and DO2 in the digital signal input unit 25 or AO1 and AO2 in the analog signal input unit 26 can be detected becomes more effective when combined with other embodiments. . For example, when combined with the second embodiment, the user can confirm the display content displayed on the display unit 51, and can select the system that is inputting the normal signal by switching the selection switch 50. It becomes possible to continue the operation (operation) of the plant equipment.

  Further, even when a failure that cannot be detected by the controller 21A including the failure detection unit 53 occurs in either the digital signal input unit 25 or the analog signal input unit 26, the input mismatch detection unit 55 and the large input deviation detection unit 56 are provided. If so, it can be detected that either the digital signal input unit 25 or the analog signal input unit 26 is abnormal.

[Fifth Embodiment]
FIG. 6 schematically shows the configuration of a digital control apparatus 20E in which plant objects (including associated instruments) are controlled as an example of the digital control apparatus according to the fifth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20E differs from the digital control device 20D in that a controller 21C is provided instead of the controller 21B, but the other points are not substantially different. Therefore, in the description of the digital control device 20E, portions that are not essentially different from the digital control device 20D are assigned the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20D that have already been described are also omitted.

  Referring to FIG. 6, the digital control device 20E includes a controller 21C, a man-machine interface that displays information output from the controller 21C, a display unit 51 as display means, and output selection means.

  The controller 21C includes an output mismatch detection unit 58 and a large output deviation detection unit 59 instead of the input mismatch detection unit 55 and the input deviation large detection unit 56 with respect to the controller 21B. The output mismatch detection means 58 of the controller 21C receives the digital signals once outputted from the DO1 and DO2 of the digital signal output unit 42 of the controller 21C via the DI1 and DI2 of the digital signal input unit 25.

  On the other hand, the output mismatch detection unit 58 also receives, for example, a digital signal (hereinafter referred to as a calculation unit digital output signal) output from the control calculation unit 37 or the detector 38 of the calculation unit. Then, the digital signal output from DO1 (feedback digital signal 1) and the feedback digital signal output from DO2 (digital feedback signal 2) are compared with the arithmetic means digital output signal.

  The 1-system digital signal and the 2-system digital signal are compared with the arithmetic means digital output signal, and when the 1-system digital signal and the 2-system digital signal do not match the arithmetic means digital output signal, ON output is performed. The digital signal output from the output mismatch detection means 58 is input to the display section 51 via the digital signal output section 42, and the fact that the 1-system and 2-system digital signals do not match the arithmetic means digital output signal. Is displayed on the display unit 51.

  On the other hand, the large output deviation detecting means 59 receives the analog signals once output from the AO1 and AO2 of the analog signal output unit 43 of the controller 21C and fed back via the AI1 and AI2 of the analog signal input unit 26. The analog signal output from the adjustment control calculation unit 40 of the calculation means (hereinafter referred to as calculation means analog output signal) is also received. Then, the analog signal output from AO1 (feedback analog signal) and the analog signal output from AO2 (feedback analog signal) are compared with the arithmetic means analog output signal.

  The large output deviation detecting means 59 compares the 1-system analog signal and the 2-system analog signal with the computing means analog output signal, and the deviation between the 1-system analog signal and the 2-system analog signal and the computing means analog signal. ON is output when is larger than the set allowable range. The analog signal output from the output deviation large detection means 59 is input to the display section 51 via the analog signal output section 43, and the deviation between the 1-system and 2-system analog signals and the arithmetic means analog signal exceeds the allowable range. Is displayed on the display unit 51.

  According to the digital control device 20E configured as described above, since the controller 21C includes the output mismatch detection means 58 and the output deviation large detection means 59, the mismatch between the 1-system and 2-system digital signals and the arithmetic means digital output signal. And monitoring whether the deviation between the 1-system and 2-system analog signals and the arithmetic means analog output signal is within an allowable range.

  In consideration of the very low possibility that DO1 and DO2 or AO1 and AO2 fail at the same time in the digital signal output unit 42 and the analog signal output unit 43, the 1-system and 2-system digital signals and the arithmetic means digital output signal When the output mismatch or deviation exceeds the allowable range, it is possible to monitor whether the deviation between the analog signal of system 1 and system 2 and the arithmetic means analog output signal is within the allowable range. Can detect that one of DO1 and DO2 or AO1 and AO2 is abnormal.

  In addition, the fact that any one of DO1 and DO2 of the digital signal output unit 42 or AO1 and AO2 of the analog signal output unit 43 can be detected becomes more effective when combined with other embodiments. . For example, when combined with the second embodiment, the user can confirm the display content displayed on the display unit 51, and can select the system that is inputting the normal signal by switching the selection switch 50. It becomes possible to continue the operation (operation) of the plant equipment.

  Further, even when a failure that cannot be detected by the controller 21A including the failure detection unit 53 occurs in either the digital signal output unit 42 or the analog signal output unit 43, the output mismatch detection unit 58 and the large output deviation detection unit 59 are provided. If so, it can be detected that either the digital signal output unit 42 or the analog signal output unit 43 is abnormal.

[Sixth Embodiment]
FIG. 7 schematically shows the configuration of a digital control device 20F that uses plant equipment (including associated instruments) as a control target as an example of the digital control device according to the sixth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20F differs from the digital control device 20E in that a controller 21D is provided instead of the controller 21C, but the other points are not essentially different. Therefore, in the description of the digital control device 20F, portions that are not essentially different from the digital control device 20E are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20E that have already been described are also omitted.

According to FIG. 7, the digital control device 20F includes a controller 21D, a man-machine interface for displaying information output from the controller 21D, a display unit 51 as display means, and output selection means. The controller 21D has, with respect to the controller 21C, both the failure detection means 53, the signal output from the failure detection means 53, and the signal output from the output mismatch detection means 58 or the large output deviation detection means 59 . Failure duplication detection determination means 61 for determining whether or not.

  The fault overlap detection determination means 61 of the controller 21D receives the digital signal output from the fault detection means 53 and the digital signal output from the output mismatch detection means 58 or the output deviation large detection means 59, and is input 2 Perform logical operations using two digital signals.

  As shown in FIG. 7, the failure duplication detection determination means 61 has an AND function 31 that performs AND calculation and a NOT function 63 that performs a negative (NOT) operation. The AND function 31 and the NOT function 63 perform a logical operation. Thus, whether or not the failure detection means 53 has detected a failure and whether or not the output mismatch detection means 58 has detected a mismatch of output signals or the output deviation large detection means 59 is within an allowable range for the deviation of the output signal. It is determined whether or not. When the failure detection unit 53 detects a failure, the ON signal is not output, and only the result detected by the failure detection unit 53 is displayed on the display unit 51.

  Further, when the failure detection means 53 does not detect a failure and the output mismatch detection means 58 detects an output signal mismatch or the output deviation large detection means 59 detects that the output signal exceeds the allowable range. Only when the output signal is ON, the ON signal is output, and the output mismatch detection means 58 detects that the output signal does not match, or the output deviation large detection means 59 detects that the output signal deviation exceeds the allowable range. That is, the failure of the digital signal output means is displayed on the display unit 51.

The fault overlap detection determination means 61 is ON only when the output mismatch detection means 58 detects an output signal mismatch or when the output deviation large detection means 59 detects that the output signal deviation exceeds the allowable range. By outputting the signal, when both the failure detection signal from the failure detection means 53 and the ON signal from the output mismatch detection means 58 or the large output deviation detection means 59 exist , the output mismatch detection means 58 or the ON signal from the large output deviation detecting means 59 is cut off so that the display section 51 does not display that the failure has been detected redundantly.

  Regarding the flow of the digital signal (input → output) in the fault duplication detection determination means 61, the digital signal output from the fault detection means 53 of the two input digital signals is first input to the NOT function 63. The NOT function 63 performs NOT calculation of the input signal. The calculation result (digital signal) output from the NOT function 63 is input to one of the AND functions 31. The digital signal output from the output mismatch detection unit 58 or the output deviation large detection unit 59 is input to the other of the AND function 31.

  The AND function 31 performs an AND calculation on the input digital signal from the NOT function 63 and the digital signal from the output mismatch detection means 58, and outputs the calculation result. The output signal of the AND function 31 is output to the outside of the fault duplication detection determination unit 61 as an output signal of the fault duplication detection determination unit 61.

  The digital signal output from the failure duplication detection determination means 61 is output to the outside of the controller 21D via the digital signal output unit 42 and then input to the display unit 51. The display unit 51 receives the digital signal output from the failure duplication detection determination unit 61, and when the received signal is an ON signal, the display unit 51 detects that the output mismatch detection unit 58 has detected an output mismatch or a large output deviation detection unit 59. Indicates that the tolerance of the output signal has been exceeded.

  According to the digital control device 20F configured as described above, the failure detection unit 53 includes the controller 21D including the failure duplication detection determination unit 61, so that the failure detection unit 53 has a failure caused in the digital signal input unit 25 and the analog input unit 26. The display unit 51 may display that the output mismatch detection means 58 has detected an output mismatch or that the input deviation large detection means 56 has detected that the deviation of the output signal exceeds the allowable range until the output signal is detected. Disappear. That is, since the substantially overlapping failure detection display is not displayed on the display unit 51, a simple and clear failure detection display can be performed for the user.

  In the digital control device 20F, the controller 21C of the digital control device 20E includes a controller 21D that further includes a failure detection means 53 and a failure overlap detection determination means 61. However, the controller 21D is replaced with the controller 21B of the digital control device 20D. It is good also as a structure further equipped with the fault detection means 53 and the fault duplication detection determination means 61 instead of having.

  Further, the controller 21D may include an input mismatch detection unit 55, an input deviation large detection unit 56, an output mismatch detection unit 58, and a large output deviation detection unit 59, a failure detection unit 53, and a failure overlap detection determination unit 61. .

[Seventh Embodiment]
FIG. 8 schematically shows the configuration of a digital control apparatus 20G in which plant objects (including accompanying instruments) are controlled as an example of the digital control apparatus according to the seventh embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20G is different from the digital control device 20E in that a controller 21E is provided instead of the controller 21C, but the other points are not substantially different. Therefore, in the description of the digital control device 20G, portions that are not essentially different from the digital control device 20E are assigned the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20F that have already been described are also omitted.

  According to FIG. 8, the digital control device 20G includes a controller 21E, a man-machine interface that displays information output from the controller 21E, a display unit 51 as display means, and output selection means. The controller 21E further includes a memory 65 as signal time difference canceling means with respect to the controller 21C.

  The memory 65 of the controller 21E temporarily outputs the feedback from the controller 21E and feeds it back to the output mismatch detection means 58 or the output deviation large detection means 59 and the calculation means (the control calculation unit 37, the detector 38 and the adjustment control calculation). It is provided for the purpose of canceling a time difference (hereinafter referred to as a signal time difference) generated between the output signal output from the unit 40).

  Since the signal time difference causes erroneous detection in the output mismatch detection means 58 or the large output deviation detection means 59, it is desirable to cancel as much as possible from the viewpoint of the reliability of failure detection of the digital control device. Therefore, an output signal from the calculation means is provided so as to be input to the output mismatch detection means 58 or the output deviation large detection means 59 via the memory 65. Further, the memory 65 stores the output signal from the computing means for an arbitrary time greater than or equal to the signal time difference, and the output signal from the computing means fetched by the signal time difference by the built-in program before the output mismatch detection means 58 or the output Output to large deviation detecting means 59.

  By providing a memory 65 as a signal time difference canceling means between the calculating means and the output mismatch detection means 58 or the output deviation large detection means 59, the controller 21E outputs the signal once and feeds it back to output mismatch detection means 58 or the large output deviation. The signal time difference between the feedback signal input to the detection means 59 and the output signal output from the calculation means can be canceled, and the mismatch or large deviation detection in the output mismatch detection means 58 or the output deviation large detection means 59 of the controller 21E. The reliability of the can be further increased.

  According to the digital control apparatus 20G configured as described above, by including the controller 21E including the memory 65, the controller 21E outputs the signal once and feeds it back to the output mismatch detection means 58 or the output deviation large detection means 59. The signal time difference between the feedback signal and the output signal output from the calculation means can be canceled, and the reliability of the mismatch or large deviation detection in the output mismatch detection means 58 or the large output deviation detection means 59 can be further improved. .

[Eighth Embodiment]
FIG. 9 schematically shows the configuration of a digital control apparatus 20H in which a control object is plant equipment (including associated instruments) as an example of the digital control apparatus according to the eighth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20H differs from the digital control device 20G in that the signal time difference canceling means of the controller 21E is a timer 67 instead of the memory 65, but the other points are not essentially different. Therefore, in the description of the digital control device 20H, portions that are not essentially different from the digital control device 20G are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20G that have already been described are also omitted.

  According to FIG. 9, the digital control device 20H includes a controller 21E, a man-machine interface that displays information output from the controller 21E, a display unit 51 as display means, and output selection means. The controller 21E of the digital control device 20H includes a timer 67 instead of the memory 65 as signal time difference canceling means.

  The timer 67 of the controller 21E is a feedback signal that is once output from the controller 21E and fed back to the output mismatch detection means 58 or the output deviation large detection means 59, and calculation means (control calculation unit 37, detector 38 and adjustment control calculation). It is the same as the memory 65 in that it is provided for the purpose of canceling the signal time difference from the output signal output from the unit 40). The timer 67 is provided between the output mismatch detection unit 58 and the digital signal output unit 42 or between the output deviation detection unit 59 and the analog signal output unit 43, and detects the output mismatch detection unit 58 or the output deviation detection. The output signal of the means 59 is input to the timer 67.

  When the output signal (ON signal) from the output mismatch detection means 58 or the large output deviation detection means 59 is input, the timer 67 is switched on after the time equal to or longer than the signal time difference has elapsed since the input. The input ON signal is set to be output. That is, even if the ON signal is input from the output mismatch detection means 58 or the output deviation large detection means 59, if the ON signal disappears (becomes OFF signal) before the same time as the signal time difference elapses, the timer Since the switch 67 is not turned on, no ON signal is output.

  By providing such a timer 67 between the output mismatch detection means 58 and the digital signal output section 42 or between the output deviation large detection means 59 and the analog signal output section 43, the timer 67 is temporarily caused by a signal time difference. The generated ON output signal (false detection) from the output mismatch detection means 58 or the large output deviation detection means 59 can be ignored, and a feedback signal obtained by substantially feeding back the output signal of the controller 21E and an output signal from the calculation means. And the signal time difference between the two can be canceled.

  According to the digital control device 20H configured as described above, by including the controller 21E including the timer 67 as the signal time difference canceling means, it is output once from the controller 21E and fed back to output mismatch detection means 58 or a large output deviation. The feedback signal input to the detection means 59 is compared with the output signal output from the calculation means, and after a mismatch or large deviation is detected, a predetermined time (an arbitrary time equal to or greater than the signal time difference) has elapsed and a timer time has elapsed. By performing the output, it is possible to perform monitoring in consideration of the signal time difference.

[Ninth Embodiment]
FIG. 10 schematically shows the configuration of a digital control apparatus 20I that uses plant equipment (including associated instruments) as a control target as an example of the digital control apparatus according to the ninth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20I is configured to perform a maintenance inspection test on at least one of the signal input / output unit related to the digital signal, that is, the digital signal input unit 25 and the digital signal output unit 42. A digital control device 20I shown in FIG. 10 shows an embodiment in which a maintenance inspection test is possible for both the digital signal input unit 25 and the digital signal output unit.

  A digital control device 20I shown in FIG. 10 includes a controller 21F having a digital test circuit 69 instead of the controller 21 with respect to the digital control device 20, a selection switch 50, a display unit 51, and a test switch 70. The difference is that the normal / test switching signal generating means 71 and the normal / test switching switch 72 are provided, but the other points are not essentially different.

  Therefore, in the description of the digital control device 20I, portions that are not essentially different from the digital control device 20 are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20H that have already been described are also omitted.

  Referring to FIG. 10, the digital control device 20I is a controller 21F, a man-machine interface that displays information output from the controller 21F, a display unit 51 as display means, output selection means, and signal transmission system switching selection. A selection switch 50 as a means, a test switch 70 as a normal / test selection means for selecting whether or not a maintenance inspection test is performed (during normal operation), and a signal path according to normal operation and test time A normal / test switching signal generating means 71 for generating a switch switching signal for switching between, and a normal / test switching switch 72 as a normal / test switching means for switching the signal path according to normal operation and testing.

  The controller 21F of the digital controller 20I further includes a digital test circuit 69 that performs a maintenance inspection test of DI1 and DI2 in the digital signal input unit 25 and the digital signal output unit 42 with respect to the controller 21.

  Output signals from the selection switch 50, the test switch 70, and the normal / test changeover switch 72 are input to a digital test circuit (hereinafter referred to as an input-side digital test circuit) 69 that performs a maintenance inspection test on the digital signal input unit 25. The Output signals from the selection switch 50 and the test switch 70 are input to a digital test circuit (hereinafter, referred to as an output side digital test circuit) 69 that performs a maintenance inspection test on the digital signal output unit 42.

  In the digital controller 20I configured as described above, when a maintenance inspection test is performed on the digital signal input unit 25, first, the user (tester) sets the test switch 70 to the test execution side (ON). Switch. Then, the switch state (ON) of the test switch 70 and the switch state of the selection switch 50 are input to the normal / test switching signal generation means 71.

  The normal / test switching signal generation means 71 performs a logical operation using two AND functions 31 and one NOT function 63. The switch state of the test switch 70 and the selection switch 50 is input as it is to one AND function 31, and the switch state of the test switch 70 is unchanged and the switch state of the selection switch 50 is NOT to the other AND function 31. Inverted via function 63 and input.

  The result of the logical operation of the two AND functions 31 is a signal output from the normal / test switching signal generating means 71, that is, switching between the normal / test switching switch 72 between the normal time (OFF) and the test time side (ON). Is output as a switch switching signal. The switch switching signal from the AND function 31 in which the switch states of the test switch 70 and the selection switch 50 are input as they are is switched to the normal / test switching switch 72 for switching the switch on the 1-system side, and the switch switching from the other AND function 31 is performed. The signal is input to the normal / test changeover switch 72 that switches the switch on the second system side.

The normal / test changeover switch 72 maintains the current state (the state in which the control target is controlled) in the signal transmission system currently selected by the selection switch 50 based on the input switch changeover signal, and vice versa. In the signal transmission system, the switch is switched to the test side (ON) so as to perform the test. For example, when the selection switch 50 selects the 1 system, 0 (OFF signal) is output to the normal / test changeover switch 72 on the 1 system side, and the normal / test changeover switch 72 is Normal time side (OFF). On the other hand, 1 (ON signal) is input to the normal / test changeover switch 72 on the second system side, and the normal / test changeover switch 72 is switched to the test side (ON). That is, a control signal necessary for control is transmitted in the first system, while a test signal necessary for performing the test is transmitted in the second system.

  On the other hand, the switch states of the test switch 70 and the selection switch 50 are also input to the digital test circuit 69. When a test execution side (ON) signal is input from the test switch 70, the switch state is built in the digital test circuit 69. A test program (not shown) starts outputting test signals to a signal transmission system that is not selected by the selection switch 50 and performs a maintenance inspection test. For example, the test signal output from the digital test circuit 69 is output stepwise for ON or OFF for a predetermined time.

  The test signal output from the digital test circuit 69 is output to the outside of the controller 21F via the DO1 and DO2 of the digital signal output unit 42 and then input to the normal / test changeover switch 72. When the normal / test changeover switch 72 is ON, the test signal input from the digital test circuit 69 via the digital signal output unit 42 is input to the digital signal input unit 25. When 72 is OFF, the test signal is not input to the digital signal input unit 25.

  Further, the digital test circuit 69 can output the determination of the test result to the display unit 51 as a man-machine interface device, and can store and store the test result in a built-in memory (not shown). Accordingly, the test result can be confirmed by electrically connecting to the maintenance support device 75 and reading out the memory of the digital test circuit 69 from the maintenance support device 75.

  On the other hand, when a maintenance inspection test is performed on the digital signal output unit 42, first, the user (tester) switches the test switch 70 to the test execution side (ON). Then, the switch state (ON) of the test switch 70 and the switch state of the selection switch 50 are input to the digital test circuit 69 via the digital signal input unit 25.

  When a test execution side (ON) signal is input to the digital test circuit 69 from the test switch 70, a test program (not shown) built in the digital test circuit 69 transmits a signal that is not selected by the selection switch 50. Start the test signal output to the system and conduct the maintenance inspection test.

  In the digital control device 20I configured as described above, even during the test, the one signal transmission system selected by the selection switch continues operation (operation) of the plant equipment to be controlled as usual. In the other signal transmission system, a maintenance inspection test of the digital signal input unit 25 and the digital signal output unit 42 can be performed.

  Further, since the test results are stored in a memory (not shown) built in the digital test circuit 69, the determination of the test results is output to the display unit 51 as a man-machine interface device or connected to the maintenance support device 75 to store the memory. The test result can be confirmed by reading. Therefore, it is possible to reduce human work required for the maintenance inspection test that is performed periodically.

  Furthermore, a more effective maintenance inspection test can be performed by combining with other embodiments.

  Note that, according to FIG. 10, the digital control device 20I is configured to be able to perform maintenance inspection tests of both the digital signal input unit 25 and the digital signal output unit 42, but both maintenance inspections are not necessarily performed. It is not limited to the embodiment in which the test can be performed. That is, the digital control device 20I configured to perform the maintenance inspection test on only the digital signal input unit 25 or the digital signal output unit 42 is also included as the digital control device according to the present embodiment.

  For example, in the case of the digital control device 20I that performs a maintenance inspection test on only the digital signal input unit 25, the output side digital test circuit 69 provided in the controller 21F and the test switch 70 provided outside the controller 21F are not required. On the contrary, in the case of the digital control device 20I that performs maintenance inspection only on the digital signal output unit 42, the input side digital test circuit 69 provided in the controller 21F, the test switch 70 provided outside the controller 21F, normal / test The switching signal generation means 71 and the normal / test changeover switch 72 are not necessary.

  Further, according to FIG. 10, the maintenance and inspection device 75 is provided outside the digital control device 20I as a man-machine interface device for reading the test result determination from the digital test circuit 69, but the digital control device 20I is provided. You may do it.

  Furthermore, in the digital control device 20I including the maintenance / inspection device 75, the display unit 51 and the maintenance / inspection device 75 may be configured by the same man-machine interface (for example, a touch panel).

[Tenth embodiment]
FIG. 11 schematically shows the configuration of a digital control apparatus 20J in which plant objects (including associated instruments) are controlled as an example of the digital control apparatus according to the tenth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20J is configured to perform a maintenance inspection test on at least one of the signal input / output unit related to the analog signal, that is, the analog signal input unit 26 and the analog signal output unit 43. In other words, the digital control device 20I is different in that it performs a maintenance / inspection test of the signal input / output unit related to the digital signal, while performing a maintenance / inspection test of the signal input / output unit related to the analog signal.

  Therefore, the digital control device 20J is different in that the controller 21G is provided instead of the controller 21F of the digital control device 20I and that the output destination of the signal output from the selection switch 50 or the normal / test changeover switch 72 is different. However, the other points are not essentially different. Therefore, in the description of the digital control device 20J, portions that are not essentially different from the digital control device 20I are assigned the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20I that have already been described are also omitted.

  The digital control device 20J includes a controller 21G instead of the controller 21F of the digital control device 20I. The controller 21G includes an analog test circuit 77 instead of the digital test circuit 69 with respect to the controller 21F.

  Output signals from the selection switch 50, the test switch 70, and the normal / test changeover switch 72 are input to an analog test circuit (hereinafter referred to as an input-side analog test circuit) 77 that performs a maintenance inspection test on the analog signal input unit 26. The Further, an output signal from the selection switch 50 and the test switch 70 is input to an analog test circuit (hereinafter referred to as an output side analog test circuit) 77 that performs a maintenance inspection test on the analog signal output unit 42.

  In the digital controller 20J configured as described above, when a maintenance inspection test is performed on the analog signal input unit 26, first, the user (tester) sets the test switch 70 to the test execution side (ON). Switch. Then, the switch state (ON) of the test switch 70 and the switch state of the selection switch 50 are input to the normal / test switching signal generation means 71.

  The normal / test switching signal generating means 71 generates a switch switching signal for selecting a signal transmission system not selected by the selection switch 50 based on the switch state (ON) of the test switch 70 and the switch state of the selection switch 50. To do. Then, the generated switch switching signal is output to the normal / test switching switch 72. The normal / test changeover switch 72 maintains the current state (the state in which the control target is controlled) in the signal transmission system currently selected by the selection switch 50 based on the input switch changeover signal, and vice versa. In the signal transmission system, the switch is switched to the test side (ON) so as to perform the test.

  On the other hand, the switch states of the test switch 70 and the selection switch 50 are also input to the analog test circuit 77. When a test execution side (ON) signal is input from the test switch 70, the switch state is built in the analog test circuit 77. A test program (not shown) starts outputting test signals to a signal transmission system that is not selected by the selection switch 50 and performs a maintenance inspection test. For example, the test signal output from the analog test circuit 77 is output stepwise for a predetermined time with outputs of 0%, 25%, 50%, 75%, and 100%.

  The test signal output from the analog test circuit 77 is output to the outside of the controller 21F via the AO1 and AO2 of the analog signal output unit 43, and then input to the normal / test changeover switch 72. The test signal input to and output from the normal / test changeover switch 72 is not output to the signal transmission system currently selected by the selection switch 50, but is output only to the reverse signal transmission system.

  Further, the analog test circuit 77 can output determination of the test result to the display unit 51 as a man-machine interface device, and can store and store the test result in a built-in memory (not shown). Accordingly, the test result can be confirmed by electrically connecting to the maintenance support device 75 and reading out the memory of the analog test circuit 77 from the maintenance support device 75.

  On the other hand, when a maintenance inspection test is performed on the analog signal output unit 43, first, the user (tester) switches the test switch 70 to the test execution side (ON). Then, the switch state (ON) of the test switch 70 and the switch state of the selection switch 50 are input to the analog test circuit 77 via the digital signal input unit 25. When the test execution side (ON) signal is input to the analog test circuit 77 from the test switch 70, the test program (not shown) built in the analog test circuit 77 transmits a signal that is not selected by the selection switch 50. Start the test signal output to the system and conduct the maintenance inspection test.

  In the digital control device 20J configured as described above, even during the test, the one signal transmission system selected by the selection switch continues to operate (operate) the plant equipment that is the control target as usual. In the other signal transmission system, a maintenance inspection test of the analog signal input unit 26 and the analog signal output unit 42 can be performed.

  Further, since the test result is stored in a memory (not shown) built in the analog test circuit 77, the determination of the test result is output to the display unit 51 as a man-machine interface device or is connected to the maintenance support device 75 to store the memory. The test result can be confirmed by reading. Therefore, it is possible to reduce human work required for the maintenance inspection test that is performed periodically.

  Furthermore, a more effective maintenance inspection test can be performed by combining with other embodiments.

  Note that, according to FIG. 11, the digital control device 20J is configured to be able to perform maintenance inspection tests of both the analog signal input unit 26 and the analog signal output unit 43, but both maintenance inspections are not necessarily performed. The point which is not limited to embodiment which can test is the same as that of the digital control apparatus 20I.

  The test signal output from the analog test circuit 77 is output in steps of 0%, 25%, 50%, 75%, and 100% for a predetermined time. For example, the output ratio, the number of signal output steps, the output time, and the like may be arbitrary.

[Eleventh embodiment]
FIG. 12 schematically shows the configuration of a digital control device 20K in which plant objects (including accompanying instruments) are controlled as an example of the digital control device according to the eleventh embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20K is different from the digital control device 20I in that a selection switch 50B is used instead of the selection switch 50 as signal transmission system switching selection means, and a test switch 70A is used instead of the test switch 70 as normal / test selection means. However, the other points are not essentially different.

  Therefore, in the description of the digital control device 20K, portions that are not essentially different from the digital control device 20I are given the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20J that have already been described are also omitted.

  According to FIG. 12, the digital control device 20K includes a controller 21F, a display unit 51 as a display means, an output selection means, a selection switch 50B as a signal transmission system switching selection means, and a normal / test selection means. A test switch 70A, a normal / test switching signal generating means 71, and a normal / test switching switch 72 are provided.

  The selection switch 50B is configured to receive the switch state from the test switch 70A as a signal and automatically select the 1-system or 2-system, while the test switch 70A is connected to the test switch 70. On the other hand, the signal transmission system (system 1 or system 2) to be tested can be selected.

  In the digital control device 20K configured as described above, when a maintenance inspection test is performed, first, a user (tester) switches the test switch 70A to switch to the test execution side (ON). Select the signal transmission system to be tested. Then, a signal is output from the test switch 70A to the selection switch 50B for the signal transmission system that performs the maintenance inspection test.

  The selection switch 50B receives the signal output from the test switch 70A, and is a signal transmission system opposite to the signal transmission system selected by the test switch 70A, that is, the signal transmission system that performs the maintenance inspection test. Is automatically selected. When the selection switch 50B automatically selects a signal transmission system for transmitting signals to the plant equipment to be controlled, in the signal transmission system selected by the test switch 70A, the digital test circuit 69 starts a maintenance inspection test and selects it. In the other signal transmission system selected by the switch 50B, signal transmission is continued to the plant equipment to be controlled.

  It should be noted that the digital test circuit 69 starts the maintenance inspection test after confirming that the signal is transmitted to the plant equipment to be controlled and the operation (operation) is continued in consideration of safety. To.

  In the digital control device 20K configured as described above, the test switch 70A is tested by including the test switch 70A and the selection switch 50B instead of the test switch 70 and the selection switch 50 of the digital control device 20I. By inputting the desired signal transmission system, it is possible to automatically select the signal transmission system in which the selection switch 50B continues signal transmission to the plant equipment to be controlled.

  That is, when a user (tester) inputs a maintenance inspection test to the test switch 70A and a signal transmission system to be subjected to the test, the maintenance inspection test is started in the signal transmission system selected by the test switch 70A. In the other signal transmission system selected by the selection switch 50B, it is possible to continue signal transmission to the plant equipment to be controlled and continue operation (operation).

  The digital control device 20K includes a test switch 70A and a selection switch 50B instead of the test switch 70 and the selection switch 50 of the digital control device 20I. However, the digital control device 20J or the digital control device 20I and You may apply to the digital control apparatus which combined both of the digital control apparatuses 20J.

[Twelfth embodiment]
FIG. 13 schematically shows the configuration of a digital control apparatus 20L as an example of the digital control apparatus according to the twelfth embodiment of the present invention, in which the control object is plant equipment (including accompanying instruments). A schematic diagram is shown.

  The digital control device 20L is different from the digital control device 20K in that it includes a controller 21H instead of the controller 21F, a selection switch 50C instead of the selection switch 50B, and a test switch instead of the test switch 70A. It differs in that it has 70B, but the other points are not essentially different.

  Therefore, in the description of the digital control device 20L, portions that are not essentially different from the digital control device 20K are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20K that have already been described are also omitted.

  According to FIG. 13, the digital control device 20L includes a controller 21H, a display unit 51 as a display means, an output selection means, a selection switch 50C as a signal transmission system switching selection means, and a normal / test selection means. A test switch 70B, a normal / test switching signal generating means 71, and a normal / test switching switch 72 are provided. The controller 21H further includes failure detection means 53 with respect to the controller 21F.

  The selection switch 50C has the same basic function as the selection switch 50B, but a failure detection signal (1 system I / O failure detection signal) which is detected and output by the failure detection means 53 of the controller 21H. Alternatively, when a 2-system I / O failure detection signal is received, a signal transmission system in which no failure is detected is selected.

  The basic function of the test switch 70B is the same as that of the test switch 70A. However, the failure detection signal (1 system I / I) detected by the failure detection means 53 of the controller 21H detects and outputs a failure in the signal transmission system. (O failure detection signal or 2 system I / O failure detection signal) is received, the difference is that the switch state is switched to the normal operation side, that is, the test unexecuted side (OFF).

  The digital control device 20L configured as described above has a controller 21H instead of the controller 21F, a selection switch 50C instead of the selection switch 50B, and a test switch 70B instead of the test switch 70A with respect to the digital control device 20K. By providing, when the failure detection means 53 of the controller 21H detects a failure of the signal transmission system during the maintenance inspection test, the test switch 70B is in the normal operation, that is, the test unexecuted side (OFF). The test can be automatically interrupted.

  Further, the digital control device 20L can select a signal transmission system in which the test switch 70B switches the switch state to the test non-execution side (OFF) and the selection switch 50B does not detect the failure, so that the failure is detected. It is possible to continue the transmission of signals to the plant equipment to be controlled using the signal transmission system that is not operated, and to continue the operation.

[Thirteenth embodiment]
FIG. 14 schematically shows the configuration of a digital control apparatus 20M that uses a plant device (including accompanying instruments) as a control target as an example of the digital control apparatus according to the thirteenth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20M differs from the digital control device 20 in that a controller 21I is provided instead of the controller 21, but the other points are not essentially different. Therefore, in the description of the digital control device 20M, portions that are not essentially different from the digital control device 20 are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the already described digital control devices 20 to 20L are also omitted.

  According to FIG. 14, the digital control device 20 </ b> M includes a controller 21 </ b> I instead of the controller 21 with respect to the digital control device 20.

  In the controller 21I, a point (hereinafter referred to as a change point) at which a signal forced change device 79 as a signal forced change unit 79 forcibly changing and inputting a signal from the outside of the digital control device 20M is set. Has been. The change points are set on the signal path inside the controller 21I, for example, α and β shown in FIG. 14, and the number of settings is arbitrary.

  The signal forced change device 79 is a man-machine interface, and when the user selects a change point set in the controller 21I, the signal is forcibly output to the change point to change the signal at the change point. When the signal to be changed is a digital signal, it is forcibly changed to ON or OFF, and when it is an analog signal, it is changed to a preset arbitrary value. Further, the display unit (not shown) of the signal forced change device 79 displays the state of the change point and the fact that the forced change is in progress.

  The digital control device 20M configured as described above includes a controller 21I in which a change point at which a signal can be forcibly changed from the signal forcible change device 79 serving as a signal forcible change means is provided in advance. In the case of a digital signal, the signal to be turned on or off can be forcibly changed to an arbitrary value set in advance.

  In addition, since the signal forced change device 79 displays the status of the change point and whether or not the forced change is in progress, for example, it is possible to prevent erroneous output at the time of testing each component unit such as the detector 38. Can do.

  In addition, although the signal forced change apparatus 79 was demonstrated as an external device of the digital control apparatus 20M, the structure which the digital control apparatus 20M comprises may be sufficient. In the case where the digital control device 20M includes the signal forced change device 79, the display unit 51 and the signal forced change device 79 may be configured by the same man-machine interface (for example, a touch panel).

[Fourteenth embodiment]
FIG. 15 schematically shows the configuration of a digital control apparatus 20N that uses plant equipment (including associated instruments) as a control target as an example of the digital control apparatus according to the fourteenth embodiment of the present invention. A schematic diagram is shown.

  The digital control device 20N is different from the digital control device 20 in that a controller 21J is provided instead of the controller 21, but the other points are not essentially different. Therefore, in the description of the digital control device 20N, portions that are not essentially different from the digital control device 20 are denoted by the same reference numerals and description thereof is omitted. Note that effects, modifications, and the like that are not essentially different from those of the digital control devices 20 to 20L already described are also omitted.

  According to FIG. 15, the digital control device 20N includes a controller 21J, a digital output selection unit 45 and an analog output selection unit 46 as output selection means. The controller 21J further includes a version information management unit 81 that detects version information with respect to the controller 21. In other words, the controller 21J includes a controller control unit 82 corresponding to the controller 21 and a version information management unit 81. With.

  The version information management unit 81 of the controller 21J detects version information for each component of the controller control unit 82 in the controller 21J, that is, a signal input unit, a calculation unit, and a signal output unit. The detected version information is stored and stored. The version information stored in the controller 21J can be read and confirmed by the user from the maintenance support device 75 by electrically connecting the controller 21J and the maintenance support device 75 as version information reading means.

  According to the digital control device 20N configured as described above, by providing the controller 21J, the user can read out and check the version information detected and stored by the controller 21J from the maintenance support device 75.

  Therefore, it is easier and more accurate to check the version information of the fault location when the fault location is restored than when checking the version information of the fault location in the ledger. It is possible to prevent occurrence of a conflict between the confirmed version information that can occur and the version information of the failure location, and to reduce the recovery time from the failure.

  As described above, according to the digital control device of the present invention, even if a failure occurs in the digital signal input unit 25, the analog signal input unit 26, the digital signal output unit 42, and the analog signal output unit 43, In contrast, if one of the signal input / output units is healthy, the plant equipment to be controlled can be operated in a safe direction.

  That is, as long as the two signal input / output units do not fail at the same time, the controlled plant equipment can be controlled in a safe direction, so that the operation (operation) of the controlled plant equipment is compared to the conventional digital control device. The probability that it will be difficult to continue can be further reduced.

  Further, at the time of carrying out the maintenance inspection test, it is possible to carry out the maintenance inspection test in the other signal transmission system while continuing the control of the control target in one signal transmission system. Further, since the test result is stored in the memory built in the digital test circuit 69 and the analog test circuit 77, the test result is confirmed by connecting the output or maintenance support device 75 to the display unit 51 and reading the memory. It is possible to reduce human work required for maintenance inspections that are performed regularly.

1 is a schematic configuration diagram schematically illustrating the configuration of a digital control device according to a first embodiment of the present invention. FIG. 3 is a schematic configuration diagram schematically illustrating a configuration of an example (modified example) that outputs an average value of an analog input unit and an analog output selection unit in the digital control device according to the first embodiment of the present invention. FIG. 5 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a second embodiment of the present invention. FIG. 9 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a third embodiment of the present invention. FIG. 10 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a fourth embodiment of the present invention. FIG. 10 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a fifth embodiment of the present invention. FIG. 10 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a sixth embodiment of the present invention. FIG. 10 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a seventh embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to an eighth embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a ninth embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a tenth embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to an eleventh embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a twelfth embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a thirteenth embodiment of the present invention. FIG. 20 is a schematic configuration diagram schematically illustrating a configuration of a digital control device according to a fourteenth embodiment of the present invention. Schematic which outlines the structure of the control apparatus used for control of plant equipment as an example of the conventional digital control apparatus.

Explanation of symbols

20, 20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20I, 20J, 20K, 20L, 20M, 20N Digital controllers 21, 21A, 21B, 21C, 21D, 21E, 21F, 21G, 21H, 21I, 21J controller (control means)
25 Digital signal input section (signal input means)
26 Analog signal input section (signal input means)
28 Digital input selection unit (input selection means)
29, 29A Analog input selection section (input selection means)
31 AND function 32 OR function 34 High value selection function 35 Low value selection function 37 Control operation part (calculation means)
38 Detector (Calculation means)
39 Subtractor (calculation means)
40 Adjustment control calculation unit (calculation means)
42 Digital signal output section (digital signal output means)
43 Analog signal output unit (digital signal output means)
45 Digital output selector (digital output selector)
46, 46A Analog output selection section (digital signal output selection means)
50, 50A, 50B, 50C selection switch (signal transmission system switching selection means)
51 Display (Display means: Man-machine interface)
53 Failure detection means 55 Input mismatch detection means 56 Input deviation large detection means 58 Output mismatch detection means 59 Output deviation large detection means 61 Fault overlap detection determination means 63 NOT function 65 Memory 67 Timer 69 Digital test circuit (test circuit)
70, 70A, 70B Test switch (normal / test selection means)
71 Normal / test switching signal generating means 72 Normal / test switching switch (normal / test switching means)
75 Maintenance support device 77 Analog test circuit (test circuit)
79 Signal forced change device (Signal forced change means: Man-machine interface)
81 Version information management means 82 Controller control section

Claims (3)

A control unit having a plurality of signal transmission systems, and processing the input signal and outputting the signal, and an output selection unit for outputting one signal based on the output signal output from the control unit ,
The control means includes a signal input means including a digital input unit and an analog input unit configured to be capable of inputting a plurality of identical signals;
Input selection means for outputting a plurality of input signals as one signal; and
Arithmetic means for processing the input signal output from the input selection means;
A signal output means comprising a digital signal output unit configured to output a plurality of identical signals, and an analog signal output unit ;
Output mismatch detection means for comparing the 1-system digital signal and the 2-system digital signal output from the digital signal output section of the signal output means and the digital signal output from the arithmetic means and for outputting an ON signal when there is a mismatch. And, when the deviation is larger than the allowable range by comparing the 1-system analog signal and 2-system analog signal output from the analog signal output section of the signal output means and the analog signal output from the arithmetic means, the output is ON. At least one of output deviation large detection means for performing,
Failure detection means for outputting a failure detection signal when a failure of the device is detected;
It is determined whether or not there are duplicate failure detection signals from the failure detection means and ON outputs from at least one of the output mismatch detection means and the large output deviation detection means. A failure duplication determination unit that cuts off the ON output from at least one of the output mismatch detection unit and the output deviation large detection unit ,
The input selection means includes a digital input selection unit that performs a logical operation when a plurality of input signals are digital signals and outputs one digital signal; and a plurality of input selection units when the input signals are analog signals. An analog input selector that selectively selects the highest or lowest analog signal and outputs one signal,
The output selection means includes a digital output selection unit that performs logical operation on a plurality of input digital signals and outputs an analog signal that alternatively selects and outputs the highest value or the lowest value of the plurality of input analog signals. And a digital control device. A control unit having a plurality of signal transmission systems, processing the input signal and outputting the signal, an output selection unit outputting one signal based on the output signal output from the control unit, and the control Display means for displaying information output from the means; signal transmission system switching selection means for accepting external input and switching the signal transmission system; and normal / test selection for selecting whether or not a maintenance inspection test has been performed. And a normal / test switching signal generating means for generating a switch switching signal for switching a signal path according to normal operation and a test, and a test during a test by switching a signal path according to a normal operation and a test. A normal / test switching means for securing one signal transmission system for transmitting a control signal and another signal transmission system independent of the one signal transmission system for transmitting a control signal during normal operation. Shi
The control means includes a signal input means including a digital input unit and an analog input unit configured to be capable of inputting a plurality of identical signals;
Input selection means for outputting a plurality of input signals as one signal; and
Arithmetic means for processing the input signal output from the input selection means;
A signal output means comprising a digital signal output unit configured to output a plurality of identical signals, and an analog signal output unit;
A test circuit for performing a maintenance inspection test of at least one of the signal input means and the signal output means,
The input selection means includes a digital input selection unit that performs a logical operation when a plurality of input signals are digital signals and outputs one digital signal; and a plurality of input selection units when the input signals are analog signals. An analog input selector that selectively selects the highest or lowest analog signal and outputs one signal,
The output selection means includes a digital output selection unit that performs logical operation on a plurality of input digital signals and outputs an analog signal that alternatively selects and outputs the highest value or the lowest value of the plurality of input analog signals. And a digital control device. A control unit having a plurality of signal transmission systems, processing the input signal and outputting the signal, an output selection unit outputting one signal based on the output signal output from the control unit, and the control Display means for displaying information output from the means, normal / test selection means for selecting whether or not a maintenance inspection test has been performed and selection of the signal transmission system, and output from the normal / test selection means Signal transmission system switching selection means for automatically switching and selecting the signal transmission system upon receiving a signal, and normal / test switching signal generation for generating a switch switching signal for switching a signal path according to normal operation and test time Means, a signal transmission system for switching a signal path in accordance with a normal operation and a test and transmitting a test signal during the test, and the one signal transmission system for transmitting a control signal during a normal operation Is Comprising a normal / test switch means for securing the pieces another independent signal transmission systems,
The control means includes a signal input means including a digital input unit and an analog input unit configured to be capable of inputting a plurality of identical signals;
Input selection means for outputting a plurality of input signals as one signal; and
Arithmetic means for processing the input signal output from the input selection means;
A signal output means comprising a digital signal output unit configured to output a plurality of identical signals, and an analog signal output unit;
A test circuit for performing a maintenance inspection test of at least one of the signal input means and the signal output means,
The input selection means includes a digital input selection unit that performs a logical operation when a plurality of input signals are digital signals and outputs one digital signal; and a plurality of input selection units when the input signals are analog signals. An analog input selector that selectively selects the highest or lowest analog signal and outputs one signal,
The output selection means includes a digital output selection unit that performs logical operation on a plurality of input digital signals and outputs an analog signal that alternatively selects and outputs the highest value or the lowest value of the plurality of input analog signals. And a digital control device.

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