Input signal detection circuit, electronic apparatus, and system

Abstract

To downsize an input signal detection circuit while retaining redundancy.SOLUTION: An input signal detection circuit includes a plurality of input terminals and a plurality of signal detection units. Each of the signal detection units includes a main signal detection unit arranged for each of the plurality of input terminal to detect signals of the input terminals, and a sub signal detection unit for generating a failure detection signal which is a signal for detecting a failure of the main signal detection unit. The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit that includes the associated main signal detection unit. The sub signal detection unit generates the failure detection signal of the main signal detection unit for the signal detection unit that is different from the signal detection unit that includes the associated sub signal detection unit. The sub signal detection unit for each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an input signal detection circuit, an electronic device, and a system. [Background technology]

[0002] In systems and electronic devices that control field devices used in plants, factories, etc., an input signal detection circuit is used to detect a state quantity of the field device based on a signal from the field device. The state quantity corresponds to, for example, a current. In order to reduce the risk of a failure due to a failure of the device, an input signal detection circuit configured in a functional safety device has been proposed. In the functional safety device, for example, a failure detection circuit that detects a failure of the input signal detection circuit is added to provide redundancy to the system, thereby reducing the risk of a serious failure.

[0003] As such a device, for example, a semiconductor integrated circuit device has been proposed that is configured to satisfy the standard for functional safety by including a target circuit, a first fault detection unit that detects faults in the target circuit, and a second fault detection unit that detects faults in the target circuit by a method different from that of the first fault detection unit (see, for example, Patent Document 1). Here, the target circuit is a circuit that processes an input signal from outside the semiconductor integrated circuit device and generates an output signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-115987 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned conventional technology, the input signal detection circuit and the fault detection circuit (fault detection unit) are arranged in the same integrated circuit (IC). This is for the purpose of miniaturizing the device. However, in this case, it is not possible to detect faults in the IC itself, and therefore redundancy is reduced. On the other hand, in order to detect faults in the IC, it is necessary to arrange the fault detection circuit for the IC outside the IC, which creates the problem that it is not possible to miniaturize the device including the input signal detection circuit.

[0006] The present disclosure proposes an input signal detection circuit that is miniaturized while maintaining redundancy, and an electronic device and a system that include the input signal detection circuit. [Means for solving the problem]

[0007] The input signal detection circuit of the present disclosure has a plurality of input terminals and a plurality of signal detection units. The signal detection units each include a main signal detection unit arranged for each of the plurality of input terminals and detecting a signal at the input terminal, and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit. The main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit of which it is included. The sub-signal detection unit generates the failure detection signal of the main signal detection unit of the signal detection unit different from the signal detection unit of which it is included. The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a system according to an embodiment of the present disclosure. [Diagram 2] 1 is a diagram illustrating a configuration example of an input signal detection circuit according to a first embodiment of the present disclosure. [Diagram 3] 3 is a diagram illustrating a configuration example of a signal detection unit according to the first embodiment of the present disclosure. FIG. [Figure 4] 4 is a diagram illustrating another configuration example of the input signal detection circuit according to the first embodiment of the present disclosure. FIG. [Diagram 5]FIG. 11 is a diagram illustrating a configuration example of an input signal detection circuit according to a second embodiment of the present disclosure. [Figure 6] FIG. 13 is a diagram illustrating a configuration example of an input signal detection circuit according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order. In the following embodiments, the same components are designated by the same reference numerals, and duplicated description will be omitted.

[0010] 1. First Embodiment [System configuration] 1 is a diagram showing a configuration example of a system according to an embodiment of the present disclosure. The figure is a block diagram showing a configuration example of a system 1. The system 1 is a system that controls a plurality of field devices. The system 1 detects the state of the field devices based on input signals from the field devices and performs control, etc.

[0011] The system 1 includes an electronic device 10 and a fault information output unit 20. Note that a field device 2 and a field device 3 are also shown in the figure.

[0012] The electronic device 10 detects input signals from a plurality of field devices and controls the plurality of field devices based on the detection results. The electronic device 10 further detects a fault in a circuit that detects the input signals and outputs the detection result to the fault information output unit 20.

[0013] The fault information output unit 20 generates fault information, which is information about a fault in a circuit that detects an input signal included in the electronic device 10, based on the detection result output from the electronic device 10. The generated fault information is output to an external device of the system 1, etc.

[0014] [Electronic device configuration] The electronic device 10 described above includes an input signal detection circuit 30, a control unit 40, and a fault detection unit 50.

[0015] The input signal detection circuit 30 detects input signals from the field devices 2 and 3. The input signal detection circuit 30 outputs a detection signal, which is the result of the detection, to the control unit 40 and the fault detection unit 50. The input signal detection circuit 30 also generates a fault detection signal for detecting a fault in a circuit (main signal detection unit 110, described later) that detects the above-mentioned input signals, and outputs the fault detection signal to the fault detection unit 50.

[0016] The control unit 40 controls the entire electronic device 10. When controlling the field devices 2 and 3, the control unit 40 can also output control signals to the field devices 2 and 3.

[0017] The fault detection unit 50 detects a fault in the main signal detection unit 110 based on a fault detection signal from the input signal detection circuit 30. The fault detection unit 50 in the figure represents an example of detecting a fault in the main signal detection unit 110 based on the fault detection signal and the detection signal. The fault detection result is output to the fault information output unit 20.

[0018] [Input signal detection circuit configuration] 2 is a diagram showing a configuration example of an input signal detection circuit according to the first embodiment of the present disclosure. The figure is a block diagram showing a configuration example of an input signal detection circuit 30. The input signal detection circuit 30 includes input terminals 31a and 32a, input terminals 31b and 32b, and signal detection units 100a and 100b. Note that field devices 2 and 3 in the figure output signal currents IIN1 and IIN2, respectively.

[0019] The input terminals 31a and 32a, as well as the input terminals 31b and 32b, are a pair of terminals to which signals from the field device 2 and the like are input. These input terminals are arranged for each field device. The signals from the field device 2 are input to the input terminals 31a and 32a. Furthermore, the signals from the field device 3 are input to the input terminals 31b and 32b. The input terminals 31a and 31b are sink side input terminals, and the input terminals 32a and 32b are source side input terminals.

[0020] The signal detection units 100a and 100b each include a main signal detection unit 110 that is arranged for each of the input terminals 31a and 32a and the input terminals 31b and 32b and detects a signal at the input terminal 31a, etc. In the input signal detection circuit 30 in the figure, the signal detection unit 100a corresponds to the input terminals 31a and 32a, and the signal detection unit 100b corresponds to the input terminals 31b and 32b. The signal detection unit 100 detects an input signal at the input terminal 31, etc., to which it corresponds. The signal detection units 100a and 100b further include a sub-signal detection unit 120 that generates a failure detection signal that is a signal for detecting a failure of the main signal detection unit 110.

[0021] The main signal detection unit 110 detects a signal at the input terminal 31 as described above. The main signal detection unit 110 in the figure detects a current flowing through the input terminal 31 and the like, and outputs a detection signal that is the detection result. The main signal detection unit 110 includes input terminals 111 and 112. The input terminal 111 is a sink-side input terminal, and the input terminal 112 is a source-side input terminal. The main signal detection unit 110 detects a current flowing from the input terminal 111 to the input terminal 112. This current detection can be performed by detecting a current value. Specifically, a signal corresponding to the current value can be generated and output as a detection signal. In this case, the detection signal is an analog signal or a digital signal. The main signal detection unit 110 can also detect the on and off of a current, and output a binarized signal corresponding to the on and off of the current as a detection signal. The main signal detection unit 110 detects a current at the input terminal 31 and the like that corresponds to the signal detection unit 100 that includes the main signal detection unit 110.

[0022] As described above, the sub-signal detection unit 120 generates a fault detection signal that is a signal for detecting a fault in the main signal detection unit 110. The sub-signal detection unit 120 in the figure detects a current flowing through the main signal detection unit 110 and outputs it as a fault detection signal. The sub-signal detection unit 120 has an input terminal 121 and an input terminal 122. The input terminal 121 is a sink side input terminal, and the input terminal 122 is a source side input terminal. The sub-signal detection unit 120 detects a current flowing from the input terminal 121 to the input terminal 122.

[0023] Furthermore, the sub-signal detection unit 120 generates a failure detection signal for the main signal detection unit 110 of a signal detection unit 100 different from the signal detection unit 100 in which the sub-signal detection unit 120 is included. In the figure, the sub-signal detection unit 120 of the signal detection unit 100a generates a failure detection signal for the main signal detection unit 110 of the signal detection unit 100b. Furthermore, the sub-signal detection unit 120 of the signal detection unit 100b generates a failure detection signal for the main signal detection unit 110 of the signal detection unit 100a.

[0024] The failure detection section 50 in FIG. 1 can detect a failure when the detection signal output from the main signal detection section 110 and the failure detection signal output from the sub-signal detection section 120 are different.

[0025] The wiring will now be described. Input terminal 32a is grounded, and input terminal 31a is connected to input terminal 121 of sub-signal detection section 120 of signal detection section 100b. Input terminal 122 of sub-signal detection section 120 of signal detection section 100b is connected to input terminal 111 of main signal detection section 110 of signal detection section 100a. Input terminal 112 of main signal detection section 110 of signal detection section 100a is grounded.

[0026] Input terminal 32b is grounded, and input terminal 31b is connected to input terminal 121 of sub-signal detection section 120 of signal detection section 100a. Input terminal 122 of sub-signal detection section 120 of signal detection section 100a is connected to input terminal 111 of main signal detection section 110 of signal detection section 100b. Input terminal 112 of main signal detection section 110 of signal detection section 100b is grounded.

[0027] In this way, the sub-signal detection unit 120 detects a failure of the main signal detection unit 110 of a signal detection unit 100 different from the signal detection unit 100 in which the sub-signal detection unit 120 is included. Therefore, even if one of the signal detection units 100 is damaged, the failure of the signal detection unit 100 can be detected by the sub-signal detection unit 120 of the other signal detection unit 100. The signal detection unit 100a and the signal detection unit 100b can also be arranged in different ICs. In this case, the sub-signal detection unit 120 can detect damage to the IC in which the signal detection unit 100 is arranged. Redundancy can be ensured while arranging the main signal detection unit 110 and the sub-signal detection unit 120 in the same IC. This allows the signal detection unit 100 to be made smaller and less expensive. The different ICs include ICs configured in different semiconductor chips arranged in the same package.

[0028] Also, the input signal detection circuit 30 in the figure can be applied as a device with a Hardware Fault Tolerance (HFT) of 1 as defined by IEC61508.

[0029] [Configuration of signal detection section] 3 is a diagram showing a configuration example of a signal detection unit according to the first embodiment of the present disclosure. The same figure is a circuit diagram showing a configuration example of the signal detection unit 100. The main signal detection unit 110 includes a resistor 113 and an OP amplifier 114. The resistor 113 is connected between input terminals 111 and 112 and configures a current detection resistor. The OP amplifier 114 operates as a buffer amplifier.

[0030] The sub-signal detection unit 120 includes resistors 123 to 126 and an OP amplifier 127. The resistor 123 is connected between the input terminals 121 and 122, and constitutes a current detection resistor. The OP amplifier 127 and the resistors 124 to 126 constitute a differential amplifier circuit. This differential amplifier circuit amplifies the terminal voltage of the resistor 123 and outputs it.

[0031] [Other configurations of the input signal detection circuit] 4 is a diagram showing another configuration example of the input signal detection circuit according to the first embodiment of the present disclosure. This diagram shows an example in which currents from the field devices 2 and 3 serve as source currents. The operation of the circuit is similar to that of the input signal detection circuit 30 in FIG. 3, and therefore a description thereof will be omitted.

[0032] In this way, the input signal detection circuit 30 of the first embodiment of the present disclosure arranges the main signal detection unit 110 and the sub-signal detection unit 120 in one signal detection unit 100. This allows the number of components to be reduced, resulting in lower costs. Furthermore, the reduced number of components allows the failure rate to be reduced. Furthermore, two signal detection units 100 each including the main signal detection unit 110 and the sub-signal detection unit 120 are arranged, and the sub-signal detection unit 120 of each signal detection unit 100 detects a failure of the main signal detection unit 110 of the other signal detection unit 100. Therefore, even if one of the signal detection units 100 fails, the failure can be detected by the sub-signal detection unit 120 of the other signal detection unit 100, and specifications required for functional safety can be met.

[0033] 2. Second Embodiment The input signal detection circuit 30 of the first embodiment described above is provided with two signal detection units 100. In contrast, the input signal detection circuit 30 of the second embodiment of the present disclosure differs from the first embodiment described above in that three or more input signal detection circuits 30 are provided.

[0034] [Input signal detection circuit configuration] 5 is a diagram showing a configuration example of an input signal detection circuit according to a second embodiment of the present disclosure. Similar to FIG. 2, this figure is a block diagram showing a configuration example of an input signal detection circuit 30. The input signal detection circuit 30 in this figure differs from the input signal detection circuit 30 in FIG. 2 in that it includes N (N is an integer equal to or greater than 3) signal detection units 100. Note that the input signal detection circuit 30 in this figure is partially omitted.

[0035] The input signal detection circuit 30 in the figure includes a signal detection unit 100a-signal detection unit 100f, and input terminals 31a and 32a, input terminals 31b and 32b, input terminals 31d and 32d, input terminals 31e and 32e, and input terminals 31f and 32f. The input terminal 32a is grounded, and the input terminal 31a is connected to an input terminal 121 of a sub-signal detection unit 120 of the signal detection unit (#2) 100b. An input terminal 122 of the sub-signal detection unit 120 of the signal detection unit (#2) 100b is connected to an input terminal 111 of a main signal detection unit 110 of the signal detection unit (#1) 100a. An input terminal 112 of the main signal detection unit 110 of the signal detection unit (#1) 100a is grounded. Similar connections are repeated up to the input terminals 31e and 32e and the signal detection unit 100e.

[0036] Input terminal 32f is grounded, and input terminal 31f is connected to input terminal 121 of sub-signal detection unit 120 of signal detection unit (#1) 100a. Input terminal 122 of sub-signal detection unit 120 of signal detection unit (#1) 100a is connected to input terminal 111 of main signal detection unit 110 of signal detection unit (#N) 100f. Input terminal 112 of main signal detection unit 110 of signal detection unit (#N) 100f is grounded.

[0037] In this way, the input signal detection circuit 30 can be configured even when there are three or more signal detection units 100. Furthermore, the multiple sub signal detection units 120 each generate a failure detection signal for the main signal detection unit 110 exclusively. Here, "exclusively" means that the multiple sub signal detection units 120 do not generate a failure detection signal for the same main signal detection unit 110. In this case, only one sub signal detection unit 120 generates a failure detection signal for one main signal detection unit 110. Note that when there are an even number of signal detection units 100, a method of repeating the configuration of the input signal detection circuit 30 in FIG. 2 can also be adopted.

[0038] Other than this, the configuration of the input signal detection circuit 30 is similar to the configuration of the input signal detection circuit 30 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0039] 3. Third embodiment In the input signal detection circuit 30 of the first embodiment described above, the sub signal detection section 120 detects the current. In contrast, the input signal detection circuit 30 of the third embodiment of the present disclosure differs from the first embodiment described above in that the sub signal detection section detects the voltage of the main signal detection section 110.

[0040] [Input signal detection circuit configuration] Fig. 6 is a diagram showing a configuration example of an input signal detection circuit according to a third embodiment of the present disclosure. Similar to Fig. 2, Fig. 6 is a block diagram showing a configuration example of an input signal detection circuit 30. The input signal detection circuit 30 in Fig. 6 differs from the input signal detection circuit 30 in Fig. 2 in that it includes a sub-signal detection unit 130 instead of the sub-signal detection unit 120.

[0041] The sub-signal detection unit 130 generates a fault detection signal based on the voltage of the input terminal of the main signal detection unit 110. The sub-signal detection unit 130 has an input terminal 131. This input terminal 131 is connected to the input terminal 111 of the main signal detection unit 110. In this case, the fault detection unit 50 in Fig. 1 can determine that a fault has occurred when the fault detection signal has a value of "0", for example.

[0042] Other than this, the configuration of the input signal detection circuit 30 is similar to the configuration of the input signal detection circuit 30 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0043] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0044] Some examples of combinations of the disclosed technical features are set out below. (1) A plurality of input terminals; a plurality of signal detection units each including a main signal detection unit arranged for each of the plurality of input terminals to detect a signal at the input terminal and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit; having the main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit that includes the main signal detection unit; The sub-signal detection unit generates the failure detection signal for the main signal detection unit of the signal detection unit different from the signal detection unit that includes the sub-signal detection unit, The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. Input signal detection circuit. (2) The input signal detection circuit according to (1), wherein the plurality of signal detection units are arranged in different integrated circuits. (3) The input signal detection circuit according to (1) or (2), wherein the main signal detection unit detects a current flowing through the input terminal as the signal. (4) The input signal detection circuit according to (3), wherein the sub-signal detection unit generates the fault detection signal based on a current flowing through the input terminal corresponding to the main signal detection unit that detects a fault in the sub-signal detection unit. (5) The input signal detection circuit according to (3), wherein the sub-signal detection unit generates the fault detection signal based on a voltage of the main signal detection unit that detects a fault in the sub-signal detection unit. (6) A plurality of input terminals; a plurality of signal detection units each including a main signal detection unit arranged for each of the plurality of input terminals to detect a signal at the input terminal and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit; a failure detection unit that detects a failure of the main signal detection unit based on the failure detection signal; having the main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit that includes the main signal detection unit; The sub-signal detection unit generates the failure detection signal for the main signal detection unit of the signal detection unit different from the signal detection unit that includes the sub-signal detection unit, The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. electronic equipment. (7) A plurality of input terminals; a plurality of signal detection units each including a main signal detection unit arranged for each of the plurality of input terminals to detect a signal at the input terminal and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit; a failure detection unit that detects a failure of the main signal detection unit based on the failure detection signal; a fault information output unit that outputs information about the main signal detection unit in which the fault has been detected; having the main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit that includes the main signal detection unit; The sub-signal detection unit generates the failure detection signal for the main signal detection unit of the signal detection unit different from the signal detection unit that includes the sub-signal detection unit, The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. system. [Explanation of symbols]

[0045] 1 System 10 Electronic equipment 20 Fault information output section 30 Input signal detection circuit 31a, 31b, 31d, 31e, 31f, 32, 32a, 32b, 32d, 32e, 32f input terminals 50 Fault detection section 100, 100a, 100b, 100c, 100d, 100e, 100f Signal detection unit 110 Main signal detector 120, 130 Sub-signal detection unit

Claims

1. A plurality of input terminals; a plurality of signal detection units each including a main signal detection unit arranged for each of the plurality of input terminals to detect a signal at the input terminal and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit; having the main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit that includes the main signal detection unit; The sub-signal detection unit generates the failure detection signal for the main signal detection unit of the signal detection unit different from the signal detection unit that includes the sub-signal detection unit, The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. Input signal detection circuit.

2. 2. The input signal detection circuit according to claim 1, wherein the plurality of signal detection sections are arranged in different integrated circuits.

3. 3. The input signal detection circuit according to claim 1, wherein the main signal detection section detects a current flowing through the input terminal as the signal.

4. 4. The input signal detection circuit according to claim 3, wherein the sub-signal detection section generates the fault detection signal based on a current flowing through the input terminal corresponding to the main signal detection section that detects a fault in the sub-signal detection section.

5. 4. The input signal detection circuit according to claim 3, wherein the sub-signal detection section generates the failure detection signal based on a voltage of the main signal detection section in which the sub-signal detection section detects a failure.

6. A plurality of input terminals; a plurality of signal detection units each including a main signal detection unit arranged for each of the plurality of input terminals to detect a signal at the input terminal and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit; a failure detection unit that detects a failure of the main signal detection unit based on the failure detection signal; having the main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit that includes the main signal detection unit; The sub-signal detection unit generates the failure detection signal for the main signal detection unit of the signal detection unit different from the signal detection unit that includes the sub-signal detection unit, The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. electronic equipment.

7. A plurality of input terminals; a plurality of signal detection units each including a main signal detection unit arranged for each of the plurality of input terminals to detect a signal at the input terminal and a sub-signal detection unit generating a failure detection signal that is a signal for detecting a failure of the main signal detection unit; a failure detection unit that detects a failure of the main signal detection unit based on the failure detection signal; a fault information output unit that outputs information about the main signal detection unit in which the fault has been detected; having the main signal detection unit detects a signal at the input terminal corresponding to the signal detection unit that includes the main signal detection unit; The sub-signal detection unit generates the failure detection signal for the main signal detection unit of the signal detection unit different from the signal detection unit that includes the sub-signal detection unit, The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the failure detection signal of the main signal detection unit. system.

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