Input signal detection circuit, electronic device and system

Abstract

The present invention relates to an input signal detection circuit, an electronic device, and a system, wherein redundancy is maintained and the size of the input signal detection circuit is reduced. The input signal detection circuit includes a plurality of input terminals and a plurality of signal detection units. Each of the signal detection units has: a main signal detection unit that is disposed for each of the plurality of input terminals and detects a signal of the input terminal; and a sub-signal detection unit that generates a fault detection signal that is a signal for detecting a fault in the main signal detection unit. The main signal detection unit detects a signal of an input terminal corresponding to the signal detection unit having the main signal detection unit. The sub-signal detection unit generates a fault detection signal of the main signal detection unit having a signal detection unit different from the signal detection unit of the sub-signal detection unit. The sub-signal detection unit of each of the plurality of signal detection units exclusively generates a fault detection signal of the main signal detection unit.

Description

Technical Field

[0001] The invention relates to an input signal detection circuit, an electronic device and a system. Background Art

[0002] Regarding systems and electronic devices that control field devices used in workshops, factories, etc., an input signal detection circuit that detects the state quantity of the field device based on a signal from the field device is used. For example, current is equivalent to the state quantity. In order to reduce the risk of obstacles caused by equipment failure, etc., an input signal detection circuit that is configured as a functional safety device is proposed. Regarding the functional safety device, for example, by adding a fault detection circuit that detects a fault in the input signal detection circuit, the system can be made redundant, which can reduce the risk of serious obstacles.

[0003] As such a device, for example, a semiconductor integrated circuit device is proposed, which includes: a target circuit; a first failure detection unit that detects a failure of the target circuit; and

[0004] The second fault detection unit detects a fault of the target circuit by a method different from that of the first fault detection unit, and is configured to meet functional safety specifications (for example, see Patent Document 1). Here, the target circuit is a circuit that processes an input signal from outside the semiconductor integrated circuit device to generate an output signal.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-115987

[0006] Regarding the above-mentioned prior art, the input signal detection circuit and the fault detection circuit (fault detection unit) are configured in the same integrated circuit (IC). This is for the purpose of miniaturization of the device. However, in this case, the fault of the IC itself cannot be detected, so the redundancy is reduced. On the other hand, in order to detect the fault of the IC, the fault detection circuit of the IC needs to be configured outside the IC, which has the problem of not being able to achieve miniaturization of the device including the input signal detection circuit. Summary of the invention

[0007] The present invention provides an input signal detection circuit capable of maintaining redundancy and realizing miniaturization, and an electronic device and a system having the input signal detection circuit.

[0008] The input signal detection circuit of the present invention has a plurality of input terminals and a plurality of signal detection units. The signal detection units respectively have: a main signal detection unit configured for each of the plurality of input terminals and detecting the signal of the input terminal; and a sub-signal detection unit generating a signal for detecting a fault of the main signal detection unit, i.e., a fault detection signal. The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having its own. The sub-signal detection unit generates the fault detection signal of the main signal detection unit of the signal detection unit different from the signal detection unit having its own. The sub-signal detection unit of each of the plurality of signal detection units exclusively generates the fault detection signal of the main signal detection unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a diagram showing a configuration example of a system according to an embodiment of the present invention.

[0010] Figure 2 It is a diagram showing a configuration example of an input signal detection circuit according to the first embodiment of the present invention.

[0011] Figure 3 It is a diagram showing a configuration example of a signal detection unit according to the first embodiment of the present invention.

[0012] Figure 4 It is a diagram showing another configuration example of the input signal detection circuit according to the first embodiment of the present invention.

[0013] Figure 5 It is a diagram showing a configuration example of an input signal detection circuit according to a second embodiment of the present invention.

[0014] Figure 6 It is a diagram showing a configuration example of an input signal detection circuit according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. The description will be given in the following order. In addition, in each of the following embodiments, the same parts are marked with the same reference numerals to omit repeated descriptions.

[0016] [First embodiment]

[0017] [System Structure]

[0018] Figure 1 1 is a diagram showing a configuration example of a system according to an embodiment of the present invention. This diagram is a block diagram showing a configuration example of a system 1. The system 1 is a system for controlling 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.

[0019] The system 1 includes an electronic device 10 and a fault information output unit 20. In addition, the figure also includes a field device 2 and a field device 3.

[0020] 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 also detects a failure in a circuit that detects the input signal and outputs the detection result to the failure information output unit 20 .

[0021] The failure information output unit 20 generates failure information, which is information for detecting a failure in a circuit of an input signal included in the electronic device 10, based on the detection result output from the electronic device 10. The generated failure information is output to external devices of the system 1 or the like.

[0022] [Structure of electronic equipment]

[0023] The electronic device 10 includes an input signal detection circuit 30 , a control unit 40 , and a failure detection unit 50 .

[0024] 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 as a detection result to the control unit 40 and the fault detection unit 50. In addition, the input signal detection circuit 30 generates a fault detection signal for detecting a fault in a circuit (main signal detection unit 110 described later) that detects the input signal, and outputs the signal to the fault detection unit 50.

[0025] The control unit 40 controls the entire electronic device 10. In addition, when controlling the field devices 2 and 3, the control unit 40 can also output a control signal to the field devices 2 and 3.

[0026] The fault detection unit 50 detects a fault in the main signal detection unit 110 based on the fault detection signal from the input signal detection circuit 30. The fault detection unit 50 in the figure shows 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.

[0027] [Structure of input signal detection circuit]

[0028] Figure 2 1 is a diagram showing a configuration example of an input signal detection circuit according to a first embodiment of the present invention. 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. In addition, the field devices 2 and 3 in the figure output signal currents IIN1 and IIN2, respectively.

[0029] Input terminals 31a and 32a and input terminals 31b and 32b are a pair of terminals for inputting signals of field device 2 and the like. The above-mentioned input terminals are configured for each field device. The signal of field device 2 is input to input terminals 31a and 32a. In addition, the signal of field device 3 is input to input terminals 31b and 32b. In addition, input terminals 31a and input terminals 31b are receiving (sink) side input terminals, and input terminals 32a and input terminals 32b are sending (source) side input terminals.

[0030] The signal detection units 100a and 100b include a main signal detection unit 110 which is respectively arranged for the input terminals 31a and 32a and the input terminals 31b and 32b and detects the signal of the input terminal 31a and the like. With respect to the input signal detection circuit 30 of 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 the input signal of the input terminal 31 and the like corresponding to itself. In addition, the signal detection units 100a and 100b further include a sub-signal detection unit 120 which generates a signal for detecting a failure of the main signal detection unit 110, that is, a failure detection signal.

[0031] The main signal detection unit 110 detects the signal of the input terminal 31 in the above-mentioned manner. The main signal detection unit 110 of the figure detects the current flowing through the input terminal 31 and the like, and outputs a detection signal as a detection result. The main signal detection unit 110 has input terminals 111 and 112. The input terminal 111 is a receiving side input terminal, and the input terminal 112 is a transmitting side input terminal. The main signal detection unit 110 detects the current flowing from the input terminal 111 to the input terminal 112. The detection of the current can be performed by detecting the 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. In addition, the main signal detection unit 110 can also detect the connection and disconnection of the current, and outputs a binary signal corresponding to the connection and disconnection of the current as a detection signal. The main signal detection unit 110 detects the current of the input terminal 31 and the like corresponding to the signal detection unit 100 having itself.

[0032] The auxiliary signal detection unit 120 generates a signal for detecting a fault of the main signal detection unit 110, that is, a fault detection signal, in the above manner. The auxiliary signal detection unit 120 of the figure detects the current flowing in the main signal detection unit 110 and outputs it as a fault detection signal. The auxiliary signal detection unit 120 has an input terminal 121 and an input terminal 122. The input terminal 121 is a receiving side input terminal, and the input terminal 122 is a transmitting side input terminal. The auxiliary signal detection unit 120 detects the current flowing from the input terminal 121 to the input terminal 122.

[0033] In addition, the sub-signal detection unit 120 generates a failure detection signal of the main signal detection unit 110 of the signal detection unit 100 which is different from the signal detection unit 100 having its own signal detection unit. In this figure, the sub-signal detection unit 120 of the signal detection unit 100a generates a failure detection signal of the main signal detection unit 110 of the signal detection unit 100b. In addition, the sub-signal detection unit 120 of the signal detection unit 100b generates a failure detection signal of the main signal detection unit 110 of the signal detection unit 100a.

[0034] In addition, when the detection signal output from the main signal detection unit 110 and the failure detection signal output from the sub-signal detection unit 120 are different, Figure 1 The fault detection unit 50 can detect the fault.

[0035] The wiring is described. The input terminal 32a is grounded, and the input terminal 31a is connected to the input terminal 121 of the sub-signal detection unit 120 of the signal detection unit 100b. The input terminal 122 of the sub-signal detection unit 120 of the signal detection unit 100b is connected to the input terminal 111 of the main signal detection unit 110 of the signal detection unit 100a. The input terminal 112 of the main signal detection unit 110 of the signal detection unit 100a is grounded.

[0036] The input terminal 32b is grounded, and the input terminal 31b is connected to the input terminal 121 of the sub-signal detection unit 120 of the signal detection unit 100a. The input terminal 122 of the sub-signal detection unit 120 of the signal detection unit 100a is connected to the input terminal 111 of the main signal detection unit 110 of the signal detection unit 100b. The input terminal 112 of the main signal detection unit 110 of the signal detection unit 100b is grounded.

[0037] In this way, the auxiliary signal detection unit 120 detects a fault in the main signal detection unit 110 of the signal detection unit 100 which is different from the signal detection unit 100 including itself. Therefore, even if one signal detection unit 100 is damaged, the auxiliary signal detection unit 120 of another signal detection unit 100 can be used to detect the fault of the signal detection unit 100. In addition, the signal detection unit 100a and the signal detection unit 100b can be respectively configured in different ICs. In this case, the auxiliary signal detection unit 120 can be used to detect the damage of the IC configured with the signal detection unit 100. The main signal detection unit 110 and the auxiliary signal detection unit 120 can be configured in the same IC and redundancy can be ensured. Thus, the signal detection unit 100 can be miniaturized and low-cost can be achieved. In addition, different ICs refer to ICs that are configured in the same package and are constituted as different semiconductor chips.

[0038] The input signal detection circuit 30 of the figure can also be applied as a device having a hardware fault tolerance (HFT: Hardware Fault Tolerance) of 1 as specified in IEC61508.

[0039] [Structure of the signal detection unit]

[0040] Figure 3 1 is a diagram showing a configuration example of a signal detection unit according to a first embodiment of the present invention. This figure is a circuit diagram showing a configuration example of a signal detection unit 100. A 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 to form a current detection resistor. The OP amplifier 114 operates as a buffer amplifier.

[0041] The auxiliary 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 to form a current detection resistor. The OP amplifier 127 and the circuit of the resistors 124 to 126 form a differential amplifier circuit. The differential amplifier circuit amplifies the terminal voltage of the resistor 123 and outputs it.

[0042] [Other structures of input signal detection circuit]

[0043] Figure 4 FIG. 1 is a diagram showing another configuration example of the input signal detection circuit according to the first embodiment of the present invention. This diagram shows an example in which the current from the field devices 2 and 3 is a source current. The operation of the circuit is similar to Figure 3 The input signal detection circuit 30 is the same as that of FIG. 3 , so the description is omitted.

[0044] In this way, the input signal detection circuit 30 of the first embodiment of the present invention configures the main signal detection unit 110 and the sub-signal detection unit 120 in one signal detection unit 100. As a result, the number of components can be reduced, and low cost can be achieved. In addition, the number of components is reduced, so the failure rate can be reduced. In addition, there are two signal detection units 100 having the main signal detection unit 110 and the sub-signal detection unit 120, and the sub-signal detection unit 120 of each signal detection unit 100 detects the failure of the main signal detection unit 110 of the signal detection unit 100 on the other side. Therefore, even if a signal detection unit 100 fails, the sub-signal detection unit 120 of the other signal detection unit 100 can be used to detect the failure, and the specifications required for functional safety can be met.

[0045] [Second embodiment]

[0046] The input signal detection circuit 30 of the first embodiment has two signal detection units 100. In contrast, the input signal detection circuit 30 of the second embodiment of the present invention is different from the first embodiment in that three or more input signal detection circuits 30 are provided.

[0047] [Structure of input signal detection circuit]

[0048] Figure 5 2 is a diagram showing a configuration example of an input signal detection circuit according to a second embodiment of the present invention. Figure 2 Similarly, FIG. 1 is a block diagram showing a configuration example of the input signal detection circuit 30. The input signal detection circuit 30 of this figure is similar to FIG. 1 in that it has N (N is an integer greater than or equal to 3) signal detection units 100. Figure 2 The input signal detection circuit 30 of FIG. 1 is different. In addition, the input signal detection circuit 30 of this figure is partially omitted.

[0049] The input signal detection circuit 30 of the figure includes signal detection units 100a to 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 the input terminal 121 of the sub-signal detection unit 120 of the signal detection unit (#2) 100b. The input terminal 122 of the sub-signal detection unit 120 of the signal detection unit (#2) 100b is connected to the input terminal 111 of the main signal detection unit 110 of the signal detection unit (#1) 100a. The input terminal 112 of the main signal detection unit 110 of the signal detection unit (#1) 100a is grounded. Next, the same wiring is repeated until the input terminals 31e and 32e and the signal detection unit 100e.

[0050] The input terminal 32f is grounded, and the input terminal 31f is connected to the input terminal 121 of the sub-signal detection unit 120 of the signal detection unit (#1) 100a. The input terminal 122 of the sub-signal detection unit 120 of the signal detection unit (#1) 100a is connected to the input terminal 111 of the main signal detection unit 110 of the signal detection unit (#N) 100f. The input terminal 112 of the main signal detection unit 110 of the signal detection unit (#N) 100f is grounded.

[0051] In this way, even when the number of signal detection units 100 is greater than or equal to 3, the input signal detection circuit 30 can be configured. In addition, the plurality of sub-signal detection units 120 respectively and exclusively generate the fault detection signal of the main signal detection unit 110. Here, exclusive means excluding the case where the plurality of sub-signal detection units 120 generate the same fault detection signal of the main signal detection unit 110. In this case, only one sub-signal detection unit 120 generates the fault detection signal of one main signal detection unit 110. In addition, when the number of signal detection units 100 is an even number, it is also possible to adopt a method of repeatedly forming Figure 2 The input signal detection circuit 30 is structured in this manner.

[0052] The configuration of the input signal detection circuit 30 other than this is the same as that of the input signal detection circuit 30 according to the first embodiment of the present invention, and thus the description thereof will be omitted.

[0053] [Third Embodiment]

[0054] The sub-signal detection unit 120 of the input signal detection circuit 30 of the first embodiment detects current. In contrast, the input signal detection circuit 30 of the third embodiment of the present invention is different from the first embodiment in that the sub-signal detection unit detects the voltage of the main signal detection unit 110 .

[0055] [Structure of input signal detection circuit]

[0056] Figure 6 1 is a diagram showing a configuration example of an input signal detection circuit according to a third embodiment of the present invention. Figure 2 Similarly, this is a block diagram showing a configuration example of the input signal detection circuit 30. The input signal detection circuit 30 of this figure is similar to the input signal detection circuit 30 in that it includes a sub-signal detection unit 130 instead of the sub-signal detection unit 120. Figure 2 The input signal detection circuit 30 is different.

[0057] The auxiliary 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 auxiliary signal detection unit 130 has an input terminal 131. The input terminal 131 is connected to the input terminal 111 of the main signal detection unit 110. In this case, Figure 1 The fault detection unit 50 can determine that there is a fault when the value of the fault detection signal is "0", for example.

[0058] The configuration of the input signal detection circuit 30 other than this is the same as that of the input signal detection circuit 30 according to the first embodiment of the present invention, and thus the description thereof will be omitted.

[0059] Furthermore, the effects described in this specification are merely illustrative and are not limiting, and other effects may also be present.

[0060] Several examples of combinations of disclosed technical features are described below.

[0061] (1) An input signal detection circuit comprising:

[0062] a plurality of input terminals; and

[0063] a plurality of signal detection units, each of which includes a main signal detection unit configured for each of the plurality of input terminals and detecting a signal of the input terminal, and a sub-signal detection unit generating a signal for detecting a failure of the main signal detection unit, i.e., a failure detection signal,

[0064] The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having itself,

[0065] 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 the sub-signal detection unit,

[0066] The sub-signal detecting unit of each of the plurality of signal detecting units exclusively generates the failure detection signal of the main signal detecting unit.

[0067] (2) The input signal detection circuit according to (1), wherein:

[0068] The plurality of signal detection units are configured on different integrated circuits.

[0069] (3) The input signal detection circuit according to (1) or (2), wherein:

[0070] The main signal detection unit detects a current flowing through the input terminal as the signal.

[0071] (4) The input signal detection circuit according to (3), wherein:

[0072] The sub-signal detection unit generates the failure detection signal based on the current flowing through the input terminal corresponding to the main signal detection unit that has detected a failure.

[0073] (5) The input signal detection circuit according to (3), wherein:

[0074] The sub-signal detection unit generates the failure detection signal based on the voltage of the main signal detection unit that has detected a failure.

[0075] (6) An electronic device comprising:

[0076] Multiple input terminals;

[0077] a plurality of signal detection units, each of which includes a main signal detection unit configured for each of the plurality of input terminals and detecting a signal of the input terminal, and a sub-signal detection unit generating a fault detection signal, which is a signal for detecting a fault of the main signal detection unit; and

[0078] a fault detection unit that detects a fault of the main signal detection unit based on the fault detection signal,

[0079] The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having itself,

[0080] 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 the sub-signal detection unit,

[0081] The sub-signal detecting unit of each of the plurality of signal detecting units exclusively generates the failure detection signal of the main signal detecting unit.

[0082] (7) A system comprising:

[0083] Multiple input terminals;

[0084] a plurality of signal detection units, each of which includes a main signal detection unit configured for each of the plurality of input terminals and detecting a signal of the input terminal, and a sub-signal detection unit generating a signal for detecting a failure of the main signal detection unit, namely, a failure detection signal;

[0085] a fault detection unit that detects a fault of the main signal detection unit based on the fault detection signal; and

[0086] a fault information output unit that outputs information of the main signal detection unit that has detected the fault,

[0087] The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having itself,

[0088] 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 the sub-signal detection unit,

[0089] The sub-signal detecting unit of each of the plurality of signal detecting units exclusively generates the failure detection signal of the main signal detecting unit.

[0090] Description of the label

[0091] 1 System

[0092] 10 Electronic devices

[0093] 20 Fault information output unit

[0094] 30 Input signal detection circuit

[0095] 31a, 31b, 31d, 31e, 31f, 32, 32a, 32b, 32d, 32e, 32f Input terminals

[0096] 50 Fault detection unit

[0097] 100, 100a, 100b, 100c, 100d, 100e, 100f signal detection unit

[0098] 110 Main signal detection unit

[0099] 120, 130 Auxiliary signal detection unit

Claims

1. An input signal detection circuit, wherein: The input signal detection circuit has: Multiple input terminals; as well as a plurality of signal detection units, each of which includes a main signal detection unit configured for each of the plurality of input terminals and detecting a signal of the input terminal, and a sub-signal detection unit generating a signal for detecting a failure of the main signal detection unit, i.e., a failure detection signal, The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having itself, 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 the sub-signal detection unit, The sub-signal detecting unit of each of the plurality of signal detecting units exclusively generates the failure detection signal of the main signal detecting unit.

2. The input signal detection circuit according to claim 1, wherein: The plurality of signal detection units are configured on different integrated circuits.

3. The input signal detection circuit according to claim 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 claim 3, wherein: The sub-signal detection unit generates the failure detection signal based on the current flowing through the input terminal corresponding to the main signal detection unit that has detected a failure.

5. The input signal detection circuit according to claim 3, wherein: The sub-signal detection unit generates the failure detection signal based on the voltage of the main signal detection unit that has detected a failure.

6. An electronic device, wherein: The electronic device comprises: Multiple input terminals; a plurality of signal detection units, each of which includes a main signal detection unit configured for each of the plurality of input terminals and detecting a signal of the input terminal, and a sub-signal detection unit generating a signal for detecting a failure of the main signal detection unit, namely, a failure detection signal; as well as a fault detection unit that detects a fault of the main signal detection unit based on the fault detection signal, The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having itself, 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 the sub-signal detection unit, The sub-signal detecting unit of each of the plurality of signal detecting units exclusively generates the failure detection signal of the main signal detecting unit.

7. A system, wherein: The system has: Multiple input terminals; a plurality of signal detection units, each of which includes a main signal detection unit configured for each of the plurality of input terminals and detecting a signal of the input terminal, and a sub-signal detection unit generating a signal for detecting a failure of the main signal detection unit, namely, a failure detection signal; a fault detection unit that detects a fault of the main signal detection unit based on the fault detection signal; as well as a fault information output unit that outputs information of the main signal detection unit that has detected the fault, The main signal detection unit detects the signal of the input terminal corresponding to the signal detection unit having itself, 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 the sub-signal detection unit, The sub-signal detecting unit of each of the plurality of signal detecting units exclusively generates the failure detection signal of the main signal detecting unit.

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