Status detection device

Abstract

The present invention provides a state detection device capable of achieving both shortening the time from detecting an abnormal state to transmitting the detection result and saving power of a communication circuit. The state detection device (1) includes: a communication circuit (16) for transmitting information to an external device; a control circuit (12) for operating the communication circuit (16) at a first timing; a battery (11) for supplying power to the communication circuit (16) and the control circuit (12); and a first explosion-proof fence (15) connected between a contact circuit (30) and the control circuit (12). The control circuit (12) applies a check signal generated based on a voltage output by the battery (11) to the contact circuit (30) at a second timing that arrives at an interval shorter than the first timing, obtains a detection signal indicating that current flows through the contact circuit (30) due to the application of the check signal to the contact circuit (30), and operates the communication circuit (16) at the timing of obtaining the detection signal, regardless of the first timing, to transmit to the external device that the state of the target device connected to the contact circuit (30) is an abnormal state.

Description

Technical Field

[0001] The invention relates to a state detection device. Background Art

[0002] Conventionally, in a contact signal conversion device that converts a switch contact signal into a control signal for operating a solenoid valve, there is known an explosion-proof barrier that limits the voltage and current of the operating power supply of the solenoid valve (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-222085

[0005] Sometimes, a contact circuit and a status detection device that detects abnormal conditions in the contact circuit are connected via an explosion-proof barrier. When the status detection device detects an abnormal condition in the contact circuit and transmits the detection result to another device, it is necessary to both shorten the time from abnormal condition detection to transmission of the detection result and reduce power consumption in the communication circuit. Summary of the Invention

[0006] In view of the above-mentioned problems, an object of the present invention is to provide a state detection device capable of achieving both shortening the time from detection of an abnormal state to transmission of the detection result and saving power of a communication circuit.

[0007] In some embodiments, a status detection device includes a communication circuit, a control circuit, a battery, and a first explosion barrier. The communication circuit transmits information to an external device. The control circuit activates the communication circuit at a first timing. The battery supplies power to the communication circuit and the control circuit. The first explosion barrier is connected between a contact circuit and the control circuit. At a second timing that arrives at a shorter interval than the first timing, the control circuit applies a check signal generated based on the voltage output by the battery to the contact circuit via the first explosion barrier. The control circuit receives a detection signal from the first explosion barrier, indicating that current is flowing through the contact circuit due to the application of the check signal to the contact circuit. Regardless of the first timing, the control circuit activates the communication circuit at the timing of receiving the detection signal, and notifies the external device that the status of the device connected to the contact circuit is abnormal. This shortens the time from when the control circuit detects the abnormal state of the contact circuit to when the detection of the abnormal state is notified to the external device. Furthermore, without shortening the first timed interval for operating the communication circuit, the time from when the control circuit detects an abnormal state in the contact circuit to when the abnormal state is detected is transmitted to an external device is shortened. Since the first timed interval for operating the communication circuit is not shortened, the power consumption of the communication circuit is reduced. As a result, both the time from when the control circuit detects an abnormal state in the contact circuit to when information indicating the abnormal state is transmitted is shortened, and power consumption of the communication circuit is reduced.

[0008] In one embodiment, the state detection device may further include a latch circuit that acquires and holds the detection signal. The control circuit can acquire the detection signal from the latch circuit. This allows the control circuit to acquire the detection signal at a timing determined by the control circuit itself. Consequently, the load on the control circuit can be reduced.

[0009] In one embodiment of the status detection device, the control circuit can obtain the detection signal from the latch circuit at a third timing that arrives at a shorter interval than the first timing. This shortens the time between the control circuit detecting an abnormal state in the contact circuit and transmitting the abnormal state detection information to an external device, without shortening the first timing interval for operating the communication circuit. As a result, both the time between the control circuit detecting an abnormal state in the contact circuit and transmitting information indicating the abnormal state detection is shortened and power consumption of the communication circuit is reduced.

[0010] In one embodiment of the status detection device, upon receiving the detection signal, the control circuit can activate the communication circuit as an interrupt process, thereby notifying the external device that the status of the device connected to the contact circuit is abnormal. This reduces the time between the control circuit detecting the abnormal state of the contact circuit and notifying the external device of the abnormal state detection, without shortening the first timed interval for activating the communication circuit. As a result, both the time between the control circuit detecting the abnormal state of the contact circuit and the transmission of information indicating the abnormal state detection is reduced and power consumption of the communication circuit is reduced.

[0011] In one embodiment of the state detection device, the battery may be a lithium-thionyl chloride primary battery. This allows the battery to supply a large amount of power to the state detection device, enabling prolonged operation. Consequently, the state detection device can be used in on-site locations such as process equipment and factories, where long-term stable operation is required.

[0012] In one embodiment of the state detection device, the control circuit may cause the battery to output a current greater than a current value based on the specifications of the lithium thionyl chloride primary battery at the second timing, thereby outputting a signal to the contact circuit in conjunction with reducing the internal resistance of the battery.

[0013] In one embodiment, the status detection device may further include a booster circuit connected between the first explosion-proof barrier and the contact circuit, and a second explosion-proof barrier connected between the booster circuit and the contact circuit. The booster circuit can boost the voltage output by the battery to generate a boosted signal, which is applied to the contact circuit via the second explosion-proof barrier as the check signal. This allows the voltage input to the contact circuit to be boosted to a level sufficient to detect the status of a device connected to the contact circuit, even if the power output from the battery is limited by the first explosion-proof barrier. Consequently, the status detection device can detect the status of a device connected to the contact circuit.

[0014] According to the state detection device of the present invention, it is possible to achieve both shortening of the time from detection of an abnormal state to transmission of the detection result and saving of power of the communication circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a circuit diagram of a state detection device according to a comparative example.

[0016] Figure 2 1 is a diagram showing the operation timing of a state detection device according to a comparative example.

[0017] Figure 3 This is a circuit diagram showing a configuration example of a state detection device according to one embodiment.

[0018] Figure 4 This is a circuit diagram showing an example of the configuration of an explosion-proof barrier.

[0019] Figure 5 This is a diagram showing the operation timing of the state detection device according to one embodiment.

[0020] Description of Reference Numerals

[0021] 1. Status detection device

[0022] 10 Transmitter (11: Battery, 12: Control Circuit, 13: Load Circuit, 14: Switch, 15: Explosion-proof Barrier, 16: Communication Circuit, 17: Latch Circuit)

[0023] 20 signal conversion device (21: boost circuit, 24: explosion-proof barrier)

[0024] 30-contact circuit. DETAILED DESCRIPTION

[0025] The embodiment of the present invention will be described in comparison with a comparative example.

[0026] (Comparative Example)

[0027] like Figure 1 As shown, a comparative example state detection device 90 includes a battery 91, a control circuit 92, a communication circuit 93, a switch 94, and an explosion-proof barrier 95. The state detection device 90 is connected to a contact circuit 96 via the explosion-proof barrier 95. The contact circuit 96 is connected to another device. The device connected to the contact circuit 96 is also called a connection target device. The state detection device 90 can detect the state of the connection target device of the contact circuit 96 by obtaining a signal corresponding to the state of the connection target device of the contact circuit 96. When the contact circuit 96 is in an open state (open state), the state of the connection target device of the contact circuit 96 is normal. When the contact circuit 96 is in a closed state (conductive state), the state of the connection target device of the contact circuit 96 is abnormal.

[0028] The battery 91 supplies power to the control circuit 92 and the communication circuit 93. The battery 91 is connected between a ground point represented by GND and a power supply point represented by VCC, and applies voltage to the power supply point. The control circuit 92 controls the operation of the communication circuit 93.

[0029] The control circuit 92 controls the switch 94 to be either open or closed. When the switch 94 is closed, the voltage applied to the power supply point from the battery 91 is output to the contact circuit 96 via the explosion-proof barrier 95.

[0030] When voltage is applied to contact circuit 96 via explosion-proof barrier 95, a current corresponding to the state of the device connected to contact circuit 96 flows through contact circuit 96. Explosion-proof barrier 95 outputs a signal based on the detection result of the current flowing through contact circuit 96 to control circuit 92 as a detection signal. Specifically, when contact circuit 96 is closed, that is, when the state of the device connected to contact circuit 96 is abnormal, explosion-proof barrier 95 detects that current is flowing through contact circuit 96. Explosion-proof barrier 95 outputs a signal indicating that current is flowing through contact circuit 96 as a detection signal. On the other hand, when contact circuit 96 is open, that is, when the state of the device connected to contact circuit 96 is normal, explosion-proof barrier 95 detects that no current is flowing through contact circuit 96. If no current is detected, explosion-proof barrier 95 does not output a detection signal.

[0031] When the control circuit 92 obtains a detection signal corresponding to the state of the device to be connected to the contact circuit 96 from the explosion-proof barrier 95 when the switch 94 is closed, the control circuit 92 can determine, based on the detection signal, that the state of the device to be connected to the contact circuit 96 is abnormal. When the control circuit 92 does not obtain a detection signal corresponding to the state of the device to be connected to the contact circuit 96 from the explosion-proof barrier 95 when the switch 94 is closed, the control circuit 92 can determine, based on the failure to obtain the detection signal, that the state of the device to be connected to the contact circuit 96 is normal.

[0032] When it is determined that the state of the connection destination device of the contact circuit 96 is abnormal, the control circuit 92 notifies the external device of the abnormal state of the connection destination device of the contact circuit 96 via the communication circuit 93 .

[0033] Therefore, the control circuit 92 controls the communication circuit 93 to a non-operating state such as stop or sleep in principle, and controls the communication circuit 93 to operate in the first cycle to reduce the power consumption of the communication circuit 93 and extend the consumption of the battery 91.

[0034] In addition, in order to extend the consumption of the battery 91 and confirm the status of the connection target device of the contact circuit 96 at a high frequency, the control circuit 92 controls the switch 94 to an open state in principle, and controls the switch 94 to a closed state in a first cycle and a second cycle shorter than the first cycle.

[0035] exist Figure 2 The timing diagram in FIG. 1 shows the working condition of the communication circuit 93 and the state of the switch 94 when the control circuit 92 controls the communication circuit 93 and the switch 94 in the first cycle and the second cycle. Figure 2The horizontal axis represents the passage of time. In the row for switch 94, two dashed lines are drawn, corresponding to the "ON" or "OFF" state of switch 94. Furthermore, the solid line overlapping the dashed line indicates whether the state of switch 94 changes over time, "ON" or "OFF." During the period when the solid line overlaps the dashed line on the "ON" side, switch 94 is closed. During the period when the solid line overlaps the dashed line on the "OFF" side, switch 94 is open. T2 represents the second period in which control circuit 92 controls switch 94 to the "ON" state.

[0036] In the row for communication circuit 93, two dashed lines are drawn, corresponding to the operating status of communication circuit 93, "ON" or "OFF." Furthermore, a solid line overlapping the dashed line indicates whether the operating status of communication circuit 93 changes over time, corresponding to either "ON" or "OFF." During the period when the solid line overlaps the dashed line on the "ON" side, communication circuit 93 operates. During the period when the solid line overlaps the dashed line on the "OFF" side, communication circuit 93 does not operate. T1 represents the first cycle in which control circuit 92 operates communication circuit 93.

[0037] As described above, the control circuit 92 can obtain a detection signal from the explosion-proof barrier 95 when current flows through the contact circuit 96 by closing the switch 94. When the detection signal is obtained, the control circuit 92 can confirm that the state of the device connected to the contact circuit 96 is abnormal. Figure 2 The timing diagram shows an example of a detection signal. Two dashed lines are drawn in the detection signal row, corresponding to the "ON" or "OFF" state of the detection signal. Furthermore, the solid line overlapping the dashed line indicates whether the detection signal state changes over time, "ON" or "OFF." During the period when the solid line overlaps the dashed line on the "ON" side, the detection signal is output from explosion-proof barrier 95. During the period when the solid line overlaps the dashed line on the "OFF" side, the detection signal is not output from explosion-proof barrier 95.

[0038] Therefore, in Figure 2 In the timing diagram, control circuit 92 detects that the detection signal has turned "ON" at the time indicated by the vertical dot-dashed line "XC," that is, that the detection signal has been output from explosion-proof barrier 95. Based on the detection signal turning "ON," control circuit 92 determines that the state of the device connected to contact circuit 96 is abnormal. After determining that the state of the device connected to contact circuit 96 is abnormal, control circuit 92 activates communication circuit 93 at the timing following the first cycle, indicated by the vertical dot-dashed line "RC," and notifies an external device of the abnormal state of the device connected to contact circuit 96 via communication circuit 93.

[0039] The control circuit 92 operates the communication circuit 93 in the first cycle. Therefore, the time taken from the control circuit 92 detecting the abnormal state of the contact circuit 96 to sending the abnormal state detection to the external device varies depending on the time when the abnormal state of the contact circuit 96 is detected. The time taken from the control circuit 92 detecting the abnormal state of the contact circuit 96 to sending the abnormal state is also called delay time. Figure 2 Indicated by D.

[0040] To shorten the delay time regardless of when contact circuit 96 detects an abnormal state in the target device, control circuit 92 can shorten the first cycle. However, shortening the first cycle increases the operating frequency of communication circuit 93, which consumes a lot of power, and thus increases the overall power consumption of state detection device 90. As a result, battery 91 depletes faster.

[0041] As described above, the comparative example state detection device 90 has a problem in that it is difficult to extend the consumption of the battery 91 by extending the cycle of operating the communication circuit 93 and shorten the delay time from detection of the abnormal state of the contact circuit 96 to transmission.

[0042] Therefore, the present invention describes a state detection device 1 (refer to Figure 3 ), the state detection device 1 can extend the battery 11 (refer to Figure 3 ) consumption, and shorten the contact circuit 30 (refer to Figure 3 The state detection device 1 can be applied to edge computer gateways. The state detection device 1 can also be used in IoT (Internet of Things) gateway terminals.

[0043] (One embodiment of the present invention)

[0044] like Figure 3 As shown, a state detection device 1 according to one embodiment includes a transmitter 10 and a signal conversion device 20. The transmitter 10 includes a battery 11, a control circuit 12, a switch 14, an explosion-proof barrier 15, a communication circuit 16, and a latch circuit 17. The signal conversion device 20 includes a boost circuit 21 and an explosion-proof barrier 24. The state detection device 1 is connected to a contact circuit 30 via the explosion-proof barrier 24 of the signal conversion device 20. In other words, the explosion-proof barrier 24 is connected between the signal conversion device 20 and the contact circuit 30. The explosion-proof barrier 15 is connected between the control circuit 12 and the contact circuit 30. The explosion-proof barrier 15 is also referred to as a first explosion-proof barrier. The explosion-proof barrier 24 is also referred to as a second explosion-proof barrier.

[0045] For example, Figure 4As shown, explosion-proof barrier 15 or explosion-proof barrier 24 includes Zener diodes ZD1 and ZD2 connected in parallel between signal line L1 and ground line L2, and a resistor R1 connected in series with signal line L1. Signal line L1 is connected between battery 11 and contact circuit 30. Resistor R1 is connected in series on the side connected to contact circuit 30. Explosion-proof barrier 24 also includes a current detection circuit for detecting current flowing through contact circuit 30. The current detection circuit may include, for example, a light-emitting diode that emits light when current flows through contact circuit 30, and a photodetector element that detects the light emitted by the light-emitting diode. The photodetector element outputs a signal indicating light detection when current flows through contact circuit 30. The light detection signal corresponds to a signal indicating current flows through contact circuit 30.

[0046] Zener diodes ZD1 and ZD2 limit the voltage applied to signal line L1. Zener diodes ZD1 and ZD2 can also be constructed by connecting multiple Zener diodes in series. A signal is transmitted from battery 11 to contact circuit 30. By connecting resistor R1 downstream of signal line L1 in the signal transmission direction, the voltage output from explosion-proof barrier 15 or explosion-proof barrier 24 is limited to the maximum voltage applied to Zener diodes ZD1 and ZD2.

[0047] Resistor R1 limits the current output from explosion-proof barrier 15 or explosion-proof barrier 24. The resistance value of resistor R1 is determined based on the upper limit of the voltage determined by Zener diodes ZD1 and ZD2 and the upper limit of the current to be determined by resistor R1.

[0048] The status detection device 1 outputs a check signal generated based on the voltage output by the battery 11 from the battery 11 of the transmitter 10 via the switch 14, the explosion-proof barrier 15, the booster circuit 21, and the explosion-proof barrier 24 to the contact circuit 30. The contact circuit 30 is connected to another device. The device connected to the contact circuit 30 is also referred to as a connection target device. When the check signal is applied from the status detection device 1 to the contact circuit 30, current flows through the contact circuit 30 depending on the state of the connection target device of the contact circuit 30. When the contact circuit 30 is in an open state (open state), the state of the connection target device of the contact circuit 30 is normal. When the contact circuit 30 is in a closed state (conductive state), the state of the connection target device of the contact circuit 30 is abnormal. When current is detected flowing through the contact circuit 30, the explosion-proof barrier 24 of the signal conversion device 20 outputs a signal indicating that current is flowing through the contact circuit 30. The signal indicating that current is flowing through the contact circuit 30 is also referred to as a detection signal. The transmitter 10 of the state detection device 1 can detect abnormality in the state of a device to which the contact circuit 30 is connected by acquiring a detection signal from the explosion-proof barrier 24 .

[0049] The battery 11 supplies power to the control circuit 12 and the communication circuit 16. The battery 11 is connected between a ground point represented by GND and a power supply point represented by VCC, and applies a voltage to the power supply point. The control circuit 12 controls the operation of the communication circuit 16.

[0050] The control circuit 12 controls the switch 14 to be either open or closed. When the switch 14 is closed, the voltage applied to the power supply point from the battery 11 is output to the signal converter 20 via the explosion-proof barrier 15.

[0051] The booster circuit 21 of the signal conversion device 20 boosts the voltage applied from the battery 11 via the switch 14 and the explosion-proof barrier 15, and outputs a boosted signal as a test signal to the contact circuit 30 via the explosion-proof barrier 24. To boost the voltage output from the battery 11, the booster circuit 21 can be configured as a chopper circuit including capacitors, inductors, or the like. Although the power input from the transmitter 10 to the booster circuit 21 is limited by the explosion-proof barrier 15, incorporating a large-capacity capacitor or inductor into the booster circuit 21 allows the voltage input to the contact circuit 30 to be boosted to a level sufficient to detect the status of the device connected to the contact circuit 30.

[0052] When a boosted signal is input from the explosion-proof barrier 24 of the signal conversion device 20 to the contact circuit 30, a current corresponding to the state of the device connected to the contact circuit 30 flows through the contact circuit 30. The explosion-proof barrier 24 outputs a detection signal based on the detection result of the current flowing through the contact circuit 30 to the transmitter 10. Specifically, when the contact circuit 30 is in a closed state, that is, when the state of the device connected to the contact circuit 30 is abnormal, the explosion-proof barrier 24 detects that current is flowing through the contact circuit 30. The explosion-proof barrier 24 outputs a detection signal indicating that current is flowing through the contact circuit 30 to the transmitter 10. The voltage of the detection signal can be the same as or lower than the voltage of the boosted signal. In other words, the voltage of the detection signal can be lower than the voltage of the boosted signal. On the other hand, when the contact circuit 30 is in an open state, that is, when the state of the device connected to the contact circuit 30 is normal, the explosion-proof barrier 24 detects that no current is flowing through the contact circuit 30. When detecting that no current is flowing through the contact circuit 30 , the explosion-proof barrier 24 does not output a detection signal to the transmitter 10 .

[0053] When the explosion-proof barrier 24 of the signal conversion device 20 outputs a detection signal to the transmitter 10, the detection signal is input to the latch circuit 17 via the explosion-proof barrier 15 of the transmitter 10. The latch circuit 17 holds the input detection signal. The control circuit 12 obtains the detection signal held in the latch circuit 17. The control circuit 12 can receive the detection signal input from the latch circuit 17 while the latch circuit 17 holds the detection signal. Alternatively, the control circuit 12 can obtain the detection signal from the latch circuit 17 at a timing determined by the control circuit 12 itself after the latch circuit 17 holds the detection signal. For example, the control circuit 12 can also obtain the detection signal from the latch circuit 17 at the timing when the switch 14 is next controlled to be closed.

[0054] If the control circuit 12 receives the detection signal, it can determine that the state of the device connected to the contact circuit 30 is abnormal. If the control circuit 12 does not receive the detection signal, it can determine that the state of the device connected to the contact circuit 30 is normal. In other words, if the control circuit 12 receives the detection signal (a signal corresponding to the state of the device connected to the contact circuit 30) when the switch 14 is closed, it can determine that the state of the device connected to the contact circuit 30 is abnormal.

[0055] When it is determined that the state of the connection destination device of the contact circuit 30 is abnormal, the control circuit 12 notifies the external device of the abnormal state of the connection destination device of the contact circuit 30 via the communication circuit 16 .

[0056] Therefore, in principle, the control circuit 12 controls the communication circuit 16 to a non-operating state such as a stop or sleep state, and controls the communication circuit 16 to operate at a first timing, thereby reducing the power consumption of the communication circuit 16 and extending the consumption of the battery 11. The first timing can be a timing that arrives periodically or at irregular intervals. In this embodiment, the first timing arrives at a first period.

[0057] Furthermore, in order to prolong the consumption of the battery 11 and frequently check the status of the target device connected to the contact circuit 30, the control circuit 12 generally controls the switch 14 to be in the open state, and controls the switch 14 to be in the closed state at a second timing that arrives at an interval shorter than the first timing. In this embodiment, the second timing arrives at a second period that is shorter than the first period.

[0058] exist Figure 5 FIG. 1 shows the operation status of the communication circuit 16 and the state of the switch 14 when the control circuit 12 controls the communication circuit 16 and the switch 14 at the first timing and the second timing as a timing diagram. Figure 5The horizontal axis represents the passage of time. In the row for switch 14, two dashed lines are drawn, corresponding to whether switch 14 is in the "ON" or "OFF" state. Furthermore, the solid line overlapping the dashed line indicates whether the state of switch 14 changes over time, corresponding to either "ON" or "OFF." During the period when the solid line overlaps the dashed line on the "ON" side, switch 14 is closed. During the period when the solid line overlaps the dashed line on the "OFF" side, switch 14 is open. T2 represents the second period in which control circuit 12 controls switch 14 to the "ON" state.

[0059] In the row for communication circuit 16, two dashed lines are drawn, corresponding to whether communication circuit 16 is in the "ON" or "OFF" operating state. Furthermore, a solid line overlapping the dashed line indicates whether the operating state of communication circuit 16 changes over time, corresponding to either "ON" or "OFF." During the period when the solid line overlaps the dashed line on the "ON" side, communication circuit 16 is operating. During the period when the solid line overlaps the dashed line on the "OFF" side, communication circuit 16 is not operating. T1 represents the first cycle in which control circuit 12 operates communication circuit 16.

[0060] As described above, the control circuit 12 closes the switch 14 to input a check signal generated from the voltage output by the battery 11 into the signal conversion device 20. The signal conversion device 20 applies the check signal voltage to the contact circuit 30 via the explosion-proof barrier 24. If the state of the device connected to the contact circuit 30 is abnormal, the check signal applied to the contact circuit 30 causes current to flow through the contact circuit 30. Upon detecting current flow through the contact circuit 30, the explosion-proof barrier 24 outputs a detection signal. The control circuit 12 obtains the detection signal from the explosion-proof barrier 24 of the signal conversion device 20. Based on the obtained detection signal, the control circuit 12 can confirm the state of the device connected to the contact circuit 30. Figure 5 The timing diagram shows an example of a detection signal. Two dashed lines are drawn in the detection signal row, corresponding to the "ON" or "OFF" state of the detection signal. Furthermore, the solid line overlapping the dashed line indicates whether the detection signal state changes over time, "ON" or "OFF." While the solid line overlaps the "ON" dashed line, the explosion-proof barrier 24 outputs a detection signal. While the solid line overlaps the "OFF" dashed line, the explosion-proof barrier 24 does not output a detection signal.

[0061] Therefore, in Figure 5In the timing diagram, control circuit 12 detects that the detection signal has turned "ON" at the time indicated by the vertical dotted line (X), that is, that the detection signal has been output from explosion-proof barrier 24. Based on the detection signal turning "ON," control circuit 12 determines that the state of the device connected to contact circuit 30 is abnormal. After determining that the state of the device connected to contact circuit 30 is abnormal, control circuit 12 activates communication circuit 16 at a temporary timing indicated by the vertical dotted line (Y), without waiting for the next first timing indicated by the vertical dotted line (R). Communication circuit 16 then notifies an external device of the abnormal state of the device connected to contact circuit 30.

[0062] After the control circuit 12 obtains the detection signal, the communication circuit 16 is operated at a temporary timing (Y), thereby shortening the time from when the control circuit 12 detects the abnormal state of the contact circuit 30 to when the detection of the abnormal state is sent to the external device, regardless of the time when the abnormal state is detected.

[0063] As described above, in the state detection device 1 of this embodiment, the control circuit 12 operates the communication circuit 16 at a first timing and, upon receiving a detection signal, at a temporary timing. This shortens the time from when the control circuit 12 detects the abnormal state of the contact circuit 30 to when the abnormal state is detected to an external device, regardless of the time at which the abnormal state is detected. Furthermore, without shortening the interval between the first timing at which the communication circuit 16 is operated, the time from when the control circuit 12 detects the abnormal state of the contact circuit 30 to when the abnormal state is detected to an external device can be shortened. By not shortening the interval between the first timing at which the communication circuit 16 is operated, the power consumption of the communication circuit 16 is reduced. As a result, both the time from when the control circuit 12 detects the abnormal state of the contact circuit 30 to when information indicating the abnormal state is detected is shortened, and power consumption of the communication circuit 16 is reduced.

[0064] Furthermore, the state detection device 1 includes the explosion-proof barrier 15 or the explosion-proof barrier 24 , and can monitor the state of the connection destination device of the contact circuit 30 as a device having an intrinsically safe explosion-proof structure.

[0065] Furthermore, the state detection device 1 includes the explosion-proof barrier 24 between the signal conversion device 20 including the boosting circuit 21 and the contact circuit 30 . Therefore, even if the voltage of the detection signal is lower than the voltage of the boosted signal, the boosted signal is not input to the transmitter 10 .

[0066] Furthermore, by including the boost circuit 21 in the signal conversion device 20, the state detection device 1 can boost the voltage input to the contact circuit 30 to a level sufficient to detect the state of the target device to which the contact circuit 30 is connected, even if the power output from the transmitter 10 is limited by the explosion-proof barrier 15.

[0067] (Other embodiments)

[0068] The transmitter 10 of the status detection device 1 may not include the latch circuit 17. In this case, the control circuit 12 receives a detection signal when it is input from the explosion-proof barrier 24 of the signal conversion device 20. Upon receiving the detection signal, the control circuit 12 may activate the communication circuit 16. Since the transmitter 10 does not include the latch circuit 17, the circuitry of the transmitter 10 can be miniaturized or its cost reduced. Upon receiving the detection signal, the control circuit 12 may activate the communication circuit 16 as an interrupt process, thereby transmitting information indicating the abnormal status of the contact circuit 30 to an external device.

[0069] State detection device 1 includes a latch circuit 17 on the line that inputs a detection signal from signal conversion device 20 to control circuit 12. This allows control circuit 12 to obtain the detection signal at a timing determined by control circuit 12 itself. Control circuit 12 can also set a third timing that arrives at a shorter interval than the first timing as the timing for obtaining the detection signal from latch circuit 17. When control circuit 12 activates communication circuit 16 when a detection signal is input to control circuit 12, control circuit 12 must implement interrupt processing based on the input of the detection signal. Interrupt processing increases the load on control circuit 12 or increases the circuit size of control circuit 12. Therefore, control circuit 12 can obtain the detection signal at a timing determined by control circuit 12 itself, thereby reducing the load on control circuit 12.

[0070] The latch circuit 17 may be included in the control circuit 12. For example, the control circuit 12 may include a memory such as a nonvolatile memory for holding the detection signal. This can achieve miniaturization of the circuit or reduction in cost.

[0071] The battery 11 may be a lithium thionyl chloride primary battery.

[0072] Lithium thionyl chloride primary batteries have high power capacity and low self-discharge, allowing for long-term use. Therefore, they are often incorporated into wireless measurement devices used in process equipment and factories, where long-term stable operation is required.

[0073] When using lithium-thionyl chloride primary batteries, if the load current flowing through the battery is low, the problem of increased internal resistance may arise due to the formation of a chloride film inside the battery. Specifically, when the internal resistance of the battery increases due to the long-term low load current, a device powered by the battery may suddenly switch to high-load operation. In this case, the current flowing through the battery increases dramatically. This increase in current while the internal resistance increases can cause a sharp drop in output voltage. Furthermore, this drop in output voltage can cause the device to stop operating or malfunction.

[0074] Therefore, a device using a lithium-thionyl chloride primary battery monitors the internal resistance of the lithium-thionyl chloride primary battery and, when the internal resistance exceeds a predetermined value, performs an operation to reduce the internal resistance. Specifically, when the internal resistance exceeds the predetermined value, a current exceeding a predetermined current flows through the lithium-thionyl chloride primary battery, thereby reducing the internal resistance. The predetermined current may be a current value determined based on the specifications of the lithium-thionyl chloride primary battery.

[0075] In the state detection device 1 of this embodiment, when the battery 11 is a lithium thionyl chloride primary battery, the control circuit 12 can reduce the internal resistance of the battery 11 by flowing a current greater than a predetermined current. Figure 3 As shown, the transmitter 10 further includes a load circuit 13. The load circuit 13 includes a load such as a resistor. When the transmitter 10 includes the load circuit 13, the control circuit 12 can cause a current to flow through the load circuit 13 in order to cause a current exceeding a predetermined current to flow through the battery 11.

[0076] The control circuit 12 may output a signal to the contact circuit 30 in conjunction with the operation of reducing the internal resistance of the lithium thionyl chloride primary battery. In this case, the control circuit 12 may control the switch 14 to be closed, so that a portion of the current flowing through the battery 11 flows through the signal conversion device 20. In other words, the first timing may be when the internal resistance of the battery 11 reaches or exceeds a predetermined value.

[0077] The signal conversion device 20 of the state detection device 1 may not include the boost circuit 21. In this case, the signal conversion device 20 inputs a voltage signal having the voltage output by the battery 11 to the contact circuit 30 as a test signal.

[0078] The state detection device 1 of the present embodiment can be applied to a device that operates with low power consumption in a normal state and operates with higher power consumption than in a normal state in an abnormal state.

[0079] When state detection device 1 does not include signal conversion device 20, it is possible to apply a check signal from explosion-proof barrier 15 to contact circuit 30. In this case, explosion-proof barrier 15 includes a current detection circuit that detects the current flowing through contact circuit 30. Furthermore, explosion-proof barrier 15 detects the current flowing through contact circuit 30 and outputs a detection signal indicating the current flowing through contact circuit 30 to control circuit 12. The current detection circuit of explosion-proof barrier 15 may have a configuration that is the same as or similar to the configuration described as the current detection circuit of explosion-proof barrier 24.

[0080] While the embodiments of the present invention have been described based on the accompanying drawings and examples, it should be noted that those skilled in the art can easily make various modifications or variations based on the present invention. Therefore, it should be noted that such modifications or variations are also within the scope of the present invention. For example, the functions included in each component or step can be rearranged in a logically consistent manner, and multiple components or steps can be combined into one or divided.

Claims

1. A state detection device, characterized in that include: a communication circuit to send information to an external device; A control circuit causes the communication circuit to operate at a first timing; a battery for supplying power to the communication circuit and the control circuit; as well as The first explosion-proof grid is connected between the contact circuit and the control circuit. The control circuit applies a check signal generated based on the voltage output by the battery to the contact circuit via the first explosion-proof barrier at a second timing that arrives at a shorter interval than the first timing. The control circuit obtains a detection signal from the first explosion-proof barrier, the detection signal indicating that current flows through the contact circuit due to the application of the inspection signal to the contact circuit. The control circuit operates the communication circuit at the timing of acquiring the detection signal, regardless of the first timing, and notifies the external device that the state of the device connected to the contact circuit is abnormal.

2. The state detection device according to claim 1, characterized in that: It also includes a latch circuit for obtaining and holding the detection signal, The control circuit obtains the detection signal from the latch circuit.

3. The state detection device according to claim 2, characterized in that: The control circuit acquires the detection signal from the latch circuit at a third timing that arrives at a shorter interval than the first timing.

4. The state detection device according to claim 1, characterized in that: When the detection signal is received, the control circuit operates the communication circuit as an interrupt process, and notifies the external device that the state of the device to which the contact circuit is connected is abnormal.

5. The state detection device according to any one of claims 1 to 4, characterized in that: The battery is a lithium thionyl chloride primary battery.

6. The state detection device according to claim 5, characterized in that: The control circuit causes the battery to output a current equal to or greater than a current value based on the specifications of the lithium thionyl chloride primary battery at the second timing.

7. The state detection device according to any one of claims 1 to 4, characterized in that: The device further includes a boost circuit connected between the first explosion-proof grid and the contact circuit, and a second explosion-proof grid connected between the boost circuit and the contact circuit. The boost circuit boosts the voltage output from the battery to generate a boost signal, and applies the boost signal as the inspection signal to the contact circuit via the second explosion-proof barrier.

Images