JP5035155B2 - Security control device and sensor determination method for security control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a security control device for, when a sensor with built-in power supply is erroneously connected, deciding the state. <P>SOLUTION: When a path for supplying the power supply to a sensor is interrupted by a switch circuit 6, a control part 2 decides that a sensor (19) is a power supply built-in type when the voltage of a signal input terminal 4 pulled down through a resistance element 7 becomes the partial potential of the built-in power supply voltage, and exceeds a ground level. That is, when a control device 1 is provided with a function for deciding the short-circuit state and disconnected state of the sensor based on the voltage of the input terminal, the erroneous connection of the power supply built-in type sensor 19 is decided by using the decision function only by adding the switch circuit 6. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a security control device that receives a detection signal from a sensor, performs a safety monitoring function, and has a function of determining a short circuit / disconnection state of the sensor, and a sensor determination method of the security control device.

For example, a security control device that monitors the occurrence of a fire based on a sensor signal output by a smoke sensor, a heat sensor, or the like has a function of detecting whether or not the state of the sensor is normal There is. In this case, there are two detection methods for detecting a disconnection state of a signal line (for example, refer to Patent Document 1) and three detection methods for detecting a short-circuit state in addition to the disconnection state. In general, the operating power of the sensor is often supplied from the security control device side.
Japanese Patent Laid-Open No. 3-51994

When building a security system using the above control device, it may be assumed that an operator mistakenly installs a sensor with a built-in power supply, but the built-in power supply of the sensor is supplied from the security control device side. If the potential is the same as that of the power source to be used, no problem occurs with respect to the function as a sensor. Further, in that case, no abnormalities appear even in the conventional detection of disconnection or short circuit, and as a result, the system is operated as it is.
However, the inventor of the present invention, when the security control device operates in a state where the sensor with built-in power supply is erroneously connected as described above, the power of both is supplied at the same time, so that the security control device and the sensor It was discovered that the power line connected between them acts as an antenna and radiates noise, which may affect other devices and systems.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a security control device capable of determining the state when a built-in power supply type sensor is erroneously connected, and a sensor determination method for the security control device. It is to provide.

According to the security control device of the first aspect, when the determination unit cuts off the path for supplying power to the sensor by the intermittent unit, the voltage of the input terminal pulled down through the resistance element is grounded. If the level is exceeded, it is determined that the sensor is of a built-in power source type. That is, if the sensor is a built-in power supply type, even if there is no power supply from the control device side, the input terminal voltage of the control device is the voltage applied by the built-in power supply with the internal resistance of the sensor and the pull-down resistor. The level is divided by.
Therefore, it is possible to determine a state in which the power built-in type sensor is erroneously connected to a security control device having a function of supplying power to the sensor, which could not be detected conventionally. In addition, when the control device has a function for determining the short-circuited state or the disconnection state of the sensor based on the voltage at the input terminal, it is possible to use the above-described determination function only by adding the intermittent means, and to correct the error of the sensor with a built-in power supply. Since the connection can be determined, the addition of components can be minimized.

  According to the security control device of claim 2, when the determination means determines that the sensor is a built-in power supply type, a warning display according to the determination result is displayed when a disconnection state and a short circuit state of the sensor are detected. This is done using display means. Therefore, a warning display in a state where the built-in power supply type sensor is erroneously connected can also be performed without adding a new configuration.

  According to the security control device of the third aspect, since the safety monitoring function is stopped when the determination unit determines that the sensor is a built-in power supply type, the control device functions in a state where the built-in power supply type sensor is erroneously connected. Thus, it is possible to reliably prevent a state where noise is radiated.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of the security control apparatus. The security control device 1 (hereinafter simply referred to as a control device) is configured around a control unit 2 (determination means) composed of a microcomputer or the like, and the sensor 5 is connected to the power supply terminal 3 and the signal input terminal 4. It has become. Then, the control device 1 supplies the operation power Vcc to the sensor 5 via a switch circuit 6 (intermittent means) such as a relay and receives the detection signal of the sensor 5 via the signal input terminal 4. It is like that.
The sensor 5 is, for example, a smoke sensor or a heat sensor, and is installed in a ceiling portion such as a room or a hallway of a residence or an office. And the control apparatus 1 outputs a detection signal when the sensor 5 detects smoke or heat, and when an occurrence of a fire or the like is recognized, an alarm operation or a notification operation is performed, or when a sprinkler is installed, Fire the fire by operating the sprinkler.

  The signal input terminal 4 is pulled down by the resistance element 7. The sensor 5 includes an internal resistance 5R of, for example, about several hundreds Ω, and a power source such as 12 V or 24 V is supplied from the control device 1. When the sensor 5 detects smoke, heat, or the like, the switch 5S (for example, a transistor) connected in parallel closes, so that the internal resistor 5R is short-circuited and enters a low impedance state. Accordingly, the voltage of the signal input terminal 4 is a potential obtained by dividing the power supply voltage Vcc by the resistance ratio of the internal resistance 5R and the resistance element 7 if the sensor 5 is in a non-detection state. Then, it becomes the same potential as the voltage Vcc.

  The signal input terminal 4 is connected to the input terminal of the sensor monitoring input circuit 8, and the output terminal of the sensor monitoring input circuit 8 is connected to the input terminal of the control unit 2. The sensor monitoring input circuit 8 is a circuit arranged to detect a short circuit or disconnection of the sensor 5 in the conventional security control device, and includes two comparators 9 (determination means) and a comparator 10.

  Between the power supply Vcc and the ground, a series circuit of the resistance element 11 and the resistance element 12 and a series circuit of the resistance element 13 and the resistance element 14 are connected. The common connection point of the resistance element 11 and the resistance element 12 is connected to the non-inverting input terminal of the comparator 9, and the common connection point of the resistance element 13 and the resistance element 14 is connected to the inverting input terminal of the comparator 10. . The signal input terminal 4 is connected to the inverting input terminal of the comparator 9 and the non-inverting input terminal of the comparator 10, and the output terminal of the comparator 9 is pulled up to 5 V via the resistance element 15 and controlled. The output terminal of the comparator 10 is pulled up to 5 V through the resistance element 16 and is connected to the input terminal of the control unit 2.

The comparator 9 detects the short-circuit state of the sensor 5 when the voltage of the signal input terminal 4 becomes 0.5 Vcc or more, for example. The comparator 10 breaks the sensor 5 when the voltage of the signal input terminal 4 becomes 0.1 Vcc or less, for example. Detect state. These detection signals are all low active. That is, if the switch 5S of the sensor 5 is short-circuited, the voltage of the signal input terminal 4 is at the Vcc level, and if the connection between the sensor 5 and the signal input terminal 4 is disconnected, the voltage of the signal input terminal 4 is grounded. Because it becomes a level. When the sensor monitoring input circuit 8 detects a short circuit state or a disconnection state, the control unit 2 changes the lighting state of the LED 17 (display means) and issues a warning notification. The resistance element 18 inserted on the cathode side of the LED 17 is for current limitation.
When a plurality of sensors are connected to the control device 1 at the same time, a plurality of sets of power supply terminals 3, signal input terminals 4, switch circuits 6, and sensor monitoring input circuits 8 are provided in parallel.

  In the case of a security control device having a conventional configuration, the operation power supply Vcc is supplied to the sensor 5 without going through the switch circuit 6, and only a short circuit or disconnection is detected by the sensor monitoring input circuit 8. However, as indicated by a broken line in FIG. 1, it is assumed that the sensor 19 of a type incorporating a power source (battery) is erroneously connected to the control device 1. In this case, the conventional control device could not recognize that the built-in power supply type sensor 19 was erroneously connected. However, in the control device 1 of this embodiment, the switch circuit 6 is provided to enable the detection. Provided. The ON / OFF control of the switch circuit 6 is performed by the control unit 2.

  Next, the operation of the present embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing the contents of the test mode for the control device 1 to confirm whether or not the sensor state is normal. This test mode is executed first when the control device 1 is turned on, for example, and when the test mode is ended, the test mode is shifted to a normal safety monitoring operation. The test mode is started from a state (= 3) in which both 2-bit operation start flags are set in a flag storage area provided in a RAM or the like built in the control unit 2. In addition, the switch circuit 6 is ON, and the LED 17 is in the off state.

  First, a wiring check is performed (step S1). The wiring check is performed with reference to the output signals of the comparator 9 and the comparator 10 in the sensor monitoring input circuit 8 (step S2). If any of the output signals is at a high level, the voltage of the signal input terminal 4 is 0.1 Vcc to Since it is within the range of 0.5 Vcc, it is determined as normal (OK).

  On the other hand, if the output signal of the comparator 9 is low level, the short circuit state of the sensor 5 is detected, and if the output signal of the comparator 10 is low level, the disconnection state of the sensor 5 is detected (step S2: NG). In this case, the process proceeds to step S9. When a short circuit is detected, the LED 18 is continuously turned on. When a disconnection is detected, the LED 18 is blinked at intervals of 0.5 seconds, for example, to indicate each abnormal state. Warning notification. The operation start flag is not cleared and remains “3”.

  If it is determined as “OK” in step S2, the control unit 2 turns off the switch circuit 6 to cut off the power supply to the sensor 5 (step S3). Then, the output signals of the comparator 9 and the comparator 10 in the sensor monitoring input circuit 8 are referred again (step S4). That is, when the appropriate sensor 5 is connected, if the power supply is cut off, the voltage of the signal input terminal 4 becomes the ground level (no voltage), so the comparator 10 detects the disconnection in step S2. As in the case, the output signal is set to a low level. Therefore, it is determined as normal (OK).

  On the other hand, as shown by a broken line in FIG. 1, when the built-in power supply type sensor 19 is connected by mistake, the voltage of the signal input terminal 4 is equal to the built-in power supply voltage even if no power is supplied from the control device 1. The potential is divided by the internal resistance 19R of the sensor 19 and the resistance value of the resistance element 7 (with voltage). If the built-in power supply voltage is approximately the same as the voltage of the power supply Vcc, the voltage of the signal input terminal 4 falls within the range of 0.1 Vcc to 0.5 Vcc, and thus it is determined that there is an abnormality (step S4: NG). In this case, the process proceeds to step S10, and the LED 18 is caused to blink, for example, at intervals of 1 second to notify the abnormal state of warning. Also at this time, the operation start flag is not cleared and remains “3”.

  If it is determined as “OK” in step S4, the control unit 2 turns on the switch circuit 6 and restarts power supply to the sensor 5 (step S5), and then performs a sensor check (step S6). Here, the operator sets the environment so as to be in a detection state according to the type of the sensor 5, and confirms whether or not the sensor 5 outputs an intended detection signal (step S7). In this case, since the sensor 5 turns on the switch 5S, the voltage of the signal input terminal 4 becomes the voltage level of the power source Vcc, and the output signal is set to the low level similarly to the case where the comparator 9 detects the short circuit in step S2. Therefore, it is determined as normal (OK). If it is normal, clearing both bit 1 and bit 0 of the operation start flag to “0” (step S8) ends the test mode. Then, the control device 1 can execute a normal safety monitoring operation by the sensor 5.

  On the other hand, if the sensor 5 does not output the detection signal as expected in step S7, the voltage of the signal input terminal 4 is in the range of 0.1 Vcc to 0.5 Vcc, and the output signals of the comparators 9 and 10 are Either high level remains (NG). In this case, the process proceeds to step S11, and the LED 18 is blinked at intervals of 2 seconds, for example, to alert the abnormal state. Then, only the bit 0 is cleared and the operation start flag becomes “2”.

When steps S9 to S11 are executed, the operation start flag is not all cleared and the process ends abnormally, and the control device 1 does not execute the normal safety monitoring operation by the sensor 5. In this case, the worker performs inspections and repairs according to each abnormality, and repeats the work of confirming the result by re-execution of the test mode.
In the flowchart of FIG. 2, the processing except for steps S3 to S5 and S10 surrounded by a broken line is the same processing as the test mode performed by the conventional security control device.

  As described above, according to the present embodiment, the control unit 2 has the signal input terminal 4 pulled down via the resistance element 7 when the switch circuit 6 cuts off the power supply path to the sensor. Is a divided potential of the built-in power supply voltage and exceeds the ground level, it is determined that the sensor (19) is a built-in power supply type. Therefore, it is possible to determine a state in which the sensor 19 with a built-in power supply is erroneously connected to the security control device 1 having a function of supplying power to the sensor, which could not be detected conventionally. In addition, when the control device 1 has a function of determining the short-circuited state or the disconnection state of the sensor based on the voltage of the signal input terminal 4, a built-in power source can be used by using the above-described determination function only by adding the switch circuit 6. Since the erroneous connection of the mold sensor 19 can be determined, the addition of components can be minimized.

  Further, when the control unit 2 determines that the sensor 19 is a built-in power supply type, the warning display according to the determination result is made using the LED 17 for displaying a warning when the disconnection state and the short-circuit state of the sensor are detected. Therefore, the warning display about the state where the power supply built-in sensor 19 is connected can also be performed without adding a new configuration. Furthermore, if the control unit 2 determines that the sensor 19 is a built-in power source type, the safety monitoring function is stopped. Therefore, when the control device 1 functions in a state where the sensor 19 is erroneously connected, noise is emitted. A state can be reliably prevented.

The present invention is not limited to the embodiments described above or shown in the drawings, and the following modifications or expansions are possible.
The setting ratio of the reference voltage to Vcc in the comparators 9 and 10 may be changed as appropriate. Moreover, what is necessary is just to change suitably also about the lighting-off state of LED17 in the case of performing a warning display, the blinking interval, etc.
Further, the display means is not limited to the LED 17, and other light emitting elements, display elements, and the like may be used.
The function of the sensor monitoring input circuit 8 may be realized by a control program of the control unit 2.
The sensor type may be an infrared sensor or a vibration sensor. The security control device may perform other safety monitoring operations such as anti-theft and intrusion prevention of suspicious persons.

The figure which is one Example of this invention and shows the structure of a security control apparatus Flow chart showing the contents of test mode

Explanation of symbols

  In the drawings, 1 is a security control device, 2 is a control unit (determination means), 5 is a sensor, 6 is a switch circuit (intermittent means), 7 is a resistance element, 8 is a sensor monitoring input circuit, and 9 is a comparator (determination means). , 17 indicate LEDs (display means).

Claims (4)

When receiving a detection signal from the sensor and performing safety monitoring, the sensor has an input terminal to which the detection signal is applied in a pulled down state through a resistance element, and the sensor has a voltage of the input terminal at a ground level. In a security control device having a function of detecting a disconnection state of the sensor and detecting a short-circuit state of the sensor when the voltage of the input terminal is at a power supply level,
Intermittent means for intermittently supplying a power supply path to the sensor;
And determining means for determining that the sensor is of a built-in power source when the voltage of the input terminal exceeds a ground level when the power supply path is interrupted by the intermittent means. Security control device. Provided with a display means for displaying a warning when the disconnection state and the short circuit state of the sensor are detected,
2. The security control apparatus according to claim 1, wherein when the determination unit determines that the sensor is a built-in power supply type, the display unit displays a warning according to the determination result.   3. The security control device according to claim 1, wherein when the determination unit determines that the sensor is a built-in power supply type, the safety monitoring function is stopped. When receiving a detection signal from the sensor and performing safety monitoring, the sensor has an input terminal to which the detection signal is applied in a pulled down state through a resistance element, and the sensor has a voltage of the input terminal at a ground level. A method of determining the type of the sensor, which is executed by a security control device having a function of detecting a disconnection state of the input terminal and detecting a short circuit state of the sensor when the voltage of the input terminal is at a power supply level,
A security control device that determines that the sensor is of a built-in power source when the voltage of the input terminal exceeds a ground level in a state where a path for supplying power to the sensor is cut off Sensor determination method.

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