JP2792294B2 - Monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device having a function of diagnosing a disconnection of an electric line connected to a non-voltage contact in order to monitor the on / off state of the non-voltage contact.

[0002]

2. Description of the Related Art Among monitoring devices for monitoring the operation state and occurrence of failures of distant devices, there is a non-voltage contact type monitoring device which receives the no-voltage contact output provided in the distant devices and monitors the operation state and occurrence of failures. There is. FIG. 3 is a main part circuit diagram for explaining such a conventional monitoring device of the non-voltage contact type.

As shown in FIG. 3, a monitoring device 10 has an input terminal 11 and a common terminal 12, and the input terminal 11 and the common terminal 12 are connected via a wire L to a remote device A, for example, for failure output. Non-voltage output contact (turns on when a failure occurs)
To connect to the A _1. Further, inside the monitoring device 10, a voltage application circuit 13 for applying a voltage between the input terminal 11 and the common terminal 12, and a decrease signal is output when the voltage between the input terminal 11 and the common terminal 12 decreases. Voltage drop monitoring circuit 1
4, an input port 15 connected to the output of the voltage drop monitoring circuit 14, and a central processing unit 16 for monitoring the input port 15.
And

[0004] voltage application circuit 13 is a resistor R _1, R ₂ and capacitor C ₁ and diode D ₁ Tokyo, each end of the resistor R ₁ and capacitor C ₁ is connected to the power supply V _CC, resistors R ₁ and the other ends of the capacitor C ₁ is connected to one end of the resistor R _2, the other end of the resistor R ₂ is connected to the anode of the diode D _1, the cathode of the diode D ₁ is connected to the input terminal 11. The common terminal 12 is grounded.

The voltage drop monitoring circuit 14 includes transistors Q _1,
Q ₂ and the resistor R _3, is composed of R _4, R ₅ Prefecture, the emitter of the transistor Q ₁ is connected to the power supply V _CC, transistor Q ₁
The base is connected to the connection point between the resistor R ₂ and the resistor R _1. The collector of the transistor Q ₁ is through a resistor R ₃ connected to the base of the transistor Q _2, the emitter of the transistor Q ₂ is grounded, the resistance R ₄ is connected between the base and emitter of the transistor Q _2, transistor Q ₂
The collectors are connected to the input port 15 with connected to the pull-up power supply V _P via a resistor R _5.

The monitoring device 10 having such a configuration operates as follows. That is, the input terminal 11 is connected to the power supply V
_CC → resistance R ₁ → resistance R ₂ → diode D ₁ → input terminal 1
A voltage is applied in a path of 1. And, usually when there is no failure of the distant device A, contact A ₁ is turned off. Therefore, no current flows through the resistors R ₁ and R ₂ , the base potential of the transistor Q ₁ becomes High, the transistor Q ₁ is turned off, and the voltage of the power supply V _CC is applied between the input terminal 11 and the common terminal 12. Apply. Further, since the transistor Q ₁ is turned off, the base of the transistor Q ₂ is the transistor Q ₂ becomes substantially the ground potential is also turned off, the collector of the transistor Q ₂ is made to the potential of substantially the pull-up power supply V _P, the input port 15
Is input as High.

[0007] When the contact A ₁ distant device A failure is turned on, the voltage between the input terminal 11 and the common terminal 12 is substantially 0V
It becomes. Then, the potential of the base of the transistor Q ₁ is reduced, the transistor Q ₁ is turned on. Then, the transistor Q ₂ is the potential of the base of the transistor Q ₂ rises turns on, the collector of the transistor Q ₂ is made in a substantially ground potential, Low is input to the input port 15.

The central processing unit 16 reads the state of the input port 15 at appropriate timing, and if the input of the input port 15 is high, determines that the remote device A is normal and has not failed, and Is low, it is determined that the remote device A is out of order. And the central processing unit 1
Reference numeral 6 denotes a monitoring display unit (not shown) of the monitoring device 10, for example.
A message such as "Distant device No. 10 / normal" or "Distant device No. 11 / failure" is displayed.

[0009]

However, among the no-voltage output contacts for various uses of distant equipment, there are contacts that hardly turn on (fail) such as no-voltage output contacts for failure output. When monitoring such a contact that hardly turns on (fails), the monitoring apparatus displays, for example, “distant device No. 10 / normal”, but the power line L
Is displayed as "Distant device No. 10 / Normal" because of the disconnection, and there is a problem that there is a suspicion that the device is actually out of order.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to diagnose a disconnection of an electric line and to notify a disconnection when the electric line is disconnected. It is an object of the present invention to provide a monitoring device that can be added with a function and that can be monitored with confidence without any doubt in monitoring data.

[0011]

According to the present invention, there is provided a voltage applying circuit for applying a voltage between an input terminal and a common terminal.
A voltage drop monitoring circuit that outputs a drop signal when the voltage between the input terminal and the common terminal drops, an input port connected to the output of the voltage drop monitoring circuit, and a central processing unit that monitors the input port. A monitoring device for connecting a contact between the input terminal and the common terminal via a wire path and monitoring the on / off state of the contact in the presence or absence of the decrease signal, wherein the monitoring device is connected in series to the voltage application circuit. A switching circuit, a discharge resistor connected between the input terminal and the common terminal, a capacitor connected between the contacts, an output port for controlling the switching circuit, and the switching circuit turned off for a predetermined period and then turned on again An intermittent off means that performs the first and second switching operations at a first time point when a first time period elapses and a second time point when a second time period elapses after the switching circuit is turned on. Reading means for reading the presence or absence of items, characterized in that from the result of the reading is provided a disconnection determination means for determining the presence or absence of disconnection of the electric line.

According to a second aspect of the present invention, the intermittent off means is executed when the contact is kept off for a predetermined time.

[0013]

By [act] constructed as described above, in the invention of claim 1, wherein, when the contact point A ₁ is off, initially the input terminal 11 by the voltage application circuit 13 through the switching circuit 18 a voltage is applied between the common terminal 12, the input terminal 1 to the capacitor C is connected between the contact point a ₁
1 and the common terminal 12 are charged, and the voltage drop monitoring circuit 14 is connected to the input port 1
The output of the drop signal to 5 is stopped. Here, the intermittent off means is connected to the switching circuit 18 via the output port 17.
The predetermined time period T _a is turned off. Then, the charge and discharge resistor R of the capacitor C to be connected in the predetermined time period T _a between the contacts A _1
10 to discharge almost completely, and the predetermined period _Ta
However, the voltage drop monitoring circuit 14 has stopped outputting the drop signal to the input port 15. Then, the intermittent off unit turns on the switching circuit 18 again and applies a voltage between the input terminal 11 and the common terminal 12.

Then, the voltage between the input terminal 11 and the common terminal 12 gradually increases due to the charging of the capacitor C by the capacitor C connected between the contacts A ₁ , and the voltage between the input terminal 11 and the common terminal 12 increases. The voltage drop monitoring circuit 14 outputs a drop signal to the input port 15 until the voltage during the period reaches a predetermined voltage or more. Thereafter, when the voltage between the input terminal 11 and the common terminal 12 rises and reaches a predetermined voltage or more, the voltage drop monitoring circuit 14 stops the drop signal to the input port 15. When the electric line L is disconnected, the capacitor C is not connected between the input terminal 11 and the common terminal 12, so that the voltage between the input terminal 11 and the common terminal 12 is not changed. Rises sharply as compared with the case where the electric line L is not disconnected.

[0015] The reading means may include the T_aperiod
Has elapsed and the switching circuit 18 is turned on t_TwoOr
The first period T_cThe first time point t at which_ThreeAnd the second
Period T_dAt the second time point t_FourIn the above-mentioned drop signal
Is read from the input port 15. Then, disconnection judgment
The determination means determines that the result of the reading is the first time point t. _Three
At the second time point t_FourNo drop signal
If it is determined that there is no disconnection in the electric line L, the first time t
_ThreeIf there is no lowering signal, it can be determined that the electric line L is disconnected.
Because

[0016] In the second aspect of the present invention, since off of the contact A ₁ to perform the intermittent off means and continues for a predetermined time, it can reduce the workload of the central processing unit 16.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the monitoring device according to the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a main part circuit diagram for explaining the monitoring device. FIG. 2 is a timing chart for explaining the monitoring device. FIG. 2A shows the output of the output port.
2B shows the input of the input port, and FIG. 2C shows the reading of the input port. In FIG. 1,
Since the same parts as the conventional ones are given the same reference numerals,
Only different points from the conventional one will be mainly described.

As shown in FIG. 1, structure differs from that of the conventional monitoring device 10, between the input terminal 11 of the discharge resistor R ₁₀ is provided a discharge resistor R ₁₀ to the voltage application circuit 13 and the common terminal 2 And a switching circuit 18 connected in series to the voltage application circuit 13. The remote device A of the electric wire L is connected in parallel with the non-voltage output contact A _{1 of} the remote device A, for example, for failure output. That is, the capacitor C is provided at the end on the side, and the output port 17 for controlling the switching circuit 18 is provided.

[0020] The software of the monitoring device 10 is different from the prior art, an intermittent off means for turning on again after switching circuit 18 has a predetermined time period T _a off, the first period from the time point t ₂ when the switching circuit 18 is turned on A first time point t ₃ at which T _c has elapsed and a second time point at which the second period T _d has elapsed.
Reading means for reading the presence or absence of reduction signal from the voltage drop monitoring circuit 14 through the input port 15 at the time t _4, the
There is provided a disconnection determining means for determining whether there is a disconnection in the electric line L based on the result of the reading.

[0021] The switching circuit 18 is resistor _{R 6, R 7, R 8} ,
Consists R ₉ and transistor Q _3, Q ₄ Prefecture, the emitter of the transistor Q ₃ are connected to the power supply V _CC, a collector of the transistor Q ₃ are connected to the emitter of the transistor to Q ₁ voltage reduction monitoring circuit 14, the transistor Q ₃ of the base is connected to the collector of the transistor Q ₄ via a resistor R _7. The resistor R ₆ is connected between the emitter and the base of the transistor Q _3. The base of the transistor Q ₄ is connected to the output port 17 via the resistor R ₈ , the emitter of the transistor Q ₄ is grounded,
Between the emitter and the base of the _fourth resistor R ₉ is connected.

The monitoring device 10 as described above can diagnose the presence or absence of a break in the electric line L in the following manner. That is, when the monitoring device 10 is monitoring the distant device A and there is no disconnection of the power line L and the contact A ₁ is off, the central processing unit 16 sets the base of the transistor Q ₄ to Hi through the output port 17.
to turn on the transistor Q ₄ in the gh. Then, the transistor Q ₃ also turns on, the current from the power supply V _CC, through a path of the power supply V _CC → transistor Q ₃ → resistor R ₁ → resistor R ₂ → diode D ₁ → resistor R ₁₀ → ground, the resistor R _Ten
That is, between the input terminal 11 and the common terminal 2, the voltage applied to the resistor R ₁₀ is applied to the case of dividing the voltage of approximately the power supply V _CC by the resistors R _1, R _2, R _10. At this time, the base of the transistor Q ₁ is become a voltage of a high potential is applied to substantially the resistance R ₂ than the potential of the input terminal 11, the transistor Q ₁ is turned off. Therefore, the transistor Q _{2 is} also off, and the collector of the transistor Q ₂ outputs High to the input port 15.

That is, the monitoring device 10 monitors the remote device A.
There is no disconnection of the electric wire L during visual inspection and the contact A ₁Is off
When the voltage is applied through the switching circuit 18 which is turned on,
The application circuit 13 connects the input terminal 11 and the common terminal 12 to each other.
Voltage is applied between contacts A₁Capacitor C connected between
Depends on the voltage between the input terminal 11 and the common terminal 12.
While the charge is charged, the voltage drop monitoring circuit 14
Has stopped outputting the drop signal to the input port 15.
(Transistor Q_TwoHigh of the collector has no drop signal
It corresponds to the stopped state, and the transistor Q_TwoCollector Low
Corresponds to an output state with a drop signal).

Here, the software of the monitoring device 10
The intermittent off means is connected to the output port 17 from the central processing unit 16.
The switching circuit 18 is switched through the predetermined period T_aTurn off
You. That is, the output port is instructed by the central processing unit 16.
Port 17 is a resistor R₈Through the transistor Q_FourBee
As shown in FIG._aSet to Low.
Then, the transistor Q_FourIs the predetermined period T_aOff and run
Jista Q_ThreeAlso a predetermined period T _aTurn off. Then, this predetermined
Period T_aThe power supply V_CC→ Transistor Q _Three→
Anti-R₁→ resistance R_Two→ Diode D₁→ resistance R_Ten→ Earth
Current does not flow in the path of_aAt contact A₁In between
The charge charged to the following capacitor C is the discharge resistance
R_TenDischarges almost completely through a predetermined period (for a predetermined period T_aIn conde
And the capacity of the capacitor C so that the sensor C is almost completely discharged.
Resistance R_TenAnd the predetermined period T_aIs set appropriately) and
In both cases, the predetermined period T_aVoltage drop monitoring circuit 1
Reference numeral 4 indicates that the output of the drop signal to the input port 15 is stopped.
You. Then, the intermittent off means again operates the transistor Q_Fourof
When the base is set to High, the switching circuit 18 is turned on, and the input is
A voltage is applied between the terminal 11 and the common terminal 12.

Then, the voltage between the input terminal 11 and the common terminal 12 is changed by the capacitor C connected between the contacts A ₁ to the power supply V _CC → the transistor Q ₃ → the resistance R ₁ → the resistance R ₂
→ diode D ₁ → line L → capacitor C The path gradually rises as the capacitor C is charged, and a period until the voltage between the input terminal 11 and the common terminal 12 reaches a predetermined voltage or more ( That is, T _{b in} FIG.
During the period, the voltage drop monitoring circuit 14 outputs a drop signal to the input port 15. That is, the input terminal 11 and the common terminal 1
Period until the voltage between the 2 reaches or exceeds a predetermined voltage (i.e. T _b period FIG. 2 (b)) is also turned on the transistor Q ₂ and the transistor Q ₁ is turned on, the collector of the transistor Q ₂ is It becomes almost earth potential and becomes Low. Thereafter, when the voltage between the input terminal 11 and the common terminal 12 further increases and reaches a predetermined voltage or more, the voltage drop monitoring circuit 1
4 stops the output of the lowering signal to the input port 15.

When the electric line L is broken, the capacitor C is not connected between the input terminal 11 and the common terminal 12, so that the input terminal 11 and the common terminal 12 are not connected. The voltage rises sharply as compared with the case where the electric line L is not disconnected. That is, FIG.
T _b shown in is shortened. The difference between whether the voltage between the input terminal 11 and the common terminal 12 rises steeply or gently has an important meaning in determining the disconnection of the electric line L.

[0027] In Kotoro, reading means is a software of the monitoring device 10, the T _a, as shown in FIG. 2 (c)
When the switching circuit 18 is turned on after a lapse of the period t
₂ in the first period T _c first time point t ₃ and the second second time point t ₄ when elapsed period T _d of the elapse of the read presence or absence of said reduction signal from the input port 15. Then, the software is a disconnection determination means of the monitoring device 10, the read result, unless the output of the first time point t ₃ the decrease signal reduction signal output by the second time point t ₄ there of the wire It is determined that there is no disconnection of the road L, and the first time point t ₃
Therefore, if there is no lowering signal, it can be determined that the electric line L is disconnected. FIG. 2B shows a case where there is no disconnection of the electric line L.

As described above, if the presence / absence of disconnection of the electric line L can be determined, it is easy for the central processing unit 16 to display the result on the monitoring display unit (not shown) of the monitoring device 10. . Further, diagnosis of the presence or absence of disconnection of the power line L as described above need not be performed in the contact A ₁ that is frequently turned on and off the distant device A, but rather, that does not turn on only most rarely The processing is preferably performed for the contact A ₁ , and is preferably performed when the contact A ₁ has been in the off state for about 24 hours continuously, which is preferable because the workload of the central processing unit 16 can be reduced.

Also, as described above, "input terminal 11 and common terminal 1
Difference or voltage is either gradually rises steeply rises between 2 has been described as "have important implications in the disconnection determination electrical line L, the first time period T _c and the second Period T _d
Is equally important. By the way, in this embodiment,
Predetermined time period T _a is approximately 2 msec, the first period T _c 70 microseconds
, Second time period T _d is 500 .mu.sec, the capacitor C and the capacitor C ₁ is 0.1μF respectively, resistor R ₁ is 330 ohms, the resistor R ₂ is 2K ohms, the discharge resistor R ₁₀ is 100K
Ω, and the maximum length of the electric line L is up to 100 m in consideration of the floating capacity of the electric line L, the distributed capacitance between the electric lines, and the line resistance of the electric line L.

The present invention is not limited to the embodiment described above, but includes a voltage application circuit, a voltage drop monitoring circuit,
The switching circuit and the like may have another configuration. Although the embodiment has been described with only one pair of input terminal and common terminal, a large number of input terminals may be provided. In this case, it goes without saying that the number of input ports is increased.

[0031]

Since the monitoring device according to the present invention is constructed as described above, according to the first aspect of the present invention, the disconnection diagnosis of the electric line is performed and the electric line is disconnected. Can be notified of disconnection, even when monitoring contacts that are hardly turned on, the monitoring device displays normal because the electric line is disconnected, It is possible to provide a safe monitoring device without suspicion that it may be out of order and without suspicion of the monitoring data. Since the workload of the device can be reduced, there is an effect that it is possible to provide a monitoring device capable of increasing the processing speed of the original work of the monitoring device.

[Brief description of the drawings]

FIG. 1 is a main part circuit diagram for explaining an embodiment of a monitoring device according to the present invention.

FIG. 2 is a timing chart for explaining one embodiment of a monitoring device according to the present invention.

FIG. 3 is a main part circuit diagram for explaining a conventional monitoring device.

[Description of Signs] 10 Monitoring device 11 Input terminal 12 Common terminal 13 Voltage application circuit 14 Voltage drop monitoring circuit 15 Input port 16 Central processing unit 17 Output port 18 Switching circuit A ₁ contact C Capacitor L Electric wire R ₁₀ Discharge resistance _Ta the predetermined period T _c first period T _d second period t ₃ the first time point t ₄ second time

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G08B 29/06 G01R 31/02

Claims (2)

(57) [Claims] A voltage application circuit for applying a voltage between an input terminal and a common terminal; a voltage decrease monitoring circuit for outputting a decrease signal when the voltage between the input terminal and the common terminal decreases; An input port connected to the output of the drop monitoring circuit, and a central processing unit that monitors the input port, wherein a contact is connected between the input terminal and the common terminal via an electric wire to detect the presence or absence of the drop signal. In a monitoring device for monitoring an on / off state of the contact, a switching circuit connected in series to the voltage application circuit, a discharge resistor connected between the input terminal and a common terminal, and a capacitor connected between the contacts An output port for controlling the switching circuit, intermittent off means for turning off the switching circuit for a predetermined period of time and then turning on the switching circuit again, and a first period from the time when the switching circuit is turned on. Reading means for reading the presence / absence of the decrease signal at a first time point between the first time point and a second time point at which the second time period has passed, and disconnection determining means for determining the presence / absence of disconnection of the electric line from the result of the reading And a monitoring device. 2. The monitoring apparatus according to claim 1, wherein said intermittent off means is executed when said contact is kept off for a predetermined time.