JPS6341300B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a system in which a master device centrally monitors and controls slave devices via a signal transmission line, and particularly relates to a control device having a function of detecting the operating state of a load connected to a power supply line. It is related to vessels.

Regarding such control slave devices, please refer to
There are those shown in Japanese Patent Application Laid-open No. 56-100589 and Japanese Patent Application Laid-open No. 132135/1982. These slave units are equipped with a switch section that is connected in series to the power supply line and the load, and a load state detection circuit that detects when the load switch changes from OFF to ON state when the switch section is in the OFF state. It is equipped with It has a function of switching the above-mentioned switch section to the on state when the state changes from the off state to the on state.

However, in the above configuration, although the control is not open-loop control (control without means for knowing the state of the load), once the switch section is turned on, subsequent switching of the load switch cannot be detected. The operating state was as if it were under open-loop control. Therefore, in this case, the child device, and by extension the parent device, had no means to check the actual operating status of the load, which presented a problem in terms of reliability.

The purpose of the present invention is to provide a control device with the function of starting and stopping the supply of power to the load with a function of detecting the state of the load (on state and off state of a switch, etc.). The objective is to provide a control slave device with improved reliability and ease of use.

In order to achieve the above object, the present invention includes a transmitting/receiving means connected to a signal transmission line, a load control means for controlling the supply of power from the power supply line to the load, and an energizing current flowing from the power supply line to the load. current detecting means for detecting the amount of current by magnetic coupling, and controlling the load control means according to at least one of a received signal by the transmitting/receiving means and an output of the current detecting means, and controlling the control content or the control result as described above. Discrimination control means for causing the transmitting and receiving means to transmit is provided. In particular, the load control means includes a switch part (such as a power relay contact) connected in series with the load, and a high impedance part (such as a series or parallel circuit of a capacitor and a resistor) connected in parallel to this.
The current detection means detects the amount of current flowing from the feeder line to the load in a stable state (not high frequency components such as rush current) using a current transformer or Hall element. It is configured to be detected by a sensor that uses magnetic coupling. The determination control means determines whether or not there is a change of more than a predetermined value in the detection signal output by the current detection means, monitors and checks the operating state of the load (on and off of a switch, etc.), and transmits and receives the signal. means to send it.

Now, the effects of the above means will be briefly described. Since the current detection means detects the current flowing to the load via the load control means, the detected energizing current includes information regarding the states of both the load control means and the load. The discrimination control means controls the load control means, and the current detection means obtains information about the load and the load control means.As a result, the discrimination control means can detect the state of the load (the detection result is logical). If this cannot be determined, it is likely that the load control means is malfunctioning.) Further, the discrimination control means controls the load control means according to the state of the load or the signal received from the master unit, and transmits information to the master unit using the transmitting/receiving means, which makes the centralized monitoring control system a closed-loop control system. I will do it. Note that using magnetic coupling as the current detection means is advantageous in terms of heat generation (effective loss) within the detection means, and detecting the amount of current in a stable state prevents malfunctions due to noise and the voltage supplied to the feeder line. This has the effect of eliminating malfunctions caused by waveform distortion.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, the feed line was used as a signal transmission line.

FIG. 1 is a diagram showing an example of the configuration of the system of the present invention, in which outdoor power supply lines 1 and 2 are connected to a breaker 3 installed indoors. In this example,
The power supply lines 4 and 5 via the breaker 3 are connected to a filter 6 that prevents carrier wave signals from entering and leaking, and are connected to the filter 6 and each indoor outlet 9, 13,
20, 27, 31, and 35 are connected by indoor power supply lines 7 and 8. Now, the central monitoring control master device 12 is the electric wire 1
0,11 to the outlet 9, and an appliance slave device (a type of control slave device) 16
is connected to the outlet 13 by electric wires 14 and 15, and a device 19 such as a television is connected to the appliance slave 16 by electric wires 17 and 18.
In addition, lamp subunit (a type of control subunit) 2
3 is connected to the outlet 20 by electric wires 21 and 22, and the lighting fixture 2 is connected to the lamp base unit 23.
6 are connected by electric wires 24 and 25. In addition, a fire sensor slave (a type of security slave)
30 is connected to the outlet 27 by electric wires 28 and 29, a gas sensor slave (a type of security slave) 34 is connected to the outlet 31 by electric wires 32 and 33, and similarly an intrusion sensor slave 38 is connected to the outlet 31 by electric wires 32 and 33.
It is assumed that the power outlet 35 is connected to the outlet 35 by electric wires 36 and 37. Outlet 9, 13, 20, 2
7, 31, 35, the main unit 12, the appliance slave unit 16, the lamp slave unit 23, the fire sensor slave unit 30, the gas sensor slave unit 34, and the intrusion sensor slave unit 38 are their main components. A certain microcomputer (details will be explained after microcomputer abbreviation)
performs initialization processing, and the parent unit 12 receives input signals from keys on its panel or slave units 16 and 2.
3, 30, 34, and 38, and the appliance slave unit 16 waits for signals from the master unit 12 or changes in status such as turning on or off the switch of the appliance 19 (including when the fuse of the appliance 19 is blown). ), and the lamp subunit 23 is also in a state of waiting for a transmission signal from the main unit 12 or an input signal of a change in status such as turning on or off the lighting fixture 26. In this state, both the appliance slave unit 16 and the lamp slave unit 23 are in the off state. The fire sensor slave unit 30 is in a state of waiting for an input signal indicating an abnormal state due to a fire, and similarly, the gas sensor slave unit 34 is in a state of waiting for an input signal of an abnormal state due to a gas leak. Further, the intrusion sensor slave unit 38 is in a state of waiting for an alarm operation designation signal from the master unit 12 or an input signal indicating an abnormal state from an intruder or the like. however,
Main unit 12 and each security slave unit 30, 34, 38
If a voltage is supplied from a backup battery, the microcomputer performs initialization processing when that voltage is supplied. Here, an example of the operation of the system shown in the figure will be briefly explained by referring to the appliance slave unit 16 from the control slave unit and the fire sensor slave unit 30 from the security slave unit. First, the operation of the appliance slave device 16 will be explained. Now, if the user presses a key on the master device 12, the master device 12 responds to the key input and sends a PWM signal (pulse width modulation signal) with a predetermined code from the electric wires 10 and 11 to the outlet 9. . This sent signal passes from the outlet 9 through the indoor power supply lines 7 and 8, and then passes through the outlet 13.
reach. Furthermore, electric wire 1 from outlet 13
4 and 15 and enters the appliance slave unit 16. The appliance slave device 16 compares the transmitted signal with a code predetermined for the appliance slave device 16, and ignores the code if they are different. If the transmission code is the same, power is supplied to the appliance 19 if the transmission code is designated as on, and power supply is stopped if the transmission code is designated as off. Here, the transmission code, that is, the PWM signal, is synchronized to a specific phase from the zero cross of the voltage (50 Hz or 60 Hz) applied to the indoor power supply lines 7 and 8. At the same time, the appliance child device 16 sends an answer back signal to the parent device 12. This answer back signal (PWM
signal) travels in the opposite direction along the same path described above to the parent unit 1.
Enter 2. The master unit 12 receives the answer back signal from the appliance slave unit 16, confirms that the previously transmitted signal has reached the appliance slave unit 16, stores the operating state of the appliance slave unit 16, and stores the status. indicate. Next to this control operation, if the user switches on the appliance 19 such as a television, the appliance slave unit 16 will generate a current that flows through the electric wires 17 and 18 (even if the appliance slave unit 16 is in the OFF state, the current will be high). a small current is being supplied to the instrument 19 via an impedance), detecting a change from its previous state;
From the change, it is determined that the appliance 19 has been switched on or off. Based on this result, the appliance subunit 16 changes state to on or off to start or stop supplying power to the appliance 19. At the same time, a signal of a predetermined code is transmitted to the parent device 12.
(Details will be explained later.) The master unit 12 receives this signal and switches the display, and the appliance slave unit 16
Changes the memory of the operating status of. Next, assume that under such a state, the power supply to the indoor power supply lines 7 and 8 is stopped due to a power outage or the breaker 3 tripping (turning off). Since there is no backup battery, the appliance slave unit 16 completely stops operating and enters the OFF state. On the other hand, parent device 12
maintains operation by back-up battery. However, the display is turned off and key inputs regarding the control slave devices 16 and 23 are ignored. The main device 12 detects a power outage depending on the presence or absence of a phase signal for synchronizing transmission and reception, and this point will be described later. Eventually, when the power outage or the breaker is turned off and power is supplied to the indoor power supply lines 7 and 8, the appliance subunit 16 performs initialization processing and stands by. The master device 12 detects the restoration of power and resets the appliance slave device 16 according to the memory contents of the master device 12 (the state before the power outage, etc.) by boring. Next, the operation of the fire sensor slave device 30 will be explained. Fire sensor slave device 3
0 monitors the occurrence of fire based on the presence or absence of smoke. now,
If a fire occurs, the fire sensor subunit 30
detects a fire and generates a buzzer sound, and also sends a PWM signal of a predetermined code to the outlet 27 from the electric wires 28 and 29. This sent signal passes from the outlet 27 through the indoor power supply lines 7 and 8 and reaches the outlet 9. Furthermore, from the outlet 9, the wires 10 and 11 are passed through the main device 1.
Enter 2. The master unit 12 receives the transmission signal from the fire sensor slave unit 30 and controls the control slave units 16 and 23.
stop the display, display the fire warning, and emit a buzzer sound. Further, key inputs regarding the control child devices 16 and 23 are ignored. The fire sensor slave device 30 generates a buzzer sound until the fire detection signal disappears, and also transmits a PWM signal of a predetermined code at regular intervals. The master device 12 receives this signal and generates a buzzer sound, but if the delay for a predetermined period continues after receiving the signal transmitted from the fire sensor slave device 30, the buzzer sound will be generated and a fire will be displayed. It stops and returns to its original state. Therefore, when the transmission signal from the fire sensor 30 disappears, the original state is restored. Here, the transmission code, that is, the PWM signal, is synchronized to a specific phase from the zero cross of the voltage (50 Hz or 60 Hz) applied to the indoor power supply lines 7 and 8. Next, indoor power supply lines 7 and 8
Suppose that the power to the device stops or the breaker 3 trips, etc. The fire sensor subunit 30 maintains its operation because of backup battery. If a fire occurs now, the fire sensor subunit 30 detects the fire and generates a buzzer sound, and also sends a PWM signal of a predetermined code to the master unit 12. The main device 12 detects the beginning of the transmission code at the rising edge of the sent signal and receives it. The following is the same as above. In other words, the fire sensor slave unit 30 (security slave unit) normally receives the voltage (50Hz or 60Hz) applied to the indoor power supply lines 7 and 8.
The signal is transmitted in synchronization with a specific phase from the zero crossing of Hz), and in the event of a power outage, the signal is transmitted asynchronously. The parent device 12 normally (similarly) receives signals in synchronization with a specific phase from the zero cross, and in the case of a power outage or the like, detects the rising edge of the transmitted signal and starts receiving. In addition, in the above transmission,
The master device 12 and slave devices 16, 23, 30, 34, and 38 first receive signals, and if there is no signal (same as noise), start transmitting. Furthermore, the display of the master unit 12 gives priority to the security slave units 30, 34, and 38 over the control slave units 16 and 23, and within the security slave units 30, 34, and 38, the gas sensor slave unit 34 is given priority over the intrusion sensor slave unit 38. The fire sensor slave 30 is prioritized over the gas sensor slave 34. In addition, security slave device 30,3
4 and 38 have a back-up battery, and when the voltage of this back-up battery drops below a predetermined level, a buzzer sound is generated.
A predetermined transmission code is sent to the parent device 12. The main device 12 displays almost the same as a signal and generates a buzzer sound.

Next, the parent device 12 in FIG. 1 will be described. Second
An example of the external shape of the parent device 12 is shown in the figure. 39 is a plug connected to outlet 9, 40 is electric wire 1 inside
0,11. 41 is an LED (light emitting diode) section for display;
Reference numerals 42 to 53 indicate one of a plurality of control devices or security devices.
The LEDs 54 to 57 light up when the displays on the LEDs 42 to 53 relate to the security device. In other words, when the LEDs 54 to 57 are off, the LEDs 42 to 53 indicate whether the control slave is on or off. LED54
lights up when there is a fire, LED 55 lights up when there is a gas leak, and LED 56 lights up when there is an intruder. The LED 57 lights up when the backup battery of the security device falls below a predetermined level. The LED 58 lights up when there is a signal or noise having almost the same carrier frequency as the signal on the indoor power supply lines 7 and 8. Reference numeral 59 is a house code switch for use when adding a parent unit, and employs a gray code. 60 is a buzzer that generates a confirmation sound when a key is input and an alarm sound when a signal is received from a security slave device. 61 is a buzzer switch for turning on or off the sound of the buzzer 60. Reference numeral 62 denotes an intrusion switch that specifies whether to turn on or off the operation of the intrusion sensor slave device. However, when the intrusion switch 62 is off, the intrusion sensor child device does not generate a buzzer sound or transmit even if it detects an intruder. 6
Reference numeral 3 indicates a key section and a switch section related to the control slave device. 64 to 75 are unit keys for selecting one from a plurality of (12) control slave devices, 76 is a memory key for storing unit keys that are frequently turned on or off by the user, and 77 is a memory key 76. 78 is a memory clear key for erasing the unit keys memorized by 78; 78 is an all-right-on key for turning on one or more lamp units with a single key input;
9 is an all-off key for turning off one or more control slave devices with a single key input. 8
0 is unit key 64-75 or memory key 7
6 is an on switch for turning on the designated control slave device, and 81 is an off switch for turning off the control slave device. (Note that similar items such as a key and a switch are called separately for the purpose of making the following explanation easier to understand.) Next, one circuit configuration of the main device 12 in Fig. 2 is shown in Fig. 3. It is shown and briefly explained. In the figure, 39 is the same plug as in FIG. 2, and 10 and 11 are electric wires connected to the plug 39. The arrows in the figure indicate the flow of signals, and the diagonal lines and numbers above the arrows indicate the number of signals. The electric wires 10 and 11 are connected to a power supply circuit 84, which supplies a DC stabilizing voltage Vcc to each block, and a battery of a backup battery circuit 85 (not shown) via a DC voltage supply line 82. ) to charge. In the event of a power outage, this backup battery circuit 85 supplies voltage Vcc to each block. Further, the power supply circuit 84 sends a pulsating voltage signal obtained by full-wave rectification of the AC voltage supplied through the electric wires 10 and 11 to the phase signal circuit 86 . The phase signal circuit 86 generates a clock signal from this pulsating voltage signal when the alternating current voltage crosses substantially at zero, and sends it to the interrupt input section INT1 of the microcomputer 98. Also, the power supply circuit 8
4 or the backup battery circuit 85 includes a reset circuit 87 and a battery check circuit 88.
send a voltage signal to. The reset circuit 87 stops the operation of the microcomputer 98 when the DC stabilized voltage Vcc output from the power supply circuit 84 or the backup battery circuit 85 falls below a predetermined level, and resets the reset input section of the microcomputer 98 when the DC stabilized voltage Vcc output from the power supply circuit 84 or the backup battery circuit 85 falls below a predetermined level.
It sends a reset signal to RESET. The battery check circuit 88 is reset by the reset circuit 87.
When the above-mentioned DC stabilizing voltage Vcc falls below a predetermined level which is set slightly higher than in the case of 1, a battery out signal is sent to the microcomputer 98. Reference numeral 89 is an oscillation negative feedback circuit, which sends two oscillation signals to the microcomputer 98. microcomputer 98
operates by generating a clock from this signal.
The oscillating negative feedback circuit 89 also sends one high frequency signal for the indoor power supply carrier to the transmitting circuit 99. The transmitting circuit 99 performs a logical product of the high frequency signal sent from the oscillation negative feedback circuit 89 and the transmitting code sent from the microcomputer 98 and outputs the result to the coupling circuit 10.
Send a signal to 0. The coupling circuit 100 includes electric wires 10,1
1, and when a signal is sent from the transmitting circuit 99, it is converted into a sine wave and sent to the electric wires 10 and 11. Conversely, when an indoor wire carrier signal is sent from the wires 10 and 11, the coupling circuit 100 tunes to it and sends the signal to the receiving circuit 101. The receiving circuit 101 detects the signal sent from the coupling circuit 100 and sends it to the interrupt input section of the microcomputer 98.
Send the receive code signal to INT0. Next, the microcomputer 98 operates the master device 12 slave devices 16, 23, 30, 34,
Since the same product type and the same program are used for both the 38 and 38, it is necessary to specify one of these settings to the microcomputer 98 (that is, in this case, the master device 12). For this purpose, a microcomputer setting code circuit 91 is provided. Furthermore, in order to prevent tampering, we decided to prepare a transmission/reception code (referred to as a mask code) that cannot be changed by the user, so a circuit for setting the mask code was required. For this purpose, a mask code circuit 92 is provided.
The code settings of these circuits 91 and 92 are read by the microcomputer 98 during initialization processing of the microcomputer 98. 93 is a house code setting switch circuit consisting of the house code switch 59 of FIG. 2 and its peripheral circuits, and is read by the microcomputer 98 as appropriate. 94 is a transmitting LED circuit consisting of the LED 58 of FIG. 2 and a driver circuit, and 90 is a buzzer circuit consisting of a buzzer 60, a buzzer switch 61, and a driver circuit. These are turned on by the microcomputer 98 and also generate a buzzer sound. 97 is a switch circuit including the intrusion switch 62, on switch 80, and off switch 81 shown in FIG. 2, and sends a signal to the microcomputer 98. 95 is LED42~ in Figure 2
It is an LED array circuit consisting of 57 and peripheral circuits.
Similarly, 96 is a key array circuit consisting of keys 64 to 79 and peripheral circuits. The microcomputer 98 sends the scan signal to the LED array circuit 95 and the key array circuit 9.
6, and this scan signal causes keys 64 to
Check the input of 79 and LED42~57
It is a dynamic drive. With the above-described circuit configuration, the main device 12 shown in FIG. 2 operates as described in FIG. 1.

Next, an example of a time chart of the control configuration described in FIG. 3 will be described with reference to FIG. 4. In the figure, 1 is an indoor power supply line 7 on which a carrier signal is superimposed,
8 AC voltage waveforms, _a1 to _a5 are the original waveforms
b ₁ to _{b 4} are waveforms on which carrier waves are superimposed. 2 is a clock ₍ INT1 input interrupt) signal sent from the phase signal circuit 86 in _FIG . An interrupt request is generated inside the microcomputer 98 at the rising edge of the signal that goes from high level to low level and then goes back to high level. 3 is carrier wave of 1
The waveform obtained by detecting b ₁ to _{b 4} is the envelope line, in which D ₁ and D ₄ are “1” signals, and D ₂ and D ₃ are “0” signals. Therefore, the signal of this waveform is
This is a signal sent from the microcomputer 98 to the transmitting circuit 99 in the figure, and is also a signal sent from the receiving circuit 101 to the microcomputer 98.
This is the signal sent to the interrupt input section INI0 of. 4 is an INT0 input interrupt signal (clock) generated inside the microcomputer 98 in FIG. 3, and is composed of the rising edge of the signal 3. That is, at the rising edge of D ₁ , the clock of E ₁ is activated, and similarly, at the rising edge of D ₂ , E _{2 is activated} .
E ₃ clock is generated at D ₃ and E ₄ clock is generated at D ₄ . In addition,
These clocks E ₁ to _{E 4} are valid in the event of a power outage, etc., and interrupt requests are accepted in E ₁ and E ₃ , but interrupts are masked in E ₂ and E ₄ . The software has been set up. 5～
8 is a scan signal sent from the microcomputer 98 in FIG. 3 to the LED array circuit 95 and the key array circuit 96, and the number is four. Scanning proceeds sequentially from 2 clocks to F ₁ , F ₃ , F ₅ , F ₇ and ends in 1 half cycle of AC voltage. In the next cycle, the process proceeds in the same manner as F ₂ , F ₄ , F ₆ , and F ₈ .
In the case of a power outage, etc., the microcomputer 98 will not take in the output signal (key input) from the key array circuit 96, and will not send the output (display) signal to the LED array circuit 95 until it receives the signal from the security device. , the processing is done in the same way. When receiving the transmission from the security slave device (same as noise), the microcomputer 98 generates an interrupt by clock E ₁ or E ₃ of 4, and starts outputting a scan signal from the middle of F ₁ or F ₂ . .

Next, an example of the general flowchart of the microcomputer 98 of the parent device 12 described in FIGS.
It will be shown and explained in the figure. In addition, this general flowchart is for the master unit 12, slave units 16 and 2.
3, 30, 34, 38 are all the same, so
To help explain later, the positions of control processing, security processing, and child-related processing are also listed. When the DC stabilizing voltage Vcc is supplied to the microcomputer 98 in FIG. 3 from the power supply circuit 84 or the backup battery circuit 85, and the reset circuit 87 sends a reset signal to the reset input section RESET of the microcomputer 98, the microcomputer 98 is reset. (POWER ON in the figure) to start initialization processing. Initialization processing involves setting specific input/output terminals, clearing RAM, and phase signal circuit 86.
power outage and frequency (50
Hz/60Hz) judgment, microcomputer setting code circuit 91
(This is set as the master device setting.), reading the settings of the mask code circuit, reading the settings of the intrusion switch of the switch circuit 97, and setting a specific transmission code. Next, if the result of the power failure determination is "YES", that is, if the aforementioned clock is not within the specific time obtained by the instruction cycle count (internal timer) of the microcomputer 98,
4. The interrupt caused by the INT0 input interrupt signal _E1 or _E3 in FIG. 4 is canceled (permitted), and if there is no interrupt, the process moves to the synchronous processing (INT1) routine. Also, if the result of power outage determination is “NO”, INT1 in Figure 4 2
Releases the interrupt caused by the input interrupt signals C ₁ to C ₃ and waits for the interrupt. Next, for convenience of explanation, we will explain a case where there is no power outage. Now, if an interrupt is generated by the INT1 input interrupt signal _C1 , the process moves to the synchronization processing (INT1) routine. Note that when an interrupt occurs, both the INT1 side and the INT0 side are disabled. In the synchronization processing (INT1) routine, first, as shown in FIG. 4, the first scan signal SCAN1 is raised, and the LED 4 in FIG.
Output display data 2 to 45 and start displaying,
Next, the key data (input) of the unit keys 64 to 67 is read, and the data of the house code switch 59 is read.If the frequency is determined to be 50Hz, delay processing (approximately 0.28m
Do S). Next, the first transmission/reception process (1) −
Move to UP-. In this process, the rising portion of D ₁ or D ₃ (the first half of the pulse) in FIG. For example, it sends a signal to the transmitting circuit 99 to start transmission, and conversely, if there is a signal, processes such as reading are performed, and if the frequency determination is 50 Hz, delay processing (approximately 0.14 mS) is performed. However, in the case of transmission, when the signal is "0", that is, when a short carrier wave signal is sent, the falling part is also processed. Next, processing for lowering the first scan signal SCAN1 is performed to finish displaying the LEDs 42 to 45, and preparation is made for the second scan signal SCAN2. After that, the second scan signal SCAN2 is raised to output the display data of LEDs 46 to 49 in FIG. 2 to start displaying, and then the unit keys 68 to 7
Processing such as reading the key data (input) of No. 1 is performed, and if the frequency determination is 50 Hz, delay processing (approximately 0.14 mS) is performed. Next, the process moves to the second transmission/reception process (1) -DOWN-. In this process, the falling part of D ₁ or D ₃ (second half of the pulse) in 3 in FIG. 4 is processed.
If a signal for transmission is being sent to the transmitting circuit 99, a signal is sent to stop it; if it is being received, a signal is sent to check whether the pulse width of the carrier signal, that is, the output signal of the receiving circuit 101, is appropriate. Determination processing is performed, and if the frequency determination is 50 Hz, delay processing (approximately 0.28 mS) is performed. Next, processing is performed to lower the second scan signal SCAN2, and processing is performed to terminate the display of LEDs 46 to 49. After that, input data of keys 64 to 79, on switch 80, and off switch 81 read in advance is performed. It also determines whether the settings of the intrusion switch 62 have been changed, and if the input is correct, the transmission code and transmission request are set according to that key or switch. It performs processing such as flag setting, storing input data, or canceling it. Also, at this time, a process such as making a confirmation sound by the buzzer 60 is performed. (Key Discrimination Process) The input data of the unit keys 64 to 75 is converted into a gray code and set in the transmission code. After that, the third scan signal SCAN3 is raised to output the display data of LEDs 50 to 53 in Fig. 2 to start displaying, and then the unit key 7
Processing such as reading key data (input) from 2 to 75 is performed, and if the frequency determination is 50 Hz, delay processing (approximately 0.28 mS) is performed. Next, the third
Proceed to the second transmission/reception process (2) -UP-. In this process, the rising portion of _D2 or _D4 in FIG. 4 is processed, and the same process as in the case of SCAN1 is performed. Next, the third scan signal
After performing the shutdown processing of SCAN3, etc.,
The display of 0 to 53 is finished, and the fourth scan signal
Prepare for SCAN4. After this, the fourth scan signal
Start up SCAN 4 and start displaying by outputting the display data of LEDs 54 to 57 in Fig. 2. Next, input the key data (input) of memory key 76, memory clear key 77, all right on key 78, and all off key 79. If processing such as reading is performed and the frequency judgment is 50Hz, delay processing (approximately 0.14m
Do S). Next, the fourth transmission/reception process (2) −
Move to DOWN−. In this process, the
It processes the falling portion of D ₂ or D ₄ , and performs the same processing as in SCAN2. Next, the fourth scan signal SCAN4 is turned down, and the display of LEDs 54 to 57 is terminated. After that, it is determined whether or not the power has recovered from the power outage, and if it has recovered, Performs processing such as frequency determination. However, since there is no power outage at this point, these determinations are not made and the process proceeds to the next routine through delay processing and the like. Many such delay processes are set in each processing routine, and the processing time from the start of synchronous processing (INT1) due to an interrupt occurrence is strictly controlled, and the processing time is the same no matter which processing routine is passed through. It is set to be. In the next routine, first, the interrupts caused by the INT1 interrupt signals C ₁ to _{C 3} are canceled, and the process shifts to delay processing. If there is no power outage, an interrupt is generated by the INT1 interrupt signal during this delay processing, and the process returns to synchronous processing (INT1) again. In other words, the time until this delay processing (in the middle) is set to the half-wave time of the AC voltage waveform in Figure 4.1. After the delay processing, that is, in the case of a power outage, Signal _C1 ~ _C3
interrupts, and then enters power outage processing. In the power outage processing, processing such as setting a flag for inhibiting the output of scan signals SCAN1 to SCAN4, setting a check start flag during power outage, and setting a setting request flag by boring the control slave after the power outage is restored are performed. These flags are checked during the synchronization processing (INT1) routine mentioned earlier, and are set as appropriate.
It is used for processing. Next, Figure 4
Cancels the interrupt caused by the INT0 input interrupt signal E ₁ or E ₃ , and if there is no interrupt, moves to the synchronous processing (INT1) routine. Note that the processing time of the microcomputer 98 from interrupt release (INT1) to interrupt release (INT0) is actually sufficiently short compared to other processing routines, and the The time management of the entire process is maintained correctly. As mentioned above,
The processing routine continues even in the event of a power outage. Next, if an interrupt occurs due to INT0 input interrupt signal E ₁ during a power outage, asynchronous processing (INT0)
Get into a routine. Note that when an interrupt occurs, both the INT1 side and the INT0 side are disabled. The asynchronous processing (INT0) routine sets the specific input/output terminals of the microcomputer 98 and scans the scan signal.
Perform memory change processing such as resetting (setting) the output prohibition flag of SCAN1 to SCAN4,
The process moves to the transmission/reception processing (1)-UP- routine of the first day of the synchronization processing (INT1) routine. however,
In reality, the process moves to the middle of this process for time adjustment. Although omitted for ease of explanation, the process of determining received signals is performed as appropriate in four transmission/reception processes. The duration of the buzzer 60 is determined by counting the number of times the processing routine described above is repeated, and the lighting of the LED 58 during transmission is controlled by the transmission/reception processing as well as by several other routines. The master unit 12 operates according to the general flowchart as described above.

Next, a circuit configuration of the appliance slave unit 16 shown in FIG. 1 will be briefly described with reference to FIG. 6. In the figure, 102 is a plug, and 14 and 15 are electric wires connected to the plug 102. The arrows in the figure indicate the flow of signals, and the diagonal lines and numbers above the arrows indicate the number of signals. The electric wires 14 and 15 are connected to a power supply circuit 105 (transformerless), and the power supply circuit 105 supplies a DC stabilizing voltage Vcc to each block and also sends a ripple voltage signal to a phase signal circuit 10.
6, and the phase signal circuit 106 sends the clock signal to the interrupt input section INT1 of the microcomputer 113. Further, the power supply circuit 105 sends a voltage signal to a reset circuit 107, and the reset circuit 107 sends a reset signal to the reset input section RESET of the microcomputer 113 as in FIG. Those having the same configuration and signal flow as those in FIG. There is a mask code circuit and a house code setting switch circuit 111, and a description of these will be omitted. (However, the microcomputer setting code is connected to the appliance slave device.) Next, 112 is a unit code setting switch circuit, which employs a gray code. The unit code setting switch circuit 112 sends a switch (key) data signal to the microcomputer 113. In addition, the electric wire 14 includes a load ON/OFF detection circuit, an electric wire 118, an operating display LED, and a 15A
A power relay circuit 119 is connected to a receptacle 121 via an electric wire 120, and the electric wire 15 is directly connected to the receptacle 121.
Connected to receptacle 121. Instrument 19 in FIG. 1 is connected to and controlled by this receptacle 121 by wires 17 and 18. Operating indicator LED and 15A power relay circuit 119
The power relay (not shown) is connected to the microcomputer 113.
The connection of the electric wires 118 and 120 is turned on and off in response to a signal from the
The LED (not shown) lights up when the contact of the power relay is turned on. Load ON/OFF
The detection circuit 117 is a high impedance circuit connected in parallel with the above-mentioned power relay (contacts), and the electric wire 1
A sensor that detects the current flowing through 18 by magnetic coupling, a processing circuit that amplifies the output signal of this sensor, rectifies it, and converts it into a DC signal, and a 2-bit A/C signal.
It consists of a D conversion circuit and sends a 2-bit signal to the microcomputer 113.

One circuit configuration of this load ON/OFF detection circuit 117 is shown in FIG. 10 and will be briefly described. For convenience of explanation, peripheral components are also shown, and the same components as those in FIG. 6 are given the same numbers. In addition, the plug 102,
The receptacle 121 and the like are omitted, and instead the instrument 19, which is the load shown in FIG. 1, is also shown. In FIG. 10, 181 represents an AC power supply, and 182 represents an electric wire 1.
It is a current (magnetic) sensor such as a current transformer or a Hall element that detects the current flowing in the electric wire 18 (that is, the electric wire 14) by magnetic coupling. 183 is 15A
This is a high impedance circuit connected in parallel with the relay contacts of the power relay circuit 119. 184 is an amplifier circuit that amplifies the output signal of the current sensor 182;
185 is a rectifier circuit that rectifies the output signal of the amplifier circuit 184 and converts it into a DC signal, and 186 is an A/D converter that converts the DC signal of the rectifier circuit 185 into an analog/digital (A/D) signal and supplies the digital signal to the microcomputer 113. /D conversion circuit. As shown in the figure, the load ON/OFF detection circuit 117 is provided in series with the AC power supply 181, the relay contacts of the 15A power relay circuit 119, and the series circuit of the load 19. The relay contacts of the 15A power relay circuit 119 and the high impedance circuit 183
A current sensor 182 detects the current flowing to the load 19 through the parallel circuit of ).
Further, the A/D conversion circuit 186 converts the aforementioned DC signal into a digital signal and supplies it to the microcomputer 113.

Here, the on and off operations of the appliance subunit 16 by turning on and off the switch of the load (appliance 19) itself will be described. In this method, the microcomputer 113 stores the state of the load ON/OFF detection circuit 117. In other words, under condition (A) in which the switch of the appliance 19 is off and the contact of the power relay described above is off, no current flows through the electric wire 118, and the load ON/OFF detection circuit 117 is activated by the microcomputer 1.
In condition (B), when a 2-bit signal 00 is sent to the wire 13, the rotation of the device 19 is on, and the contact of the power relay is off, the electric wire 15, the receptacle 121, and the device 1
switch 9, electric wire 120, and a high impedance circuit connected in parallel with the contacts of the aforementioned power relay;
A small current _I1 flows through the electrical circuit called wire 118, and the load
The ON/OFF detection circuit 117 sends a signal 01 to the microcomputer 113. Further, under condition (C) in which the switch of the instrument 19 is on and the power relay contact is on, a large current _I2 flows, and the detection circuit 117 is connected to the microcomputer 11.
In condition (D) where the switch of the device 19 is off and the contact of the power relay is on, a signal of 00 is sent to the microcomputer 11 as in condition (A).
Sent to 3. Therefore, there are three signals 00, 01, and 11, and under these conditions (A) to (C), the microcomputer 113 performs the operations described below. However, the amount of current to be applied shall be checked as appropriate.

[1] Under the condition (A) above, when the microcomputer 113 stores signal 00.

(i) When an on command (signal) is sent from the master unit 12, the microcomputer 113
An answer back (on) signal is once sent to the main unit 12, and then a signal indicating that the main unit 12 has been set to off is sent. (After a short period of time has elapsed.) (ii) When an off command (signal) is transmitted from the master device 12, the microcomputer 113 simply sends an answerback (off) signal to the master device 12.

(iii) When the switch of the device 19 is turned on, the microcomputer 113 checks that the signal 00 has changed to 01, that is, the condition
(B) When checked, the operating status LED and 15A power relay circuit 119 are displayed.
Sends a signal to turn on the operating indicator LED, turn on the power relay contact, and change the stored data from 00 to 11.
Furthermore, the master device 12 is notified by transmitting that it has been set to on. Note that the condition is (C).

[2] Under the condition (B) above, when the microcomputer 113 stores signal 01.

(i) When an on command (signal) is sent from the master unit 12, the microcomputer 113
At the same time, it sends an answer back (on) signal to 2, and also sends a signal to the operating indicator LED and 15A power relay circuit 119, lights up the operating indicator LED, turns on the power relay contact, and transfers the stored data from 01 to 15A power relay circuit 119. 1
Change to 1. The condition becomes (C).

(ii) When an off command (signal) is transmitted from the master device 12, the microcomputer 113 simply sends an answerback (off) signal to the master device 12.

(iii) When the switch of the appliance 19 is turned off, the microcomputer 113 checks that the signal 01 changes to 00, determines that the switch of the appliance 19 is turned off, and changes the stored data to 01. to 00.

[3] Under the condition (C) above, when the microcomputer 113 stores the signal 11.

(i) When an ON command (signal) is transmitted from the master device 12, the microcomputer 113 simply sends an answer back (ON) signal to the master device 12.

(ii) When an off command (signal) is sent from the master unit 12, the microcomputer 113
At the same time as sending an answer back (off) signal to 2, a signal is sent to the operating display LED and the 15A power relay circuit 119, indicating that the unit is operating.
Turn off the LED and turn off the power relay contact, and change the stored data from 11 to 01.
Change to The condition becomes (B).

(iii) When the switch of the device 19 is turned off, the microcomputer 113 checks that the signal 11 has changed to 00, that is, the condition
(D) When checked, the operating status LED and 15A power relay circuit 119 are displayed.
It sends a signal to turn off the operating LED, turn off the power relay contact, and change the stored data from 11 to 00. Further, the parent device 12 is notified by transmitting that it has been set to off. Note that the condition is (A).

Therefore, in this algorithm, condition (D) occurs as a transition stage, but it does not stop at this condition, and the microcomputer 113 does not store 00 in condition (D), and does not store 00 in condition (A). Judgment (D) is not performed. (However, it is also possible to generate condition (D), store data, and make a determination.) With the circuit configuration as described above, the appliance subunit 16 operates as shown in FIG.

In addition, in response to the off command from the master unit 12,
For the stored value (xy) of a 2-bit signal, x, y
It is also possible to change only one of them. This method is for giving priority to the command of the parent device, but it is a design problem.

Next, the general flowchart of the microcomputer 113 will be briefly described. This general flowchart is essentially the same as the main unit and the sub unit, and is one thing, and is shown in FIG. In the previous explanation, in order to clarify the operation of the master unit 12, explanations regarding the control slave unit and the security slave unit were omitted. Therefore, the points that are different from the case of the parent device 12 will be described. First, the load is turned on/off in the initialization process.
The output signal of the detection circuit 117 is stored. Also,
Processing regarding SCANs 1 to 4 is not performed. SCAN
In place of the processing for turning off the power in step 1, the operating display LED and the 15A power relay circuit 119 are driven and loaded.
Performs processing such as checking the output (signal) of the ON/OFF detection circuit 117. Key discrimination processing as described above is not performed. Further, the data of the unit code setting switch circuit 112 is processed at the position where the CCAN1 falls. The hardware differences between the lamp slave device 23 and the appliance slave device 16 in Fig. 1 are that the operating indicator LED and the power relay of the 15A power relay circuit 119 are replaced with a triac (for 3A), and the microcontroller There are only slight differences, such as the setting of the setting code circuit 109 being set to the lamp slave unit 23, and the only difference in terms of software is that the trial drive etc. is driven by the transmission signal from the all light on key 78 of the master unit 12. This is the point.

Next, a circuit configuration of the fire sensor slave device 30 shown in FIG. 1 will be briefly described with reference to FIG. 7. In the figure, 122 is a flag, and 28 and 29 are electric wires connected to the flag 122. The arrows in the figure indicate the flow of signals, and the diagonal lines and numbers above the arrows indicate the number of signals. The circuits having the same configuration and signal flow as those in FIG. Outage check circuit, 135 oscillation negative feedback circuit,
136 transmitting circuit, 137 coupling circuit, 138 receiving circuit, 130 microcomputer setting code circuit (however, the setting is the code of the fire sensor slave) 131 mask code circuit, 132 house code setting switch There are 139 buzzer circuits (however, there is no buzzer switch 61).
Furthermore, there is a unit code setting switch circuit 133 which has the same configuration and signal flow as the one in FIG. 6, and a description thereof will be omitted. Reference numeral 140 denotes an LED circuit for displaying during operation, and the LED is appropriately turned on by the microcomputer 134. Reference numeral 141 is a fire sensor circuit, which detects a fire by illuminating smoke with light by lighting an LED and detecting light scattered by the smoke with a photodiode. Microcomputer 134
sends a signal to the fire sensor circuit 141 at predetermined time intervals and receives a data signal indicating the presence or absence of a fire. If there is a fire, the buzzer circuit 139
A signal is sent to the in-operation display LED circuit 140 to generate a buzzer sound and turn on the LED.
Also, at almost the same time, a signal indicating the occurrence of a fire is transmitted to the parent device 12. This transmission is repeated at specific time intervals. Note that this sensing method may use a temperature-sensitive type such as a thermistor, and the microcomputer 13
4 performs a similar operation.

Next, the general flowchart of the microcomputer 134 will be briefly described. This general flowchart is the same as FIG. In the previous explanation, in order to clarify the operation of the master unit 12 or the control slave unit 16, the explanation regarding the security slave unit was omitted. Therefore, the points that are different from the case of the parent device 12 (and the control child device 16) will be described. First, processing regarding SCANs 1 to 4 is not performed. However, the data of the unit code setting switch 133 is set at the position of the start-up process of SCAN1. No key discrimination processing or control processing is performed.
Security processing is performed at the start-up processing position of SCAN3. Microcomputer 13 of fire sensor slave device 30
4 performs processing related to sending a drive signal to the fire sensor circuit 141 and receiving a data (fire) signal in this security processing, and also sends a drive signal to the operating display LED circuit 140 and the buzzer circuit 139.

Next, FIG. 8 shows a circuit configuration of the gas sensor slave 34 shown in FIG. 1. The explanation of the figure is almost the same as that of FIG. 7, so the different points will be explained.
160 is a gas sensor circuit, which detects gas (city gas, city gas,
or propane gas) to detect leaks. The oscillation negative feedback circuit 154 sends a high frequency signal to the gas sensor circuit 160 while the microcomputer 153 is in operation.
send to On the other hand, the microcomputer 153 sends signals to the gas sensor circuit 160 at predetermined time intervals. The gas sensor circuit 160 drives a gas-sensitive semiconductor sensor based on the logical product of these two signals, and sends a data signal indicating the presence or absence of gas leak to the microcomputer 153. If there is a gas leak, a signal is sent to the buzzer circuit 158 and the operating indicator LED circuit 59 to generate a buzzer sound and turn on the LED. In addition, a signal indicating the occurrence of gas leakage is transmitted to the master device 12 in substantially the same manner. This transmission is repeated at specific time intervals. The master unit 12 performs display and alarm in the same way as the fire sensor slave unit 30. Next is the general flowchart of the microcomputer 153, which is almost the same as the case of the fire sensor subunit 30, but the difference is in the security processing shown in FIG. It performs processing related to receiving the (gas leak) signal, and also sends drive signals to the operating display LED circuit 159 and buzzer circuit 158.

Next, FIG. 9 shows a circuit configuration of the intrusion sensor slave device 38 of FIG. 1. The explanation of the figure is almost the same as that of FIG. 7, so the different points will be explained.
180 is an intrusion sensor circuit, which includes a transmitting ultrasonic element and a receiving ultrasonic element (sensor: not shown).
The presence of an intruder (the presence or absence of human movement) is detected by The microcomputer 179 is an intrusion sensor circuit 180
send a signal at predetermined time intervals to
Receive data on the presence or absence of an intruder. If there is an intruder, a signal is basically sent to the buzzer circuit 176 and the operating indicator LED circuit 178 to generate a buzzer sound and turn on the LED. (It will be locked. The reset is done by the intrusion switch 62 of the master device 12.)
made by. )Also, almost at the same time, the parent device 12
sends a signal that there is an intruder. This transmission is repeated at specific time intervals. Intrusion sensor slave device 3
The operation of No. 8 is different from that of other security devices. That is, when the intrusion switch 62 provided in the master device 12 is turned on or off, the master device 12 transmits a command (signal) to turn on or turn off the alarm operation to the intrusion sensor child device 38. This mode of operation is carried out in the same manner as in the case of a control slave. When the microcomputer 179 of the intrusion sensor subdevice 38 receives this off command, it does not send a signal to the buzzer circuit 176 even if it detects the presence of an intruder, and therefore no buzzer sound is generated. (Sends a signal to the operating LED circuit 178.) Also,
A signal indicating an intrusion is not sent to the master device 12. In addition,
This sensing method may be another method such as one using an infrared sensor, and the microcomputer 179 performs a similar operation.

Next, the general flowchart of the microcomputer 179 will be briefly described. This general flowchart is the same as FIG. Points different from the explanation regarding the parent device 12 will be described. First, in the initialization process, the alarm operation is set to OFF. Also,
Processing regarding SCANs 1 to 4 is not performed. Key determination processing is not performed. Further, the data of the unit code setting switch circuit 117 is performed at the start-up processing position of SCAN1. Security processing is performed at the start-up processing position of SCAN3. Microcomputer 1
In this security process, 79 sends a drive signal to the intrusion sensor circuit 180 and sends data (intrusion).
It performs processing related to signal reception, and also sends drive signals to the operating display LED circuit 159 and buzzer circuit 158. Although the general flowchart has been explained, the specific flowchart includes the processing routines described above. Also, in the block diagram of the circuit configuration of the security slave, each sensor circuit 141,
Even if 160 and 180 are simply used as interface circuits and a commercially available security device is connected, the same operation is performed. In addition, when AC voltage (power) is supplied to the indoor power supply lines 7, 8, 4, and 5 in the master unit 12 and slave units 16, 23, 30, 34, and 38 in Fig. 1, at the time of transmission, A slight deviation was provided (depending on the type). This changes the priority of transmission to slave device 30, slave device 34, slave device 38, and master device 1.
2, child device 23, and child device 16.

Note that although the PWM method is used for communication in this embodiment, other methods may be used, such as a method using FM or PPM.

Further, in FIG. 6, the connection point of the load ON/OFF detection circuit 117 may be at the position of the electric wire 120 or at the position of the electric wire 15 connected to the receptacle 121, and the effects of the present invention will not be affected by this.
Furthermore, in FIGS. 6 and 1, the effects of the present invention can be obtained even if the output of the A/D conversion circuit 186 is 2 bits or less or more than 2 bits. By increasing the number of bits, it is possible to support multi-stage load control. Conversely, if you set it to 1 bit, there will be no processing related to signals 0 and 1, and the conditions will be 0 and 0.
The result is a judgment of only 1,1. In the case of this one bit, the amount of current flowing corresponding to 0 and 1 may be used as the threshold value (memory value, change value), and the high impedance circuit 183 may be omitted. In addition, microcomputer 1
13 stores the state of the load ON/OFF detection circuit 117, but the effects of the present invention will not change even if it is stored in other storage means.
When the output of the A/D conversion circuit 186 is set to 1 bit, the storage means may be replaced with reference signal generation means, and the effects of the present invention will not be lost even in this case.

In addition, the system may be a slave device other than a crime prevention or disaster prevention sensor (security), that is, a slave device of an environmental sensor such as a bath side sensor or a rain detection sensor, or a system having both of them may be used.

The present invention is also effective in a system equipped with an alarm slave device that receives transmission signals from a security slave device and issues an alarm. The present invention is also effective in a system provided with slave devices.

Although the signal from the negative feedback circuit supplied to the microcomputer, that is, the signal at the fundamental oscillation frequency of the microcomputer, is used as the carrier of the carrier wave, a transmitting circuit may be used in which the frequency of this signal is divided and transmitted. Also,
A dedicated oscillation circuit may be provided.

In addition, the lamp unit may be provided with a dimming function,
Furthermore, a wireless remote control function using infrared rays, ultrasonic waves, radio waves, etc. may be provided.

Further, the present invention is effective even if the parent device or the slave device is provided with a voice generation function based on voice synthesis, and furthermore, an operation function based on voice recognition.

Note that at least one of the parent device and the slave device may be provided with a lock mechanism or the like for prohibiting key (switch) input.

Moreover, in the key inputs of the parent device during transmission and reception, only the last series of key inputs may be valid.

Note that the present invention is also effective even if a small filter is provided to prevent noise from entering from the outlet. Further, a sealing type security device or the like may be provided.

Furthermore, a master device or slave device having a timer function may be provided.

The present invention can also be used when one of a plurality of intrusion sensor child devices is selected by the parent device to turn on/off the alarm.

Note that a parent device that can be connected (communicated) with a telephone may be provided, and a demand (total current amount detection control) function may also be provided.

Furthermore, it may also include a type of home appliance that incorporates a control slave or the like.

As described above, according to the present invention, load control becomes a closed loop and becomes reliable, and a remote parent device can monitor the actual status of the load, thereby improving reliability and ease of use. can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of a central monitoring control system in which a control slave device according to the present invention is used, FIG. 2 is a front view showing an example of the external shape of the parent device shown in FIG. 1, and FIG. 2 is a block diagram showing one circuit configuration of the parent device, FIG. 4 is a diagram showing an example of a time chart of the circuit configuration of FIG. 3, and FIG.
Figures 6 to 4 are diagrams showing an example of the general flowchart of the microcomputer of the master unit, Figure 6 is a block diagram showing one circuit configuration of the appliance slave unit of Figure 1, and Figure 7 is the same as that of Figure 1. Figure 8 is a block diagram showing the circuit configuration of the fire sensor slave unit, Figure 8 is a block diagram showing the circuit configuration of the gas sensor slave unit shown in Figure 1, and Figure 9 is a block diagram showing the circuit configuration of the intrusion sensor slave unit shown in Figure 1. The block diagram shown in Figure 10 is the load ON/OFF detection circuit 11.
FIG. 7 is a block diagram showing one circuit configuration of No.7. 12...Main unit, 16...Appliance slave unit,
23...Lamp subunit, 30...Fire sensor subunit,
34... Gas sensor slave device, 38... Intrusion sensor slave device, 117... Load ON/OFF detection circuit, 182
...Current (magnetic) sensor, 186...A/D conversion circuit.

Claims (1)

[Scope of Claims] 1. A control slave device of a centralized monitoring and control system that is connected between a power supply line and a load, is connected to a parent device via a signal transmission path, and is centrally monitored and controlled by the parent device, a transmitting/receiving means connected to the signal transmission path; a load control means for controlling the supply of power from the power supply line to the load; and detecting the amount of current flowing from the power supply line to the load by magnetic coupling. a current detection means for controlling the load control means according to at least one of a reception signal by the transmission and reception means and an output of the current detection means, and a discrimination control means for controlling the load control means and transmitting control contents or control results to the transmission and reception means. and the load control means and the current detection means are arranged so that the load, the load control means, and the current detection means are connected in series to the power supply line. Control child of the system. 2. In claim 1, when controlling the load control means, the output of the current detection means is stored, and based on this stored value, it is determined whether or not there is a change in the output of the current detection means thereafter. A control slave device for a centralized monitoring control system, characterized in that the discrimination control means controls the load control means and causes the transmission/reception means to transmit data when a change greater than a value occurs. 3. The control of the centralized monitoring and control system according to claim 1, wherein the load control means includes a switch section such as a relay contact, and a high impedance section connected in parallel with the switch section. Child organ. 4. The control slave device for a centralized monitoring and control system according to claim 1, wherein the power supply line is a signal transmission path.