JPH06303679A - Detector for system-down of remote control system - Google Patents

Abstract

PURPOSE:To detect system-down of a slave set early with simple configuration. CONSTITUTION:When a power failure takes place in a power supply of an indoor equipment 2, a voltage V applied to a reset circuit 11 is being decreased. When the voltage V is decreased to a preset voltage (e.g. 4.5V), an output of the reset circuit 11 goes to an L level and a reset output is provided. Thus, a cathode side of a light emitting diode D1 of a photocoupler CP1 goes to an L level, the light emitting diode D1 is turned on and the photocoupler CP1 is turned on. That is, a voltage E0 between bus lines L1 and L2 is decreased to 1/2-1/3 (e.g. nearly 5V) of a stationary voltage by the presence of a resistor R1 by turning on a photo transistor(TR) Q1 or Q2 of the photocoupler CP1. The system-down of the indoor equipment 2 is easily recognized by allowing an outdoor equipment to detect a voltage drop of the bus lines L1 and L2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control system such as an air conditioning control system in which at least one outdoor unit and a plurality of indoor units are connected via a pair of bus lines. The present invention relates to a system down detecting device of a remote control system suitable for detecting the system down.

[0002]

2. Description of the Related Art FIG. 8 is a schematic block diagram of a conventional air conditioning control system for business use, showing an outdoor unit 1 as one master unit and an indoor unit 2 (three units in this example) as plural slave units. Indoor unit 2 ₁
Shows a _~ 2, but not limited to three) and are connected by a bus line L. When a transmission signal is transmitted from the outdoor unit 1 to each indoor unit 2 via the bus line L and the indoor unit 2 has its own address matched, the indoor unit 2 is controlled based on the control data following the address data. It is like this. Here, the data transmission method between the outdoor unit 1 and each indoor unit 2 is a polling method. In this polling method, the outdoor unit (parent device) 1 is each indoor unit (child device) 2 _1.
Are sequentially accessed to monitor the state of the indoor unit 2.
Therefore, when a certain indoor unit 2 goes down due to a momentary power failure or unexpected power off, the outdoor unit 1
It is possible for the side to detect the system down immediately.

[0003]

By the way, in the case of the CSMA / CD system as shown in FIG. 9, since communication with the connection terminal (indoor unit 2 or central control terminal 3) is made only when necessary, communication with the connection terminal is performed. Very few to do (1 in 5 minutes
About times). Therefore, there is a problem that it is difficult to detect the system down of the terminals 2 and 3 (detected due to transmission abnormality).

For example, when the compressor of the outdoor unit 1 in the cooling mode is in operation and the system of the indoor unit 2 goes down due to a momentary power failure or unexpected power off, liquid refrigerant returns from the indoor unit 2 and It adversely affects reliability. Therefore, in such a case, the outdoor unit 1 becomes the indoor unit 2 as soon as possible.
It is necessary to stop the compressor of the outdoor unit 1 as soon as possible by detecting the system down.

In the so-called inside / outside transmission system shown in FIG. 8, since the polling method is adopted by the independent local bus for only inside / outside transmission, the system down of the indoor unit can be detected immediately, but as shown in FIG. In the case of the CSMA / CD system, the outdoor unit 1 and the indoor unit 2 communicate with each other only when necessary as described above, and therefore it takes too much time to detect the system down. In other words, in the CSMA / CD system,
The connection terminal sends data on the transmission line (bus line L) as needed, but in order to prevent the traffic on the transmission line from increasing, it is a system that does not perform periodic transmission such as polling as much as possible. Therefore, it takes quite a long time (about 5 minutes) to detect the transmission abnormality.

In the CSMA / CD system as well, as means for informing the outdoor unit of the system down of the indoor unit,
A method as shown in FIGS. 10 and 11 can be considered. That is, FIG. 10 shows a method using a backup power source, and shows a block diagram of a main part of the indoor unit (terminal) 2. Reference numeral 21 in the figure denotes a power supply unit that receives power from an AC power supply AC that is separately wired and supplies power to each circuit in the indoor unit 2. Further, the data transmission unit 22 is for notifying the outdoor unit, which is the parent device, of a system down of the indoor unit 2 such as a power failure. Further, a backup power supply 24 composed of a rechargeable battery is provided, and the power supply unit 21 is always charged. The power supply unit 21 and the backup power supply 24 are switched by the switch element 23, and the power is supplied from the power supply unit 21 to the data transmission unit 22 under normal conditions. When the system goes down, such as an instantaneous power failure or unexpected power off, the power supply unit 21 detects this and the switch element 23
Is switched to the backup power supply 24 side.
As a result, the power source of the data transmitting unit 22 is supplied from the backup power source 24. In this way, when a power failure is detected (when the system is down), the backup power supply 24 is switched to and transmission abnormal data is sent from the data transmission unit 22 to the outdoor unit via the bus line L.

However, in the case of FIG. 10, the backup power supply 24 is required for this purpose,
Moreover, a considerably large capacity backup power supply 24 is required in order to send out data with abnormal transmission.

As another method, as shown in FIG. 11, there is a method in which power is supplied from the bus line L. In this method, since data is superimposed and transmitted from the outdoor unit to the DC power supply for polarity determination for non-polarity correspondence, power is supplied from this DC power supply to the power supply unit 25 as the backup power supply via the bus line L. It is a thing. Figure 1
As in the case of 0, power is supplied from the power supply unit 21 to the data transmission unit 22, but when the system goes down, the power supply unit 21
Detects a power failure, switches the switch element 23 to the power supply unit 25 side, and supplies power from the backup power supply unit 25 to the data transmission unit 22. And when there is an instantaneous power failure,
The system down information (abnormal transmission data) is sent from the data transmission unit 22 onto the bus line L.

However, even in the method shown in FIG. 11, the current capacity supplied from the bus line L is originally a DC current for polarity determination, and the capacity is small, and the data transmission section 22 for transmitting the transmission abnormality data is used. There is a problem that can not drive.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to detect a system down of a remote control system capable of quickly detecting a system down of a slave unit with a simple structure. To provide a device.

[0011]

Therefore, in a system down detecting device of a remote control system according to a first aspect of the present invention, a master unit 1 and a plurality of slave units 2 are connected via a pair of bus lines L ₁ and L _2. Each of the slaves 2 is connected to a load, and a direct-current power on which a transmission signal is superimposed is supplied from the master 1 to each slave 2 via the bus lines L ₁ and L ₂ , and each slave 2 is connected to the slave 2. The connected loads are individually supplied with power from the power line, and the load is controlled via the slave unit 2 by the transmission signal from the master unit 1, and data is transmitted only between the master unit 1 and the slave unit 2 when necessary. In the remote control system adapted to perform transmission, each slave unit 2
In addition, the detecting means 11 for detecting the power supply voltage on the load side, and the pair of bus lines L by receiving a signal from the detecting means 11 when the power supply voltage drops when the system of the slave unit 2 side is down due to an instantaneous power failure or the like. ₁ and a control unit CP ₁ for lowering the voltage between L ₂ for a certain period of time to notify the master unit 1 side of the system down of the slave unit 2.

According to a second aspect of the present invention, there is provided a system down detecting device for a remote control system, wherein the remote control system is an air conditioning control system including at least one outdoor unit 1 and a plurality of indoor units 2. Outdoor unit 1 and child unit 2
Is the indoor unit 2.

Further, the system down detecting device of the remote control system according to claim 3 is characterized in that the detecting means is constituted by the reset circuit 11 of the microcomputer and the controlling means is constituted by the photocoupler CP ₁ .

[0014]

According to the system down detecting device of the remote control system of the _{first aspect} , the voltage between the pair of bus lines L ₁ and L ₂ is controlled by the control means CP ₁ at the time of system down due to momentary power failure or unexpected power off. When the master unit 1 side detects the voltage drop between the bus lines L ₁ and L ₂ only by lowering the voltage for a certain period of time, the master unit 1 side can quickly know the system down of the slave unit 2 side. With the configuration of this device, conventionally, it took about 5 minutes to detect a system down, but it can now be detected within 1 second.
Therefore, the subsequent processing can be smoothly transferred, measures can be taken when the system is down, and damage can be eliminated or minimized.

Further, according to the system down detecting device of the remote control system of the second aspect, the system down of the indoor unit 2 can be promptly known on the outdoor unit 1 side, so that the compressor of the outdoor unit 1 should be stopped early. You can Therefore, the reliability of the air conditioning control system is not impaired.

Further, according to the system down detecting device of the remote control system of the third aspect, the detecting means is constituted by the reset circuit 11 of the microcomputer, and the controlling means is constituted by the photocoupler CP _1. With such a configuration, it is possible to detect the system down, and it is possible to reduce the cost.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the system down detecting device of the remote control system of the present invention will be described in detail with reference to the drawings. The transmission system according to the present embodiment is a CSMA / CD system, and FIG. 3 shows a schematic configuration diagram of a home bus system that is designed to be non-polarized.

To the bus line L, for example, three terminals, terminals A to C, are connected, and from each of the terminals A to C, an AM is connected.
A transmission signal having an I waveform is transmitted. Figure 4
(A) shows the transmission waveform of the terminal A, and (b) shows the transmission waveform of the terminal B. Further, FIG. 4C shows a waveform on the bus line (transmission path) L. Here, terminal A and terminal B
If the two start transmission at the same time, the terminal A and the terminal B compete with each other, and the terminal A has different transmission data and reception data as shown in FIG. In the pulse, the terminal A detects the loss of contention and stops transmitting data from the terminal A thereafter. On the other hand, in the terminal B, even if the terminal B competes with the terminal A, the terminal B wins and continues the data transmission. The waveform on the bus line L in this case is the waveform shown in FIG.

In the case of FIG. 4, the terminals A and B compete normally (when the transmission polarities match), and
As shown in FIG. 5, when terminals having different transmission polarities compete with each other, both terminals stop transmitting data and data is not transmitted. That is, as shown in FIGS. 5A and 5B, the polarity of the transmission waveform of the terminal A and the polarity of the transmission waveform of the terminal B are 1
In the case of a shift of 80 ° (reverse polarity), if the terminal B having the opposite polarity and the normal terminal A compete with each other, the stard bit and the data are canceled and normal transmission cannot be performed. FIG. 5C shows a waveform on the bus line L in this case. Therefore, as shown in FIG. 4, the transmission polarities (the polarities of the start bits) must be matched in order to perform a normal competition.

FIG. 6 shows a structure in which power is superimposed on a pair of bus lines L ₁ and L ₂ , and a DC power source E for superimposition is connected to the pair of bus lines L ₁ and L _{2 on the} terminal side which is a master unit. Connected in between, the voltage E of the DC power supply E is superimposed on the bus lines L ₁ and L ₂ . Then, from the terminal of the master unit to the other terminals via the bus lines L ₁ and L ₂ , together with the power from the DC power source E, the data is superimposed and transmitted via the driver 5. In the figure, 6 is a receiver for receiving data from other terminals, and 7 and 8 are bus lines L ₁ and L _2.
It is a photocoupler for detecting the presence or absence of a power source and the polarity.

FIG. 7 shows an AMI waveform when data is superimposed on the DC power source E. As described above, the first normal stard bit has a plus side waveform. If the start bit on the minus side as shown by the broken line in FIG. 7 is used, the polarities become opposite and the terminals cannot normally compete with each other, and data transmission cannot be performed normally.

Next, specific examples of the present invention will be described. FIG. 1 shows a circuit diagram of a main part of an indoor unit 2 as a slave unit (terminal). In the present invention, when the system is down due to a momentary power failure or unexpected power off, the data is superimposed on the bus lines L ₁ and L ₂ together with transmission data. DC power supply for polarity determination (Fig. 6
The DC power source E) shown in (3) is short-circuited (or a state close to a short-circuit) for a certain period of time. In the master unit (outdoor unit), the power supply voltage for polarity determination is constantly monitored, and the system down of the indoor unit is known by detecting a decrease in this voltage.

In FIG. 1, reference numeral 11 is a reset circuit of a microcomputer for controlling the indoor unit 2, and a voltage V is applied as a power source of the reset circuit 11.
The voltage V is a power source from an AC power source that is separately supplied to the indoor unit 2, and the voltage V is monitored by the reset circuit 11. The reset circuit 11 is composed of a dedicated IC. CP ₁ is a photocoupler, and includes a light emitting diode D ₁ on the light emitting side and a pair of phototransistors Q ₁ and Q ₂ on the light receiving side. Photo coupler C
The phototransistors Q ₁ and Q ₂ side of P ₁ are connected to the pair of bus lines L ₁ and L ₂ via a resistor R ₁ .
The output terminal of the reset circuit 11 is connected to the cathode of the light emitting diode D ₁ of the photocoupler CP ₁ , and the output of the reset circuit 11 is L when the system is down.
The level signal is output. In addition, a photocoupler CP including a light emitting diode D ₂ and a phototransistor Q _3
2 is for detecting the system down for other terminals, the light emitting diode D ₂ via a Zener diode ZD ₁ is connected to a pair of bus lines L _1, L _2.

Next, the operation will be described with reference to FIGS. Here, the voltage E ₀ between the bus lines L ₁ and L ₂ is 15 to
The voltage V is 20V, and the voltage V supplied to the reset circuit 11 of the indoor unit 2 is 5V. When the voltage V drops to a preset voltage, for example, about 4.5V, the reset circuit 11 outputs an L level signal.

As shown in FIG. 2, when a power failure occurs in the power source on the indoor unit 2 side at time t ₁ , the voltage V supplied to the reset circuit 11 decreases. When the voltage V drops to 4.5V at time t _2, the output of the reset circuit 11 resets an output is issued at the L level, thereby become the cathode side of the light emitting diode D ₁ of the photocoupler CP ₁ becomes L level Then, the light emitting diode D ₁ is turned on,
The photocoupler CP ₁ is turned on. That is, when the phototransistor Q ₁ or Q _{2 of the} photocoupler CP ₁ is turned on, the voltage E ₀ between the bus lines L ₁ and L ₂ is about 1/2 to 1/3 of the steady value due to the presence of the resistor R ₁ . For example, about 5V
Fall to. By detecting the voltage drop of the bus lines L ₁ and L ₂ by the outdoor unit, it is possible to easily know the system down of the indoor unit 2 side. For example, when the photocoupler 7 or 8 shown in FIG. 6 reduces the voltage of the bus lines L ₁ and L ₂ , the photocoupler 7 or 8 is turned off,
The outdoor unit side can easily know that the system of the indoor unit has gone down. Note that, as shown in FIG. 2, when the voltage V further decreases, the light emitting diode D ₁ also turns off at time t ₃ , and the photocoupler CP ₁ turns off. Therefore, the voltage E ₀ between the bus lines L ₁ and L ₂ also returns to the original voltage value.

In the above embodiment, the voltage between the bus lines L ₁ and L ₂ is reduced to about 5 V when the system is down, but it may be completely short-circuited. Also, when the indoor unit system is down (when the power is turned off), the bus line L
_{If 1} and L ₂ are short-circuited (or voltage drop) and this state is continued for a long time, the polarity cannot be determined, so that other terminals cannot normally perform transmission. Therefore, in the present embodiment, when the system of the indoor unit is down, the bus lines L ₁ and L ₂ are short-circuited (or the voltage is reduced) for a certain time as described above, so that the entire transmission is not affected. . Further, in order to short-circuit the transmission path for a fixed time when the power supply of the terminal (indoor unit) is turned off (system down), the reset circuit 11 of the microcomputer and the photocoupler CP ₁ constitute the present invention.

Next, the operation of the photocoupler CP ₂ will be described. In the normal state, the voltage E ₀ between the bus lines L ₁ and L ₂ is 15 to 20 V, so the Zener diode ZD ₁ is on, and therefore the photocoupler CP ₂
Is turned on, and the collector potential of the phototransistor Q ₃ is
It is at the L level as shown in FIG. However, when the system of another terminal (indoor unit) goes down, the voltage between the bus lines L ₁ and L ₂ is lowered or short-circuited as described above, so that the Zener diode ZD ₁ is turned off and the photocoupler CP ₂ is turned off. Will also be off. Therefore, the collector potential of the phototransistor Q ₃ of the photocoupler CP ₂ becomes H level as shown in FIG. 2, and by detecting this H level signal, it is possible to detect that the system of another terminal is down (indoor unit). ) Can be found at.

Further, even when the terminal goes down, the photo coupler CP ₂ can similarly detect it. Therefore, this signal can be used to display the system down on the indoor unit side.

[0029]

According to the system down detection device of the remote control system of the first aspect, the control means only lowers the voltage between the pair of bus lines for a predetermined time when the system is down due to an instantaneous power failure or unexpected power off. By detecting the voltage drop between the bus lines on the master unit side, the master unit side can quickly know the system down on the slave unit side. With the configuration of this device, conventionally, it took about 5 minutes to detect a system down, but it can be detected within 1 second. Therefore, the subsequent processing can be smoothly transferred, and measures for system down can be taken. It can be done and the damage can be eliminated or minimized.

Further, according to the system down detecting device of the remote control system of the second aspect, the system down of the indoor unit can be quickly known on the outdoor unit side, so that the compressor of the outdoor unit can be stopped early. Therefore, the reliability of the air conditioning control system is not impaired.

Further, according to the system down detecting device of the remote control system of the third aspect, since the detecting means is constituted by the reset circuit of the microcomputer and the controlling means is constituted by the photocoupler, the constitution is simple. The system down can be detected, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a main part of an indoor unit (terminal) according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a home bus system according to an embodiment of the present invention.

FIG. 4 is an operation explanatory diagram in the case where the terminals normally compete with each other in the case where the transmission polarities match each other according to the embodiment of the present invention.

FIG. 5 is an operation explanatory diagram when the terminals compete with each other when the transmission polarities are opposite polarities in the embodiment of the present invention.

FIG. 6 is a circuit diagram of a main part of a master device according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram when data is superimposed on the DC power supply according to the embodiment of this invention.

FIG. 8 is a system configuration diagram of a polling method.

FIG. 9 is a system configuration diagram of a CSMA / CD system.

FIG. 10 is a circuit diagram of a main part of a conventional example.

FIG. 11 is a circuit diagram of a main part of another conventional example.

[Explanation of symbols]

1 outdoor unit 2 indoor unit 11 reset circuit CP ₁ photo coupler L ₁ bus line L ₂ bus line

Claims (3)

[Claims] 1. A parent device (1) and a plurality of child devices (2) are connected via a pair of bus lines (L ₁ ) (L ₂ ) and a load is applied to each of these child devices (2). Is connected to each slave device (2) via a bus line (L ₁ ) (L ₂ ) and a DC power source on which a transmission signal is superimposed is supplied from the master device (1) to each slave device (2). Each of the loaded loads is individually supplied with power from the power supply line, and the load is controlled via the slave unit (2) by the transmission signal from the master unit (1), and the master unit (1) and the slave unit (2) are controlled.
In the remote control system in which data transmission is performed only when necessary between the slave unit and each slave unit (2), a detection unit (11) for detecting the power supply voltage on the load side, and a slave unit (2) such as a momentary power failure. ) Side system down occurs when the power supply voltage drops, the signal from the detection means (11) is received to lower the voltage between the pair of bus lines (L ₁ ) (L ₂ ) for a certain period of time, and the master unit ( A system down detecting device for a remote control system, characterized in that a control means (CP ₁ ) for notifying a system down of a child device (2) is provided on the side 1). 2. The remote control system comprises at least one
It is an air conditioning control system comprising an outdoor unit (1) of more than one unit and a plurality of indoor units (2), and the master unit is an outdoor unit (1),
The system down detection device for a remote control system according to claim 1, wherein the slave unit (2) is an indoor unit (2). 3. The system down of the remote control system according to claim 1, wherein said detecting means is constituted by a reset circuit (11) of a microcomputer, and said controlling means is constituted by a photocoupler (CP). Detection device.