JP2000172324A - Controller for unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller which can execute maintenance and inspection without stopping the operation of a unit. SOLUTION: A signal line 22 wired in a unit, a control box 9 connected to the signal line 22, a switch element 28 which is connected to the signal line 22 and controls the operation of fitted parts and the DC power source 23 of the switch element 28 are installed. The switch means 28 is provided with a switch means, a storage means holding a self-ID code, a transmission/reception means transferring data with the control box 9 through the signal line 22 and a switch element side control means controlling the switch means based on data from the transmission/reception means. The switch element side control means holds the state of detached time when the control box 9 is detached from the signal line 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for equipment such as a commercial / home refrigerator, a low-temperature showcase, a prefabricated refrigerator, an air conditioner, and a vending machine.

[0002]

2. Description of the Related Art Conventionally, for example, a commercial refrigerator incorporates a compressor, a condenser, a cooler and the like constituting a cooling device, or a compressor and a condenser are separately provided, and a refrigerant discharged from the compressor is provided. Is condensed in a condenser and depressurized by a decompression device, and then supplied to a cooler to exert a cooling effect. Cooling to low temperature.

In addition, frost formed on the cooler by the cooling operation is heated and melted by a defroster (defrost heater), and dew adhering by a cooling action is removed by heating by a dew-proof heater. On the other hand, a condenser fan is provided around the compressor and the condenser, and the condenser fan is air-cooled by the condenser fan.

In order to perform such various operation controls,
The refrigerator is equipped with a controller constituted by a microcomputer. Further, various sensors for detecting the temperature of the inside of the refrigerator, the cooler, and the condenser are mounted, and switches for controlling the operation of mounted components such as a compressor, a defroster, a dew-proof heater, and a fan in the refrigerator are also mounted. And the controller controls the operation of the mounting parts by each switch.

[0005]

SUMMARY OF THE INVENTION In such a refrigerator,
Maintenance to check the status of each switch
Inspection), disconnect the controller from the control system,
Instead, it is extremely preferable to be able to perform work by connecting a personal computer for maintenance.However, in the past, each switch returns to the initial state immediately after disconnecting the controller. There was a problem.

The present invention has been made to solve the above-mentioned conventional technical problems, and provides a control device capable of performing maintenance and inspection without stopping the operation of the equipment. .

[0007]

A control device according to the present invention controls a signal line wired to a device, main control means connected to the signal line, and operation of a mounting part connected to the signal line. A switching element, and a power supply for the switching element. The switching element includes switching means, storage means having its own ID code, and transmission / reception means for exchanging data with the main control means via a signal line. When,
And a switching element-side control means for controlling the switching means based on the data from the transmission / reception means.When the main control means is disconnected from the signal line, the switching element-side control means changes the state at the time of the disconnection. It is characterized by holding.

According to a second aspect of the present invention, in addition to the above, the device control device further comprises switching means for disconnecting the main control means from the signal line and enabling connection of the external control device to the signal line. Is connected to the signal line, and the switching element exchanges data with an external control device via the signal line.

According to the present invention, the switching element side control means of the switching element controls the switching means based on the data from the main control means received by the transmission / reception means via the signal line. The control of the device can be executed without any trouble. In this case, since the switching element has its own ID code in the storage means, by connecting the switching element to the signal line, the main control means can identify the switching element, and the wiring of the switching element is completed. .

Thus, the switching elements can be wired by so-called plug-in, and the wiring can be significantly simplified.

In particular, a power supply for the switching element is provided, and the switching element side control means keeps the state at the time of the disconnection when the main control means is disconnected from the signal line. The switching means disconnects the main control means from the signal line by the switching means, and connects the external control device to the signal line to exchange data with the switching element. When performing maintenance and inspection of
Since the switching element retains the state at the time when the main control unit is disconnected, the operation state of the device can be maintained without any trouble even during the maintenance.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic sectional view of a commercial refrigerator 1 as an embodiment of a device to which the present invention is applied, and FIG. 2 is a wiring diagram of an electric system of the refrigerator 1. In FIG. 1, a refrigerator 1 has a main body 5 composed of a heat insulating box 2 opening to the front, and a storage room 3 inside the heat insulating box 2. The front opening of the storage room 3 is closed by a door 4 so that it can be opened and closed. In the storage room 3, a cooler 6 constituting a refrigeration cycle of the cooling device and an in-compartment fan 7 driven by a motor are provided.

A defroster (electric heater) 30 (FIG. 2) for defrosting is attached to the cooler 6, and a dew-proof heater 8 for preventing dew condensation is provided on the opening edge of the heat insulating box 2.
Is provided, and an operation panel 11 of a control box 9 as a main control means is attached to a front surface of the door 4.

On the other hand, a machine room 12 is formed below the heat insulating box 2, and in the machine room 12, together with the cooler 6, a compressor 1 constituting a refrigeration cycle of a cooling device.
3, a condenser 14, a condenser fan 16, and the like.

When the compressor 13 is operated, the high-temperature and high-pressure refrigerant discharged from the compressor 13 radiates heat in the condenser 14 to be condensed, is decompressed by a decompression device (not shown), and is supplied to the cooler 6. Is done. In the cooler 6, the refrigerant evaporates and exerts a cooling function. Thereafter, the low-temperature gas refrigerant returns to the compressor 13 again. When the in-compartment fan 7 is operated, the cool air cooled by the cooler 6 is circulated into the storage room 3, whereby the storage room 3 is cooled.

When the condenser fan 16 is operated, outside air flows through the condenser 14 and the compressor 13, so that the air is cooled. Further, the defroster 30 is energized every predetermined time or at a predetermined time. When the defroster 30 is energized, heat is generated and the cooler 6 is heated to perform defrosting. Furthermore, when the dew-proof heater 8 is energized, the opening edge of the heat-insulating box 2 is heated to prevent dew condensation.

Next, in FIG. 2, reference numeral 21 denotes an AC power supply line wired in the main body 5 of the refrigerator 1, and reference numeral 22 denotes a signal line for transmitting and receiving data. The AC power line 21 is connected to the compressor 13, the fans 7, 16 and the defroster 3.
0, while being connected to the drive substrate 26 of the dew-proof heater 8,
The control box 9 and the drive board 26 are connected to the signal line 22.

The signal line 22 has a chip-shaped internal temperature sensor 27 as a sensor for detecting the temperature in the storage room 3.
A chip-shaped defrost sensor 10 as a sensor for detecting the temperature of the cooler 6; a chip-shaped high-temperature sensor 20 as a sensor for detecting the temperature of the condenser 14; and a plurality of chips attached to the drive board 26 Are connected via connectors.

Further, a memory 25 as a storage device is attached to the drive board 26, and is connected to the signal line 22. Further, a DC power supply 23 composed of a rectifier circuit is further attached to the drive board 26. This DC power supply 23
Is Vc from the commercial AC power supplied from the AC power line 21.
c power source (for example, DC + 5V), and
To the control box 9. The Vcc power generated by the DC power 23 is also supplied to the memory 25.

The drive board 26 has a switching element 2
8 are provided for the compressor 13, the fans 7 and 16, the defroster 30, and the dew-proof heater 8.

The structure of the control box 9 is shown in FIG.
Shown in The control box 9 is provided with a controller (substrate) 36. This controller 36
It comprises a CPU (microcomputer) 31, a memory 32 as storage means, an I / O interface 33, a bus I / O interface 34 as transmission / reception means, and the like. The control box 9 has a display 37 formed of a liquid crystal display panel, a switch 38 as input means (keyboard, mouse, etc.),
A switching device 39 or the like as switching means is provided. The display 37 and the switch 38 are connected to an I / O interface 33 and disposed on the operation panel 11.

The bus I / O interface 3
Reference numeral 4 is connected to the signal line 22 via the switch 39, and exchanges data with the temperature sensor 27, the switching elements 28,... Via the signal line 22. An external laptop PC P (external control device) or the like can be connected to the switch 39 via a communication line 42. The switch 39 always connects the bus I / O interface 34 and the signal line 22, but when the personal computer P is connected, the bus I / O interface 34 (that is, the control box 9) is connected to the signal line 22. Then, the personal computer P is connected to the signal line 22.

The controller 36 includes a predetermined communication protocol for performing data communication with the internal temperature sensor 27, the defrost sensor 10, the high temperature sensor 20, the switching element 28, the memory 25, and the personal computer P, and the sensors 27 to be described later. , 10, 20 and software for searching for and identifying the switching element 28 are set. The personal computer P searches for a predetermined communication protocol for performing data communication with the sensors 27, 10, 20 and the switching element 28, the memory 25 and the controller 36, and the sensors 27, 10, 20, and the switching element 28 to be described later. It is assumed that software and the like for identification by setting are set.

Next, FIG. 4 shows the configuration of the inside temperature sensor 27, the defrost sensor 10, and the high temperature sensor 20. still,
Since the sensors 27, 10, and 20 have the same configuration, the internal temperature sensor 27 will be described below. The internal temperature sensor 27 includes a CPU 43 as a sensor-side control unit, a memory 44 as a storage unit, and an I / O as a transmission / reception unit.
The interface 46, the A / D converter 47, and the A
It comprises a sensor unit 48 as a detecting element connected to the / D converter 47, a capacitor 49 as a power storage element, a diode 51 as a rectifying element, and the like.

In this case, the capacitor 49 is connected to the diode 5
1, and each element is connected to a connection point between the diode 51 and the capacitor 49. And
A potential (high potential) of, for example, +5 V is applied to the signal line 22, and data is composed of pulses that fall from the high potential to a low potential of 0 V, for example.

The internal temperature sensor 27 has Vcc (D
A power supply terminal 45 is provided, which is connected to a connection point between the diode 51 and the capacitor 49, and the Vcc power supply terminal 45 is connected to the DC power supply line 24. Thus, each element operates by power supply from the DC power supply line 24.

The Vcc power supply terminal 45 is connected to the DC power supply line 24.
Temperature sensor 27 is connected to the signal line 22
Is connected, power is supplied to each element as it is while the high-potential and low-potential pulse signals constituting the data are at the high potential, and the capacitor 49 is also charged. And
Since the capacitor 49 is discharged while the potential is low, as long as there is a pulse signal on the signal line 22, the power of each element is covered.

Further, the CPU 43 takes in the temperature data detected by the sensor unit 48 via the A / D converter 47 and temporarily writes it into the memory 44. Then, the controller 36 is connected to the controller 36 via the signal line 22 by the I / O interface 46.
, The temperature data written in the memory 44 is transferred to the signal line 2 by the I / O interface 46.
2 to the controller 36.

Here, the internal temperature sensor 2 is stored in the memory 44.
7 stores an ID code of itself, identification data indicating that the sensor is a sensor, set value data such as a low temperature / high temperature alarm temperature, a protocol for performing data communication with the controller 36, and the like. If a failure occurs in the internal temperature sensor 27, the failure data is also written to the memory 44 and transmitted to the controller 36.

Further, the memory 44 stores sensor image data on the display 37 of the controller 36 and software for displaying the image data on the display 37 of the controller 36.

On the other hand, the structure of the switching element 28 is shown in FIG. The switching element 28 includes a CPU 58 as a switching element side control unit, a memory 59 as a storage unit, an I / O interface 61 as a transmission / reception unit, an I / O interface 62 as a driver, and an I / O interface 62 as a driver. , A transistor 63 as a switching means, a capacitor 64 as a power storage element, a diode 66 as a rectifying element, and the like.

In this case, the capacitor 64 is connected to the diode 6
6, and each element is connected to a connection point between the diode 66 and the capacitor 64. The switching element 28 is provided with a Vcc (DC + 5V) power supply terminal 55, which is connected to a connection point between the diode 66 and the capacitor 64. The Vcc power supply terminal 55 is connected to the DC power supply line 24. Thus, each element operates by power supply from the DC power supply line 24.

The Vcc power supply terminal 55 is connected to the DC power supply line 24.
, The switching element 28 is connected to the signal line 2
2, power is supplied to each element as it is while the high-potential and low-potential pulse signals constituting data are at the high potential, and the capacitor 64 is also charged. Since the capacitor 64 is discharged while the potential is low, the power of each element is covered as long as the signal line 22 has a pulse signal.

When ON / OFF data is transmitted from the controller 36 via the signal line 22 by the I / O interface 61, the CPU 58 turns ON / OFF the ON / OFF data.
The transistor 63 is turned on / off by the I / O interface 62 based on the F data. CPU5
8 indicates the current operating state (ON or OF) when ON / OFF data is not transmitted from the controller 36.
F) is self-holding.

Here, the memory 59 stores an ID code of the switching element 28 itself, identification data indicating that the element is a switching element, a protocol for performing data communication with the controller 36, and the like. If a failure has occurred in the switching element 28, the data is also written into the memory 59, and the controller 36
Sent to.

Further, the memory 59 stores switching element image data to be displayed on the display 37 of the controller 36 and software for displaying the image data on the display 37 of the controller 36.

Each switching element 28 is wired on the drive board 26 as shown in FIG.
8. That is, 69 is a photocoupler composed of a photodiode 69A and a phototriac 69B, 71 is a resistor, 72 is a diode as a rectifying element,
74 is a capacitor as a storage element.

In this case, the capacitor 74 is connected to the diode 7
2 is connected between the connection point of the diode 72 and the capacitor 74 and the collector terminal (indicated by S2 in FIG. 5) of the transistor 63 of the switching element 28.
1 and the photodiode 69A are connected in series. The terminal S1 (FIG. 5) of the switching element 28 is connected before the diode 72. The phototriac 69B is interposed between the AC power line 21 and the compressor 13, the fans 7, 15, the defroster 30, and the dew-proof heater 8, respectively.

A Vcc power supply terminal 60 is connected to a connection point between the diode 72 and the capacitor 74, and the Vcc power supply terminal 60 is connected to the DC power supply line 24. Thus, the photodiode 69A operates by power supply from the DC power supply line 24.

When the diode 72 is connected to the signal line 22, power is supplied to the photodiode 69A via the resistor 71 as long as the high-potential and low-potential pulse signals constituting data are at the high potential. The capacitor 74
Is also charged. While the potential is low, the capacitor 74 is discharged from the capacitor 74 to supply power to the photodiode 69A. Therefore, even if the Vcc power supply terminal 60 is not connected to the DC power supply line 24,
As long as there is a pulse signal, the switching unit 68 operates.

The memory 25 on the drive board 26 includes:
Stores data on the correspondence between the switching elements 28 on the drive board 26, the compressors 13, the fans 7, 16, the anti-condensation heater 8, and the defroster 30. In this case, the correspondence is the I
The memory 2 is used as a data table showing the correspondence between the D code and, for example, a part code of each of the compressor 13, the fans 7 and 16, the dew-proof heater 8 and the defroster 30.
5 is stored.

Then, the controller 36 operates the memory 2
The data communication to each of the switching elements 28 is performed with reference to the data table in FIG. The creation of the data table in the memory 25 is performed in an inspection process during the production of the refrigerator 1.

The operation of the above configuration will be described. First, it is assumed that the personal computer P is not connected to the switch 39, and the operation during production of the refrigerator 1 will be described. Each sensor 2
7, 10, 20 and the switching element 28.
2 is connected to the controller 36 (C
PU 31) firstly connects each element (sensor 27,
10, 20, the connection status of the switching elements 28...) Is searched.

In this case, the controller 36 sends IDs to all the sensors 27, 10, 20 and the switching elements 28.
Make a request and in response all sensors 27, 10, 2
0, the switching element 28... Replies its own ID code or the like to the controller 36. The controller 36 is connected to the internal temperature sensor 27, the defrost sensor 10 and the high temperature sensor 20 on the signal line 22 based on the returned ID code and the like, and the switching element 28 for the compressor 13 and the switching element for the defroster 30. 2
8. It is recognized that the switching elements 28 for the internal fan 7 and the switching element 28 for the dew-proof heater 8 (actually, there is also a condenser fan) are connected.

The controller 36 stores the connection status of the recognized temperature sensors 27, 10, 20 and the switching elements 28,... In the memory 32, and thereafter transmits data to each element using the ID code. become.

The sensors 27, 10, and 20 upload the sensor image data in the respective memories 44 and software for displaying the sensor image data to the controller 36 via the signal line 22. Further, from each of the switching elements 28,..., The switching element image data in the respective memory 59 and software for displaying the switching element image data are transmitted to the controller 36 via the signal line 22.
Will be uploaded to.

The CPU 31 of the controller 36 stores the uploaded sensor image data of the sensors 27, 10, 20, the switching element image data of the switching elements 28, and software in the memory 32.

Then, based on the recognition result, the controller 36 further displays windows W1 to W7 as shown in FIG. The switching elements (control I / O) 28 are displayed side by side in correspondence with each other.

When any one of the sensors or the switching elements is removed from the signal line 22, the controller 36 deletes the corresponding window. Also,
Conversely, if a sensor or switching element is added, the image data and software
6 and the controller 36 additionally displays a corresponding window.

Next, in the inspection process of the refrigerator 1, the personal computer P is connected to the switch 39. At this time, the controller 36 is disconnected from the signal line 22 as described above. In this state, from the personal computer P, the memory 2 is connected via the signal line 22.
5, parameters (data) such as the type (freezing / refrigeration), control method, and function (temperature zone) of the refrigerator 1 are written.

Thereafter, the personal computer P is disconnected from the switch 39, and the controller 36 is connected to the signal line 22 again.
When the controller 36 is connected to the signal line 22, the controller 36 accesses the memory 25, reads the parameters written as described above from the memory 25, and holds the parameters in its own memory 32. Thus, the setting of the parameters from the personal computer P to the controller 36 is completed.

Next, the controller 36 is turned ON / OFF.
The data is transmitted to the signal line 22 together with the ID codes of the switching elements 28 and 28 corresponding to the compressor 13 and the in-compartment fan 7, and the cooling operation is started by activating the compressor 13 and the in-compartment fan 7. Then, the CPU 31 of the controller 36 polls the sensors 27, 10, and 20 at a predetermined cycle. This polling is performed based on the above-mentioned ID code. CPU for sensors 27, 10, 20
43 transmits the temperature data to the controller 36 in response to the polling. The CPU 31 of the controller 36 once writes the received temperature data in the memory 32, and then performs the function assignment of each sensor based on the transition of the temperature data after starting the cooling operation.

That is, if the temperature according to the temperature data has risen after a certain period of time after the start of the cooling operation, the controller 36 assigns a function to the effect that the sensor of the ID is the high-temperature sensor 10 and the memory 32 To memorize. If the temperature according to the temperature data has dropped and the temperature is relatively high, the controller 36 performs a function assignment to the effect that the sensor of the ID is the internal temperature sensor 27 and stores the function in the memory 32. Further, when the temperature according to the temperature data is lowered and the temperature is relatively low, the controller 36 performs a function assignment to the effect that the sensor of the ID is the defrost sensor 20 and stores the function in the memory 32. Thus, the function of each sensor is assigned to the controller 36 without setting in advance.

Next, the actual control operation after the installation of the refrigerator 1 will be described. The CPU 31 of the controller 36 polls the sensors 27, 10, and 20 at a predetermined cycle as described above. This polling is performed based on the above-mentioned ID code. CPU 43 of sensors 27, 10, and 20
Transmits the temperature data to the controller 36 in response to the polling as described above. CPU 3 of controller 36
1 temporarily writes the received temperature data into the memory 32, compares the temperature data from the internal temperature sensor 27 with the set temperature in the parameters set as described above, and outputs ON / OFF data to the compressor 13. Is transmitted to the signal line 22 together with the ID code of the switching element 28.

When the CPU 58 of the switching element 28 receives the ON / OFF data of its own ID code, it turns ON / OFF the transistor 63 based on the received data as described above.
I do. By turning ON / OFF the transistor 63, the photodiode 69A turns ON (light emission) / OFF (turns off).
And the photo triac 69B is turned ON /
The compressor 13 is started /
Stopped.

The CPU 31 of the controller 36
The ON / OFF data is transmitted to the signal line 22 together with the ID code of the switching element 28 of the defroster 30, and the defroster 30 is energized at a predetermined cycle or at a predetermined time to defrost the cooler 6. Then, based on the temperature data from the defrost sensor 10 received as described above, defrost control of the cooler 6 (end at a predetermined temperature) is executed.

Since the fans 7, 16 and the dew-proof heater 8 are continuously energized, ON / OFF data to that effect is
It is transmitted based on the ID code of each switching element 28. Then, each switching element 28 is connected to the ON / O
The fan 7 or 16 or the dew-proof heater 8 is operated or energized based on the FF data.

Here, the display unit 3 by the controller 36 is used.
7 and 8 will be described with reference to FIGS. 8 and 9. FIG. Although FIG. 8 shows the window W1 corresponding to the in-compartment temperature sensor 27, the other sensors 10 and 20 are the same, and the description is omitted. The controller 36 is provided with the internal temperature sensor 2
Based on temperature data from 7, graphic G of thermometer
The temperature in the storage room 3 (hereinafter referred to as the internal temperature) is indicated by 1 and the numerical value N1.

The angle of the arrow graphic G2 indicates whether the inside temperature is currently rising, has not changed (shown), or has dropped. Furthermore, the numerical value N
2, the high temperature alarm temperature and the low temperature alarm temperature are displayed by N3,
When the trend frame G3 is clicked, the history of the internal temperature is displayed in a graph (another window).

Next, FIG. 9 shows a window W4 corresponding to the switching element 28 of the compressor 13, but the other switching elements 28 are the same, and the description is omitted. The controller 36 opens and closes the switching element 28 (OFF / O of the compressor 13) by the switch graphic G4 based on the ON / OFF data.
N) Display status. The OPEN / CLOSE display G5 displays the status in characters.

The controller 36 controls each sensor 27,
If the temperature data from any of the sensors does not change after the start of operation based on the temperature data from 10 and 20, it is determined that the sensor has failed. If the temperature data from all the sensors does not change, it is determined that the cooling device itself such as the compressor 13 has failed. If the temperature data from the sensor cannot be acquired, it is determined that the line to the sensor has been disconnected.

Further, even when data from the switching elements 28.
Is determined to be a failure or disconnection. CP of controller 36
When such a failure occurs, U31 displays the sensor 27, 10, 20 or the switching element 28 on the display 37.
To indicate that a failure has occurred.

On the other hand, the controller 36 writes history data relating to the operation history and the failure history of the refrigerator 1 to the memory 25 based on the data from the sensors 27, 10, and 20 and the switching elements 28.

Next, maintenance of the refrigerator 1 (maintenance
When performing (inspection), the personal computer P is connected to the switch 39. As a result, the controller 36 is disconnected from the signal line 22 as described above, and the personal computer P is connected to the signal line 22 instead. When a predetermined key operation is performed on the personal computer P, the personal computer P accesses the memory 25 and reads the written history data.

The personal computer P exchanges data between the sensors 27, 10, 20 and the switching elements 28,... Via the signal line 22, and the sensors 27, 10, 20 and the switching elements 28,. Capture the current state of.
As a result, the operating state and the history of the failure of the refrigerator 1 and the current state are taken into the personal computer P and can be checked, so that a service person or the like can perform maintenance very quickly and accurately.

In particular, in this case, since the controller 36 is once disconnected from the signal line 22, the switching element 28
Cannot receive the ON / OFF data, but in the case described above, the CPU 58 of the switching element 28 keeps the current ON / OFF state by itself, so that the compressor 13 and the fans 7, 16 and the like are maintained even during the maintenance. The operation state can be maintained without any trouble.

Although the embodiment has been described with reference to a sensor for detecting temperature, the present invention is also effective as a humidity sensor or a pressure sensor by using an element for detecting humidity or pressure as the sensor section.

Further, in the embodiments, the present invention has been described using a commercial refrigerator. However, the present invention is not limited to this. The present invention is also effective for home automation and security systems.

[0069]

As described above in detail, according to the present invention, the switching element side control means of the switching element controls the switching means based on data from the main control means received by the transmission / reception means via the signal line. The main control means of the device can execute the control of the device without any trouble. In this case, the switching element stores its own I
Since the D code is possessed, the main control means can identify the switching element by connecting the switching element to the signal line, and the wiring of the switching element is completed.

As a result, the switching elements can be wired by a so-called plug-in, and the wiring can be significantly simplified.

In particular, since a power supply for the switching element is provided, and the switching element side control means holds the state at the time of disconnection when the main control means is disconnected from the signal line. The switching means disconnects the main control means from the signal line by the switching means, and connects the external control device to the signal line to exchange data with the switching element. When performing maintenance and inspection of
Since the switching element retains the state at the time when the main control unit is disconnected, the operation state of the device can be maintained without any trouble even during the maintenance.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a commercial refrigerator according to an embodiment of the present invention.

FIG. 2 is an electrical wiring diagram of the refrigerator of FIG. 1;

FIG. 3 is a block diagram of an electric circuit of the control box.

FIG. 4 is a block diagram of an electric circuit of the temperature sensor.

FIG. 5 is a block diagram of an electric circuit of the switching element.

FIG. 6 is an electric circuit diagram of a switching unit using a switching element.

FIG. 7 is a diagram illustrating a display state of a display unit of a control box.

FIG. 8 is a diagram showing a window corresponding to the internal temperature sensor displayed on the display.

FIG. 9 is a view showing a window corresponding to the switching element of the compressor displayed on the display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerator 6 Cooler 7 In-compartment fan 8 Dew-proof heater 9 Control box 10 Defrost sensor 13 Compressor 14 Condenser 16 Condenser fan 20 High temperature sensor 22 Signal line 23 DC power supply 24 DC power supply line 25 Memory 27 In-house temperature sensor 28 Switching Element 30 Defroster 31, 43, 58 CPU 32, 44, 59 Memory 37 Display 39 Switch 42 Communication line 45, 55, 60 Vcc power supply terminal 46, 61 I / O interface 48 Sensor unit 49, 64 Capacitor 51, 66 Diode 63 Transistor 69 Photocoupler 69A Photodiode 69B Phototriac P PC

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsumi Maekawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Kazuya Imamura 2--5 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Tsutomu Ishikura 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5H223 AA11 AA15 CC08 DD03 EE02 EE08 EE22

Claims (2)

[Claims] 1. A signal line wired to a device, main control means connected to the signal line, a switching element connected to the signal line for controlling operation of a mounting component, and a power supply for the switching element. The switching element comprises: a switching unit, a storage unit having its own ID code, a transmission / reception unit for transmitting / receiving data to / from the main control unit via the signal line, and based on data from the transmission / reception unit. A switching element-side control means for controlling the switching means, wherein the switching element-side control means, when the main control means is disconnected from the signal line, holds a state at the time of the disconnection. A control device for equipment. And a switching unit for disconnecting the main control unit from the signal line and enabling connection of an external control device to the signal line, wherein the switching element is connected to the signal line while the external control device is connected to the signal line. 2. The device control device according to claim 1, wherein data is transmitted to and received from the external control device via a device.