Air conditioner and method of controlling the same

Abstract

An air conditioner and a method of controlling the air conditioner are disclosed. It is an aspect of the present invention to provide an air conditioner and a method of controlling the air conditioner, which is capable of improving a structure to supply stable power, and effectively reset an outdoor unit and at least one indoor unit, in a multi-unit type air conditioner that is operated with the plurality of indoor units connected to the outdoor unit through a communication line. The air conditioner further includes reset control units, which are provided on the outdoor unit and the at least one indoor unit, respectively, to receive a reset signal transmitted through the communication line and to reset the outdoor unit or the at least one indoor unit.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 2003-78743, filed Nov. 7, 2003 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Apparatuses and methods consistent with the present invention relate, in general, to an air conditioner and, more particularly, to a multi-unit type air conditioner that is operated with a plurality of indoor units connected to a single outdoor unit through a communication line and a refrigerant line.

2. Description of the Related Art

In a multi-unit type air conditioner in which a plurality of indoor units are connected to a single outdoor unit through a single communication line, a unique address is set for each of the indoor units to allow communications to be smoothly performed between the outdoor unit and the indoor units. When each of the indoor units transmits a temporary address to the outdoor unit to set a unique address, the outdoor unit sets a unique address of the indoor unit to the received temporary address, or generates a unique address corresponding to the received temporary address and assigns the indoor unit the unique address.

In the multi-unit type air conditioner, the outdoor unit and all of the indoor units communicate with each other through the single communication line and are supplied with power through a single power line. The outdoor unit takes charge of the communications and the power supply. Furthermore, when a control unit (microcomputer) provided on each of the indoor units is not properly operated, the outdoor unit also takes charge of a reset to initialize the control unit.

Resets of an outdoor unit and indoor units in a conventional multi-unit type air conditioner are performed by cutting off power supply to the outdoor unit and resuming the power supply. It is possible to reset the outdoor unit and the indoor units all together under a charge of the outdoor unit as described above, since the outdoor unit and the indoor units are constructed to be supplied with power through a single power line.

SUMMARY OF THE INVENTION

Illustrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any of the problems described above.

Accordingly, it is an aspect of the present invention to provide an apparatus and a method of controlling an air conditioner, which is capable of improving a structure so as to supply stable power, and effectively reset an outdoor unit and indoor units, in a multi-unit type air conditioner that is operated with a plurality of indoor units connected to a single outdoor unit through a communication line.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, of may be learned by practice of the invention.

In particular, the present invention contemplates, an air conditioner including an outdoor unit, at least one indoor unit, and reset control units. The at least one indoor unit is connected to the outdoor unit through a communication line. The reset control units are provided on the outdoor unit and the at least one indoor unit, respectively, to receive a reset signal transmitted through the communication line and to reset the outdoor unit or the at least one indoor unit.

It is also contemplated that an embodiment of the present invention includes a method of controlling an air conditioner including one of the outdoor unit and the at least one indoor unit generating a reset signal and transmitting the reset signal through the communication line, and a remaining one of the outdoor unit and the at least one indoor unit receiving the reset signal transmitted through the communication line and being reset.

It is further contemplated that the present invention provides a method of controlling an air conditioner including the outdoor unit being first reset in response to resumption of power supply when the power supply to the outdoor unit and the at least one indoor unit was discontinued and the power supply is resumed, and the reset outdoor unit resetting the at least one indoor unit.

Also provided is a method of controlling an air conditioner including at least one of the plurality of indoor units being set as a master indoor unit, the master indoor unit generating a reset signal to reset the outdoor unit when the outdoor unit may not generate reset signals to reset the plurality of the indoor units, and the outdoor unit receiving the reset signal generated from the master indoor unit and being reset.

According to a further non-limiting aspect of the invention, there is provided an air conditioner including an outdoor unit, at least one indoor unit, and power supply units. The at least one indoor unit is connected to the outdoor unit through a communication line, and the power supply units are provided on the outdoor unit and the at least one indoor unit, respectively, to individually supply power to the outdoor unit and the at least one indoor unit.

According to a further aspect of the present invention, there is provided means for receiving a reset signal transmitted through the communication line and for resetting at least one of the outdoor unit and the at least one indoor unit. The means for receiving being provided on the outdoor unit and the at least one indoor unit, respectively. The means for receiving of the at least one indoor unit detects whether a communication signal input through the communication line corresponds to the reset signal and generates a first reset control signal if it is determined that the communication signal corresponds to the reset signal. The means for receiving of the outdoor unit detects whether the communication signal input through the communication line corresponds to the reset signal and generates a second reset control signal if it is determined that the communication signal corresponds to the reset signal.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a block diagram showing a construction of a multi-unit type air conditioner, according to a non-limiting, illustrative embodiment of the present invention;

FIGS. 2A to 2B are block diagrams showing constructions of an outdoor unit and each of indoor units of FIG. 1, according to the present invention;

FIG. 3 is a waveform diagram of a reset signal transmitted through a communication line of the present invention;

FIGS. 4A to 4B are views showing reset control units of FIGS. 2A to 2B; and

FIGS. 5 to 7 are flowcharts showing a non-limiting, illustrative method of controlling the air conditioner of the present invention.

DETAILED DESCRIPTION OF NON-LIMITING, ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

An air conditioner and a method of controlling the air conditioner according to embodiments of the present invention are described with reference to FIGS. 1 to 7 below. FIG. 1 is a block diagram showing a construction of a multi-unit type air conditioner according to an non-limiting embodiment of the present invention. As shown in FIG. 1, a plurality of indoor units 104a to 104h and a single outdoor unit 102 are connected to each other through a refrigerant line 108, and form a single refrigerant cycle. The plurality of the indoor units 104a to 104h are commonly connected to the outdoor unit 102 through a single communication line 106, and the outdoor unit 102 takes charge of communications. Power supply units 116 and 110a to 110h are provided to the outdoor unit 102 and the plurality of the indoor units 104a to 104h, respectively, thus individually supplying power to the outdoor unit 102 and the plurality of the indoor units 104a to 104h. Furthermore, circuit breakers 112 and 114a to 114h are connected to the outdoor unit 102 and the plurality of the indoor units 104a to 104h, respectively, so that the power supply to the outdoor unit 102 and the plurality of the indoor units 104a to 104h is cut off by the circuit breakers 112 and 114a to 114h when an abnormality (for example, caused by a lightning bolt or overvoltage) in the power supply to the outdoor unit 102 and the plurality of the indoor units 104a to 104h is incurred.

The outdoor unit 102 and the plurality of the indoor units 104a to 104h are each provided with one of the power supply units 116 and 110a to 110h and one of the circuit breakers 112 and 114a to 114h, so that the power supply unit 116 of the outdoor unit 102 has only a capability to supply an amount of power that the outdoor unit 102 requires, and also each of the power supply units 110a to 110h of the indoor units 104a to 104h has only a capability to supply an amount of power that each of the indoor units 104a to 104h requires. Accordingly, a structure, in which power is individually supplied to the outdoor unit 102 and the plurality of the indoor units 104a to 104h, considerably reduces a burden of power supply of the outdoor unit 102 than a structure, in which power is supplied to the indoor units 104a to 104h through the outdoor unit 102. Furthermore, the circuit breakers 112 and 114a to 114h are provided to the outdoor unit 102 and the indoor units 104a to 104h, respectively, so that a problem of stability of power supply is individually taken care of by the outdoor unit 102 and the indoor unit 104a to 104h and, thus, a burden of ensuring the stability of the power supply, which an outdoor unit 102 took care of in a conventional multi-unit type air conditioner, is considerably reduced.

FIGS. 2A to 2B are block diagrams showing constructions of the outdoor unit 102 and each of the indoor units 104a to 104h, respectively, each of which shows components regarding reset control. In this case, a reset is an operation of compulsory initializing a control unit (microcomputer) to be properly operated when the control unit provided on the outdoor unit 102 or each of the indoor units 104a to 104h is not properly operated.

As shown in FIGS. 2A to 2B, the outdoor unit 102 and indoor units 104a to 104h of the multi-unit type air conditioner each include one of reset control units 212 and 202, one of reset drive units 214 and 204, and one of control units 216 and 206.

The reset control units 212 and 202 distinguish reset signals from general communication signals, and generate reset control signals 212a and 202a when the reset signals are received, respectively. The control units 216 and 206 correspond to microcomputers, and control overall operations of the outdoor unit 102 and the indoor units 104a to 104h, respectively. The reset drive units 214 and 204 respond to the reset control signals 212a and 202a, respectively, and then reset the control units 216 and 206, respectively. The reset drive unit 214 of the outdoor unit 102 responds to not only a reset control signal 212a but also a variation of power 208 input through the power supply unit 116 shown in FIG. 1 and then resets the control unit 216 of the outdoor unit 102. In this case, the variation of the power 208 may be exemplified by an increase of a source voltage lower than a critical level above the critical value.

The communication line is directly connected to each of the control units 206 and 216, and the above-described structure enables each of the control units 206 and 216 to determine whether a reset signal currently transmitted through the communication line 106 is directed thereto. If the reset signal currently transmitted through the communication line is not directed thereto, each of the control units 206 and 216 do not receive the reset signal.

FIG. 3 is a view showing a construction of a reset signal 302 transmitted through a communication line, according to the multi-unit type air conditioner of the present invention. As shown in FIG. 3, an electrical characteristic of the reset signal 302 is that a voltage signal having a uniform level (for example, 5 V) is maintained for a predetermined time t_r, which is used to allow the reset signal to be distinguished from general communication signals transmitted and received between the outdoor unit 102 and the indoor units 104a to 104h. A data signal 304 having an address of the outdoor unit 102 or one of the indoor units 104a to 104h to be reset is generated in front of the reset signal 302. The outdoor unit 102 and/or irrelevant indoor units reject the reset signal 302 without an address thereof attached, so that only an outdoor unit 102 or one of the indoor units 104a to 104h, which is not properly operated, is reset in response to the reset signal 302.

FIGS. 4A to 4B are views showing the reset control units of FIGS. 2A to 2B. As shown in FIG. 4A, a reference signal of 5 V is input to a non-inverting input terminal (+) of a comparator 402a, and a communication signal transmitted through the communication line 106 is input to an inverting input terminal (−). The reset signal has an electrical characteristic in which a Direct Current (DC) having 5 V is maintained for a predetermined time t_r and the reference signal also has a same electrical characteristic. The reset control unit 202 is a unit to detect whether a communication signal transmitted through the communication line 106 corresponds to the reset signal. When the reset signal is received through the communication line 106, the comparator 402a generates the reset control signal 202a of a positive value and operates the reset drive unit 204. In an exemplary case, the reset drive unit 204 is operated only while the reset control signal 202a maintains the positive value for the predetermined time t_r, like the reset signal.

FIG. 4B is a view showing a construction of another reset control unit 202′, which is based on a delay relay 402b. The delay relay 402b has a characteristic in which, if a signal having a special condition is input for a constant time, the delay relay is excited and then turned on. When the reset control unit 202 receives the communication signal through the delay relay 402b, allows the delay relay 402b to be excited and turned on only if the received communication signal has a same electrical characteristic (for example, DC voltage of 5 V is maintained for the predetermined time) as the reset signal and thus generates the reset control signal 202a. In an exemplary embodiment, the delay relay 402 may operate the reset drive unit 204 in response to only the reset signal.

FIGS. 5 to 7 are flowcharts showing a method of controlling the air conditioner of the present invention. FIG. 5 is a flowchart showing a process of resetting the indoor units 104a to 104h under the charge of the outdoor unit 102. Resets are needed to initialize control units of part or all of the indoor units 104a to 104h when the control units are not properly operated in operation 502. The outdoor unit 102 generates address data and reset signals for the indoor units, which are not properly operated, to reset the indoor units in operation 504. Since an indoor unit whose control unit 206 is not properly operated may not directly receive a reset signal, the reset control unit 202 and the reset drive unit 204 located in front of the control unit 206 are operated by the reset signal and reset the control unit 206 in operation 506. Meanwhile, the indoor units, which are properly operated, reject the reset signals because the addresses included in the reset signals are not the addresses thereof. Accordingly, only the indoor units, which are not properly operated, receive the reset signals and are reset.

FIG. 6 is a flowchart showing a process of resetting the outdoor unit 102 and the indoor units 104a to 104h when power supply was discontinued due to a hindrance and is resumed. If the power supply is discontinued due to a hindrance, such as a lightning bolt or overvoltage, the outdoor unit 102 and all of the indoor units 104a to 104h are not operated in operation 602. If the power supply is resumed thereafter in operation 604, the control unit 216 of the outdoor unit 102 is first reset and re-operated in operation 606. As shown in FIG. 2B, the reset drive unit 214 of the outdoor unit 102 resets the control unit 216 of the outdoor unit 102 in response to not only the reset control signal 212a but also a variation of the power 208 input through the power supply unit 116, so that an automatic reset of the outdoor unit 102 is performed as the power supply is resumed. When the outdoor unit 102 is reset and re-operated, the outdoor unit 102 tracks and resets the indoor units 104a to 104h simultaneously in operation 608. The tracking of the indoor units 104a to 104h performed by the outdoor unit 102 is an operation of the outdoor unit 102 detecting whether each of the indoor units 104a to 104h exists through communications. In this case, only some of the indoor units 104a to 104h, which are determined to exist, are reset.

FIG. 7 is a flowchart showing a process of resetting the outdoor unit 102 when the control unit 216 of the outdoor unit 102 is not properly operated. If the control unit 216 of the outdoor unit 102 taking charge of the communications with the indoor units 104a to 104h is not properly operated, the control unit 216 may not reset the indoor units 104a to 104h as well as the outdoor unit 102 in operation 702. Accordingly, one of the indoor units 104a to 104h is set as a master indoor unit, like the indoor unit 104a shown in FIG. 1, and the master indoor unit 104a performs a reset of the outdoor unit 102 when the outdoor unit 102 is not properly operated. The master indoor unit 104a transmits a reset signal to the outdoor unit 102, which is not properly operated, to reset the outdoor unit 102 in operation 704. The outdoor unit 102 is reset by the reset signal transmitted from the master indoor unit 104a in operation 706. After the outdoor unit 102 is reset, resets of the indoor units 104a to 104h are performed under a charge of the outdoor unit 102. That is, the reset outdoor unit 102 determines whether one or more indoor units to be reset (that is, indoor units that are not properly operated) exist in operation 708, and transmits reset signals to the indoor units if the indoor units, which are not properly operated 710. All the indoor units 104a to 104h may be set as master indoor units to provide against a situation in which the outdoor unit 102 and the master indoor unit 104a are not properly operated. In this case, priorities are assigned to the indoor units 104a to 104h, so that, when an indoor unit having a highest priority is not properly operated, an indoor unit having a next higher priority is operated as the master indoor unit, thus improving stability of reset control.

An air conditioner and a method of controlling the air conditioner according to the present invention allow power to be individually supplied to an outdoor unit and indoor units, thus reducing a size of a power supply unit of the outdoor unit and reducing a burden on the outdoor unit, thus, making it more stable. Furthermore, the air conditioner and the method of controlling the air conditioner are capable of selectively resetting the outdoor unit and the indoor units, so that the air conditioner and the method are effective in that time that is typically required to re-operate a compressor provided on the outdoor unit is reduced and a number of reoperating times is considerably reduced. Additionally, the air conditioner and the method of controlling the air conditioner use an existing communication line, so that it is not necessary to install additional communication lines to reset components, even in a structure that individually supplies power.

Although a few exemplary embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. An air conditioner, comprising:

an outdoor unit;

at least one indoor unit connected to the outdoor unit through a communication line; and

reset control units provided on the outdoor unit and the at least one indoor unit, respectively, to receive a reset signal transmitted through the communication line and to reset at least one of the outdoor unit and the at least one indoor unit.

2. The air conditioner as set forth in claim 1, wherein:

the at least one indoor unit is reset by a reset signal generated from the outdoor unit; and

the outdoor unit is reset by a reset signal generated from the at least one indoor unit.

3. The air conditioner as set forth in claim 2, wherein:

a plurality of indoor units are provided, and at least one of the indoor units is set as a master indoor unit; and

the master indoor unit generates the reset signal to reset the outdoor unit.

4. The air conditioner as set forth in claim 1, wherein:

the outdoor unit and the at least one indoor unit each comprise a control unit; and

the reset signal is a signal to reset each of the control units.

5. The air conditioner as set forth in claim 4, wherein:

the reset signal is attached with an address of at least one of the outdoor unit and the indoor unit to be reset; and

only the outdoor or the indoor unit designated by the address is reset in response to the reset signal.

6. The air conditioner as set forth in claim 1, wherein the reset signal has an electrical characteristic which is distinguished from general communication signals transmitted through the communication line.

7. The air conditioner as set forth in claim 6, wherein:

the reset control unit of the at least one indoor unit is a first reset control unit to detect whether a communication signal input through the communication line corresponds to the reset signal and to generate a first reset control signal if it is determined that the communication signal corresponds to the reset signal; and

the reset control unit of the outdoor unit is a second reset control unit to detect whether the communication signal input through the communication line corresponds to the reset signal and to generate a second reset control signal if it is determined that the communication signal corresponds to the reset signal.

8. The air conditioner as set forth in claim 7, wherein the first and second reset control units each comprise a comparator to respectively: receive a reference signal having a same electrical characteristic as the reset signal, receive the communication signal transmitted through the communication line, compare the communication signal with the reference signal, determine that the reset signal has been generated if the reference signal and the communication signal coincide with each other, and generate the first reset control signal and the second reset control signal.

9. The air conditioner as set forth in claim 7, wherein the first and second reset control units each comprise a delay relay to respectively: receive the communication signal transmitted through the communication line, and be turned on when the communication signal has a same electrical characteristic as the reset signal, and generate the first reset control signal and the second reset control signal.

10. The air conditioner as set forth in claim 9, wherein the electrical characteristic of the reset signal includes a voltage signal having a constant level which is maintained during predetermined time.

11. The air conditioner as set forth in claim 7, wherein the at least one indoor unit further comprises a first reset drive unit to generate a first reset drive signal to reset a control unit thereof, the first reset drive unit generates the first reset drive signal in response to the first reset control signal generated from the first reset control unit.

12. The air conditioner as set forth in claim 7, wherein the outdoor unit further comprises a second reset drive unit to generate a second reset drive signal to reset a control unit thereof, the second reset drive unit generates the second reset drive signal in response to at least one of the second reset control signal generated from the second reset control unit and a predetermined variation of supplied power.

13. A method of controlling an air conditioner in which at least one indoor unit is connected to an outdoor unit through a communication line, power is individually supplied to the outdoor unit and the at least one indoor unit, and the outdoor unit and the at least one indoor unit receive reset signals transmitted through the communication line and are reset, comprising:

generating a reset signal and transmitting the reset signal through the communication line by one of the outdoor unit and the at least one indoor unit; and

receiving the reset signal transmitted through the communication line by the other one of the outdoor unit and the at least one indoor unit, such that the other one is reset.

14. The method as set forth in claim 13, wherein the at least one indoor unit comprises a first control unit, a first reset control unit, and a first reset drive unit, the method further including,

controlling overall operations of the at least one indoor unit with the first control unit;

detecting, with the first reset control unit, whether a communication signal input through the communication line corresponds to the reset signal and generating a first reset control signal if it is determined that the communication signal corresponds to the reset signal; and

generating a first reset drive signal, with the first reset drive unit, to reset the first control unit, the first reset drive unit generating the first reset drive signal in response to the first reset control signal generated from the first reset control unit.

15. The method as set forth in claim 13, wherein the outdoor unit comprises a second control unit, a second reset control unit, and a second reset drive unit, the method further including,

controlling overall operations of the outdoor unit with the second control unit;

detecting, with the second reset control unit, whether a communication signal input through the communication line corresponds to the reset signal and generating a first reset control signal if it is determined that the communication signal corresponds to the reset signal; and

generating a second reset drive signal, with the second reset drive unit, to reset the second control unit, the second reset drive unit generating the second reset drive signal in response to at least one of the second reset control signal and a predetermined variation of supplied power.

16. The method as set forth in claim 13, further including, attaching the reset signal with an address of one of the outdoor unit and the at least one indoor unit which is to be reset; and

wherein only the one of the outdoor unit or the at least one indoor unit designated by the address is reset in response to the reset signal.

17. A method of controlling an air conditioner in which at least one indoor unit is connected to an outdoor unit through a communication line, power is individually supplied to the outdoor unit and the at least one indoor unit by a power supply, and the outdoor unit and the at least one indoor unit receive reset signals transmitted through the communication line and are reset, comprising:

resetting the outdoor unit first in response to resumption of the power supply when the power supply to the outdoor unit and the at least one indoor unit is discontinued and resumed; and

resetting the at least one indoor unit with the reset outdoor unit.

18. The method as set forth in claim 17, wherein the at least one indoor unit comprises a plurality of indoor units, and the outdoor unit, when re-operated by the reset, tracks a plurality of the indoor units and resets the plurality of the indoor units.

19. The method as set forth in claim 17, wherein the at least one indoor unit comprises a first control unit, a first reset control unit, and a first reset drive unit, the method further including,

controlling overall operations of the at least one indoor unit with the first control unit;

detecting, with the first reset control unit, whether a communication signal input through the communication line corresponds to the reset signal and generating a first reset control signal if it is determined that the communication signal corresponds to the reset signal; and

generating, with the first reset drive unit, a first reset drive signal to reset the first control unit, the first reset drive unit generating the first reset drive signal in response to the first reset control signal generated from the first reset control unit.

20. The method as set forth in claim 17, wherein the outdoor unit comprises a second control unit, a second reset control unit, and a second reset drive unit, the method further including,

controlling overall operations of the outdoor unit the second control unit;

detecting, with the second reset control unit, whether a communication signal input through the communication line corresponds to the reset signal and generating a first reset control signal if it is determined that the communication signal corresponds to the reset signal; and

generating, with the second reset drive unit, a second reset control signal to reset the second control unit, the second reset drive unit generating the second reset drive signal in response to at least one of the second reset control generated from the second reset control unit and a predetermined variation of supplied power.

21. A method of controlling an air conditioner in which a plurality of indoor units are connected to an outdoor unit through a communication line, power is individually supplied to the outdoor unit and the plurality of the indoor units, and the outdoor unit and the plurality of the indoor units receive reset signals through the communication line and are reset, comprising:

setting at least one of the plurality of indoor units as a master indoor unit;

generating, with the master indoor unit, a reset signal to reset the outdoor unit when the outdoor unit may not generate reset signals to reset the plurality of the indoor units; and

receiving, with the outdoor unit, the reset signal generated from the master indoor unit and being reset.

22. The method as set forth in claim 21, further including,

attaching each of the reset signals with an address of the outdoor unit or one of the plurality of indoor units to be reset; and

wherein only the outdoor unit or one of the plurality of indoor units designated by the address is reset in response to the each of the reset signals.

23. An air conditioner, comprising:

an outdoor unit;

at least one indoor unit connected to the outdoor unit though a communication line; and

power supply units to individually supply power to the outdoor unit and the at least one indoor unit.

24. The air conditioner as set forth in claim 23, wherein the power supply unit of the outdoor unit is adapted to supply power corresponding to that required by the outdoor unit.

25. The air conditioner as set forth in claim 23, further comprising circuit breakers provided on the outdoor unit and the at least one indoor unit, respectively, to cut off at least one of the power supply to the outdoor unit and the at least one indoor unit when an abnormality of power supply to the outdoor unit and the at least one indoor unit is incurred.

26. An air conditioner, comprising:

an outdoor unit;

at least one indoor unit connected to the outdoor unit through a communication line;

power supply units to individually supply power to the outdoor unit and the at least one indoor unit; and

reset control units provided on the outdoor unit and the at least one indoor unit, respectively, to receive a reset signal transmitted through the communication line and to reset at least one of the outdoor unit and the at least one indoor unit.

27. An air conditioner, comprising:

an outdoor unit;

at least one indoor unit connected to the outdoor unit through a communication line; and

means for receiving a reset signal transmitted through the communication line and for resetting at least one of the outdoor unit and the at least one indoor unit, the means for receiving provided on the outdoor unit and the at least one indoor unit, respectively.

28. The air conditioner as set forth in claim 27, wherein the means for receiving of the at least one indoor unit detects whether a communication signal input through the communication line corresponds to the reset signal and generates a first reset control signal if it is determined that the communication signal corresponds to the reset signal; and

the means for receiving of the outdoor unit detects whether the communication signal input through the communication line corresponds to the reset signal and generates a second reset control signal if it is determined that the communication signal corresponds to the reset signal.

29. The air conditioner as set forth in claim 28, wherein the means for receiving of the at least one indoor unit and the means for receiving of the outdoor unit each respectively: receive a reference signal having a same electrical characteristic as the reset signal, receive the communication signal transmitted through the communication line, compare the communication signal with the reference signal, determine that the reset signal has been generated if the reference signal and the communication signal coincide with each other, and generate the first reset control signal and the second reset control signal.