Abstract: A method for controlling a multi-unit air conditioner is disclosed which is capable of preventing frost from being formed on the outer surface of a refrigerant line. In order to control an air conditioner including an outdoor unit, a plurality of indoor units corresponding to the out door unit, and a plurality of refrigerant lines for connecting the indoor units to the outdoor unit, respectively, the method includes the steps of measuring respective states of the refrigerant lines using a measurement sensor, determining respective states of the refrigerant lines, based on measurement data obtained by the measurement sensor, and controlling an operation state of an operating one or operating ones of the indoor units, in accordance with the determined state of the refrigerant line associated with the operating indoor unit or each operating indoor unit.

Abstract: An air conditioner having a service valve assembly which comprises a connection body connected with a refrigerant pipe through which a refrigerant flows, and having a penetration passage through which the refrigerant flows; an opening/closing unit disposed in the connection body, and having a blocking hole for opening/closing the passage of the refrigerant flowing through the penetration passage; a plurality of ports disposed at the connection body, respectively, by a particular interval therebetween, connected with the penetration passage, and having an opened end portion, respectively; and a filter unit removably coupled to each end portion of the ports such that the refrigerant flowing through the penetration passage is bypassed to the ports to thus be filtered thereby, whereby it is possible to basically solve the problem in a blocking caused by moisture and foreign materials within a circulation system of the air conditioner, and to simplify the construction of the system by being provided with a filter

Abstract: An apparatus for monitoring an air conditioner is disclosed. The apparatus includes a first wireless device connected to the air conditioner, and a second wireless device connected to a monitoring terminal. The first wireless device transmits and receives monitoring result information and monitoring-related information based on a monitoring program installed in the monitoring terminal in a local-area wireless communication manner, and the second wireless device transmits and receives the monitoring-related information and monitoring result information based on the monitoring program in the local-area wireless communication manner. Therefore, local-area wireless communication can be carried out between the air conditioner and the monitoring terminal, thereby making it possible to significantly save trouble for installation of monitoring instruments, such as cables and a converter, and to significantly curtail costs and manpower for monitoring work.

Abstract: In a data transmission apparatus for transmitting data between a main system and a microcomputer a controller generates transmission control signals based on first control signals received from the main system, and a memory system receives the transmission control signals and second control signals from the microcomputer. The memory system transfers data between the main system and the microcomputer based on the transmission control signals and the second control signals.

Abstract: A data transmission apparatus for transmitting a data between a main system and a microcomputer which can apply to the system the microcomputer which is not provided with a logic circuit performing an interface with the main system, sense both the main system and microcomputer by using an error sensing bit to sense a problem in transmission, and improve a transmission speed of the system by increasing a size of the data to be processed at one time, includes: a signal controller sensing the data transmission and outputting first and second transmission control signals; a data transmission detector communicating the data transmission to the microcomputer according to the first control signal from the signal controller; and a double buffer latching the data for a predetermined period in order for the main system or microcomputer to read through a corresponding port the data to be transmitted according to the first and second transmission control signals from the signal controller, and a method thereof.