Patent Publication Number: US-2023134009-A1

Title: Heat-pump system, indicator, usage-side unit, and information output method

Description:
TECHNICAL FIELD 
     The present invention relates to a heat-pump system comprising a plurality of usage-side units and a plurality of indicators. 
     BACKGROUND ART 
     JP 2017 053509 A proposes a heat-pump system comprising a plurality of usage-side units and a plurality of indicators for outputting information relating to the heat-pump system. The indicators are connected to the usage-side units, respectively. Each usage-side unit is configured to send alarm information to the connecting indicator when a refrigerant leakage has occurred. Each indicator is configured to, when it has received the alarm information from the connecting usage-side unit, output the alarm information on its display. Thereby, it is possible to inform a user of each usage-side unit of the occurrence of the refrigerant leakage. 
     Meanwhile, there are cases in which alarm information of any of the usage-side units is desired to be outputted in one location. For example, in a monitoring room of a hotel, it is necessary for a monitoring person to promptly discern alarm information of any of air-conditioning units installed in different guest rooms. However, it is costly and burdensome to connect an information output device in the monitoring room to each of the air-conditioning units disposed in separate locations in order to obtain information therefrom. 
     Thus, as also proposed by JP 2017 053509 A, the usage-side units may form a communication network, and the information output device may be connected to this network via one of the usage-side units. Information originating from any of the usage-side units is transmitted in the network by means of communication signals, and then transferred to the information output device via one of the usage-side unit. Thereby, it is possible to allow the information output device to obtain information from each of the usage-side units without individual connections. Hence, the alarm information can be outputted from not only the indicator connected to the usage-side unit with an abnormality but also the information output device. 
     However, providing the information output device which has a configuration different from the indicators would also increase the system cost. Moreover, when the location in which all the alarm information should be outputted needs to be changed, moving and re-connecting the information output device would be burdensome. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] JP 2017 053509 A 
     SUMMARY OF INVENTION 
     The object of the present invention is to provide a heat-pump system with high manageability and high usability at a low cost. 
     A first aspect of the present invention provides a heat-pump system comprising a plurality of usage-side units and a plurality of indicators for outputting information relating to the heat-pump system, wherein: each usage-side unit has an indicator-side communication section configured to transmit first and second unit signals to a predetermined indicator which is one of the indicators, an inter-unit communication section configured to transmit and receive inter-unit signals to and from the other usage-side unit, an information originating section configured to originate alarm information, send the originated alarm information to the predetermined indicator by means of a first unit signal, and send the originated alarm information to the other usage-side unit by means of an inter-unit signal, and an inter-unit signal processing section configured to, when alarm information has been received from the other usage-side unit by means of an inter-unit signal, transfer the received alarm information to the predetermined indicator by means of a second unit signal, and, if there is the rest usage-side unit which has not originated nor received the received alarm information, transfer the received alarm information to the rest usage-side unit by means of another inter-unit signal; and each indicator has a mode management section configured to accept selection from a plurality of operation modes of the indicator including a first mode, a unit-side communication section configured to receive or acquire first and second unit signals from the usage-side unit, and an indicator output section configured to, when alarm information has been received or acquired by means of a second unit signal during the indicator is operating in the first mode, output the alarm information. 
     With this heat-pump system according to the first aspect, it is possible to switch, just by selecting the first mode or not, the behaviour of each indicator regarding whether to output alarm information originated by the usage-side unit other than the predetermined usage-side unit which transmits first and second unit signals to the indicator. Thereby, it is possible to easily and arbitrarily impart, to any of the indicators, a function to output alarm information regardless of its origin. An information output device having a configuration different from the indicators and dedicated to outputting all alarm information is not required anymore. Moreover, compared with a system in which an information output device is connected to each of the usage-side units, it is possible to easily install a central information output function. Hence, a refrigerant system with high manageability and high usability can be provided at a low cost. 
     According to a preferred embodiment of the refrigerant system mentioned above, the indicator output section is further configured to, when alarm information has been received or acquired by means of a first unit signal, output the alarm information. 
     With this configuration, the indicator can output alarm information regardless of its operation mode if the alarm information is originated by the predetermined usage-side. In the above-mentioned case of the hotel for instance, only information originated by the air-conditioning unit in the guest room may be important for a guest using the guest room, while all alarm information originated by any of the indoor-units may be important for the monitoring person. Thus, by the heat-pump system according to the above embodiment, both an information output suitable for a supervisor of the whole system and an information output suitable for a user of a specific usage-side unit can be achieved by the same indicator, and these different types of information output are selectable for each indicator as desired. Hence, it is possible to further improve the usability of the refrigerant system at low cost. 
     A second aspect of the present invention provides an indicator for outputting information relating to a heat-pump system including a plurality of usage-side units which form a communication network, comprising: a mode management section configured to accept selection from a plurality of operation modes of the indicator including a first mode; a unit-side communication section configured to receive or acquire first and second unit signals from a predetermined usage-side unit which is one of the usage-side units, the first unit signal being used for information originated by the predetermined usage-side unit, the second unit signal being used for information not originated by the predetermined usage-side unit; and an indicator output section configured to, when alarm information has been received or acquired by means of a second unit signal during the indicator is operating in a first mode, output the alarm information. 
     With this indicator according to the second aspect, it is possible to switch, just by selecting the first mode or not, the behaviour of each indicator regarding whether to output the alarm information originated by the usage-side unit other than the predetermined usage-side unit which transmits first and second unit signals to the indicator. Thereby, it is possible to easily and arbitrarily impart, to any of the indicators, a function to output alarm information regardless of its origin. An information output device having a configuration different from the indicators and dedicated to outputting all alarm information is not required anymore. Hence, a refrigerant system with high manageability and high usability can be provided at a low cost. 
     According to a preferred embodiment of the indicator mentioned above, the indicator output section is further configured to, when alarm information has been received or acquired by means of a first unit signal, output the alarm information. 
     With this configuration, the indicator can output alarm information regardless of its operation mode if the alarm information is originated by the predetermined usage-side unit. Hence, it is possible to further improve the usability of the refrigerant system at low cost. 
     According to another preferred embodiment of any one of the indicators mentioned above, the indicator further comprises: a unit signal processing section configured to, when information has been received or acquired by means of a second unit signal during the indicator is not operating in the first mode, restrain the information from being outputted by the indicator output section. 
     With this configuration, the indicator does not output the alarm information if the first mode is not selected and the alarm information is not originated by its predetermined usage-side unit, while allowing other information to be outputted. In other words, when the first mode is selected, the indicator outputs alarm information originating from any of the plurality of usage-side units, and, when the first mode is not selected, the indicator outputs alarm information only if it is originated by the predetermined usage-side unit. Thereby, it is possible to output various information from the indicators while limiting the output of alarm information to the case where the predetermined unit of the indicator has originated the alarm information and the case where the first mode has been selected to the indicator. Hence, it is possible to further improve the usability of the refrigerant system at low cost. 
     According to further another preferred embodiment of any one of the indicators mentioned above which has the unit signal processing section, the unit signal processing section is further configured to, when non-alarm information has been received or acquired by means of any of first and second signals during the indicator is operating in the first mode, restrain the non-alarm information from being outputted by the indicator output section. 
     With this configuration, the indicator to which the first mode has been selected does not output information unless it is the alarm information. Thereby, it is possible to prevent the indicator operating in the first mode from outputting unnecessary information. Hence, it is possible to further improve the usability of the refrigerant system at low cost. 
     According to further another preferred embodiment of any one of the indicators mentioned above which has the unit signal processing section, the operation modes further includes a second mode; and the unit signal processing section is further configured to, when non-alarm information has been received or acquired by means of a first unit signal during the indicator is operating in the second mode, restrain the non-alarm information from being outputted by the indicator output section. 
     With this configuration, the indicator does not output information if the second mode is selected and the information is originated by its predetermined usage-side unit but not the alarm information. Thereby, it is possible to easily and arbitrarily impart, to any of the indicators, a function to output only the alarm information originated by its predetermined usage-side unit. The user of the predetermined usage-side unit can discern the alarm information originated by the predetermined usage-side unit without being bothered by other unnecessary information. Hence, in a case where only alarm information is required, it is possible to further improve the usability of the refrigerant system at low cost. 
     According to further another preferred embodiment of any one of the indicators mentioned above, the indicator further comprises: a terminal-side communication section configured to receive terminal signals from a mobile terminal by means of wireless communication, wherein the mode management section is configured to, when a request on the selection from the operation modes has been received by means of a terminal signal, accept the request. 
     With this configuration, whether or not to operate in the first mode is changed according to the mode information received from the mobile terminal. Thereby, it is possible to select the first mode as desired by using the mobile terminal which is movable and different from the indicator. Thus, a human interface dedicated only for accepting the mode selection can be omitted from the indicator. Thereby, production cost of the indicator can be reduced, and usability of the refrigerant system is further improved. 
     According to further another preferred embodiment of any one of the indicators mentioned above which has the terminal-side communication section, the unit-side communication section is further configured to transmit indicator signals to the predetermined usage-side unit and, when address information which is to be set as identification information of the predetermined usage-side unit has been received by means of a terminal signal, transfer the address information to the predetermined usage-side unit by means of an indicator signal. 
     With this configuration, the address information received from the mobile terminal is transferred the predetermined usage-side unit. Thereby, it is possible to set new identification information to the predetermined usage-side unit by using the mobile terminal which is movable and different from the indicator. A human interface dedicated only for receiving the new identification setting can be omitted from the indicator. Thereby, production cost of the indicator can be reduced, and usability of the refrigerant system is further improved. 
     According to further another preferred embodiment of any one of the indicators mentioned above, the alarm information includes identification information of usage-side units in which an abnormality has occurred. 
     With this configuration, when the alarm information is received or acquired, the indicator can notify a user of both the occurrence of the abnormality and the identification information of the usage-side unit in which the abnormality has occurred. Thereby, it is possible for the user to discern where the abnormality has occurred. Hence, the manageability of the heat-pump system can be further improved at a low cost. 
     According to further another preferred embodiment of any one of the indicators mentioned above with which the alarm information includes the identification information, the abnormality includes a refrigerant leakage. 
     With this configuration, it is possible to inform the user of the occurrence of the refrigerant leakage. Thus, it is possible to further improve the manageability and safety of the refrigerant system at low cost. 
     A third aspect of the present invention provides a usage-side unit as one of a plurality of usage-side units of a heat-pump system, comprising: an indicator-side communication section configured to transmit first and second unit signals to an indicator, an inter-unit communication section configured to transmit and receive inter-unit signals to and from the other usage-side unit, an information originating section configured to originate alarm information, send the originated alarm information to the indicator by means of a first unit signal, and send the originated alarm information to the other usage-side unit by means of an inter-unit signal, and an inter-unit signal processing section configured to, when alarm information has been received by means of an inter-unit signal, transfer the received alarm information to the indicator by means of a second unit signal, and, if there is the rest usage-side unit which has not originated nor received the received alarm information, transfer the received alarm information to the rest usage-side unit by means of another inter-unit signal. 
     With this usage-side unit according to the third aspect, the alarm information originated in any of the plurality of the usage-side unit is to be shared by them. The shared alarm information is sent by each usage-side unit to an indicator by means of a first unit signal when the alarm information has been originated by the usage-side unit itself, and by means of a second unit signal when the alarm information has been not originated by the usage-side unit itself. Thereby, it is possible to send all alarm information regardless of its origin to the indicator while allowing the indicator to know whether or not the sent alarm information was originated by the usage-side unit. This makes possible for the indicator to select, from among all shared alarm information, alarm information to be outputted according to origins of the alarm information. 
     According to a preferred embodiment of the usage-side unit mentioned above, the indicator-side communication section is further configured to receive indicator signals from the indicator; the usage-side unit further comprises an indicator signal processing section configured to, when address information which is to be set as identification information of the usage-side unit has been received by means of an indicator signal, set the address information as identification information of the usage-side unit; and the information originating section is configured to, when an abnormality has occurred in the usage-side unit, originate alarm information including the set identification information. 
     With this configuration, it is possible to, when the abnormality has occurred in the usage-side unit, make the predetermined indicator notify a user of both the occurrence of the abnormality and the identification information of the usage-side unit in which the abnormality has occurred. Thereby, it is possible for the user to discern where the abnormality has occurred. Hence, the manageability of the heat-pump system can be further improved at a low cost. 
     A fourth aspect of the present invention provides an information output method in an indicator for outputting information relating to a heat-pump system including a plurality of usage-side units which form a communication network, comprising: accepting selection from a plurality of operation modes of the indicator including a first mode; receiving or acquiring any of first and second unit signals from a predetermined usage-side unit which is one of the usage-side units, the first unit signal being used for information originated by the predetermined usage-side unit, the second unit signal being used for information not originated by the predetermined usage-side unit; and, when alarm information has been received or acquired by means of a second unit signal during the indicator is operating in a first mode, outputting the alarm information. 
     With this information output method according to the fourth aspect, it is possible to switch, just by selecting the first mode or not, the behaviour of each indicator regarding whether to output the alarm information originated by the usage-side unit other than the predetermined usage-side unit which transmits first and second unit signals to the indicator. Thereby, it is possible to easily and arbitrarily impart, to any of the indicators, a function to output alarm information regardless of its origin. An information output device having a configuration different from the indicators and dedicated to outputting all alarm information is not required anymore. Hence, a refrigerant system with high manageability and high usability can he provided at a low cost. 
     According to a preferred embodiment of the information output method mentioned above, the method further comprises, when alarm information has been received or acquired by means of a first unit signal, outputting the alarm information. 
     With this configuration, the indicator can output alarm information indicated by a first unit signal regardless of its operation mode if the alarm information is originated by the predetermined usage-side unit. Hence, it is possible to further improve the usability of the refrigerant system at low cost. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    shows a schematic configuration of a heat-pump system according to an embodiment of the present invention. 
         FIG.  2    shows an example of appearance of an indicator shown in  FIG.  1   . 
         FIG.  3    is a block diagram indicating a functional configuration of a unit controller shown in  FIG.  1   . 
         FIG.  4    is a block diagram indicating a functional configuration of an indicator shown in  FIG.  1   . 
         FIG.  5    is a schematic table indicating operation patterns of the indicator upon receiving a signal from the unit controller. 
         FIG.  6    is a block diagram indicating a functional configuration of a mobile terminal shown in  FIG.  1   . 
         FIG.  7    is a flow chart indicating a process performed by a communication control section of the unit controller. 
         FIG.  8    is a flow chart indicating a process performed by an indicator control section of the indicator. 
         FIG.  9    is a sequential diagram indicating an example of an operation the heat-pump system. 
         FIGS.  10 A to  10 F  are plan views of the indicator showing examples of a display state thereof. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Detailed Description of Preferred Embodiment 
     A preferred embodiment of a heat-pump system according to the present invention will be described with reference to the drawings. 
     System Configuration 
       FIG.  1    shows a schematic configuration of a heat-pump system according to an embodiment of the present invention. 
     As shown in  FIG.  1   . a heat-pump system  100  according to the present embodiment comprises a heat-source-side unit  210 , a plurality of usage-side units  220  each having a unit controller  300 , a plurality of indicators  400 , and a mobile terminal  500 . For instance, the heat-pump system  100  is an air-conditioning system, and the heat-source-side unit  210  and the usage-side units  220  are an outside unit and indoor units, respectively. 
     In this embodiment, the explanations will be made on a premise that: the first usage-side unit  220 _ 1  having the first unit controller  300 _ 1 , and the first indicator  400 _ 1  are disposed in a first target area  611 _ 1 ; the second usage-side unit  220 _ 2  having the second unit controller  300 _ 2 , and the second indicator  400 _ 2  are disposed in a second target area  611 _ 1 ; and the supervisor-use indicator  400 _S is disposed in a monitoring room  612 . However, the arrangement of these devices is not limited to this. Two or more of the usage-side units  220  may be disposed in the same target area  611 . Two or more of the indicators  400  may be disposed in the same target area  611 . The supervisor-use indicator  400 _S may be disposed in a different place, e.g. one of the target areas  611 . Two or more of the supervisor-use indicators  400 _S may also be provided. 
     All the unit controllers  300  including the first and second unit controllers  300 _ 1 ,  300 _ 2  have substantially the same configuration. Thus, each of the unit controllers  300  will be called just as “the unit controller  300 ” when the explanation is applicable to all the unit controllers  300 . Similarly, each of the usage-side units  220  including the first and second unit units  220 _ 1 ,  220 _ 2  will also be called just as “the usage-side unit  220 ” when the explanation is applicable to all the usage-side units  220 . All the indicators  400  including the first and second indicators  400 _ 1 ,  400 _ 2  and the supervisor-use indicator  400 _S also have substantially the same configuration. Thus, in this embodiment, each of the indicators  400  is also called just as “the indicator  400 ” when the explanation is applicable to all the indicators  400 . 
     The heat-source-side unit  210  is configured to supply cold heat and/or hot heat to the usage-side units  220  by circulating refrigerant via refrigerant pipes (not shown). The heat-source-side unit  210  is also configured to communicate with the usage-side units  220  via wired/wireless communication paths  231 . These communication paths  231  may be established by LAN (Local Area Network). 
     The usage-side unit  220  is configured to utilize the cold heat and/or hot heat supplied from the heat-source-side unit  210 . For instance, the usage-side unit  220  has a heat exchanger and an air blower (not shown) to perform a heat exchange between the refrigerant and an air in the target area  611 . The usage-side unit  220  also has a leakage sensor  221  in addition to the unit controller  300 . 
     The leakage sensor  221  is configured to, when a refrigerant leakage has occurred in the usage-side unit  220 , detect this refrigerant leakage, and inform of it to the unit controller  300 . The leakage sensor  221  may be a semi-conductor gas sensor reactive to the refrigerant, and is disposed inside or outside the usage-side unit  220 . The usage-side unit  220  need not necessarily include the leakage sensor  221 , i.e. may utilize an external leakage sensor. In this case, the unit controller  300  has a wired/wireless communication interface for communicating with the external leakage sensor to transmit signals thereto or/and receive signals therefrom. 
     The unit controllers  300  of the usage-side units  220  are configured to form a communication network via wired/wireless communication paths  232 . This communication network may be established by LAN (Local Area Network). For instance, the unit controllers  300  are connected in series by the wired/wireless communication paths  232  as shown in  FIG.  1   . In this embodiment, the explanations will be made on a premise that the first unit controller  300 _ 1 , the second unit controller  300 _ 2 , and the other unit controllers (not shown) are serially connected in this order. However, the connection configuration of the unit controllers  300  is not limited to this. 
     The unit controller  300  is configured to communicate with one or more of the indicators  400  via one or more of via wired/wireless communication paths  233 . These communication paths  233  may be established by LAN (Local Area Network). In this embodiment, the explanations will be made on a premise that the first indicator  400 _ 1  and the supervisor-use indicator  400 _S are connected with the first unit controller  300 _ 1 , and that the second indicator  400 _ 2  is connected with the first unit controller  300 _ 1 . Thus, the first indicator  400 _ 1  and the supervisor-use indicator  400 _S can directly communicate with the first unit controller  300 _ 1 , but not with the any other unit controller  300  such as the second unit controller  300 _ 2 . The second indicator  400 _ 2  can directly communicate with the second unit controller  300 _ 2 , but not with the any other unit controller  300  such as the first unit controller  300 _ 1 . 
     Hereinafter, the unit controller  300  with which the indicator  400  under explanation can communicate, without an intervention of any other unit controller  300 , will be referred to as “the connecting unit controller  300 ” as necessary. Similarly, the usage-side unit  220  having the connecting unit controller  300  will be referred to as “the connecting usage-side unit  220 ” as necessary. The indicator  400  with which the unit controller  300  under explanation can communicate, without an intervention of any other unit controller  300 , will also be referred to as “the connecting indicator  400 ” as necessary. 
     The unit controller  300  is also configured to receive information from the connecting indicator  400 , and operate according to the received information. Thus, the first unit controller  300  operates according to information received from the first indicator  400 _ 1  and the supervisor-use indicator  400 _S, the second unit controller  300  operates according to information received from the second indicator  400 _ 2 . However, the supervisor-use indicator  400 _S does not necessarily have a function of transmitting such information to the first indicator  400 _ 1 . This limitation of functions may be achieved by later-mentioned setting of a first mode. 
     The unit controller  300  is further configured to originate alarm information, and share the originated alarm information with all the other unit controllers  300  by using the above-mentioned communication network formed by the unit controllers  300 . The unit controller  300  is also configured to send the shared alarm information to the connecting indicator  400  regardless of whether or not the alarm information is originated by the unit controller  300  itself. 
     For instance, when the first unit controller  300 _ 1  has originated alarm information, the first unit controller  300 _ 1  transmits the originated alarm information to the second unit controller  300 _ 2 , the first indicator  400 _ 1 , and the supervisor-uses indicator  400 _S. The second unit controller  300 _ 2  transfers the received alarm information to the second indicator  400 _ 2  and the further other unit controller  300  (not shown). Meanwhile, when the second unit controller  300 _ 2  has generated alarm information, the second unit controller  300 _ 2  transmits the originated alarm information to the first unit controller  300 _ 1 , the further other unit controller (not shown), and the second indicator  400 _ 2 . The first unit controller  300 _ 1  transfers the received alarm information to the first indicator  400 _ 1  and the supervisor-use indicator  400 _S. 
     In this embodiment, the explanations will be made on a premise that the unit controller  300  is configured to originate alarm information when a refrigerant leakage has occurred in the usage-side unit  220  to which the unit controller  300  belongs, e.g. when the leakage sensor  221  which belongs to the same usage-side unit  220  has detected a refrigerant leakage. However, a trigger of originating alarm information is not limited to this. The trigger may be an occurrence of another abnormality, such as an excessive increase in refrigerant pressure, an excessive increase in air resistance, and/or other malfunctions of the usage-side unit  220 . 
     The indicator  400  is configured to output information relating to the heat-pump system  100 . More specifically, the indicator  400  is configured to receive or acquire information from the connecting unit controller  300 , and output the received or acquired information. Here, outputting information may include outputting: a visual image such as a picture, a symbol, a text or light; a sound such as a buzzer or a speech sound; and/or a vibration which represent a type and/or a content of information and indicates a reception of the information. Meanwhile, as detailed later, the indicator  400  is also configured to restrict its information output depending on: whether or not the information has been originated by the connecting unit controller  300 ; whether or not the information is alarm information, and whether or not the indicator  400  is operating in a specific mode. 
     In addition, the indicator  400  is configured to communicate with the mobile terminal  500  via a wireless communication path  234 . This wireless communication is preferably a short-range radio communication, such that only one of the indicators  400  can establish this communication with the mobile terminal  500  at a time. For instance, when the mobile terminal  500  in the first target area  611 _ 1 , only the first indicator  400 _ 1  among the indicators  400  can communicate with the mobile terminal  500 . The indicator  400  is configured to receive information from the mobile terminal  500 , operate according to the received information, and further transfer the received information to the unit controller  300  depending on the type of the information. 
       FIG.  2    shows an example of appearance of the indicator  400 . 
     As shown  FIG.  2   , the indicator  400  may have a casing  401 , an on/off button  402 , a display panel  403  including a display area  404  and an operation area  405 , a loudspeaker  406 , and an LED (Light Emitting Diode)  407 . 
     The casing  401  has a plate-like outer shape, and is formed with a back surface for being attached to a wall or the like and a main surface on the opposite side of the back surface. The casing  401  covers most part of the indicator  400 . The on/off button  402  is disposed on one of the surfaces of the casing  401 , and configured to receive user operations for switching on and off the indicator  400 . The display panel  403  is disposed on the main surface of the casing  401 , and configured to display information by means of texts, symbols, pictures or the like. The display panel  403  may be a touch panel display. The display area  404  is configured to change its display contents. The operation area  405  is configured to receive user operations for switching on and off the information display by the indicator  400 . The operation area  405  is also configured to receive user operations for changing the display contents, the operation of the indicator  400 , and the operation of the usage-side unit  220 . The loudspeaker  406  is configured to output information by means of a sound. The LED  407  is configured to output information by means of light. 
     The mobile terminal  500  of  FIG.  1    is configured to receive requests relating to the heat-pump system  100  from a user  620  of mobile terminal  500 . The user  620  is a monitoring person of the heat-pump system  100  who normally resides in the monitoring room  612 , for instance. The mobile terminal  500  is also configured to transmit information based on the received request to the indicator  400  which is connected with the mobile terminal  500  via the wireless communication path  234 . The mobile terminal  500  may be further configured to receive information from the indicator  400 , and output the received information by means of a visual image, a sound, and/or a vibration. The mobile terminal  500  may be a smart phone, a tablet device or the like. 
     Although not shown, the unit controller  300 , the indicator  400 , and the mobile terminal  500  each include an arithmetic circuit such as a CPU (Central Processing Unit), a work memory used by the CPU such as a RAM (Random Access Memory), and a recording medium storing control programs and information used by the CPU such as a ROM (Read Only Memory). The unit controller  300 , the indicator  400 , and the mobile terminal  500  are each configured to perform information processing and signal processing by the CPU executing the control programs to control operation thereof, so as to achieve their functions and operations. 
     With the above heat-pump system  100 , it is possible to output information relating to the heat-pump system  100 , including alarm information relating to any of the usage-side units  220 , from any of the indicators  400 . Moreover, it is possible for the user  620  to operate each of the usage-side units  220  and each of the indicators  400  by using the mobile terminal  500  such that, for instance, desired information is outputted from the closest indicator  400 . 
     However, there are cases where outputting all the information originated by any of the usage-side units  220  is not preferable. For instance, when a refrigerant leakage has occurred in the second usage-side unit  220 _ 2 , the alarm information should be outputted from the second indicator  400 _ 2  and the supervisor-use indicator  400 _S, but not from the first indicator  400 _ 1 . Meanwhile, the information originated by the first usage-side unit  220 _ 1  should be outputted from the first indicator  400 _ 1  and the supervisor-use indicator  400 _S, but not from the second indicator  400 _ 2 . In this regard, the heat-pump system  100  is configured to regulate the information output from the indicators  400  such that only necessary information output is performed in each of the indicators  400 . 
     Functional Configuration of Unit Controller 
       FIG.  3    is a block diagram indicating a functional configuration of the unit controller  300 . 
     As shown in  FIG.  3   , the usage-side unit  220  includes a system-side communication section  310 , an indicator-side communication section  320 , an inter-unit communication section  330 , an operation control section  340 , an abnormality detection section  350 , a unit storage section  360 , and a communication control section  370 . 
     The system-side communication section  310  is configured to establish the communication path  231  with the heat-source-side unit  210  to communicate therewith (see  FIG.  1   ). 
     The indicator-side communication section  320  is configured to establish the communication path  233  with the indicator  400  (a predetermined indicator) to communicate therewith (see  FIG.  1   ). In particular, the indicator-side communication section  320  is configured to transmit first unit signals and second unit signals to the indicator  400 , and receive indicator signals from the indicator  400 . Here, a first unit signal is a signal used for information originated by the unit controller  300  itself, and a second unit signal is a signal used for information not originated by the unit controller  300  itself. Details regarding the first and second unit signals will be explained later. The indicator-side communication section  320  may be connected with a plurality of the indicators  400 . 
     The inter-unit communication section  330  is configured to establish the communication path  232  with the other unit controller  300  to communicate therewith (see  FIG.  1   ). In particular, the inter-unit communication section  330  is configured to transmit and receive inter-unit signals to and from the other unit controller  300  of the other usage-side unit  220 . The inter-unit communication section  330  may be connected with a plurality of the other unit controllers  300 . 
     The system-side communication section  310 , the indicator-side communication section  320 , and the inter-unit communication section  330  may be a LAN interfaces, and may use the same communication protocol or different communication protocols. 
     The operation control section  340  is configured to control the operation of the usage-side unit  220  for utilizing the cold heat and/or hot heat supplied from the heat-source-side unit  210  according to operation information provided from the communication control section  370 . For instance, the operation control section  340  is configured to control the flow of the refrigerant in the heat exchanger and operation of the air blower. The operation information may include instructions for changing a target temperature of the air in the target area  611 , changing an air volume level of the air blower, changing an operation mode between a cooling operation mode and a heating operation mode, on/off of the operation for utilizing the cold heat and/or hot heat, and so on. 
     The abnormality detection section  350  is configured to, when a predetermined abnormality has occurred in the usage-side unit  220 , detect this occurrence of the abnormality. For instance, the abnormality detection section  350  is configured to receive the information from the leakage sensor  221  when a refrigerant leakage has occurred (see  FIG.  1   ). 
     The unit storage section  360  stores information in a form readable and rewritable by the communication control section  370 . The stored information includes identification (ID) information of the usage-side unit  220 . The unit storage section  360  may store an initial ID information which has been set to the usage-side unit  220  in advance. In this embodiment, the explanations will be made on a premise that a text “01” has been initially set to the first usage-side unit  220 _ 1  and a text “02” has been initially set to the second usage-side unit  220 _ 2 . 
     The communication control section  370  is configured to control the communications with the heat-source-side unit  210 , the one or more of other unit controllers  300 , and the one or more of connecting indicators  400 . The communication control section  370  may be achieved by an application software installed to or updated in the unit controller  300 . The communication control section  370  includes an indicator signal processing section  371 , an information originating section  372 , and an inter-unit signal processing section  373 . 
     The indicator signal processing section  371  is configured to receive indicator signals transmitted from the connecting indicator  400  via the indicator-side communication section  320 , and process the received indicator signals. More specifically, the indicator signal processing section  371  is configured to, when operation information has been received by means of an indicator signal, pass it to the operation control section  340 . In addition, the indicator signal processing section  371  is configured to, when address information has been received by means of an indicator signal, rewrite the ID information stored in the unit storage section  360  by the obtained address information or add the obtained address information to the unit storage section  360  so as to set it as ID information of the usage-side unit  220 . 
     The indicator signal processing section  371  is also configured to, when indication information has been received by means of an indicator signal, pass it to the information originating section  372 . The indication information is information which indicates that status information indicating the operation status of the usage-side unit  220  is requested from the indicator  400 . 
     It should be noted that information which is sent, transferred, received, or acquired by means of a signal may be information contained in the signal, information a location of which is specified by the signal, or information an identification of which has been shared by a sender of the signal and a receiver of the signal in advance is specified by the signal. Thus, sending or transferring information by means of a signal may be transmitting a signal containing the information itself, transmitting a signal specifying a location of the information, or transmitting a signal specifying an identification of the information. Receiving or acquiring information by means of a signal may be extracting the information included in a signal, accessing a location specified by a signal to obtain the information, or identifying the information from an identification specified by a signal. A signal containing information, specifying a location of information, or specifying an identification of information may be expressed as a signal “indicating” the information. 
     The information originating section  372  is configured to originate information including alarm information. The information originating section  372  may originate, as mentioned above, alarm information when an occurrence of a refrigerant leakage has been informed of by the leakage sensor  221  via the abnormality detection section  350 . The information originating section  372  is further configured to send the originated information to the connecting indicator  400  by a first unit signal via the indicator-side communication section  320 , and also send the same originated information to the other usage-side unit  220  by means of an inter-unit signal via the inter-unit communication section  330 . 
     The information originating section  372  is preferably configured to read the latest ID information of the usage-side unit  220  from the unit storage section  360 , and embed the read ID information into the alarm information. Thereby, the alarm information includes ID information of the usage-side units  220  in which an abnormality has occurred. The latest ID information may be the initially set ID information if any other ID information has been set, or the ID information subsequently and lastly set by the indicator signal processing section  371 . 
     The information originating section  372  is also configured to originate the status information and send it to the indicator  400  by a first unit signal via the indicator-side communication section  320 . The status information may indicate the operation mode, the target temperature, the air volume level of the air blower or the like of the usage-side unit  220 . The information originating section  372  may send the status information autonomously and periodically, or send the status information passively upon receiving the indication information from the indicator  400  via the indicator signal processing section  371 . 
     The inter-unit signal processing section  373  is configured to receive inter-unit signals transmitted from the unit controller  300  of the other usage-side unit  220  via the inter-unit communication section  330 , and process the received inter-unit signals. More specifically, the inter-unit signal processing section  373  is configured to, when information has been received by means of an inter-unit signal, send it to the indicator  400  (a predetermined indicator) by a second unit signal via the indicator-side communication section  320 . Such information includes alarm information originated by one of the other usage-side units  220 . 
     The inter-unit signal processing section  373  is also configured to, if there is any rest usage-side unit  220 , transfer the information to the rest usage-side unit  220  by means of another inter-unit signal via the inter-unit communication section  330 . Here, the “rest usage-side unit  220 ” means the other usage-side unit  220  which has not originated nor received the information that the inter-unit signal processing section  373  received. 
     The unit controller  300  may also be configured to operate according to commands from the heat-source-side unit  210 , and send information relating to the usage-side unit  220  to the heat-source-side unit  210 . 
     With the above configuration, the unit controller  300  can originate alarm information including ID information, share alarm information with the other the unit controller  300  and the connecting indicator  400  regardless of the origin of the alarm information. The unit controller  300  can also differentiate alarm information originated by itself and other alarm information from each other by using a first unit signal for the former alarm information and a second unit signal for the latter alarm information. 
     The difference of a first unit signal and a second unit signal is not limited to a certain form, but need to be shared between the usage-side unit  220  and the connecting indicator  400  in advance such that the indicator  400  can distinguish them. For instance, a first unit signal and a second unit signal are: transmitted using predetermined different commands; transmitted in predetermined different timings in a transmission frame; and/or appended with predetermined different symbols. The indicator  400  may request the connecting usage-side unit  220  to send information to the indicator  400  specifying the origin of the information. In this case, the transmitted signal in reply to the request specifying the connecting usage-side unit  220  may be a first unit signal, and the transmitted signal in reply to the request not specifying the connecting usage-side unit  220  may be a second unit signal. 
     Functional Configuration of Indicator 
       FIG.  4    is a block diagram indicating a functional configuration of the indicator  400 . 
     As shown in  FIG.  4   , the indicator  400  includes a terminal-side communication section  410 , a unit-side communication section  420 , an indicator input section  430 , an indicator output section  440 , an indicator storage section  450 , and an indicator control section  460 . 
     The terminal-side communication section  410  is configured to establish the communication path  234  with the mobile terminal  500  to communicate therewith (see  FIG.  1   ). In particular, the terminal-side communication section  410  is configured to receive terminal signals from the mobile terminal  500 . The terminal-side communication section  410  may he a short-range radio communication interface device. 
     The unit-side communication section  420  is configured to establish the communication path  233  with the unit controller  300  (a predetermined usage-side unit) to communicate therewith (see  FIG.  1   ). In particular, the unit-side communication section  420  is configured to transmit indicator signals to the unit controller  300 , and receive or acquire first and second unit signals from the unit controller  300 . The system-side communication section  310  may be a LAN interface. 
     The indicator input section  430  is configured to receive user operations to the indicator  400 . The indicator input section  430  may be a mechanical key, a mechanical dial, a touch panel, a microphone, or the like. The indicator input section  430  may include the above-mentioned on/off button  402  and/or operation area  405  (see  FIG.  2   ). 
     The indicator output section  440  is configured to output information provided from the indicator control section  460  by a visual image and/or a sound. The information to be outputted includes alarm information and status information. The indicator output section  440  may be a loudspeaker, a display device, an electric light, a vibrator, or the like. The indicator output section  440  may include the above-mentioned display area  404 , loudspeaker  406 , and/or LED  407 . 
     The indicator storage section  450  stores information in a form readable and rewritable by the indicator control section  460 . The information to be stored includes mode setting information that indicates which of a plurality of predetermined operation modes has been set to indicator  400 . In the different predetermined operation modes, the indicator  400  behaves in different manners. 
     In this embodiment, the predetermined operation modes includes a first mode, a second mode, and a third mode. The first mode is an operation mode for outputting information from the indicator  400  regardless of the origin of the information. The second mode is an operation mode for outputting only alarm information originated by the connecting unit controller  300 . The third mode is an operation mode for outputting only information originated by the connecting unit controller  300 . However, the predetermined operation modes are not limited to these modes. For instance, the predetermined operation modes may include only the first and second modes, or only the first and third modes. The indicator storage section  450  may store mode setting information indicating the third mode as an initial operation mode which has been set to the indicator storage section 45 in advance. 
     The indicator control section  460  is configured to control the communications with the connecting unit controller  300  and the communications with the mobile terminal  500 , and the operations of the indicator  400 . The indicator control section  460  may be achieved by an application software installed to or updated in the indicator  400 . The indicator control section  460  includes a terminal signal processing section  461 , a mode management section  462 , and a unit signal processing section  463 . 
     The terminal signal processing section  461  is configured to receive terminal signals transmitted from the mobile terminal  500  via the terminal-side communication section  410 , and process the received indicator signals. More specifically, terminal signal processing section  461  is configured to, when mode information has been received by means of a terminal signal, pass it to the mode management section  462 . The mode information is information indicating a request on a selection from the above-mentioned predetermined operation modes, i.e. which of the first to third modes should be set to the indicator  400 . 
     In addition, the terminal signal processing section  461  is configured to, when any one of the operation information, the address information, and the indication information has been received by means of a terminal signal, transfer it to the connecting unit controller  300  by means of an indicator signal via the terminal-side communication section  410 . 
     The mode management section  462  is configured to accept selection from the above-mentioned predetermined operation modes of the indicator  400 . More specifically, the mode management section  462  is configured to, when the mode information is received from the terminal signal processing section  461 , rewrite the mode setting information stored in the indicator storage section  450  or add the mode setting information to the indicator storage section  450  as indicated by the received mode information. Thereby, the mode management section  462  sets the operation mode to the indicator  400  according to the received mode information. For instance, the received mode information indicates the first mode, the mode management section  462  sets the first mode to the indicator  400 . The mode management section  462  may also accept the request on the operation mode selection from the user  620  via the indicator input section  430  (see  FIG.  1   ). 
     The unit signal processing section  463  is configured to receive or acquire unit signals, which include the first and second unit signals mentioned above, transmitted from the connecting unit controller  300  via the unit-side communication section  420 , and process the received unit signals. More specifically, the unit signal processing section  463  is configured to, when information has been received by means of any one of first and second unit signals, pass it to the indicator output section  440  such that the information is outputted. Meanwhile, the unit signal processing section  463  is also configured to regulate information output from indicator output section  440  such that only information necessary for the indicator  400  is outputted therefrom. 
       FIG.  5    is a schematic table indicating operation patterns of the indicator  400  upon receiving a signal from the unit controller. 
     As shown in the schematic table  464  of  FIG.  5   , the unit signal processing section  463  switches its behaviour depending on: which of first unit signal and second unit signal has been received; whether the information indicated by the received unit signal is alarm information; and which of the first to third modes has been set to the indicator  400 . 
     When the indicator  400  is operating in the first mode, the unit signal processing section  463  is configured to restrain information indicated by a received second unit signal and information which is not alarm information (hereinafter referred to as “non-alarm information”) from being outputted by the indicator output section  440 . On the other hand, if the received signal indicates alarm information, the unit signal processing section  463  allows the indicator output section  440  to output the alarm information regardless of whether the received signal is a first unit signal or a second unit signal. 
     When the indicator  400  is operating in the second mode, the unit signal processing section  463  is configured to restrain the information which is indicated by a first unit signal and non-alarm information from being outputted by the indicator output section  440 . On the other hand, if the received signal is a first unit signal indicating alarm information, the unit signal processing section  463  allows the indicator output section  440  to output the alarm information. 
     When the indicator  400  is operating in the third mode, the unit signal processing section  463  is configured to restrain the information which is indicated by a second unit signal from being outputted by the indicator output section  440 . On the other hand, if the received signal is a first unit signal, the unit signal processing section  463  is configured to operate according to information indicated by a first unit signal. For example, the unit signal processing section  463  allows the indicator output section  440  to output alarm information and status information indicated by a first unit signal. 
     In other words, the unit signal processing section  463  is configured to, when alarm information has been received or acquired by means of a second unit signal during the indicator  400  is operating in the first mode, or when alarm information has been received or acquired by means of a first unit signal, allows the indicator output section  440  to output the alarm information. Consequently, the indicator output section  440  is configured to output information indicated by a unit signal received or acquired from the usage-side unit  220 , on condition that the unit signal is a second unit signal indicating alarm information and has been received or acquired during the indicator  400  is operating in the first mode, or that the unit signal is a first unit signal indicating alarm information. The unit signal processing section  463  may determine which mode has been set to the indicator  400  (i.e. in which mode the indicator  400  is operating) by referring to the mode setting information stored in the indicator storage section  450 . 
     With the above configuration, the operation mode of the indicator  400  can be switched as desired among the first mode in which alarm information is outputted regardless of its origin, the second mode in which only alarm information originated by the connecting unit controller  300  is outputted, and the third mode in which only information originated by the connecting unit controller  300  is outputted. For instance, the first mode is suitable for the supervisor-use indicator  400 _S, the third mode is suitable for the first and second indicators  400 _ 1 ,  400 _ 2 , and the second mode is suitable for the indicator  400  (not shown) additionally connected to the first unit controller  300 _ 1  or the second unit controller  300 _ 2  (see  FIG.  1   ). 
     Functional Configuration of Mobile Terminal 
       FIG.  6    is a block diagram indicating a functional configuration of a mobile terminal shown in  FIG.  1   . 
     As shown  FIG.  6   , the mobile terminal  500  includes a terminal communication section  510 , a terminal input section  520 , and a terminal control section  530 . 
     The terminal communication section  510  is configured to establish the communication path  234  with the indicator  400  to communicate therewith (see  FIG.  1   ). In particular, the terminal communication section  510  is configured to transmit terminal signals to the indicator  400 . The terminal communication section  510  may be further configured to receive signals from the indicator  400 . The terminal communication section  510  may be a short-range radio communication interface device. 
     The terminal input section  520  is configured to receive user operations to the mobile terminal  500 . The terminal input section  520  may be a touch panel display, mechanical keys, a microphone, or the like. 
     The terminal control section  530  is configured to receive requests relating to the heat-pump system  100  from the user  620  via terminal input section  520 , and send information according to the received request to the indicator  400  by a terminal signal via the terminal communication section  510 . 
     More specifically, when a request for setting one of the predetermined operation modes to the indicator  400  has been received, the terminal control section  530  is configured to send mode information indicating the request. When a request for setting selected or inputted address information to be set to the user-side unit  220  has been received, the terminal control section  530  is configured to send address information indicating the request. When a request for controlling the operation of the usage-side unit  220  in a certain manner has been received, the terminal control section  530  is configured to send operation information indicating the request. When a request for outputting certain information on the operation of the usage-side unit  220 , the terminal control section  530  is configured to send operation information indicating the request. The terminal control section  530  may also be configured to output or response to signals received from the indicator  400 , The terminal control section  530  may be achieved by an application software installed to or updated in the mobile terminal  500 . 
     With the above configuration, the mobile terminal  500  can send information for controlling operations of the usage-side unit  220  and the indicator  400  according to the operation by the user  620 . Thus, the mobile terminal  500  allows the user  620  to select the operation mode of the indicator  400 , change the ID information of the usage-side unit  220 , control the operation of the usage-side unit  220 , and know the operation status of the usage-side unit  220 . As a result, human interfaces of the indicator  400  can be simplified, and the user  620  can make the above operations without touching the indicator  400 . 
     It is preferable that there are two types of the terminal control section  530 . The first type is for a supervisory use and configured to send at least the mode information and the address information among the above information. The first type is for a private use and configured to send at least the operation information and the indication information among the above information. In this case, it is also preferable that the terminal control section  530  can be switched between these types only by authorized people or authorized devices. 
     Operation of Unit Controller 
       FIG.  7    is a flow chart indicating a process performed by the communication control section  370  of the unit controller  300 . 
     In step S 1010 , the indicator signal processing section  371  determines whether an indicator signal has been received, if an indicator signal has been received (S 1010 : Yes), the indicator signal processing section  371  proceeds to step S 1020 , and if not (S 1010 : No), proceeds to later-mentioned step 1080. 
     In step S 1020 , the indicator signal processing section  371  determines whether the received indicator signal indicates address information. If address information is indicated (S 1020 : Yes), the indicator signal processing section  371  proceeds to step S 1030 , and if not (S 1020 : No), proceeds to later mentioned step 1040. In step 1030, the indicator signal processing section  371  sets the indicated address information as ID information of the usage-side unit  220 . 
     In step S 1040 , the indicator signal processing section  371  determines whether the received indicator signal indicates operation information. If operation information is indicated (S 1040 : Yes), the indicator signal processing section  371  proceeds to step S 1050 , and if not (S 1040 : No), proceeds to later-mentioned step 1060. In step 1050, the indicator signal processing section  371  passes the indicated operation information to the operation control section  340  so as to control the usage-side unit  220  according to the operation information. 
     In step S 1060 , the indicator signal processing section  371  determines whether the received indicator signal indicates indication information. If indication information is indicated (S 1060 : Yes), the indicator signal processing section  371  proceeds to step S 1070 , and if not (S 1060 : No), proceeds to later-mentioned step 1080. Before proceeding to step 1080, the indicator signal processing section  371  may execute a certain process based on the received indicator signal. In step 1070, the indicator signal processing section  371  passes the indicated indication information to the information originating section  372  so as to originate status information of the usage-side unit  220  and send it to the indicator  400  by a first unit signal. 
     In step S 1080 , the inter-unit signal processing section  373  determines whether an inter-unit signal has been received. If an inter-unit signal has been received (S 1080 : Yes), the inter-unit signal processing section  373  proceeds to step S 1090 , and if not (S 1080 : No), proceeds to later-mentioned step 1100. In step S 1090 , the inter-unit signal processing section  373  transfers information indicated by the received inter-unit signal to the indicator  400  by means of a second unit signal. If there is the rest usage-side unit  220 , the inter-unit signal processing section  373  transfers the same information to the rest usage-side unit  220  as well. 
     In step S 1100 , the information originating section  372  determines whether alarm information need to be outputted, e.g. whether an abnormality such as a refrigerant leakage has occurred in the usage-side unit  220 . If alarm information need to be outputted (S 1100 : Yes), the information originating section  372  proceeds to step S 1110 , and if not (S 1100 : No), proceeds to later-mentioned step 1120. In step S 1110 , the information originating section  372  originates alarm information. In other words, the information originating section  372  sends alarm information including the ID information of the usage-side unit  220  to the indicator  400  by a first unit signal, and send the same information to the other unit controller  300  (the other usage-side unit  220 ). 
     The information originating section  372  may execute other process depending on the type of the occurred abnormality. For instance, when a refrigerant leakage has occurred, the information originating section  372  may control the operation control section  340  to shut off refrigerant valves (not shown) of the usage-side unit  220 , output a flash or a buzzer from the usage-side unit  220 , and/or send a request to the heat-source-side unit  210  to stop its operation. 
     In step S 1120 , the communication control section  370  determines whether a termination of operation has been designated. The designation may be made by a user operation, another device, or the communication control section  370  itself. If the termination of the operation has not been designated (S 1120 : No), the communication control section  370  proceeds back to step S 1010 , and if designated (S 1120 : Yes), terminates its operation. 
     By the above process, the usage-side unit  220  can properly and swiftly react to signal receptions and abnormality occurrences. It should be noted that the execution order of above-mentioned steps S 1010  to S 1070 , steps S 1080  and S 1090 , and steps S 1100  and S 1110  may be changed. The execution order of the execution order of steps S 1020  and S 1030 , steps S 1040  and S 1050 , and steps S 1060  and S 1070  may also be changed. 
     Operation of Indicator 
       FIG.  8    is a flow chart indicating a process performed by the indicator control section  460  of the indicator  400 . 
     In step S 2010 , the terminal signal processing section  461  determines whether a terminal signal has been received. If a terminal signal has been received (S 2010 : Yes), the terminal signal processing section  461  proceeds to step S 2020 , and if not (S 2010 : No), proceeds to later-mentioned step 2060. 
     In step S 2020 , the terminal signal processing section  461  determines whether the received terminal signal indicates mode information. If mode information is indicated (S 2020 : Yes), the terminal signal processing section  461  proceeds to step S 2030 , and if not (S 2020 : No), proceeds to later mentioned step 2040. In step 2030, the terminal signal processing section  461  passes the indicated mode information to the mode management section  462  so as to set the operation mode of the indicator  400  as requested by the mode information. In other words, the indicator  400  accepts, from the user  620 , selection from the plurality of operation modes of the indicator  400 . 
     In step S 2040 , the terminal signal processing section  461  determines whether the received terminal signal indicates one of address information, operation information, and indication information. If any one of them is indicated (S 2040 : Yes), the terminal signal processing section  461  proceeds to step S 2050 , and if not (S 2040 : No), proceeds to later-mentioned step 2060. Before proceeding to step 2060, the terminal signal processing section  461  may execute a certain process based on the received terminal signal. In step 2050, the terminal signal processing section  461  transfers the indicated information to the usage-side unit  220 . 
     In step S 2060 , the unit signal processing section  463  determines whether a first unit signal has been received. If a first unit signal has been received (S 2060 : Yes), the unit signal processing section  463  proceeds to step S 2070 , and if not (S 2060 : No), proceeds to later-mentioned step 2100. 
     In step S 2070 , the unit signal processing section  463  determines whether the received first unit signal indicates alarm information. If alarm information is indicated (S 2070 : Yes), the unit signal processing section  463  proceeds to later-mentioned step S 2120 , and if not (S 2070 : No), proceeds to step 2080. In step 2080, the unit signal processing section  463  determines whether the indicator  400  is operating in any one of the first mode and the second mode, If the indicator  400  is operating in any one of the first mode and the second mode (S 2080 : Yes), the unit signal processing section  463  proceeds to later-mentioned step S 2100 , and if not (S 2080 : No), proceeds to step S 2090 . 
     In step 2090, the unit signal processing section  463  determines whether the received first unit signal indicates status information. If status information is indicted (S 2090 : Yes), the unit signal processing section  463  proceeds to later-mentioned step S 2120 , and if not (S 2080 : No), proceeds to step S 2100 . Before proceeding to step 2120, the unit signal processing section  463  may execute a certain process based on the received first unit signal. 
     In step S 2100 , the unit signal processing section  463  determines whether a second unit signal has been received. If a second unit signal has been received (S 2100 : Yes), the unit signal processing section  463  proceeds to step S 2110 , and if not (S 2100 : No), proceeds to later-mentioned step 2130. 
     In step S 2110 , the unit signal processing section  463  determines whether the received second unit signal indicates alarm information and the indicator  400  is operating in the first mode. If alarm information is indicated and the indicator  400  is operating in the first mode (S 2110 : Yes), the unit signal processing section  463  proceeds to step S 2120 , and if not (S 2110 : No), proceeds to later mentioned step S 2130 . Before proceeding to step 2130, the unit signal processing section  463  may execute a certain process based on the received second unit signal. 
     In step S 2120 , the unit signal processing section  463  passes the indicated information to the indicator output section  440  so as to output the information from the indicator  400 . In other words, when alarm information has been received or acquired by means of a first unit signal, when a first unit signal indicating status information has been received or acquired during the indicator  400  is operating in the third mode, and when alarm information has been received or acquired by means of a second unit signal during the indicator  400  is operating in the first mode, the indicator  400  outputs the information. 
     In step S 2130 , the indicator control section  460  determines whether a termination of operation has been designated. The designation may be made by a user operation, another device, or the indicator control section  460  itself. If the termination of the operation has not been designated (S 2130 : No), the indicator control section  460  proceeds back to step S 2010 , and if designated (S 2130 : Yes), terminates its operation. 
     By the above process, the indicator  400  can properly and swiftly react to signal receptions, in particular, properly regulate its information output. It should be noted that the execution order of above-mentioned steps S 2010  to S 2050 , steps S 2060  to S 2090 , and steps S 2100  and S 2110  may be changed. Moreover, the execution order of the above-mentioned steps S 2020  and S 2030 , and steps S 2040  and S 2050  may also be changed. 
     Operation of Mobile Terminal 
     The terminal control section  530  of the mobile terminal  500  repeatedly determines whether the requests on the heat-pump system  100  mentioned above has been inputted by the user  620 , and transmits, when the request has been inputted, the corresponding information to the indicator  400 , including mode information, address information, operation information, and indication information. Thereby, the mobile terminal  500  can properly and swiftly make a request according to intentions of the user  620 , in particular, properly select the operation mode of each indicator  400  and set ID information to each usage-side unit  220 . 
     Operation of System 
       FIG.  9    is a sequential diagram indicating an example of an operation the heat-pump system  100 . 
     As shown in  FIG.  9   , the second mode is set to the indicators  400 _S,  400 _ 1 ,  400 _ 2  and ID information “0001” is set to the usage-side units  220 _ 1 ,  200 _ 2  for instance. When a request of setting the first mode is made in the mobile terminal  500  when it is in the vicinity of the supervisor-use indicator  400 _S (S 4110 ), the mobile terminal  500  send mode information indicating the first mode to the supervisor-use indicator  400 _S (S 4120 ). As a result, the supervisor-use indicator  400 _S sets the first mode to itself (S 4130 ). 
     Then, when the mobile terminal  500  is brought to the vicinity of the second indicator  400 _ 2  and a request of setting an address “0001” is made in the mobile terminal  500  (S 4210 ), the mobile terminal  500  sends address information indicating the address “0001” to the second indicator  400 _ 2  (S 4220 ). The second indicator  400 _ 2  (S 4220 ) transfers this address information to the second usage-side unit  220 _ 2  (S 4230 ), and the second usage-side unit  220 _ 2  sets the address “0001” as its new ID information (S 4240 ). These steps S 4110  to S 4240  belong to a setting phase of the heat-pump system  100  for achieving appropriate information output. 
     After the above setting phase, if an abnormality has occurred in the second usage-side unit  220 _ 2  (S 4310 ), the second usage-side unit  220 _ 2  originates alarm information and send it to the second indicator  400 _ 2  by a first unit signal, and to the first usage-side unit  220 _ 1  by an inter-unit signal (S 4320 ). As a result, the second indicator  400 _ 2  outputs a buzzer and displays the text “0001” (S 4320 ), because the alarm information has been indicated by a first unit signal. 
     The first usage-side unit  220 _ 1  transfers the alai in information to the first indicator  400 _ 1  and the supervisor-use indicator  400 _S by second unit signals (S 4340 ). However, the first indicator  400 _ 1  does not output a buzzer nor display the text “0001” (S 4350 ), because the alarm information has been indicated by a second unit signal and the first indicator  400 _ 1  is operating in the second mode. Meanwhile, the supervisor-use indicator  400 _S outputs a buzzer and displays the text “0001” (S 4360 ), because the supervisor-use indicator  400 _S is operating in the first mode. These steps S 4310  to S 4360  belong to a use phase the heat-pump system  100  for outputting information when necessary. 
     Accordingly, the indicator  400  can behave in different ways to output information depending on which operation mode is set and whether the information has been originated by the connecting usage-side unit  220 . 
       FIGS.  10 A to  10 D  are plan views of the indicator  400  showing examples of a display state thereof. 
     When the indicator  400  is not operating or has not received any information, it displays no information as shown in  FIG.  10 A . When the indicator  400  has received status information such as a target temperature by a first unit signal, it displays the received information as shown in  FIG.  10 B . When the indicator  400  operating in the first mode has received alarm information, it displays the received information as shown in  FIG.  10 C  if the originating usage-side unit  220  maintains the ID information as initially set. On the other hand, if the originating usage-side unit  220  has changed its ID information based on the address information, the new ID information is displayed as shown in  FIG.  10 D . 
     Hence, the ID information to be displayed in the indicators  400  can be changed as desired by the user  620 . This helps the user  620  as a monitoring person of the heat-pump system  100  to grasp the relationship between the displayed alarm information and the usage-side unit  220  which is the origin of the alarm information. For instance, it is allowed to the user  620  to swiftly know in which usage-side unit  220  an abnormality has occurred. 
     It should be noted that a plurality of the usage-side units  220  may form a unit group in which the usage-side units  220  operate in the same manner or cooperating manner. In such a unit group, a plurality of the indicators  400  may include a main usage-side unit  220  which represents the unit group to originate alarm information towards the outside of the unit group and transfer alarm information from the outside of the unit group. In this case, the ID information change may be necessary for only the main usage-side unit  220 . In general, the usage-side units  220  initially have sequential serial numbers within the unit group as their ID information. Thus, the indicator  400  connected to the usage-side unit  220  other than the main usage-side unit  220  may display such initial ID information as shown in  FIG.  10 E , while the supervisor-use indicator  400 _S displays the new ID information of the main usage-side unit  220  as shown in  FIG.  10 D . When this indicator  400  is activated in the first mode, it may display an alarm mark as shown in  FIG.  10 F . 
     Advantageous Effect 
     According to the heat-pump system  100 , it is possible to output alarm information originated by one of the usage-side units  220  from only the indicator  400  directly connecting to the usage-side units  220  which originated the alarm information and the other arbitrarily selected indicator  400 . Moreover, such a regulated information output can be achieved without providing any information output device having a different configuration from the indicators  400 . Hence, the manageability and usability of the refrigerant system  100  can be improved at a low cost. 
     Modifications 
     The abnormalities which trigger alarm information are not limited to the above-mentioned abnormalities. For instance, abnormalities in the heat-source-side unit  210  may also trigger origination of alarm information. Such abnormalities may include a case where discharge temperature of a refrigerant compressor (not shown) of the heat-source-side unit  210  has exceeded a predetermined value, a case where rotational speed of the refrigerant compressor has exceeded a predetermined value, or the like. In this case, any one of the heat-source-side unit  210  and the usage-side units  220  may detect occurrence of the abnormality to originate alarm information. In any case, the originating unit should originate alarm information indicating the heat-source-side unit  210  as a location of the abnormality has occurred. The indicator  400  outputs the alarm information to indicate that an abnormality has occurred in the heat-source-side unit  210 . It is preferable that only the indicator  400  which is operating in the first mode outputs such alarm information. 
     While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, unless specifically stated otherwise, the size, shape, location or orientation of the various components can be changed as needed and/or desired so long as the changes do not substantially affect their intended function. Unless specifically stated otherwise, components that are shown directly connected or contacting each other can have intermediate structures disposed between them so long as the changes do not substantially affect their intended function. The functions of one element can be performed by two, and vice versa unless specifically stated otherwise, The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only. 
     REFERENCE SIGNS LIST 
       100 : Heat-Pump System 
       210 : Heat-Source-Side Unit 
       220 : Usage-Side Unit 
       221 : Leakage Sensor 
       231 ,  232 ,  233 .  234 : Communication Path 
       300 : Unit Controller 
       310 : System-Side Communication Section 
       320 : Indicator-Side Communication Section 
       330 : Inter-Unit Communication Section 
       340 : Operation Control Section 
       350 : Abnormality Detection Section 
       360 : Unit Storage Section 
       370 : Communication Control Section 
       371 : Indicator Signal Processing Section 
       372 : Information Originating Section 
       373 : Inter-Unit Signal Processing Section 
       400 : Indicator 
       401 : Casing 
       402 : On/Off Button 
       403 : Display Panel 
       404 : Display Area 
       405 : Operation Area 
       406 : Loudspeaker 
       407 : LED 
       410 : Terminal-Side Communication Section 
       420 : Unit-Side Communication Section 
       430 : Indicator Input Section 
       440 : Indicator Output Section 
       450 : Indicator Storage Section 
       460 : Indicator Control Section 
       461 : Terminal Signal Processing Section 
       462 : Mode Management Section 
       463 : Unit Signal Processing Section 
       464 : Schematic Table 
       500 : Mobile Terminal 
       510 : Terminal Communication Section 
       520 : Terminal. Input Section 
       530 : Terminal Control Section 
       611 : Target Area 
       612 : Monitoring Room 
       620 : User