Patent Description:
As described in <CIT>, an air-conditioning system including a plurality of air-conditioning outdoor units, a plurality of air-conditioning indoor units, and a communication network connecting these units is known.

In the air-conditioning system, for example, one air conditioner refrigerant system is configured by connecting one outdoor unit and a plurality of indoor units with a communication line. Furthermore, by connecting a plurality of outdoor units with a communication line, communication between different air conditioner refrigerant systems becomes possible. Further, a controller may be installed so as to be able to communicate with a plurality of outdoor units. In this case, the controller can control all the outdoor units and all the indoor units belonging to the air-conditioning system. Another method is known from <CIT>, where a plurality of air conditioning units are daisy-chain connected to each other by a switching hub provided in an outdoor unit, in which an integrated transmission line and internal/external transmission lines are connected to each other by a gateway connected to the switching hub so as to be capable of separating data transmission. Another method is described in <CIT>, which uses a dwelling unit monitoring system that monitors the occurrence of a fire in each dwelling unit of an apartment house having a plurality of dwelling units at a monitoring center.

The communication line includes a plurality of conductive wires, such as two conductive wires, for example. In this case, an operator who installs the air-conditioning system may erroneously short-circuit the two conductive wires. Depending on the design of the communication network included in the air-conditioning system, all the outdoor units and all the indoor units belonging to the air-conditioning system may become inoperable due to such a short circuit of the communication line. Therefore, a design is desired in which a short circuit at a certain point of the communication line does not interfere with the operation of the devices belonging to the air-conditioning system.

A communication network system of a first aspect includes a first transmission channel, a second transmission channel, a first device, a second device, and a third device. The second transmission channel is different from the first transmission channel. The first device is connected to the first transmission channel and is not connected to the second transmission channel. The second device is connected to the second transmission channel and is not connected to the first transmission channel. The third device electrically connects the first transmission channel and the second transmission channel. The third device does not transmit a short-circuit state occurring in one of the first transmission channel and the second transmission channel to the transmission channel other than the one of the first transmission channel and the second transmission channel, thereby enabling communication between the devices connected to the transmission channel other than the one.

According to this configuration, a short-circuit state occurring in one of the first transmission channel and the second transmission channel is not transmitted to the other. Therefore, the devices connected to the transmission channel in which a short circuit is not occurring can communicate.

A communication network system of a second aspect is the communication network system of the first aspect, including a plurality of second transmission channels, a plurality of second devices, and a plurality of third devices. Each of the plurality of third devices electrically connects the first transmission channel and one of the plurality of second transmission channels. Each of the plurality of third devices does not transmit a short-circuit state occurring in one of the first transmission channel and the plurality of second transmission channels to the transmission channel other than the one of the first transmission channel and the plurality of second transmission channels, thereby enabling communication between the first device or the second device connected to the transmission channel other than the one.

According to this configuration, a short-circuit state occurring in one transmission channel is not transmitted to the other transmission channels. Therefore, the devices connected to the transmission channels in which a short circuit is not occurring can communicate.

A communication network system of a third aspect is the communication network system of the second aspect, in which each of the plurality of third devices includes a communication unit configured to transmit and receive a signal.

According to this configuration, when a failure such as a short circuit of the communication line occurs in one of the first transmission channel and the second transmission channels, the failure does not spread to the other. Therefore, it is possible to suppress the occurrence of a situation in which communication cannot be performed both in the first transmission channel and in the second transmission channels.

A communication network system according to a fourth aspect is the communication network system according to the third aspect, in which each of the plurality of third devices includes an impedance component.

According to this configuration, because the first transmission channel and the second transmission channels are electrically connected via the impedance component of the third device, the third device does not relay communication. Therefore, the communication traffic can be improved.

A communication network system of a fifth aspect is the communication network system of the fourth aspect, in which the impedance component has an impedance larger than a characteristic impedance of the first transmission channel at a frequency of a signal transmitted by the first transmission channel.

According to this configuration, the signal transmitted by the first transmission channel is attenuated before being received by the communication unit regardless of the presence or absence of a short circuit or the like on the first transmission channel. Therefore, the communication unit is less likely to be affected by a short circuit or the like.

A communication network system of a sixth aspect is the communication network system of the fourth aspect or the fifth aspect, in which each of the plurality of third devices includes a circuit board. The impedance component is mounted on the circuit board.

According to this configuration, the impedance component is mounted on the circuit board. Therefore, it is easy to introduce the impedance component into the third device.

A communication network system of a seventh aspect is the communication network system of the fourth aspect to the sixth aspect, in which the first transmission channel includes a first communication line and a second communication line. Each of the plurality of second transmission channels includes a third communication line and a fourth communication line. The impedance component includes at least one of a resistor, a capacitor, and an inductor that is connected directly or via another element to at least one of the first communication line, the second communication line, the third communication line, and the fourth communication line.

According to this configuration, the impedance component is composed of a resistor, a capacitor, and an inductor. Therefore, the impedance component can realize a stable impedance.

A communication network system of an eighth aspect is the communication network system of the seventh aspect, in which each of the plurality of third devices includes a first impedance component and a second impedance component as the impedance component. The first impedance component is disposed between the first transmission channel and the communication unit. The second impedance component is disposed between any of the plurality of second transmission channels and the communication unit.

According to this configuration, when a failure such as a short circuit of the communication line occurs both in the first transmission channel and in the second transmission channels, the failure does not spread to the communication unit of the third device. Therefore, the third device can operate normally.

A communication network system of a ninth aspect is the communication network system of the eighth aspect, in which the impedance component includes a first element, a second element, a third element, and a fourth element. The first element has a first end connected to the first communication line or the third communication line, and a second end connected to a first terminal of the communication unit. The second element has a first end connected to the second communication line or the fourth communication line, and a second end connected to a second terminal of the communication unit. The third element has a first end connected to the first end of the first element, and a second end connected to the first end of the second element. The fourth element has a first end connected to the second end of the first element, and a second end connected to the second end of the second element. All of the first element, the second element, the third element, and the fourth element include at least one of a resistor, a capacitor, and an inductor.

According to this configuration, the impedance component is a filter composed of four elements.

A communication network system of a tenth aspect is the communication network system of the eighth aspect, in which the impedance component includes a first element, a second element, a third element, a fourth element, and a fifth element. The first element has a first end connected to the first communication line or the third communication line, and a second end. The second element has a first end connected to a second end of the first element, and a second end connected to a first terminal of the communication unit. The third element has a first end connected to the second communication line or the fourth communication line, and a second end. The fourth element has a first end connected to a second end of the third element, and a second end connected to a second terminal of the communication unit. The fifth element has a first end connected to the second end of the first element, and a second end connected to the second end of the third element. All of the first element, the second element, the third element, the fourth element, and the fifth element include at least one of a resistor, a capacitor, and an inductor.

According to this configuration, the impedance component is a filter composed of five elements.

A communication network system of an eleventh aspect is the communication network system of the eighth aspect, in which the impedance component includes a first element and a second element. The first element has a first end connected to the first communication line or the third communication line, and a second end connected to a first terminal of the communication unit. The second element has a first end connected to the second communication line or the fourth communication line, and a second end connected to a second terminal of the communication unit. Both the first element and the second element include at least one of a resistor, a capacitor, and an inductor.

According to this configuration, the impedance component is a filter composed of two elements.

A communication network system of a twelfth aspect is the communication network system of the eighth aspect, in which the impedance component includes a first element, a second element, and a third element. The first element has a first end connected to the first communication line or the third communication line, and a second end connected to a first terminal of the communication unit. The second element has a first end connected to the second communication line or the fourth communication line, and a second end connected to a second terminal of the communication unit. The third element has a first end connected to the second end of the first element, and a second end connected to the second end of the second element. All of the first element, the second element, and the third element include at least one of a resistor, a capacitor, and an inductor.

According to this configuration, the impedance component is a filter composed of three elements.

A communication network system of a thirteenth aspect is the communication network system of the eighth aspect, in which the impedance component includes a first element, a second element, and a third element. The first element has a first end connected to the first communication line or the third communication line, and a second end connected to a first terminal of the communication unit. The second element has a first end connected to the second communication line or the fourth communication line, and a second end connected to a second terminal of the communication unit. The third element has a first end connected to the first end of the first element, and a second end connected to the first end of the second element. All of the first element, the second element, and the third element include at least one of a resistor, a capacitor, and an inductor.

A communication network system of a fourteenth aspect is the communication network system of the seventh aspect, in which the first transmission channel includes a first communication line and a second communication line. Each of the plurality of second transmission channels includes a third communication line and a fourth communication line. The impedance component includes a first element, a second element, a third element, a fourth element, a fifth element, and a sixth element. The first element has a first end connected to the first communication line, and a second end. The second element has a first end connected to a second end of the first element, and a second end connected to the third communication line. The third element has a first end connected to the second end of the first element, and a second end. The fourth element has a first end connected to the second communication line, and a second end. The fifth element has a first end connected to the second end of the fourth element, and a second end connected to the fourth communication line. The sixth element has a first end connected to the second end of the fourth element, and a second end. All of the first element, the second element, the third element, the fourth element, the fifth element, and the sixth element include at least one of a resistor, a capacitor, and an inductor.

According to this configuration, the impedance component is a filter composed of six elements.

A communication network system of a fifteenth aspect is the communication network system of any one of the first aspect to the fourteenth aspect, in which each of the second transmission channels constitutes an air conditioner refrigerant system together with the second device connected to the second transmission channel and the third device connected to the second transmission channel. The first transmission channel connects the plurality of air conditioner refrigerant systems to each other.

According to this configuration, an adverse effect of a communication failure is unlikely to spread among the plurality of air conditioner refrigerant systems.

A communication network system of a sixteenth aspect is the communication network system of any one of the first aspect to the fifteenth aspect, in which the first device includes a controller.

According to this configuration, the controller is connected only to the first transmission channel. Therefore, the adverse effect of the failure of the controller is less likely to spread to the second transmission channel.

A communication network system of a seventeenth aspect is the communication network system of any one of the first aspect to the sixteenth aspect, in which each of the plurality of second devices is an air-conditioning indoor unit. Each of the plurality of third devices is an air-conditioning outdoor unit.

According to this configuration, the communication network system constitutes an air conditioner. Therefore, the air in a target space can be conditioned.

An air-conditioning outdoor unit according to an eighteenth aspect electrically connects a first transmission channel and a second transmission channel different from the first transmission channel. The air-conditioning outdoor unit constitutes an air-conditioning apparatus in cooperation with a controller and an air-conditioning outdoor unit. The air-conditioning outdoor unit does not transmit a short-circuit state occurring in one of the first transmission channel and the second transmission channel to the transmission channel other than the one of the first transmission channel and the second transmission channel, thereby enabling communication of a device connected to the transmission channel other than the one.

According to this configuration, the air-conditioning outdoor unit is less likely to be adversely affected by a communication failure.

An air-conditioning outdoor unit of a nineteenth aspect is the air-conditioning outdoor unit of the eighteenth aspect, in which the air-conditioning apparatus includes a plurality of second transmission channels, a plurality of second devices, and a plurality of third devices. The air-conditioning outdoor unit electrically connects the first transmission channel and any of the plurality of second transmission channels. The air-conditioning outdoor unit does not transmit a short-circuit state occurring in one of the first transmission channel and the plurality of second transmission channels to the transmission channel other than the one of the first transmission channel and the plurality of second transmission channels, thereby enabling communication between the first device or the second device connected to the transmission channel other than the one.

An air-conditioning outdoor unit of a twentieth aspect is the air-conditioning outdoor unit of the eighteenth aspect or the nineteenth aspect, further including the communication unit and an impedance component disposed between the communication unit and at least one of the first transmission channel and the second transmission channel.

According to this configuration, the impedance component suppresses transmission of a short-circuit state occurring in one transmission channel to the other transmission channel.

<FIG> shows a circuit of a communication network system <NUM> according to a first embodiment of the present disclosure. The communication network system <NUM> constitutes an air-conditioning system. The communication network system <NUM> includes a controller <NUM>, a plurality of air-conditioning outdoor units 10a to 10e, a plurality of air-conditioning indoor units 20aa to 20ef, a first transmission channel <NUM>, and a plurality of second transmission channels 60a to 60e.

The controller <NUM> is a device configured to control all of the air-conditioning outdoor units 10a to 10e and the air-conditioning indoor units 20aa to 20ef.

The air-conditioning outdoor units 10a to 10e constitute air conditioner refrigerant systems 30a to 30e, respectively, and function as heat sources.

Each of the air-conditioning indoor units 20aa to 20ef provides conditioned air to a user.

The air-conditioning indoor units 20aa to 20af, together with the air-conditioning outdoor unit 10a, belong to the air conditioner refrigerant system 30a. The air-conditioning indoor units 20ba to 20bf, together with the air-conditioning outdoor unit 10b, belong to the air conditioner refrigerant system 30b. The air-conditioning indoor units 20ca to 20cf, together with the air-conditioning outdoor unit 10c, belong to the air conditioner refrigerant system 30c. The air-conditioning indoor units 20da to 20df, together with the air-conditioning outdoor unit 10d, belong to the air conditioner refrigerant system 30d. The air-conditioning indoor units 20ea to 20ef, together with the air-conditioning outdoor unit 10e, belong to the air conditioner refrigerant system 30e.

In each of the air conditioner refrigerant systems 30a to 30e, a refrigerant circuit not shown in <FIG> is configured.

The first transmission channel <NUM> connects the controller <NUM> to all of the plurality of air-conditioning outdoor units 10a to 10e. The first transmission channel <NUM> connects the plurality of air conditioner refrigerant systems 30a to 30e to each other.

The first transmission channel <NUM> includes a first communication line <NUM> and a second communication line <NUM>.

The second transmission channels 60a to 60e are each a transmission channel different from the first transmission channel <NUM>.

Each of the second transmission channels 60a to 60e is connected to any of the air-conditioning outdoor units 10a to 10e and to any of the air-conditioning indoor units 20aa to 20ef, thereby constituting one of the air conditioner refrigerant systems 30a to 30e.

The second transmission channels 60a to 60e include third communication lines 61a to 61e and fourth communication lines 62a to 62e, respectively.

The controller <NUM> is connected to the first transmission channel <NUM>. The controller <NUM> is not connected to any of the second transmission channels 60a to 60e.

Each of the air-conditioning indoor units 20aa to 20ef is connected to one of the second transmission channels 60a to 60e. None of the air-conditioning indoor units 20aa to 20ef is connected to the first transmission channel <NUM>.

Each of the air-conditioning outdoor units 10a to 10e electrically connects the first transmission channel <NUM> to one of the second transmission channels 60a to 60e.

<FIG> shows an internal configuration of an air-conditioning outdoor unit <NUM>. The internal configurations of the plurality of air-conditioning outdoor units 10a to 10e shown in <FIG> are identical or similar to the configuration of the air-conditioning outdoor unit <NUM> shown in <FIG>.

As shown in <FIG>, the air-conditioning outdoor unit <NUM> includes a refrigerant circuit control unit <NUM>, a communication unit <NUM>, a first impedance component <NUM>, a second impedance component <NUM>, and a circuit board <NUM>. The circuit board <NUM> includes a first internal wire <NUM> and a second internal wire <NUM>. At least the first impedance component <NUM> and the second impedance component <NUM> are mounted on the circuit board <NUM>. The refrigerant circuit control unit <NUM> and the communication unit <NUM> may also be mounted on the circuit board <NUM>.

The refrigerant circuit control unit <NUM> controls a refrigerant circuit, which is not shown in <FIG>. The refrigerant circuit includes a compressor, an expansion valve, a fan motor, a heat exchanger, various sensors, and the like.

The communication unit <NUM> transmits and receives signals to and from devices other than the air-conditioning outdoor unit <NUM>. The communication unit <NUM> transmits a command received from the controller <NUM> to the refrigerant circuit control unit <NUM>. The communication unit <NUM> acquires the state of the air-conditioning indoor units 20aa to 20ef from the refrigerant circuit control unit <NUM>. The communication unit <NUM> includes a first terminal 12a and a second terminal 12b. The first terminal 12a is connected to the first internal wire <NUM>. The second terminal 12b is connected to the second internal wire <NUM>.

The first impedance component <NUM> is a circuit having a predetermined impedance. The first impedance component <NUM> is disposed between the first transmission channel <NUM> and the communication unit <NUM>.

The second impedance component <NUM> is a circuit having a predetermined impedance. The second impedance component <NUM> is disposed between the second transmission channel <NUM> (that is, any one of the plurality of second transmission channels 60a to 60e described above) and the communication unit <NUM>.

The impedances of the first impedance component <NUM> and the second impedance component <NUM> are both larger than the characteristic impedance of the first transmission channel <NUM> at the frequency of the signal transmitted by the first transmission channel <NUM>.

As shown in <FIG>, the first impedance component <NUM> includes a first terminal 13a, a second terminal 13b, a third terminal 13c, and a fourth terminal 13d. The first terminal 13a is connected to the first communication line <NUM> of the first transmission channel <NUM>. The second terminal 13b is connected to the second communication line <NUM> of the first transmission channel <NUM>. The third terminal 13c is connected to the first terminal 12a of the communication unit <NUM> via the first internal wire <NUM>. The fourth terminal 13d is connected to the second terminal 12b of the communication unit <NUM> via the second internal wire <NUM>.

<FIG> shows an example of a circuit configuration of the first impedance component <NUM> and the second impedance component <NUM>. The first impedance component <NUM> will be described below with reference to <FIG>.

The first impedance component <NUM> includes a first element Z11, a second element Z12, a third element Z13, and a fourth element Z14.

The first element Z11 has a first end Z11a and a second end Z11b. The first end Z11a of the first element Z11 is connected to the first communication line <NUM>. The second end Z11b of the first element Z11 is connected to the first terminal 12a of the communication unit <NUM>.

The second element Z12 has a first end Z12a and a second end Z12b. The first end Z12a of the second element Z12 is connected to the second communication line <NUM>. The second end Z11b of the second element Z12 is connected to the second terminal 12b of the communication unit <NUM>.

The third element Z13 has a first end Z13a and a second end Z13b. The first end Z13a of the third element Z13 is connected to the first end Z11a of the first element Z11. The second end Z13b of the third element Z13 is connected to the first end Z12a of the second element Z12.

The fourth element Z14 has a first end Z14a and a second end Z14b. The first end Z14a of the fourth element Z14 is connected to the second end Z11b of the first element Z11. The second end Z14b of the fourth element Z14 is connected to the second end Z12b of the second element Z12.

As shown in <FIG>, the second impedance component <NUM> has a first terminal 14a, a second terminal 14b, a third terminal 14c, and a fourth terminal 14d. The first terminal 14a is connected to the third communication line <NUM> of the second transmission channel <NUM>. The second terminal 14b is connected to the fourth communication line <NUM> of the second transmission channel <NUM>. The third terminal 14c is connected to the first terminal 12a of the communication unit <NUM> via the first internal wire <NUM>. The fourth terminal 14d is connected to the second terminal 12b of the communication unit <NUM> via the second internal wire <NUM>.

Referring again to <FIG>, the second impedance component <NUM> will be described.

The second impedance component <NUM> includes a first element Z11, a second element Z12, a third element Z13, and a fourth element Z14.

The first element Z11 has a first end Z11a and a second end Z11b. The first end Z11a of the first element Z11 is connected to the third communication line <NUM>. The second end Z11b of the first element Z11 is connected to the first terminal 12a of the communication unit <NUM>.

The second element Z12 has a first end Z12a and a second end Z12b. The first end Z12a of the second element Z12 is connected to the fourth communication line <NUM>. The second end Z11b of the second element Z12 is connected to the second terminal 12b of the communication unit <NUM>.

For all of the first element Z11, the second element Z12, the third element Z13, and the fourth element Z14 described above with reference to <FIG>, elements Z shown in <FIG> may be included. In <FIG>, the element Z having a first end Za and a second end Zb is a resistor R. In <FIG>, the element Z is a capacitor C. In <FIG>, the element Z is an inductor L.

(<NUM>-<NUM>)
A short-circuit state occurring in one of the first transmission channel <NUM> and the plurality of second transmission channels <NUM> is not transmitted to another transmission channel of the first transmission channel <NUM> and the plurality of second transmission channels <NUM> in which a short-circuit state is not occurring, due to the interposition of the first impedance component <NUM> and the second impedance component <NUM>. As a result, communication between the controller <NUM> or the air-conditioning indoor unit <NUM> connected to the other transmission channel is not hindered. Therefore, the controller <NUM> or the air-conditioning indoor unit <NUM> can continue to operate.

(<NUM>-<NUM>)
Because the first transmission channel <NUM> and the second transmission channel <NUM> are electrically connected via the air-conditioning outdoor units 10a to 10e, the air-conditioning outdoor units 10a to 10e do not relay communication. That is, the air-conditioning outdoor units 10a to 10e do not perform a process of first receiving a signal from the first transmission channel <NUM> and then transmitting a signal onto the second transmission channel <NUM>. Therefore, the communication traffic can be improved.

(<NUM>-<NUM>)
When a failure such as a short circuit of a communication line occurs both in the first transmission channel <NUM> and in the second transmission channel <NUM>, the failure does not spread to the communication unit <NUM> of the air-conditioning outdoor unit <NUM>. Therefore, the air-conditioning outdoor unit <NUM> can operate normally.

(<NUM>-<NUM>)
A signal transmitted by the first transmission channel <NUM> is attenuated before being received by the communication unit <NUM>, regardless of the presence or absence of a short circuit or the like occurring in the first transmission channel <NUM>. Therefore, the communication unit <NUM> is less likely to be affected by a short circuit or the like.

(<NUM>-<NUM>)
The first impedance component <NUM> and the second impedance component <NUM> are mounted on the circuit board <NUM>. Therefore, it is easy to introduce the first impedance component <NUM> and the second impedance component <NUM> into the air-conditioning outdoor unit <NUM>.

(<NUM>-<NUM>)
The first impedance component <NUM> and the second impedance component <NUM> are composed of a resistor R, a capacitor C, and an inductor L. Therefore, the first impedance component <NUM> and the second impedance component <NUM> can realize a stable impedance.

(<NUM>-<NUM>)
Due to the presence of the first impedance component <NUM> and the second impedance component <NUM>, the adverse effect of a communication failure is less likely to spread among the plurality of air conditioner refrigerant systems 30a to 30e.

(<NUM>-<NUM>)
The controller <NUM> is connected only to the first transmission channel <NUM>. Therefore, the adverse effect of the failure of the controller <NUM> is unlikely to spread to the second transmission channel <NUM>.

<FIG> shows a circuit configuration according to a first modification of the first embodiment. At least one of the first impedance component <NUM> and the second impedance component <NUM> may have the circuit configuration of <FIG> according to the first modification, instead of the circuit configuration of <FIG>.

The impedance components include a first element Z21, a second element Z22, a third element Z23, a fourth element Z24, and a fifth element Z25.

The first element Z21 has a first end Z21a and a second end Z21b. The first end Z21a of the first element Z21 is connected to the first communication line <NUM> or the third communication line <NUM>.

The second element Z22 has a first end Z22a and a second end Z22b. The first end Z22a of the second element Z22 is connected to the second end Z21b of the first element Z21. The second end Z21b of the second element Z22 is connected to the first terminal 12a of the communication unit <NUM>.

The third element Z23 has a first end Z23a and a second end Z23b. The first end Z23a of the third element Z23 is connected to the second communication line <NUM> or the fourth communication line <NUM>.

The fourth element Z24 has a first end Z24a and a second end Z24b. The first end Z24a of the fourth element Z24 is connected to the second end Z23b of the third element Z23. The second end Z24b of the fourth element Z24 is connected to the second terminal 12b of the communication unit <NUM>.

The fifth element Z25 has a first end Z25a and a second end Z25b. The first end Z25a of the fifth element Z25 is connected to the second end Z11b of the first element Z11. The second end Z25b of the fifth element Z25 is connected to the second end Z23b of the third element Z23.

With this configuration as well, the controller <NUM> or the air-conditioning indoor unit <NUM> that is not related to the cause of the short circuit can continue communication and operation.

<FIG> shows a circuit configuration according to a second modification of the first embodiment. At least one of the first impedance component <NUM> and the second impedance component <NUM> may have the circuit configuration of <FIG> according to the second modification, instead of the circuit configuration of <FIG>.

The impedance component has a first element Z31 and a second element Z32.

The first element Z31 has a first end Z31a and a second end Z31b. The first end Z31a of the first element Z31 is connected to the first communication line <NUM> or the third communication line <NUM>. The second end Z31b of the first element Z31 is connected to the first terminal 12a of the communication unit <NUM>.

The second element Z32 has a first end Z32a and a second end Z32b. The first end Z32a of the second element Z32 is connected to the second communication line or the fourth communication line. The second end Z31b of the second element Z32 is connected to the second terminal 12b of the communication unit <NUM>.

<FIG> shows a circuit configuration according to a third modification of the first embodiment. At least one of the first impedance component <NUM> and the second impedance component <NUM> may have the circuit configuration of <FIG> according to the third modification, instead of the circuit configuration of <FIG>.

The impedance components include a first element Z41, a second element Z42, and a third element Z43.

The first element Z41 has a first end Z41a and a second end Z41b. The first end Z41a of the first element Z41 is connected to the first communication line <NUM> or the third communication line <NUM>. The second end Z41b of the first element Z41 is connected to the first terminal 12a of the communication unit <NUM>.

The second element Z42 has a first end Z42a and a second end Z42b. The first end Z42a of the second element Z42 is connected to the second communication line <NUM> or the fourth communication line <NUM>. The second end Z42b of the second element Z42 is connected to the second terminal 12b of the communication unit <NUM>.

The third element Z43 has a first end Z43a and a second end Z43b. The first end Z43a of the third element Z43 is connected to the second end Z41b of the first element Z41. The second end Z43b of the third element Z43 is connected to the second end Z42b of the second element Z42.

<FIG> shows a circuit configuration according to a fourth modification of the first embodiment. At least one of the first impedance component <NUM> and the second impedance component <NUM> may have the circuit configuration of <FIG> according to the fourth modification, instead of the circuit configuration of <FIG>.

The impedance component includes a first element Z51, a second element Z52, and a third element Z53.

The first element Z51 has a first end Z51a and a second end Z51b. The first end Z51a of the first element Z51 is connected to the first communication line <NUM> or the third communication line <NUM>. The second end Z51b of the first element Z51 is connected to the first terminal 12a of the communication unit <NUM>.

The second element Z52 has a first end Z52a and a second end Z52b. The first end Z52a of the second element Z52 is connected to the second communication line <NUM> or the fourth communication line <NUM>. The second end Z52b of the second element Z52 is connected to the second terminal 12b of the communication unit <NUM>.

The third element Z53 has a first end Z53a and a second end Z53b. The first end Z53a of the third element Z53 is connected to the first end Z51a of the first element Z51. The second end Z53b of the third element Z53 is connected to the first end Z52a of the second element Z52.

Only one of the first impedance component <NUM> and the second impedance component <NUM> may be mounted on the circuit board <NUM>.

<FIG> shows a circuit of a communication network system <NUM> according to a sixth modification of the first embodiment of the present disclosure. The sixth modification of the first embodiment is different from the first embodiment shown in <FIG> in the number of devices.

As shown in <FIG>, the communication network system <NUM> according to the sixth modification of the first embodiment includes one air-conditioning outdoor unit <NUM>, one air-conditioning indoor unit <NUM>, and one second transmission channel <NUM>.

When a short-circuit state occurs in the first transmission channel <NUM>, communication between the controller <NUM> and the air-conditioning outdoor unit <NUM> becomes impossible. However, even in this case, communication between the air-conditioning outdoor unit <NUM> and the air-conditioning indoor unit <NUM> is possible. Therefore, the air-conditioning outdoor unit <NUM> and the air-conditioning indoor unit <NUM> can continue to operate as an air-conditioning system or an air-conditioning apparatus.

The communication network system <NUM> may include one air-conditioning outdoor unit <NUM> and a plurality of air-conditioning indoor units <NUM>.

The second embodiment differs from the first embodiment in the configuration of the air-conditioning outdoor units 10a to 10e.

The communication network system <NUM> according to the second embodiment of the present disclosure includes the circuit shown in <FIG> as in the first embodiment. Specifically, the communication network system <NUM> includes a controller <NUM>, a plurality of air-conditioning outdoor units 10a to 10e, a plurality of air-conditioning indoor units 20aa to 20ef, a first transmission channel <NUM>, and a plurality of second transmission channels 60a to 60e.

<FIG> shows an internal configuration of the air-conditioning outdoor unit <NUM> of the second embodiment. The internal configurations of the plurality of air-conditioning outdoor units 10a to 10e shown in <FIG> are identical or similar to the configuration of the air-conditioning outdoor unit <NUM> shown in <FIG>.

As shown in <FIG>, the air-conditioning outdoor unit <NUM> includes a refrigerant circuit control unit <NUM>, a communication unit <NUM>, an impedance component <NUM>, and a circuit board <NUM>. The circuit board <NUM> includes a first internal wire <NUM> and a second internal wire <NUM>. At least the impedance component <NUM> is mounted on the circuit board <NUM>. The refrigerant circuit control unit <NUM> and the communication unit <NUM> may also be mounted on the circuit board <NUM>.

The functions of the refrigerant circuit control unit <NUM> and the communication unit <NUM> are the same as in the first embodiment. The communication unit <NUM> includes a first terminal 12a and a second terminal 12b. The first terminal 12a is connected to the first internal wire <NUM>. The second terminal 12b is connected to the second internal wire <NUM>.

The impedance component <NUM> is a circuit having a predetermined impedance. The impedance component <NUM> is disposed between the first transmission channel <NUM>, the second transmission channel <NUM> (that is, any one of the plurality of second transmission channels 60a to 60e described above), and the communication unit <NUM>.

The impedance of the impedance component <NUM> is larger than the characteristic impedance of the first transmission channel <NUM> at the frequency of the signal transmitted by the first transmission channel <NUM>.

As shown in <FIG>, the impedance component <NUM> includes a first terminal 19a, a second terminal 19b, a third terminal 19c, a fourth terminal 19d, a fifth terminal 19e, and a sixth terminal 19f. The first terminal 19a is connected to the first communication line <NUM> of the first transmission channel <NUM>. The second terminal 19b is connected to the first communication line <NUM> of the second transmission channel <NUM>. The third terminal 19c is connected to the first terminal 12a of the communication unit <NUM> via the first internal wire <NUM>. The fourth terminal 19d is connected to the second communication line <NUM> of the first transmission channel <NUM>. The fifth terminal 19e is connected to the second communication line <NUM> of the second transmission channel <NUM>. The sixth terminal 19f is connected to the second terminal 12b of the communication unit <NUM> via the second internal wire <NUM>.

<FIG> shows an example of a circuit configuration of the impedance component <NUM>. The impedance component <NUM> includes a first element Z61, a second element Z62, a third element Z63, a fourth element Z64, a fifth terminal Z65, and a sixth terminal Z66.

The first element Z61 has a first end Z61a and a second end Z61b. The first end Z61a of the first element Z61 is connected to the first communication line <NUM>.

The second element Z62 has a first end Z62a and a second end Z62b. The first end Z62a of the second element Z62 is connected to the second end 61b of the first element <NUM>. The second end Z62b of the second element Z62 is connected to the third communication line <NUM>.

The third element Z63 has a first end Z63a and a second end Z63b. The first end Z63a of the third element Z63 is connected to the second end Z61b of the first element Z61. The second end Z63b of the third element Z63 is connected to the first terminal 12a of the communication unit <NUM>.

The fourth element Z64 has a first end Z64a and a second end Z64b. The first end Z64a of the fourth element Z64 is connected to the second communication line <NUM>.

The fifth element Z65 has a first end Z65a and a second end Z65b. The first end Z65a of the fifth element Z65 is connected to the second end 64b of the fourth element <NUM>. The second end Z65b of the fifth element Z65 is connected to the fourth communication line <NUM>.

The sixth element Z66 has a first end Z66a and a second end Z66b. The first end Z66a of the sixth element Z66 is connected to the second end Z64b of the fourth element Z64. The second end Z66b of the sixth element Z66 is connected to the second terminal 12b of the communication unit <NUM>.

All of the first element Z61, the second element Z62, the third element Z63, the fourth element Z64, the fifth element Z65, and the sixth element Z66 described above with reference to <FIG> may include the element Z shown in <FIG>. In <FIG>, the element Z having a first end Za and a second end Zb is a resistor R. In <FIG>, the element Z is a capacitor C. In <FIG>, the element Z is an inductor L.

When a failure such as a short circuit of a communication line occurs in one of the first transmission channel <NUM> and the second transmission channel <NUM>, the failure does not spread to the other. Therefore, it is possible to suppress the occurrence of a situation in which communication cannot be performed both in the first transmission channel <NUM> and in the second transmission channel <NUM>.

In addition, because the first transmission channel <NUM> and the second transmission channel <NUM> are electrically connected via the air-conditioning outdoor units 10a to 10e, the air-conditioning outdoor units 10a to 10e do not relay communication. That is, the air-conditioning outdoor units 10a to 10e do not perform a process of first receiving a signal from the first transmission channel <NUM> and then transmitting a signal onto the second transmission channel <NUM>. Therefore, the communication traffic can be improved.

Some of the plurality of air-conditioning outdoor units 10a to 10e may have the configuration of the air-conditioning outdoor unit <NUM> according to the first embodiment.

While embodiments of the present disclosure have been described above, it will be understood that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as set forth in the appended claims.

Claim 1:
A communication network system (<NUM>) comprising:
a first transmission channel (<NUM>);
a second transmission channel (<NUM>) different from the first transmission channel;
a first device (<NUM>) connected to the first transmission channel and not connected to the second transmission channel;
a second device (<NUM>) connected to the second transmission channel and not connected to the first transmission channel; and
a third device (<NUM>) electrically connecting the first transmission channel and the second transmission channel, the third device not transmitting a short-circuit state occurring in one of the first transmission channel and the second transmission channel to a transmission channel other than the one of the first transmission channel and the second transmission channel,
the communication network system (<NUM>) further comprising:
a plurality of the second transmission channels (60a to 60e);
a plurality of the second devices (20aa to 20ef); and
a plurality of the third devices (<NUM>, 10a to 10e),
wherein each of the plurality of the third devices (<NUM>, 10a to 10e) electrically connects the first transmission channel and one of the plurality of the second transmission channels,
each of the plurality of the third devices (<NUM>, 10a to 10e) does not transmit a short-circuit state occurring in one of the first transmission channel and the plurality of the second transmission channels to a transmission channel other than the one of the first transmission channel and the plurality of the second transmission channels;
wherein each of the plurality of third devices includes an impedance component (<NUM>, <NUM>, <NUM>),
and wherein the impedance component (<NUM>, <NUM>, <NUM>) has an impedance larger than a characteristic impedance of the first transmission channel at a frequency of a signal transmitted by the first transmission channel.