TECHNICAL FIELD
[0001] The present invention relates to a detection device.
BACKGROUND ART
[0003] In the related art, there is a communication system in which a plurality of cordless
extension units are bus-connected to one base device via a communication line. For
example, in the case of an air-conditioning system for business use installed in a
large-size building or the like, the cordless extension unit is an indoor unit, and
the base device is, for example, a management device such as an outdoor unit or an
air-conditioning management device at a center, or the like. In such an air-conditioning
system, information related to an operation of each of the connected indoor units
(for example, set temperature information, sensor information, and the like) is acquired
sequentially and managed collectively in the management device. In addition, in such
an air-conditioning system, operations of the plurality of indoor units can also be
controlled collectively by the management device. For example, in the office building,
it is possible to collectively start (ON) operations of the indoor units in the office
building before the attendance time of workers and collectively stop (OFF) operations
of all the indoor units after leaving time according to a previously set schedule
using the function. Accordingly, convenience is improved for an air-conditioning manager
or the like.
[0004] Incidentally, in the communication system in which the above-mentioned bus connecting
system is employed, terminating resistors are generally set in the base device and
the cordless extension units disposed at a terminal end of a communication line. When
a communication speed is increased and a communication wiring length is increased,
an influence of the reflection of the communication signal at the terminal end may
become large, and a signal waveform may be disturbed. On the other hand, since terminating
resistors that are constant and appropriate for communication are set in the base
device and the cordless extension units disposed close to the terminal end of the
communication line, reflection of the signal can be minimized, and the communication
can be performed without disturbing a signal waveform.
[0005] However, if a terminating resistor is installed temporarily, for example, when the
number of cordless extension units connected to the communication line is changed
due to expansion or removal or when there is replacement with a communication line
of a different length or type, the cordless extension unit that sets the terminating
resistor must be changed or the setting must be changed every time. In the related
art, in the air-conditioning system for business use installed in a large-size building
or the like, since a manager or the like of the air-conditioning system performs setting
of the terminating resistor, there is a need to find the indoor unit disposed near
the terminal end of the communication line. However, in such an air-conditioning system,
since a plurality of indoor units are connected to an elongated communication wiring,
it is not easy to manually find the indoor unit disposed near the terminal end of
communication line from the indoor units.
[Citation List]
[Patent Document]
SUMMARY OF INVENTION
[Problems to be Solved by the Invention]
[0007] In order to solve the above-mentioned problems, the present invention is directed
to providing a detection device capable of detecting a communication device of a terminal
end of a communication line.
[Means for Solving the Problems]
[0008] A detection device of an embodiment is connected to a plurality of communication
devices by a communication line. The detection device has a reception unit, a measurement
unit and a detection unit. The reception unit receives signals with prescribed pulse
widths transmitted from the plurality of communication devices. The measurement unit
measures the pulse widths of the signals received by the reception unit. The detection
unit is configured to detect the communication devices disposed near the terminal
end of the communication line as terminal-end communication devices on the basis of
the plurality of pulse widths measured by the measurement unit.
BRIEF DESCRIPTION OF DRAWINGS
[0009]
FIG. 1 is the entire configuration view of an air-conditioning system 100 according
to a first embodiment.
FIG. 2 is a schematic view showing detection of a communication device 20 disposed
near a terminal end of a communication line 30 by a communication device 10 according
to the first embodiment.
FIG. 3 is a schematic view showing detection of the communication device 20 disposed
near the terminal end of the communication line 30 by the communication device 10
according to the first embodiment.
FIG. 4 is a schematic view showing detection of the communication device 20 disposed
near the terminal end of the communication line 30 by the communication device 10
according to the first embodiment.
FIG. 5 is a schematic view showing detection of the communication device 20 disposed
near the terminal end of the communication line 30 by the communication device 10
according to the first embodiment.
FIG. 6 is a block diagram showing a functional configuration of the communication
device 10 according to the first embodiment.
FIG. 7 is a view showing an example of a configuration of a communication device information
table t1 stored in the communication device 10 according to the first embodiment.
FIG. 8 is a view showing an example of a configuration of a pulse width storage table
t2 stored in the communication device 10 according to the first embodiment.
FIG. 9 is a schematic diagram showing a configuration of the communication device
20 according to the first embodiment.
FIG. 10 is a flowchart showing an example of an operation of the communication device
10 according to the first embodiment.
FIG. 11 is a flowchart showing an operation in pulse signal output processing of the
communication device 20 according to the first embodiment.
FIG. 12 is a flowchart showing an operation in terminating resistor setting processing
of the communication device 20 according to the first embodiment.
FIG. 13 is a flowchart showing an operation in communication speed switching processing
of the communication device 20 according to the first embodiment.
FIG. 14 is the entire configuration view of an air-conditioning system 200 according
to a variant of the first embodiment.
DESCRIPTION OF EMBODIMENTS
[0010] Hereinafter, a detection device of an embodiment will be described with reference
to the accompanying drawings.
(First embodiment)
[0011] Hereinafter, a configuration of an air-conditioning system 100 according to a first
embodiment will be described.
[0012] FIG. 1 is the entire configuration view of the air-conditioning system 100 according
to the first embodiment. The air-conditioning system 100 shown in FIG. 1 is, for example,
an air-conditioning system installed in an office building. As shown in FIG. 1, the
air-conditioning system 100 is configured to include an outdoor unit 1 that is an
outdoor unit of an air-conditioner, and an indoor unit 2-1, an indoor unit 2-2 and
an indoor unit 2-3 that are indoor units of the air-conditioner. Further, in the following
description, when there is no need to describe the indoor unit 2-1, the indoor unit
2-2 and the indoor unit 2-3 in a distinguishable manner, they are simply referred
to as "the indoor unit 2." The outdoor unit 1 and the indoor units 2 are configured
as a refrigerating cycle by being connecting by a coolant pipeline. In addition, the
outdoor unit 1 and the indoor units 2 are connected by a communication line 30, and
the outdoor unit 1 and the indoor units 2 can exchange signals.
[0013] In this way, the air-conditioning system 100 includes the outdoor unit 1 and the
plurality of indoor units 2. The outdoor unit 1 collectively controls operations of
the plurality of indoor units 2. Further, the number of the plurality of indoor units
2 controlled by the outdoor unit 1 is not limited to three, and an arbitrary number
of indoor units may be used.
[0014] The outdoor unit 1 includes the communication device 10 that is a base device on
communication. In addition, the indoor unit 2-1, the indoor unit 2-2 and the indoor
unit 2-3 include a communication device 20-1, a communication device 20-2 and a communication
device 20-3 that are cordless extension units for communication, respectively. Further,
in the following description, when there is no need to describe the communication
device 20-1, the communication device 20-2 and the communication device 20-3 in a
distinguishable manner, they are simply referred to as "a communication device 20."
[0015] As shown in FIG. 1, the communication device 10, the communication device 20-1, the
communication device 20-2 and the communication device 20-3 are connected by the communication
line 30 with a bus connecting system. Since only the outdoor unit 1 is disposed outdoors
and the indoor units 2 are installed indoors, the communication device 10 of the outdoor
unit 1 is conventionally installed at a position near one terminal end of the communication
line 30.
[0016] The communication device 10 has a communication function of being configured to perform
communication with the plurality of communication devices 20. For example, the communication
device 10 can acquire information showing an operating status of the indoor unit 2
or can acquire information showing a temperature or a humidity of a room in which
the indoor unit 2 is installed by receiving a signal transmitted from the communication
device 20. In addition, the communication device 10 can control an operating state
of the indoor unit 2 via, for example, the communication device 20 by transmitting
the signal to the communication device 20.
[0017] The communication device 10 includes a terminating resistor 11, which will be described
below. Accordingly, the communication device 10 always has a function of a terminating
device. In addition, as described below in detail, the communication device 10 also
includes a function as a detection device configured to detect the communication device
20 of the indoor unit installed near the terminal end on the communication line 30.
[0018] In addition, the communication device 20 includes a terminating resistor setting
unit 21 provided with a terminating resistor, which will be described below. The terminating
resistor setting unit 21 performs switching of settings of the terminating resistor
or release of the settings on the basis of a command transmitted from the communication
device 10 (the detection device). Accordingly, the communication device 20 may or
may not have a function as a terminating device.
[0019] Both of the communication device 10 and the communication device 20 can perform communication
by switching between communication in a high speed communication mode that is a mode
of performing communication at a high speed and communication in a low speed communication
mode that is a mode of performing communication at a speed relatively lower than the
high speed.
[0020] In an initial state before the air-conditioning system 100 is operated, the terminating
resistor is in a state in which the setting released in the terminating resistor setting
unit 21 of all of the communication devices 20. Accordingly, in the initial state,
since none of the communication devices 20 have a function of a terminating device,
reflection of the signal transmitted by the communication line 30 is likely to occur,
and the signal waveform is likely to be disturbed. Especially when communication is
performed at a high speed, since the influence of the reflection of the signal tends
to be large, in the initial state, both of the communication device 10 and the communication
device 20 are set to a low speed communication mode.
[0021] The communication device 10 performs control such that reflection of the signal transmitted
by the communication line 30 can be minimized and communication with the communication
device 20 can be performed at a high speed communication mode. Specifically, the communication
device 10 includes a detection function operating as a detection device and configured
to detect and identify one of the communication devices 20 (i.e., the communication
device 20-3) disposed near the terminal end of the communication line 30. Then, the
communication device 10 transmits a command for switching a state in which a terminating
resistor is set to the terminating resistor setting unit 21 of the detected communication
device 20. As described below, while the communication device (detection device) 20
should be able to identify the communication device 20 disposed closest to the terminal
end of the communication line 30, since the plurality of communication devices 20
cannot be distinguished when they have similar wiring lengths, one of the communication
devices 20 disposed near the terminal end is identified. This also achieves the purpose
of improving stability of sufficient communication (waveform).
[0022] The terminating resistor setting unit 21 of the communication device 20 disposed
near the terminal end of the communication line 30 is switched to a state in which
the terminating resistor is set according to the received command. Accordingly, the
communication device 20 disposed near the terminal end of the communication line 30
becomes a terminating device. Then, the terminating resistor that is an appropriate
constant for communication can be set in the communication device 10 and the communication
device 20 disposed near both of the terminal ends of the communication line 30, reflection
of the signal can be minimized, and the communication can be performed without disturbing
the signal waveform.
[0023] Hereinafter, a method of detecting the communication device 20 disposed closest to
the terminal end of the communication line 30 due to the function as the detection
device of the communication device 10 will be described.
[0024] First, the communication device 10 commands output of pulse signals with a prescribed
pulse width to the communication devices 20 in sequence. The communication device
10 receives the pulse signals output from the communication devices 20, and measures
pulse widths of the pulse signals. Then, the communication device 10 identifies the
shortest pulse width of the plurality of measured pulse widths. The communication
device 10 detects the communication device 20 that has transmitted the pulse signal
with the specified pulse width as the communication device 20 disposed at the terminal
end of the communication line 30 or near the terminal end.
[0025] FIGS. 2, 3, 4 and 5 are schematic views showing detection of the communication device
20 disposed near the terminal end of the communication line 30 by the communication
device 10 according to the first embodiment.
[0026] As shown in FIG. 2, for example, when a pulse signal with a prescribed pulse width
w is transmitted from the communication device 20-1, there is a pulse signal A that
reaches the communication device 10 directly. In addition, in the initial state, since
reflection of the signal occurs when the terminating resistor is not set in any of
the communication devices 20, as shown in FIG. 2, there is a pulse signal B that reflects
and reaches the communication device 20-3 disposed at the terminal end of the communication
line 30.
[0027] In this case, a moving distance until the pulse signal B is transmitted from the
communication device 20-1 to the communication device 10 is greater than a moving
distance until the pulse signal A is transmitted from the communication device 20-1
to the communication device 10. For this reason, the pulse signal B reaches the communication
device 10 later than the pulse signal A. Accordingly, the communication device 10
recognizes two pulse signals (the pulse signal A and the pulse signal B) that overlap
each other with a time lag as one pulse signal. That is, as shown in FIG. 2, the communication
device 10 recognizes that a pulse signal with a pulse width x (x > w) in which the
pulse signal A and the pulse signal B overlap each other has been received.
[0028] FIG. 3 shows a pulse signal recognized by the communication device 10 when the pulse
signal with the pulse width w is transmitted from the communication device 20-1. In
this case, as shown in FIG. 2, the pulse width with the pulse signal recognized by
the communication device 10 is x (x > w).
[0029] FIG. 4 shows a pulse signal recognized by the communication device 10 when the pulse
signal with the pulse width w is transmitted from the communication device 20-2. When
the pulse signal is transmitted from the communication device 20-2, a difference between
the moving distance until the pulse signal B is transmitted from the communication
device 20-1 to the communication device 10 and the moving distance until the pulse
signal A is transmitted from the communication device 20-1 to the communication device
10 is smaller than that in the case in which the pulse signal is transmitted from
the communication device 20-1. For this reason, the time lag between the two overlapping
pulse signals (the pulse signal A and the pulse signal B) is smaller than that in
the case of the pulse signal shown in FIG. 3. For this reason, as shown in FIG. 4,
the communication device 10 recognizes that a pulse signal with a pulse width y (x
> y > w) in which the pulse signal A and the pulse signal B overlap each other is
received.
[0030] FIG. 5 shows a pulse signal recognized by the communication device 10 when the pulse
signal with the pulse width w is transmitted from the communication device 20-3. When
the pulse signal is transmitted from the communication device 20-3, since the communication
device 20-3 is disposed nearest the terminal end of the communication line 30, reflection
of the signal does not occur. That is, only the pulse signal A reaches the communication
device 10. For this reason, as shown in FIG. 5, the communication device 10 recognizes
that a pulse signal with a pulse width z (x > y > w ≠z) is received. Further, the
reason why the pulse width shown in FIG. 5 is not the same as the pulse width w of
the pulse signal at the time of transmission from the communication device 20-3 is
that the pulse width changes slightly due to causes other than reflection (for example,
signal attenuation) or the like.
[0031] As shown in FIGS. 3 to 5, the pulse width of the pulse signal transmitted from the
communication device 20, which is closer to the communication device 10, is recognized
by the communication device 10 as a longer pulse width. The pulse width of the pulse
signal transmitted from the communication device 20-3 farthest from the communication
device 10 (i.e., disposed nearest the terminal end of the communication line 30 opposite
to the communication device 10) is recognized by the communication device 10 as the
shortest pulse width.
[0032] From the above, the communication device 10 identifies the shortest pulse width of
the plurality of measured pulse widths, and detects the communication device 20 that
has transmitted the pulse signal with the specified pulse width as the communication
device 20 disposed near the terminal end of the communication line 30.
[0033] Hereinafter, a functional configuration of the communication device 10 will be described
in more detail.
[0034] FIG. 6 is a block diagram showing a functional configuration of the communication
device 10 according to the first embodiment. As shown in FIG. 6, the communication
device 10 is configured to include the terminating resistor 11 and a signal transmission/reception
circuit 12.
[0035] As shown in FIG. 6, the terminating resistor 11 is always connected to the communication
line 30 that is a two-line type communication line. Accordingly, the terminating resistor
11 makes the communication device 10 always function as a terminating device.
[0036] The signal transmission/reception circuit 12 is a main part as a detection device,
and is a circuit configured to perform transmission and reception of the signal in
communication between the communication devices 20. The signal transmission/reception
circuit 12 is a signal transmission/reception circuit included in the communication
device 10 disposed nearest one terminal end of the communication line 30 as described
above. In addition, the signal transmission/reception circuit 12 detects the communication
device disposed near the other terminal end of the communication line 30 (hereinafter,
referred to as "a terminal-end communication device"). The signal transmission/reception
circuit 12 controls a setting state of the terminating resistor in each of the communication
devices 20 by transmitting a command to each of the communication devices 20.
[0037] As shown in FIG. 6, the signal transmission/reception circuit 12 is configured to
include a control unit 120, a command unit 121, a transmission unit 122, a reception
unit 123, a measurement unit 124, a storage unit 125, a detection unit 126, and a
communication speed switching unit 127.
[0038] The control unit 120 controls processing by each functional block provided in the
signal transmission/reception circuit 12. Accordingly, for example, the control unit
120 controls transmission and reception of the signal in communication between the
communication devices 20. In addition, for example, the control unit 120 controls
processing of detecting the terminal-end communication device. In addition, for example,
the control unit 120 controls transmission of various types of commands to the communication
devices 20.
[0039] The control unit 120 is a processor such as a central processing unit (CPU) or the
like. Further, the control unit 120 may be realized using hardware such as a large-scale
integrated circuit (LSI), an application specific integrated circuit (ASIC), or the
like. In addition, each of the functional blocks provided in the signal transmission/reception
circuit 12 may have a configuration realized by executing a program stored in the
storage unit 125 using the control unit 120 that is a processor such as a CPU or the
like.
[0040] The command unit 121 controls transmission of various types of commands transmitted
to the communication devices 20. The command unit 121 outputs various types of commands
to the communication devices 20 via the transmission unit 122. As shown in FIG. 6,
the command unit 121 includes a pulse signal output command unit 121a, a terminating
resistor setting command unit 121b, and a communication speed switching command unit
121c.
[0041] The pulse signal output command unit 121a outputs a pulse signal output command (a
third command) indicating a command for outputting a pulse signal to the communication
device 10 thereof to each of the communication devices 20. Further, the pulse signal
output command may be configured to be transmitted to each of the communication devices
20 through broadcasting or multicasting. Further, the signal output from each of the
communication devices 20 according to the pulse signal output command is a test signal
that is output experimentally, and is previously set to output a pulse with exactly
the same time width in any of the communication devices 20.
[0042] The terminating resistor setting command unit 121b outputs a terminating resistor
setting command (a first command) indicating a command for setting a terminating resistor
to the terminal-end communication device when the terminal-end communication device
is detected by the detection unit 126.
[0043] Further, the terminating resistor setting command unit 121b may output a command
for releasing the setting of the terminating resistor (a fourth command) to the terminal-end
communication device when at least one communication device 20 is added or removed.
After that, the signal transmission/reception circuit 12 may be configured to detect
the terminal-end communication device again, and set the terminating resistor for
the detected terminal-end communication device.
[0044] The communication speed switching command unit 121c may output a communication speed
switching command (a second command) indicating a command for switching the communication
setting such that a communication speed in communication with the communication device
10 thereof becomes higher (i.e., a command for switching the setting to a high speed
communication mode) to the communication device 20 when the terminating resistor setting
command is output by the terminating resistor setting command unit 121b.
[0045] Further, the communication speed switching command unit 121c may output a command
for switching the communication setting for decreasing the communication speed in
communication with the communication device 10 thereof to be lower (i.e., a command
for switching the setting to a low speed communication mode) (a fifth command) to
each of the communication devices 20 connected to the communication line 30 when at
least one of the communication devices 20 is added or removed. After that, the signal
transmission/reception circuit 12 may be configured to detect the terminal-end communication
device again, and set the terminating resistor for the detected terminal-end communication
device.
[0046] The transmission unit 122 and the reception unit 123 are communication interfaces
configured to be connected to the communication devices 20 through communication.
Further, the transmission unit 122 and the reception unit 123 may be a functional
unit constituted by one piece of hardware.
[0047] The transmission unit 122 outputs various signals (pulse signals) to the communication
devices 20 via the communication line 30 under the control of the control unit 120.
Further, the various signals include the signals output from the command unit 121
and showing the pulse signal output command, the terminating resistor setting command,
and the communication speed switching command, which are described above.
[0048] The reception unit 123 acquires various signals (pulse signals) output from the communication
devices 20 via the communication line 30. Further, the various signals also include
a pulse signal that is a test signal output from each of the communication devices
20 according to acquisition of the pulse signal output command. The reception unit
123 outputs the acquired pulse signal to the measurement unit 124 when the pulse signal
that is a test signal is acquired.
[0049] The measurement unit 124 acquires the pulse signal that is the test signal transmitted
from each of the communication devices 20 from the reception unit 123. The measurement
unit 124 measures the pulse width of the acquired pulse signal. The measurement unit
124 stores the measurement value with the pulse width of the pulse signal transmitted
from each of the communication devices 20 in the storage unit 125. For example, the
measurement unit 124 stores the previously stored measurement value in the storage
unit 125 by writing the pulse width in the storage table t2, which will be described
below.
[0050] The storage unit 125 stores various types of programs and theta tables used in the
signal transmission/reception circuit 12. The storage unit 125 is a non-volatile recording
medium (a non-transient recording medium) such as a flash memory, a hard disk drive
(HDD), or the like. In addition, the storage unit 125 may further have a volatile
recording medium such as a random access memory (RAM), a register, or the like.
[0051] In addition, the storage unit 125 stores a communication device information table
t1 and a pulse width storage table t2, which will be described below.
[0052] FIG. 7 is a view showing an example of a configuration of the communication device
information table t1 stored in the communication device 10 according to the first
embodiment. As shown in FIG. 7, the communication device information table t1 is data
of a two-dimensional table form constituted by rows of two items of "identification
number" and "address." The value stored in the item of the identification number is
an identification number for identifying each of the communication devices 20. For
example, it is shown that the identification numbers corresponding to the communication
device 20-1, the communication device 20-2, and the communication device 20-3 are
"c1," "c2" and "c3" stored in the communication device information table t1 shown
in FIG. 7.
[0053] In addition, the communication device information table t1 is a table in which the
identification numbers assigned to the communication devices 20 and the addresses
required to cause the communication device 10 to perform communication with each of
the communication devices 20 correspond to each other. For example, as shown in FIG.
7, the address of the communication device 20-1 to which the identification number
"c1" is assigned is expressed as "aaa.bbb."
[0054] The communication device information table t1 is a table that is previously stored
in the storage unit 125. The communication device 10 refers the address corresponding
to the communication device 20 of a transmission destination using the communication
device information table t1 when the signal is transmitted to the specified communication
device 20. Then, the communication device 10 designates the referred address and transmits
the signal. For example, as shown in FIG. 7, the communication device 10 can transmit
the signal to the communication device 20-1 to which the identification number "c1"
is assigned by designating the address referred to as "aaa.bbb" and transmitting the
signal.
[0055] FIG. 8 is a view showing an example of a configuration of the pulse width storage
table t2 stored in the communication device 10 according to the first embodiment.
As shown in FIG. 8, the pulse width storage table t2 is data of a two-dimensional
table format constituted by rows of two items of "identification number" and "pulse
width." The value stored in the item of the identification number is an identification
number for identifying each of the communication devices 20 like the communication
device information table t1.
[0056] The pulse width storage table t2 is a table for temporarily storing pulse widths
of pulse signals that are test signals output from the communication devices 20. The
pulse width storage table t2 is in a state in which a value of an item of at least
"pulse width" is not stored in the initial state. Whenever the pulse widths of the
pulse signals output from the communication devices 20 are measured by the measurement
unit 124, data showing the measurement value is written in the pulse width storage
table t2.
[0057] Accordingly, the pulse width storage table t2 exemplified in FIG. 8 shows a state
in which, while measurement of the pulse width of the pulse signal output from the
communication device 20-1 to which the identification number "c1" is assigned and
the pulse width of the pulse signal output from the communication device 20-2 to which
the identification number "c2" is assigned are completed, measurement of the pulse
width of the pulse signal output from the communication device 20-3 to which the identification
number "c3" is assigned is not yet performed. Finally, measurement of the pulse widths
from all the communication devices 20 is completed, and the pulse width storage table
t2 is filled.
[0058] The pulse width storage table t2 exemplified in FIG. 8 shows that the measurement
value of the pulse width of the pulse signal output from the communication device
20-1 to which the identification number "c1" is applied was "1.4" (a unit is ms (millisecond)).
[0059] Description will be performed again by returning to FIG. 6.
[0060] The detection unit 126 refers the pulse width storage table t2 stored in the storage
unit 125. The detection unit 126 identifies a value of the narrowest pulse width by
referring a value stored in the item of "pulse width" of the pulse width storage table
t2. Then, the detection unit 126 refers the value stored in the item of "identification
accompaniment" of the pulse width storage table t2, and acquires the value of the
identification number corresponding to the value of the narrowest pulse width. The
detection unit 126 detects the communication device 20 to which the acquired identification
number is assigned as the terminal-end communication device near the terminal end.
[0061] The detection unit 126 outputs the information showing the detected communication
device 20 as the terminal-end communication device (for example, an identification
number) to the terminating resistor setting command unit 121b. The terminating resistor
setting command unit 121b outputs the terminating resistor setting command to the
communication device 20 (the terminal-end communication device) based on the information
acquired from the detection unit 126.
[0062] When the terminating resistor setting command is output from the terminating resistor
setting command unit 121b, the communication speed switching command unit 121c outputs
a communication speed switching command to all the communication devices 20. Accordingly,
in the communication device 20, the communication setting is switched to increase
the communication speed in communication with the communication device 10 to be higher
(i.e., switched to the high speed communication mode). Further, the communication
speed switching command unit 121c may output the communication speed switching command
to at least one communication device 20.
[0063] The communication speed switching unit 127 switches the communication setting to
increase the communication speed in communication with the communication device 20
to be higher (i.e., switching the setting to the high speed communication mode) when
the terminating resistor setting command is output from the terminating resistor setting
command unit 121b). After that, the communication device 10 performs exchange of conventional
information between the communication devices 20 in the high speed communication mode.
[0064] Further, the communication speed switching unit 127 may allow the terminal-end communication
device to open the terminating resistor while switching the communication setting
to decrease the communication speed in communication with the communication device
20 connected to the communication line 30 (i.e., switching the setting to a low speed
communication mode) when at least one communication device 20 is added or removed.
After that, the signal transmission/reception circuit 12 may be configured to detect
the terminal-end communication device again, and set the terminating resistor for
the detected terminal-end communication device. It is possible to improve stability
of communication between the communication device 10 and the communication devices
20 and increase measurement accuracy of the pulse width in the measurement unit 124
using the low speed communication mode in searching of the terminal-end communication
device.
[0065] Hereinafter, a configuration of the communication device 20 will be described.
[0066] FIG. 9 is a schematic diagram showing the configuration of the communication device
20 according to the first embodiment. Further, since the configurations of the communication
devices 20 are the same as each other, FIG. 9 shows only the communication device
20-2 and the communication device 20-3 as an example. As shown in FIG. 9, the communication
device 20 is configured to include the terminating resistor setting unit 21, and a
signal transmission/reception circuit 22.
[0067] The terminating resistor setting unit 21 is configured to include the terminating
resistor. The terminating resistor setting unit 21 acquires the terminating resistor
setting command transmitted from the communication device 10. The terminating resistor
setting unit 21 is switched to a state in which the terminating resistor is set when
the terminating resistor setting command is acquired. Further, FIG. 9 shows a state
in which the terminating resistor is switched to a setting state because the communication
device 20-3 is the terminal-end communication device, and the terminating resistor
is in a setting-released state because the communication device 20-2 is not the terminal-end
communication device.
[0068] The signal transmission/reception circuit 22 is a circuit configured to perform transmission
and reception of the signal in communication between the communication devices 10.
In addition, the signal transmission/reception circuit 12 acquires the pulse signal
output command transmitted from the communication device 10. The signal transmission/reception
circuit 12 outputs the pulse signal with the prescribed pulse width w to the communication
device 10 when the pulse signal output command is acquired.
[0069] In addition, the signal transmission/reception circuit 12 acquires the communication
speed switching command transmitted from the communication device 10. The signal transmission/reception
circuit 12 switches the communication setting to increase the communication speed
in communication with the communication device 10 to be higher (i.e., switching the
setting to the high speed communication mode) when the communication speed switching
command is acquired.
[0070] Hereinafter, an operation of the communication device 10 will be described.
[0071] FIG. 10 is a flowchart showing an example of an operation of the communication device
10 according to the first embodiment. For example, the operation of the communication
device 10 shown in FIG. 10 is started in the initial state before the air-conditioning
system 100 is operated.
[0072] First, the control unit 120 executes processing of substituting 1 for a variable
i (step S001). Then, the control unit 120 executes processing from step S002 to step
S005, which will be described below, n times (i.e., three times in the case of the
configuration shown in FIG. 1) when the number of terminals connected to the communication
device 10 is n.
[0073] The pulse signal output command unit 121a transmits the pulse signal output command
to the communication device 20-i (i = 1 to n) via the transmission unit 122 and the
communication line 30 (step S002).
[0074] When the pulse signal transmitted from the communication device 20-i (i = 1 to n)
according to the pulse signal output command transmitted in step S002 is received
by the reception unit 123 (in step S003, YES), the measurement unit 124 measures the
pulse width of the received pulse signal (step S004). Meanwhile, when the pulse signal
transmitted from the communication device 20-i (i = 1 to n) according to the pulse
signal output command transmitted in step S002 is not received (in step S003, NO),
the communication device 10 waits until the pulse signal is received by the reception
unit 123.
[0075] The measurement unit 124 stores the value showing the measured pulse width in the
storage unit 125 by writing the value in the pulse width storage table t2 stored in
the storage unit 125 (step S005).
[0076] The detection unit 126 refers the pulse width storage table t2 stored in the storage
unit 125, and identifies the communication device 20-j from which the pulse signal
with the narrowest pulse width is output (i.e., in the case of the configuration shown
in FIG. 1, the communication device 20-j is specified) (step S006).
[0077] The terminating resistor setting command unit 121b transmits the terminating resistor
setting command to the communication device 20-j via the transmission unit 122 and
the communication line 30 (step S007).
[0078] The communication speed switching command unit 121c transmits the communication speed
switching command to all the communication devices 20 via the transmission unit 122
and the communication line 30 (step S008).
[0079] The communication speed switching unit 127 switches the communication setting to
increase the communication speed in communication with the communication device 20
to be higher (i.e., switching the setting to the high speed communication mode) (step
S009).
[0080] An operation as the detection device in the communication device 10 shown by the
flowchart of FIG. 10 is terminated as described above.
[0081] Hereinafter, an operation of the communication device 20 will be described.
[0082] FIG. 11 is a flowchart showing an operation in pulse signal output processing of
the communication device 20 according to the first embodiment. The operation of the
communication device 20 shown in FIG. 11 is started when the pulse signal output command
transmitted from the communication device 10 in step S002 shown in FIG. 10 is received
in the communication device 20.
[0083] The signal transmission/reception circuit 22 receives the pulse signal output command
transmitted from the communication device 10 via the communication line 30 (step S101).
[0084] The signal transmission/reception circuit 22 outputs the pulse signal with the prescribed
pulse width (for example, the pulse width w) to the communication device 10 via the
communication line 30 (step S102).
[0085] An operation of the communication device 20 shown by the flowchart of FIG. 11 is
terminated as described above.
[0086] FIG. 12 is a flowchart showing an operation in terminating resistor setting processing
of the communication device 20 according to the first embodiment. The operation of
the communication device 20 shown in FIG. 12 is started when the terminating resistor
setting command transmitted from the communication device 10 in step S007 shown in
FIG. 10 is received in the communication device 20.
[0087] The terminating resistor setting unit 21 acquires the terminating resistor setting
command transmitted from the communication device 10 via the communication line 30
(step S111).
[0088] The terminating resistor setting unit 21 is switched to a state in which the terminating
resistor is set (step S112).
[0089] The operation of the communication device 20 shown by the flowchart of FIG. 12 is
terminated as described above.
[0090] FIG. 13 is a flowchart showing an operation in communication speed switching processing
of the communication device 20 according to the first embodiment. The operation of
the communication device 20 shown in FIG. 13 is started when the communication speed
switching command transmitted from the communication device 10 in step S008 shown
in FIG. 10 is received in the communication device 20.
[0091] The signal transmission/reception circuit 22 receives the communication speed switching
command transmitted from the communication device 10 via the communication line 30
(step S121).
[0092] The signal transmission/reception circuit 22 switches the communication setting to
increase the communication speed in communication with the communication device 10
to be higher (i.e., switching the setting to the high speed communication mode) (step
S122).
[0093] The operation of the communication device 20 shown by the flowchart of FIG. 13 is
terminated as described above.
[0094] Hereinafter, a configuration of an air-conditioning system 200 according to a variant
of the first embodiment will be described.
[0095] FIG. 14 is the entire configuration view of the air-conditioning system 200 according
to the variant of the first embodiment.
[0096] The configuration of the air-conditioning system 200 according to the variant of
the first embodiment shown in FIG. 14 is distinguished from the configuration of the
air-conditioning system 100 according to the first embodiment shown in FIG. 10 in
that the communication line 30 is branched off in the middle, and the system includes
an indoor unit 2-4 and an indoor unit 2-5 provided with a communication device 20-4
and a communication device 20-5.
[0097] As shown in FIG. 14, unlike the first embodiment, when the position of the communication
line 30 on which the communication device 10 is installed is one terminal end, the
other terminal end are present at two positions. That is, two terminal-end communication
devices of the communication device 20-3 and the communication device 20-5 are present.
[0098] In this case, when the communication device 10 can previously discriminate the communication
device 20 connected from the communication device 10 toward the communication device
20-3 along the communication line 30 and the communication device 20 connected from
the communication device 10 toward the communication device 20-5 via the communication
line 30, the communication device 10 may divide the processing into two parts, the
setting of the terminating resistor with respect to the communication line 30 from
the communication device 10 toward the communication device 20-3 and the setting of
the terminating resistor with respect to the communication line 30 from the communication
device 10 toward the communication device 20-5, and the processing according to the
first embodiment may be executed respectively.
[0099] Meanwhile, even when the communication device 10 cannot discriminate the communication
device 20 connected from the communication device 10 toward the communication device
20-3 along the communication line 30 and the communication device 20 connected from
the communication device 10 toward the communication device 20-5 along the communication
line 30, the setting of the terminating resistor with respect to the communication
device 20-3 and the communication device 20-5 is possible.
[0100] In this case, like the first embodiment, the communication device 10 acquires the
pulse signals that are test signals from all the communication devices 20, and measures
the pulse widths, respectively. Then, the communication device 10 identifies the communication
device 20 from which the pulse signal with the narrowest pulse width is output and
the communication device 20 from which the pulse signal with the pulse width having
a difference from the narrowest pulse width, which is smaller than a prescribed threshold,
is output. Then, the communication device 10 is switched to a state in which the terminating
resistor is set to the plurality of specified communication devices 20.
[0101] In FIG. 14, both of the communication device 20-3 and the communication device 20-5
are communication devices connected to the communication line 30 at positions of the
terminal ends of the communication line 30. Accordingly, as shown in FIG. 5, no reflection
occurs in any of the pulse signals transmitted from the communication device 20-3
and the communication device 20-5. For this reason, basically, the pulse signals transmitted
from the communication device 20-3 and the communication device 20-5 are recognized
by the communication device 10 as any of the pulse signals with the pulse width z.
[0102] Further, as described above, the reason why the pulse width (z) shown in FIG. 5 is
not the same as the pulse width w of the pulse signal at the time of transmission
from the communication device 20-3 is that the pulse width is slightly varied due
to a cause other than the reflection (for example, signal attenuation) or the like.
For example, due to these changes, the pulse width of the pulse signal output from
the communication device 20-3 and the pulse width of the pulse signal transmitted
from the communication device 20-5 do not always exactly coincide with each other.
(Second embodiment)
[0103] Hereinafter, a second embodiment will be described.
[0104] In the above-mentioned first embodiment, the communication device 10 is configured
to acquire the pulse signals (the test signals) output from the communication devices
20, and detect the communication device 20, which has output the pulse signal acquired
as the narrowest pulse width, as the terminal-end communication device.
[0105] Meanwhile, the communication device 10 according to the second embodiment acquires
the pulse signals (the test signals) output from the communication devices 20. Then,
the communication device 10 according to the second embodiment includes an estimation
unit (not shown) configured to estimate a length of the communication line 30 between
the communication device 10 and each of the communication devices 20 on the basis
of the measured pulse width. Further, the estimation method in this case is considered
as, for example, a method of previously holding information in which the length of
the communication line 30 between the communication device 10 and the communication
device 20 corresponds to the pulse width received in the communication device 10 in
the case of the length using the communication device 10 and performing estimation
on the basis of the information.
[0106] According to the communication device 10 related to the second embodiment, an air-conditioning
manager or the like can estimate the communication device 20 estimated to have the
largest length of the communication line 30 using the estimation unit as the terminal-end
communication device. Accordingly, the air-conditioning manager or the like can easily
identify the terminal-end communication device, and set the terminating resistor with
respect to the terminal-end communication device.
[0107] Hereinabove, while the embodiment has been described, in the above-mentioned embodiment,
in order to simplify the description, only the signal reflection was targeted as a
factor to change the signal waveform of the pulse signal. However, in actuality, the
signal waveform changes according to the length of the communication line 30 and the
number of intervening communication devices 20, and the like. For example, as the
length of the communication line 30 is increased, amplitude of the pulse signal may
be attenuated depending on a resistance component, or a gradient may change due to
a capacitance component or the like.
[0108] However, in any case, as the length of the communication line 30 is increased (i.e.,
the position of the communication device 20 is goes away from the communication device
10, or the like), the waveform of the pulse signal is changed to narrow the pulse
width. Accordingly, detection accuracy of the terminal-end communication device according
to the embodiment is further increased.
[0109] Further, in the above-mentioned embodiment, while the used signal is the pulse signal
constituted by values of 0 and 1, there is no limitation thereto. For example, even
in the case of a signal for communication or the like pursuant to HBS Standard (home
bus system: Electronic Industries Association of Japan (EIAJ) Standard, ET-2101),
after converting to the pulse signal constituted by values of 0 and 1 as described
above, the processing in the above-mentioned embodiment may be executed.
[0110] According to the at least one embodiment as described above, since the reception
unit configured to receive the signals with the prescribed pulse widths transmitted
from the plurality of communication devices 20, the measurement unit configured to
measure the pulse widths of the signals received by the reception unit, and the detection
unit configured to detect the communication device disposed near the terminal end
of the communication line 30 on the basis of the plurality of measured pulse widths
are provided, it is possible to automatically detect the communication device 20 of
the terminal end of the communication line 30 without human intervention. Accordingly,
since the terminating resistor can be set to the communication device 20 of the terminal
end of the communication line 30, the communication between the communication device
10 and each of the communication devices 20 can be performed at a higher speed.
[0111] A part of or the entire communication device 10 according to the embodiment may be
realized by a computer. In this case, the program configured to realize the function
may be recorded on a computer-readable recording medium, and the program recorded
on the recording medium may be realized by being read and executed by a computer system.
Further, "the computer system" disclosed herein includes an OS or hardware such as
peripheral devices or the like. In addition, "the computer-readable recording medium"
refers to a portable medium such as a flexible disk, a magneto-optic disk, an ROM,
a CD-ROM, or the like, and a storage device such as a hard disk or the like built
in the computer system. Further, "the computer-readable recording medium" may include
a medium configured to dynamically hold a program for a short time, for example, a
communication line when the program is transmitted via a network such as the Internet,
a communication line such as a telephone line or the like, or a medium configured
to temporarily hold a program, for example, a volatile memory in the computer system
that becomes a server or a client in this case. In addition, the program may be configured
to realize a part of the above-mentioned function, and the function may be further
realized by combination with the program already stored in the computer system or
may be realized using hardware such as a programmable logic device (PLD), a field
programmable gate array (FPGA), or the like.
[0112] In the embodiment, while circuit parts for communication or control processing for
communication are simplified by using both the communication device 20 configured
to perform conventional communication and the detection device configured to set the
terminating resistor to the communication device 20 of the terminal end, these two
devices may be separated, and a detection device having a function of detecting the
communication device 20 of the terminal end and setting the terminating resistor to
the communication device 20 may be provided separately.
[0113] While some embodiments of the present invention have been described, these embodiments
are presented as examples and are not intended to limit the scope of the present invention.
[Reference Signs List]
[0114]
- 1
- Outdoor unit
- 2
- Indoor unit
- 10
- Communication device (detection device)
- 11
- Terminating resistance
- 12
- Signal transmission/reception circuit
- 20
- Communication device
- 21
- Terminating resistance setting unit
- 22
- Signal transmission/reception circuit
- 30
- Communication line
- 100
- Air-conditioning system
- 120
- Control unit
- 121
- Command unit
- 121a
- Pulse signal output command unit
- 121b
- Terminating resistance setting command unit
- 121c
- Communication speed switching command unit
- 122
- Transmission unit
- 123
- Reception unit
- 124
- Measurement unit
- 125
- Storage unit
- 126
- Detection unit
- 127
- Communication speed switching unit
- 200
- Air-conditioning system
1. Erkennungsvorrichtung (10), die mit einer Vielzahl von Kommunikationsvorrichtungen
(20) über eine Kommunikationsleitung (30) verbindbar ist, wobei die Erkennungsvorrichtung
aufweist:
eine Empfangseinheit (123), die so konfiguriert ist, dass sie Signale mit vorgeschriebenen
Impulsbreiten empfängt, die von der Vielzahl von Kommunikationsvorrichtungen gesendet
werden;
eine Messeinheit (124), die konfiguriert ist, um die Impulsbreiten der von der Empfangseinheit
empfangenen Signale zu messen; und
eine Erkennungseinheit (126), die so konfiguriert ist, dass sie eine der Kommunikationsvorrichtungen,
die in der Nähe eines Endes der Kommunikationsleitung angeordnet ist, als eine Kommunikationsendvorrichtung
auf der Basis der Mehrzahl der von der Messeinheit gemessenen Impulsbreiten erkennt.
2. Erkennungsvorrichtung nach Anspruch 1, wobei die Erkennungseinheit so konfiguriert
ist, dass sie die Kommunikationsendvorrichtung erkennt, indem sie die eine der Kommunikationsvorrichtungen
identifiziert, die das Signal mit der schmalsten Impulsbreite der von der Empfangseinheit
empfangenen Signale gesendet hat.
3. Erkennungsvorrichtung nach Anspruch 1 oder 2, die ferner eine Befehlseinheit (121)
aufweist, die so konfiguriert ist, dass sie einen ersten Befehl ausgibt, der einen
Befehl zum Setzen eines Abschlusswiderstandes an die Kommunikationsendvorrichtung
wiedergibt, wenn die Kommunikationsendvorrichtung von der Erkennungseinheit erkannt
wird.
4. Erkennungsvorrichtung nach Anspruch 3, ferner aufweisend eine Kommunikationsgeschwindigkeits-Umschalteinheit
(127), die so konfiguriert ist, dass sie die Kommunikationseinstellung umschaltet,
um eine Kommunikationsgeschwindigkeit bei der Kommunikation mit den Kommunikationsvorrichtungen
zu erhöhen, so dass sie höher ist, wenn der erste Befehl von der Befehlseinheit ausgegeben
wird.
5. Erkennungsvorrichtung nach Anspruch 4, wobei die Kommunikationsgeschwindigkeits-Umschalteinheit
so konfiguriert ist, dass sie die Kommunikationseinstellung umschaltet, um eine Kommunikationsgeschwindigkeit
bei der Kommunikation mit den durch die Kommunikationsleitung verbundenen Kommunikationsvorrichtungen
zu verringern, so dass sie niedriger ist, wenn mindestens eine der Kommunikationsvorrichtungen
hinzugefügt oder entfernt wird.
6. Erkennungsvorrichtung nach einem der Ansprüche 3 bis 5, wobei die Befehlseinheit so
konfiguriert ist, dass sie einen zweiten Befehl ausgibt, der einen Befehl zum Umschalten
der Kommunikationseinstellung wiedergibt, um eine Kommunikationsgeschwindigkeit für
mindestens eine Kommunikationsvorrichtung zu erhöhen, so dass sie höher ist, wenn
der erste Befehl ausgegeben wird.
7. Erkennungsvorrichtung nach einem der Ansprüche 3 bis 6, wobei die Befehlseinheit so
konfiguriert ist, dass sie einen dritten Befehl ausgibt, der einen Befehl zum Übertragen
eines Signals mit der vorgeschriebenen Impulsbreite an die Vielzahl von Kommunikationsvorrichtungen
wiedergibt.
8. Erkennungsvorrichtung nach einem der Ansprüche 3 bis 7, wobei die Befehlseinheit so
konfiguriert ist, dass sie einen vierten Befehl ausgibt, der einen Befehl zum Freigeben
der Einstellung eines Abschlusswiderstandes an die Kommunikationsendvorrichtung anzeigt,
wenn mindestens eine Kommunikationsvorrichtung hinzugefügt oder entfernt wird.
9. Erkennungsvorrichtung nach einem der Ansprüche 3 bis 8, wobei die Befehlseinheit so
konfiguriert ist, dass sie einen fünften Befehl ausgibt, der einen Befehl zum Umschalten
der Kommunikationseinstellung wiedergibt, um eine Kommunikationsgeschwindigkeit bei
der Kommunikation mit der durch die Kommunikationsleitung verbundenen Kommunikationsvorrichtung
zu verringern, wenn mindestens eine Kommunikationsvorrichtung hinzugefügt oder entfernt
wird.
10. Erkennungsvorrichtung nach einem der Ansprüche 1 bis 9, die ferner eine Schätzeinheit
umfasst, die so konfiguriert ist, dass sie eine Länge der Kommunikationsleitung auf
der Grundlage der Mehrzahl der von der Messeinheit gemessenen Impulsbreiten schätzt.
11. Erkennungsvorrichtung nach einem der Ansprüche 1 bis 10, wobei die Kommunikationsvorrichtung
eine Kommunikationsvorrichtung ist, die in einer Inneneinheit einer Klimaanlage vorgesehen
ist, und die Erkennungsvorrichtung in einer Verwaltungsvorrichtung vorgesehen ist,
die so konfiguriert ist, dass sie eine Außeneinheit oder die Mehrzahl von Inneneinheiten
der Klimaanlage verwaltet.