JP4499624B2 - Heating terminal device - Google Patents

Description

  The present invention relates to a heating terminal apparatus that performs heating using a heat medium supplied from a heat source apparatus as a heat source, and more particularly to a communication mode between the heat source apparatus and the heating terminal apparatus.

  2. Description of the Related Art Conventionally, for example, a heating terminal device such as a warm air heater or a floor heater that heats a room using hot water supplied from a heat source as a heat source is known. The heating terminal device and the heat source device are communicably connected, and when the user operates the operation switch provided in the heating terminal device to instruct the start of the heating operation, the heating terminal device and the heat source device On the other hand, a signal requesting the start of operation is transmitted, whereby the heat source unit starts operating and supply of hot water to the heating terminal device is started.

  Here, as a communication specification between the heat source device and the heating terminal device, one-way communication that can only transmit a signal from the heating terminal device to the heat source device and cannot transmit a signal from the heat source device to the heating terminal device is performed. There is a heating system that employs a heating system (for example, see Patent Document 1) that adopts and a bidirectional communication specification that allows signals to be transmitted and received between the heat source device and the heating terminal device.

And since the required circuit configuration is different between one-way communication and two-way communication, when installing the heating system, select a heating terminal device with the same communication specification according to the communication specification of the heat source unit. Need to be installed. However, since the appearance of the heating terminal device is the same even if the internal communication specifications are different, it is conceivable that the installer mistakenly installs the heating terminal device with a communication specification different from that of the heat source machine. There is an inconvenience that the communication between the heat source device and the heating terminal device becomes impossible and the heating operation cannot be executed.
JP 2001-116268 A

  An object of the present invention is to provide a heating terminal device that solves the above inconvenience and prevents communication between the heat source device and the heating terminal device from being disabled due to an error in combination with the heat source device.

  The present invention has been made to achieve the above object, and the first aspect of the present invention is connected to a heat source device in a communicable manner, and performs heating using a heat medium supplied from the heat source device as a heat source. A heating terminal device comprising: a first terminal and a second terminal connected to a heat source device via a communication cable; and a first energization path connecting the first terminal and the second terminal. A first switch circuit provided to switch the first energization path between a conductive state and a cut-off state; an energization detecting means for detecting presence / absence of energization in the first energization path; and the first terminal A second switch circuit which is provided in a second energization path connecting the second terminal and switches the second energization path between a conduction state and a cutoff state; the first terminal; and the second terminal When the heat source device is connected to the terminal of the second terminal via a communication cable, the second switch A predetermined response request signal is transmitted to the heat source unit by switching the first switch circuit between a closed state and an open state with the path open, and then the second switch circuit is opened and the second switch circuit is opened. When a predetermined response signal is received from the heat source device within a predetermined time by closing the switch circuit of 1 and detecting whether the first energization path is energized by the energization detecting means, the heat source device Detects that the heat source device is bidirectional communication specification, and when the response signal is not received, communication specification detection means for detecting that the heat source device is one-way communication specification, and the communication specification detection means When the two-way communication specification is detected, the second switch circuit is maintained in an open state, and the first switch circuit is switched between a closed state and an open state, and a signal is transmitted to the heat source unit. And the first A bidirectional communication control means for receiving a signal from the heat source unit by detecting energization by the energization detection unit with the switch circuit closed, and the heat source unit has a one-way communication specification by the communication specification detection unit. Unidirectional communication control means for maintaining the first switch circuit in an open state and switching the second switch circuit between a closed state and an open state to transmit a signal to the heat source unit It is characterized by comprising.

  A second aspect of the present invention is a heating terminal device that is communicably connected to a heat source device and performs heating using a heat medium supplied from the heat source device as a heat source, via a heat source device and a communication cable. A first terminal and a second terminal connected to each other, and an energization path connecting the first terminal and the second terminal, wherein the energization path is switched between a conduction state and a cutoff state. 1 switch circuit, energization detecting means for detecting the presence or absence of energization in the energization path, a resistor provided in the energization path, a second switch circuit connected in parallel with the resistor, the first When a heat source device is connected to the terminal and the second terminal via a communication cable, the second switch circuit is opened, and the first switch circuit is switched between an open state and a closed state. After transmitting a predetermined response request signal to the heat source unit, The switch circuit 2 is opened and the first switch circuit is closed, and the energization detecting means detects whether or not the first energization path is energized. When the response signal is received, it is detected that the heat source device is a two-way communication specification, and when the response signal is not received, a communication specification detection unit that detects that the heat source device is a one-way communication specification, When the communication specification detecting means detects that the heat source device is bidirectional communication specification, the second switch circuit is maintained in an open state, and the first switch circuit is in an open state and a closed state. And a bidirectional communication control means for receiving a signal from the heat source apparatus by transmitting the signal to the heat source apparatus and detecting the energization by the energization detection means with the first switch circuit closed. , When the communication specification detecting means detects that the heat source device is one-way communication specification, the first switch circuit is maintained in a closed state, and the second switch circuit is closed and opened. And a one-way communication control means for transmitting a signal to the heat source device.

  In the present invention, when the communication specification detecting means of the first aspect and the second aspect are connected to a heat source device via a communication cable by the first terminal and the second terminal, The response request signal is transmitted to the heat source device by opening the second switch circuit and switching the first switch circuit between a closed state and an open state. In this case, if the connected heat source unit has a bidirectional communication specification, the response signal is returned from the heat source unit that has received the response request signal, but the connected heat source unit has a one-way communication specification. The response signal is not returned from the heat source device. Therefore, the communication specification detection means confirms whether or not the response signal is received within the predetermined time after transmitting the response request signal, so that the connected heat source unit has a bidirectional communication specification. It can be detected whether it is a one-way communication specification.

  Then, when the communication specification detecting means detects that the connected heat source machine has the bidirectional communication specification, the bidirectional communication control means performs bidirectional communication with the heat source machine. Further, when the communication specification detecting means detects that the connected heat source machine is one-way communication specification, the one-way communication control means performs one-way communication with the heat source machine.

  In this case, communication between the heating terminal device and the heat source device is possible as long as the heating terminal device of the present invention is connected to the heat source device regardless of whether the heat source device is a bidirectional communication specification or a one-way communication specification. It becomes possible. Therefore, the installer of the heating terminal device does not need to select the heating terminal device according to the difference in the communication specifications (two-way communication / one-way communication) of the heat source device. It is possible to prevent the communication between the heating terminal device from being disabled.

  Further, according to the first aspect of the present invention, since the impedances of the first energization path and the second energization path can be individually set, the first in the case of performing bidirectional communication. The energization amount in the energization path and the energization amount in the second energization path when performing one-way communication can be efficiently set according to the input / output specifications of the signal of the communication means of the connected heat source unit .

  According to the second aspect of the present invention, when the second switch circuit is in an open state, the first terminal and the second terminal are connected via the resistor, When the second switch circuit is in a closed state, the first terminal and the second terminal are connected by bypassing the resistor. Therefore, the impedance between the first terminal and the second terminal can be changed by switching the second switch circuit between a closed state and an open state. Thus, the energization amount between the first terminal and the second terminal when performing bidirectional communication, and the energization between the first terminal and the second terminal when performing unidirectional communication. The quantity can be efficiently set according to the input / output specification of the signal of the communication means of the connected heat source machine.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of a circuit configuration of a heating terminal device and a connection mode with a heat source device in the first embodiment, and FIG. 2 is an explanatory diagram of a circuit configuration of the heating terminal device in a second embodiment.

  [First Embodiment] First, the first embodiment will be described with reference to FIG. The heating terminal device 1 illustrated in FIG. 1 is, for example, a hot air heater or a floor heater, and is used by being communicably connected to a heat source device 100 having a bidirectional communication specification or a heat source device 150 having a one-way communication specification. . Then, the heating operation is performed using a heat medium such as hot water supplied from the heat source apparatus 100 or the heat source apparatus 150 as a heat source.

  The heating terminal device 1 includes a microcomputer 10 (hereinafter referred to as a microcomputer 10) that controls the overall operation of the heating terminal device 1, photocouplers 20, 21, 22, a diode bridge 30, and plugs 41 of communication cables 50a and 50b. The receptacle 40 is connected.

  And between the 1st terminal 40a and the 2nd terminal 40b of the receptacle 40, the 1st electricity supply path 5 and the 2nd electricity supply path 6 are connected. The light emitting diode 22a of the photocoupler 20 and the photo diode 20 are connected between the resistors 35 and 36 of the first current path 5 via a diode bridge 30 for making the first terminal 40a and the second terminal 40b nonpolar. The light receiving transistor 21b of the coupler 21 is connected in series.

  Here, the anode of the light emitting diode 21a of the photocoupler 21 (corresponding to the first switch circuit of the present invention) is connected to the power source V1, and the cathode is connected to the output terminal OUT10 of the microcomputer 10. Therefore, when the output voltage of OUT10 is at the Hi level (≈V1), the light emitting diode 21a is not energized, the light receiving transistor 21b is turned off (open state), and the first energization path 5 is cut off. On the other hand, when the output of OUT10 is at the Lo level (≈0 V), the light emitting diode 21a is energized, the light receiving transistor 21b is turned on (closed), and the first energization path 5 is in a conducting state. Therefore, the microcomputer 10 can switch the first energization path 51 between the conduction state and the interruption state by switching the output voltage of OUT10 to the Lo level / Hi level.

  When a current of a predetermined level or more flows through the first energization path 5, the light receiving transistor 20b is turned on (closed) by the light emission of the light emitting diode 20a of the photocoupler 20 (corresponding to the energization detecting means of the present invention), The voltage input to the input terminal IN10 of the microcomputer 10 becomes Hi level. On the other hand, when the current exceeding the predetermined level does not flow through the first energization path 5, the light emitting diode 20a of the photocoupler 20 does not emit light, so that the light receiving transistor 20b is turned off (opened) and the microcomputer 10 input terminal IN10. The voltage input to becomes the Lo level. Therefore, the microcomputer 10 can detect whether or not the first conduction path 5 is energized based on the voltage (Lo level / Hi level) input to IN10.

  Further, when the output voltage of the output terminal OUT11 of the microcomputer 10 is at the Hi level, the light emitting diode 22a of the photocoupler 22 (corresponding to the second switch circuit of the present invention) is not energized, and the light receiving transistor 22b is OFF ( Open state) and the second energization path 6 is cut off. On the other hand, when the output voltage of OUT11 is at the Lo level, the light emitting diode 22a is energized, the light receiving transistor 22b is turned on (closed state), and the second energizing path 6 is in a conducting state. Therefore, the microcomputer 10 can switch the second energization path 6 between the conductive state and the cut-off state by switching the output level of OUT11 to the Hi level / Lo level.

  Next, the two-way communication specification heat source unit 100 includes a microcomputer 110 (hereinafter referred to as a microcomputer 110) that controls communication with the heating terminal device 1, photocouplers 120 and 121, and plugs 141 of the communication cables 50a and 50b. A receptacle 140 to be connected is provided.

  The first terminal 140a of the receptacle 140 is connected to the power source V2 via the resistor 130. Further, between the second terminal 140b of the receptacle 140 and the GND, the light emitting diode 120a of the photocoupler 120, the light receiving transistor 121b of the photocoupler 121, and the resistor 132 are connected in series.

  The anode of the light emitting diode 121a of the photocoupler 121 is connected to the output terminal OUT20 of the microcomputer 110, and the cathode is connected to GND via the resistor 133. Therefore, when the output of OUT20 is at the Hi level (≈V2), the light emitting diode 121a is energized and the light receiving transistor 121b is turned on (closed state). On the other hand, when the output of OUT20 is at the Lo level (≈0 V), the light emitting diode 121a is not energized and the light receiving transistor 121b is turned off (open state). Therefore, the microcomputer 110 can switch between conduction / interruption between the second terminal 140b and GND by switching to the output (Hi level / Lo level) of OUT20.

  When a current flows from the power source V2 connected to the first terminal 140a to the GND from the second terminal 140b through the light receiving transistor 121b, the light emitting diode 120a of the photocoupler 120 is energized and the light receiving transistor 120b is turned on. (Closed state), and the voltage input to the input terminal IN20 of the microcomputer 110 becomes Hi level. On the other hand, when the light receiving transistor 121b is OFF, the light emitting diode 120a of the photocoupler 120 is not energized, the light receiving transistor 120 is turned OFF (open state), and the voltage input to the input terminal IN20 of the microcomputer 110 becomes Lo level. . Therefore, the microcomputer 110 can detect whether the first terminals 140a and 140b are in the conductive state or in the cut-off state based on the voltage input to IN20.

  Next, the one-way communication specification heat source unit 150 is connected to the microcomputer 160 (hereinafter referred to as the microcomputer 160) that controls communication with the heating terminal device 1, the buffer element 170, and the plugs 141 of the communication cables 50a and 50b. The receptacle 180 is provided.

  The first terminal 180 a of the receptacle 180 is connected to the power source V 3, and the second terminal 180 b is connected to the input of the buffer element 170. The output of the buffer element 170 is connected to the input terminal IN30 of the microcomputer 160. Here, when the first terminal 180a and the second terminal 180b are brought into conduction, the input voltage from the buffer element 170 to IN30 becomes the Lo level (≈0 V). When the first terminal 180a and the second terminal 180b are cut off, the input voltage from the buffer element 170 to IN30 becomes Hi level (≈V3).

  Therefore, the microcomputer 160 can detect whether the first terminal 180a and the second terminal 180b are in a conductive state or a disconnected state from the input (Hi / Lo) to the IN30.

  Next, the operation | movement of the communication specification detection means 11, the bidirectional | two-way communication control means 12, and the one-way communication control means 13 with which the microcomputer 10 of the heating terminal device 1 was equipped is demonstrated. First, the communication specification detection unit 11 is configured such that when the heating terminal device 1 is installed and the power is first turned on, the heat source unit connected via the communication cables 50a and 50b is a two-way communication specification heat source unit 100. Or a one-way communication specification heat source device 150 is detected.

  Specifically, when the heating terminal device 1 is installed and the power is turned on for the first time and the microcomputer 10 starts to operate, the communication specification detection unit 11 sets the output of OUT11 to Hi level and the light receiving transistor of the photocoupler 22 22b is turned OFF and the 2nd electricity supply path 6 is made into a cutoff state. Then, the communication specification detection means 11 switches the output of OUT10 to Hi level / Lo level and transmits a “response request signal”.

  Here, in the heat source device 100 of the two-way communication specification, the output of OUT20 is set to Hi level except during transmission, whereby the light receiving transistor 121b of the photocoupler 121 is in the ON state. Therefore, when the heat source device 100 of the bidirectional communication specification is connected to the heating terminal device 1, when the light receiving transistor 21b of the photocoupler 21 of the heating terminal device 1 is turned on / off, the heat source device 100 is accordingly changed. The state where the light-emitting diode 120a of the photocoupler 120 is energized and the state where the energization of the light-emitting diode 120a is cut off are switched. When the light emitting diode 120a of the photocoupler 120 is energized, the light receiving transistor 120b is turned on, so that the input to the IN20 of the microcomputer 110 becomes Hi level. On the other hand, when energization to the light emitting diode 120a of the photocoupler 120 is cut off, the light receiving transistor 120b is turned off, so that the input to the IN20 of the microcomputer 110 becomes Lo level.

  Therefore, the microcomputer 110 can receive the signal transmitted from the heating terminal device 1 by detecting the level (Hi / Lo) of the voltage input to IN20. When the microcomputer 110 receives the “response request signal” from the heating terminal device 1, the microcomputer 110 switches the output of OUT 20 between the Hi level and the Lo level and returns a “response signal”.

  Here, after transmitting the “response request signal”, the communication specification detection means 11 of the heating terminal device 1 maintains the output of OUT10 at the Lo level. Therefore, when the microcomputer 110 of the heat source device 100 switches the output of OUT20 to the Hi level / Lo level, the state in which the light emitting diode 20a of the photocoupler 20 of the heating terminal device 1 is energized and to the light emitting diode 20a accordingly. The state where the power supply to is cut off is switched.

  When the light emitting diode 20a of the photocoupler 20 is energized, the light receiving transistor 20b is turned on, so that the voltage input to IN10 of the microcomputer 10 becomes Lo level. On the other hand, when energization of the light-emitting diode 20a of the photocoupler 20 is interrupted, the light receiving transistor 20b is turned off, so that the voltage input to IN10 of the microcomputer 10 becomes Hi level. Therefore, the communication specification detection means 11 of the heating terminal device 1 can receive the “response signal” transmitted from the heat source device 100 by detecting the level (Hi / Lo) of the voltage input to IN10. .

  Therefore, when the communication specification detection means 11 receives the “response signal” within a predetermined time after transmitting the “response request signal”, the connected heat source device is a heat source device of the bidirectional communication specification. 100 can be detected.

  On the other hand, when the heating terminal device 1 is connected to the heat source device 150 having the one-way communication specification, since the transmission from the heat source device 150 to the heating terminal device 1 cannot be performed, a “response request signal” is transmitted from the heating terminal device 1. Even if this is done, a “response signal” is not returned. Therefore, when the communication specification detecting means 11 does not receive the “response signal” within a predetermined time after transmitting the “response request signal”, the connected heat source device is the heat source device 150 of the one-way communication specification. Can be detected.

  When the communication specification detection unit 11 detects that the heat source unit connected to the heating terminal device 1 is the heat source unit 100 with the bidirectional communication specification, the bidirectional communication unit 12 communicates with the heat source unit 100. Two-way communication with. Specifically, the bidirectional communication control means 12 transmits a signal to the heat source unit 100 by switching the output of OUT10 to Hi level / Lo level. Further, the bidirectional communication control means 12 receives a signal transmitted from the heat source device 100 by recognizing the level of the voltage input to IN10.

  When the communication specification detecting unit 11 detects that the heat source unit connected to the heating terminal device 1 is the one-way communication specification heat source unit 150, the one-way communication control unit 13 communicates with the heat source unit 150. One-way communication is performed. Specifically, the one-way communication control means 15 transmits a signal to the heat source unit 150 by switching the output of OUT11 to Hi level / Lo level.

  In the first embodiment, the photocoupler 22 is used as the second switch circuit of the present invention, but a relay may be used.

  In addition, since the resistors 35 and 36 are connected to the first conduction path 5, the impedance of the first conduction path 5 is higher than that of the second conduction path 6. Then, the impedance of the first conduction path 5 is matched with the input / output impedance of the signal of the heat source apparatus 100, and the impedance of the second conduction path 6 is matched with the input impedance of the signal of the heat source apparatus 150, thereby efficiently communicating. It can be performed.

  [Second Embodiment] Next, a second embodiment will be described with reference to FIG. The heating terminal device 200 shown in FIG. 2 is, for example, a hot air heater or a floor heater, and is similar to the heating device 100 of the first embodiment described above, the heat source device 100 having a bidirectional communication specification (see FIG. 1). ) Or a heat source device 150 (see FIG. 2) having a one-way communication specification. Then, the heating operation is performed using a heat medium such as hot water supplied from the heat source apparatus 100 or the heat source apparatus 150 as a heat source.

  The heating terminal device 200 has two energization paths (the first energization path 5 and the first energization path 5), in that only one energization path 201 is connected between the first terminal 40 a and the second terminal 40 b of the receptacle 40. It differs from the heating terminal device 1 in the said 1st Embodiment to which the 2 electricity supply paths 6) were connected. In addition, the relay 220 (without the photocoupler 22 shown in FIG. 1) and having a contact 220b connected in parallel with the resistor 210 provided in the first energization path 5 (in the second switch circuit of the present invention). Is different from the heating terminal device 1 in the first embodiment. In addition, about the structure same as the heating terminal device 1 shown in FIG. 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  One end of the coil 220a of the relay 220 is connected to the power source V1, and is connected to the output terminal OUT11 of the microcomputer 10. In this case, when the output voltage of OUT11 of the microcomputer 10 is at the Lo level (≈0V), the coil 220a of the relay 220 is energized and the contact 220b of the relay 220 is closed (conducted). Further, when the output voltage of OUT11 of the microcomputer 10 is at the Hi level (≈V1), the energization to the coil 220a of the relay 220 is cut off, and the contact 220b of the relay 220 is opened (cut off).

  Therefore, when the output of OUT11 is at the Hi level, the resistor 210 is inserted into the first energization path 5, and when the output of OUT11 is at the Lo level, the resistor 210 is bypassed and the first energization path is set. The impedance of 5 decreases.

  Here, the resistance value of the resistor 210 is such that the current supplied to the buffer 170 is limited when the contact 220b of the relay 220 is open when connected to the heat source device 150 of the one-way communication specification. The output of the buffer 170 is set to the Lo level by the current supplied to the buffer 170 when the contact 220b of the relay 220 is in the closed state. And the one-way communication control means 13 of the microcomputer 10 transmits a signal to the heat source unit 150 of the one-way communication specification by switching the output of OUT11 to the Hi level / Lo level.

  Moreover, the communication specification detection means 11 is the same as that in the first embodiment described above, when the heating terminal device 200 is installed and the power is first turned on, via the communication cables 50a and 50b (see FIG. 1). Then, a process is performed to determine whether the heat source device connected in this way is the heat source device 100 (refer to FIG. 1) of the two-way communication specification or the heat source device 150 of the one-way communication.

  Specifically, when the heating terminal device 20 is installed and the power is turned on for the first time and the microcomputer 10 starts to operate, the communication specification detection unit 11 sets the output of OUT11 to the Hi level and sets the contact 220b of the relay 220. The open state is set, and the impedance of the energization path 201 is high. Then, the communication specification detection means 11 switches the output of OUT10 to Hi level / Lo level, transmits a “response request signal”, and when the “response signal” is returned, the connected heat source unit performs bidirectional communication. It is detected that the heat source device 100 is of the specification, and when the “response signal” is not returned, it is detected that the connected heat source device is the heat source device 150 of the one-way communication specification.

  When the communication specification detection unit 11 detects that the heat source unit connected to the heating terminal device 200 is the two-way communication specification heat source unit 100, the two-way communication control unit 12 communicates with the heat source unit 100. Bidirectional communication is performed between them. When the communication specification detection unit 11 detects that the heat source unit connected to the heating terminal device 200 is the one-way communication specification heat source unit 150, the one-way communication control unit 13 communicates with the heat source unit 150. One-way communication is executed in

  In the second embodiment, the resistor 210 is bypassed by the contact 220b of the relay 220, but may be bypassed by a non-contact such as a transistor.

  Further, the impedance of the current path 201 when the contact 220b of the relay 220 is opened is matched with the impedance of the signal input / output circuit of the heat source apparatus 100, and the current path 201 when the contact 220b of the relay 220 is closed. By matching the impedance to the impedance of the signal input / output circuit of the heat source device 150, communication can be performed efficiently.

Explanatory drawing of the connection aspect with the circuit structure of the heating terminal device in 1st Embodiment of this invention, and a heat-source equipment. Explanatory drawing of the circuit structure of the heating terminal device in the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heating terminal apparatus (of 1st Embodiment), 5 ... 1st electricity supply path, 10 ... Microcomputer, 11 ... Communication specification detection means, 12 ... Two-way communication control means, 13 ... One-way communication control means, 20 ... Photocoupler (energization detecting means) 21... Photocoupler (first switch circuit) 22... Photocoupler (second switch circuit) 40 a... First terminal 40 b. Heat source machine (with two-way communication specification), 150 ... (one-way communication specification) heat source machine, 200 ... (second embodiment) heating terminal device, 220 ... relay (second switch circuit)

Claims (2)

A heating terminal device that is communicably connected to a heat source device and performs heating using a heat medium supplied from the heat source device as a heat source,
A first terminal and a second terminal connected to the heat source device via a communication cable;
A first switch circuit provided in a first energization path connecting the first terminal and the second terminal to switch the first energization path between a conduction state and a cutoff state; Energization detection means for detecting the presence or absence of energization in the energization path of
A second switch circuit that is provided in a second energization path connecting the first terminal and the second terminal and switches the second energization path between a conductive state and a cutoff state;
When a heat source device is connected to the first terminal and the second terminal via a communication cable, the second switch circuit is opened, and the first switch circuit is closed and opened. After the predetermined response request signal is transmitted to the heat source device by switching to the above, the second switch circuit is opened and the first switch circuit is closed. When a predetermined response signal is received from the heat source unit within a predetermined time by detecting the presence / absence of energization of the electric circuit, the heat source unit is detected as having a bidirectional communication specification, and the response signal has not been received. Communication specification detecting means for detecting that the heat source device is one-way communication specification,
When the communication specification detection means detects that the heat source device is bidirectional communication specification, the second switch circuit is maintained in an open state, and the first switch circuit is in a closed state and an open state. And a bidirectional communication control means for receiving a signal from the heat source apparatus by transmitting the signal to the heat source apparatus and detecting the energization by the energization detection means with the first switch circuit closed. ,
When the communication specification detecting means detects that the heat source device is one-way communication specification, the first switch circuit is maintained in an open state, and the second switch circuit is in a closed state and an open state. And a one-way communication control means for transmitting a signal to the heat source device. A heating terminal device that is communicably connected to a heat source device and performs heating using a heat medium supplied from the heat source device as a heat source,
A first terminal and a second terminal connected to the heat source device via a communication cable;
A first switch circuit provided in an energization path connecting the first terminal and the second terminal to switch the energization path between a conduction state and a cutoff state; and detecting presence / absence of energization in the energization path Energization detection means to perform,
A resistor provided in the current path, and a second switch circuit connected in parallel with the resistor;
When a heat source device is connected to the first terminal and the second terminal via a communication cable, the second switch circuit is opened, and the first switch circuit is opened and closed. After the predetermined response request signal is transmitted to the heat source device by switching to the above, the second switch circuit is opened and the first switch circuit is closed. When a predetermined response signal is received from the heat source unit within a predetermined time by detecting the presence / absence of energization of the electric circuit, the heat source unit is detected as having a bidirectional communication specification and the response signal is not received Communication specification detecting means for detecting that the heat source device is one-way communication specification,
When the communication specification detecting means detects that the heat source device is bidirectional communication specification, the second switch circuit is maintained in an open state, and the first switch circuit is in an open state and a closed state. And a bidirectional communication control means for receiving a signal from the heat source apparatus by transmitting the signal to the heat source apparatus and detecting the energization by the energization detection means with the first switch circuit closed. ,
When the communication specification detecting means detects that the heat source device is one-way communication specification, the first switch circuit is maintained in a closed state, and the second switch circuit is closed and opened. And a one-way communication control means for transmitting a signal to the heat source device.

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