JP2001086579A - Two-wire type communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-wire type communication system that can read data intermittently received in timing surely matched with the data transmission time and can be configured at a low cost. SOLUTION: In the two-wire type communication system where a main body device 2 supplies operating power to a remote commander 3 and transmits data thereto, the main body device 2 is provided with a power supply means 10 that supplies the operating power for a 1st prescribed time, a forced OFF means 11 that stops supply of the operating power and transmission of data for a 2nd prescribed time, and a data transmission means 12 that transmits the data in the unit of one bit for a 3rd prescribed time. The remote commander 3, on the other hand, is provided with a state change detection section 22 that detects stop of the operating power and a data reception means 23 that reads the data after a lapse of a 4th prescribed time from that point of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-wire communication system, and more particularly to a two-wire communication system capable of supplying operating power from a main unit to a remote controller and transmitting and receiving data. It is about.

[0002]

2. Description of the Related Art For example, in a hot water supply apparatus, a water heater main body installed outdoors or the like and a remote controller for remotely controlling the water heater main body (hereinafter, "remote control")
The hot water temperature and the amount of hot water set by the remote controller are transmitted to the water heater main unit as instruction information, and the operating state of the water heater main unit is transmitted to the remote controller as operation information. . In the water heater main body, the amount of heating and the amount of water are controlled based on the instruction information transmitted from the remote controller. On the other hand, in the remote controller, the display is performed based on the operation information transmitted from the water heater main body.

[0003] Various communication systems have been proposed as a communication system between the water heater main body and the remote controller. One of the communication systems is to connect the water heater main body and the remote controller with a two-wire communication line. It is known that an operation power is intermittently supplied to a remote controller via a line in a short cycle and data is transmitted one bit or several bits at a time during the period, that is, during a period in which power is not supplied (for example, JP-A-9-247768). According to this, since electric power for operating the control means and the display means in the recommon is supplied from the water heater main body, it is possible to arrange the remote control even in a place where there is no outlet such as a bathroom.
In the above description, a hot water supply device has been described as an example, but the same applies to an air conditioner.

Next, an example of a conventional communication system will be specifically described with reference to FIGS. FIG. 6 is an electric circuit diagram showing a communication circuit conventionally used, and FIG.
FIG. 3 is an explanatory diagram for explaining an operation of a conventional communication system. As shown in FIG. 6, the apparatus 30 includes a main body apparatus 31 (for example, a water heater main body) and a remote controller 32, and is connected by a two-polarity non-polar communication line 33.

The main unit 31 includes a microcomputer 3
4, a power supply control unit 35, a signal transmission control unit 3
6, and each function of the signal reception control unit 37 and the like.
The power supply control unit 35 controls the supply of power to the remote controller 32 from a power supply circuit 39 connected to an external commercial power supply by controlling a switch circuit 38 including a resistor and a transistor. The signal transmission control unit 3
Reference numeral 6 denotes processing for transmitting data relating to operation information from the main unit 31 to the remote controller 32, and the signal reception controller 37 processes data relating to instruction information transmitted from the remote controller 32. .

The remote controller 32 is, like the main unit 31,
A microcomputer 40 is provided, and has functions such as a signal transmission control unit 41 and a signal reception control unit 42. The signal transmission control unit 41 performs a process for transmitting data relating to the instruction information from the remote controller 32 to the main unit 31. The signal reception control unit 42 transmits the data relating to the driving information transmitted from the main unit 31. To be processed. The remote controller 32 includes a bridge circuit 43 for rectifying the power supplied from the main unit 31, and a power supply circuit 4 that uses the supplied power for operating the remote controller 32.
4 are provided.

FIG. 7 shows a waveform when data is transmitted from the main unit 31 to the remote controller 32. In FIG.
(A) is an output waveform from the power supply control unit 35 of the main body device 31, that is, a waveform indicating a power supply state. Here, after the 2 mSec off state (start bit), 1
The on state and the off state are alternately repeated every mSec.

FIG. 7B shows a main unit 31.
Is an output waveform from the signal transmission control unit 36, that is, a waveform indicating a data output state. The signal transmission control unit 36
The multi-bit data is transmitted in units of one bit. When the power supply by the power supply control unit 35 is off, the data is transmitted one bit at a time. That is,
The supply of power and the transmission of data (1 bit) are sequentially performed as a series of transmission operations, and this transmission operation is repeated until all data of a plurality of bits are transmitted. FIG. 7B shows data in which a plurality of bits are all Hi. Then, a composite of the waveform (a) of the operating power and the waveform (b) of the data is transmitted to the remote controller 32 via the communication line 33.

On the other hand, FIG.
2 is a waveform of data input to the second signal reception control unit 42. By the way, in the communication method as described above, it is necessary to synchronize communication in order to surely transmit and receive data. Therefore, in the conventional communication method, the remote controller 32 detects the start bit transmitted from the main unit 31 and starts counting the time from the start bit detection time, and reads data at a predetermined time. Specifically, as shown in FIGS. 7C and 7D, when the signal reception control unit 42 of the remote controller 32 continuously detects that the input signal is in the Hi state for 1.5 mSec, Recognizing that it is the start bit of reception,
From that point, data is read every 2 mSec.

[0010]

However, since the remote controller 32 reads data at predetermined time intervals based on the detection time point of the start bit transmitted from the main unit 31, the remote controller 32 can be reliably synchronized. Is the start bit detection time, that is, only the reference point. That is, when data is actually read, the accuracy of the high-frequency oscillator provided in the main unit 31 and the accuracy of the high-frequency oscillator provided in the remote controller 32 are affected. The magnitude of the error increases as the length of the data increases. Therefore, in the conventional method, when the length of the data is relatively long, the timing of transmitting the data and the timing of reading the data do not match, and the transmission data may not be recognized.

The use of a high-frequency oscillator having a very stable oscillation frequency as the high-frequency oscillator of the main unit 31 and the remote controller 32 can reduce the time lag to some extent. And it was not practical because it greatly increased product costs.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a two-wire communication system that can read data transmitted intermittently at a timing that matches the data reliably and can be configured at low cost. Is what you do.

[0013]

The two-wire communication system according to the first aspect of the present invention uses a two-wire communication line to supply operating power and transmit data from a main unit to a remote controller. This is a two-wire communication system that performs And a power supply unit configured to supply the operating power for a first predetermined time; and a forced off unit configured to stop supplying the operating power and transmitting the data for a second predetermined time. A data transmission unit for transmitting the data composed of a plurality of bits in units of one bit during a third predetermined time; and a power transmission unit, the forcible off unit, and the data transmission unit. And a main body side communication control means for repeating the transmission operation until all the data of a plurality of bits are transmitted. The remote controller may further include a state change detecting unit configured to detect that the supply of the operation power has been stopped, and the data change after a fourth predetermined time has elapsed since the supply of the operation power was stopped. The data receiving means for reading the data transmitted from the transmitting means, the state change detecting means and the data receiving means are sequentially operated as a series of receiving operations, and the receiving operation is performed until all the data is received. And a remote-control-side communication control means that is repeated.

Therefore, according to the two-wire communication system of the first aspect of the present invention, in the main unit, first, the power supply means operates to supply operating power to the remote controller for the first predetermined time. . Next, by the forced off means, the second
The supply of the operating power and the transmission of data are stopped for a predetermined time. This ensures that the signal to the remote controller changes from the power supply state (ON state) to the power stop state (OFF state). After the lapse of the second predetermined time, the data transmitting means operates and transmits one bit of data. Then, this series of transmission operations, that is, the operations of supplying and stopping the power for operation, and transmitting data are repeatedly performed, and all data including a plurality of bits are transmitted.

On the other hand, in the remote controller connected to the main unit, the supply of the operating power is stopped.
When the data is detected by the state change detecting means, the data receiving means operates, and after a lapse of a fourth predetermined time from the detection, the data is read and recognized as data transmitted from the data transmitting means of the main unit. I do.

That is, 1-bit data is read after a certain period of time from when the supply of the operating power is stopped. In other words, the remote controller synchronizes communication with the main unit every time it receives one bit of data. Therefore, the data transmitted from the main unit is always read at the same timing regardless of the length of the data.

The two-wire communication system according to the second aspect of the present invention supplies power for operation from a main unit to a remote controller using a two-wire communication line, and transmits power from the remote controller to the main unit. This is a two-wire communication system for transmitting data. And the main unit is:
Power supply means for supplying the operating power for a first predetermined time, forced off means for stopping supply of the operating power for a second predetermined time, and supply of the operating power are stopped After a lapse of a third predetermined time from the point in time, a data receiving unit that reads the data transmitted from the data transmitting unit described later, the power supply unit, the forcible off unit, and the data receiving unit are sequentially received. And a main body side communication control unit that operates sequentially as an operation and repeats the reception operation until all the data is received. The remote controller may further include a state change detecting unit configured to detect that the supply of the operating power is stopped, and a fourth state control unit that determines whether the supply of the operating power is stopped.
A data transmission unit that transmits the data composed of a plurality of bits in a unit of one bit for a fifth predetermined time after a predetermined time has elapsed, a state change detection unit, and the data transmission unit, the data transmission unit comprising: And a remote-control-side communication control unit that repeats the transmission operation until all the data of a plurality of bits are transmitted.

Therefore, according to the two-wire communication system of the second aspect of the invention, in the main unit, first, the power supply means operates to supply operating power to the remote controller for the first predetermined time. . Next, by the forced off means, the second
The supply of the operating power is stopped for a predetermined time. This ensures that the signal to the remote controller changes from the power supply state (ON state) to the power stop state (OFF state). After a lapse of a third predetermined time from when the supply of the operating power is stopped, the data receiving unit reads 1-bit data transmitted from the remote controller, and recognizes the data as data transmitted from the data transmitting unit. Then, the series of receiving operations, that is, the operations of supplying and stopping the operation power and receiving data are repeatedly performed, and all transmitted data is received.

On the other hand, in the remote controller connected to the main unit, the supply of the operating power is stopped.
When detected by the state change detecting means, the data transmitting means operates, and after a lapse of a fourth predetermined time from the detected time, one of the data composed of a plurality of bits is output.
Only bits are transmitted for a fifth predetermined time. Then, the series of transmission operations, that is, the operations of detecting a state change and transmitting data are repeatedly performed, and all data including a plurality of bits are transmitted.

That is, the remote controller transmits 1-bit data after a fixed time (fourth predetermined time) with respect to the time point when the supply of the operating power is stopped. After (time), 1-bit data is read. In other words, every time one bit of data is transmitted / received, communication between the main unit and the remote controller is synchronized. Therefore, the third predetermined time,
By appropriately setting the lengths of the fourth predetermined time and the fifth predetermined time, data transmitted from the remote controller is always read at the same timing regardless of the length of the data.

The two-wire communication system according to the third aspect of the present invention uses a two-wire communication line to supply operating power from a main unit to a remote controller and transmit main unit data, and This is a two-wire communication system in which remote controller-side data is transmitted from a remote controller to the main unit. And a power supply unit for supplying the operating power for a first predetermined time;
Forcibly turning off the supply of the operating power and transmission of the main body side data for a predetermined time, and transmitting the main body side data composed of a plurality of bits in 1-bit units for a third predetermined time. Main body data transmission means capable of reading the remote control data transmitted from the remote control data transmission means, which will be described later, after a lapse of a fourth predetermined time since the supply of the operating power is stopped. Body-side data receiving means, and the power supply means,
The forced off means, and the main body side data transmission means,
A body-side transmission control unit that operates sequentially as a series of transmission operations and repeats the transmission operation until all of the plurality of bits of the body-side data are transmitted, the power supply unit, the forcible off unit, and the body-side data And a main unit-side reception control unit that operates the reception unit sequentially as a series of reception operations and repeats the reception operation until all the remote control-side data is received. The remote controller may further include a state change detecting unit configured to detect that the supply of the operating power has been stopped, and a state change detecting unit configured to determine whether the supply of the operating power has been stopped. A remote control side data receiving unit capable of reading the main body side data transmitted from the side transmitting unit, and a plurality of bits after a sixth predetermined time has elapsed from the time when the supply of the operating power is stopped. The remote control data transmitting means, the state change detecting means, and the remote control data receiving means capable of transmitting the remote control data in a unit of one bit for a seventh predetermined time as a series of receiving operations. While operating sequentially, the remote control side reception control means that repeats the reception operation until all the main body side data is received, the state change detection means, and The serial remote controller data transmission means, causes the sequential operation as a series of transmission operations, and a remote control transmission control means for repeating the transmission operation until the remote control data of the plurality of bits are transmitted all.

Therefore, according to the two-wire communication system of the third invention, when data is transmitted from the main unit to the remote controller, the operation is the same as that of the two-wire communication system of the first invention. Then, the remote controller reads 1-bit data a fixed time after the supply of the operating power from the main device is stopped.
That is, every time one bit of data is received, synchronization is established with the main unit.

Conversely, when data is transmitted from the remote controller to the main unit, the supply of operating power from the main unit is stopped in the same manner as in the operation of the two-wire communication system according to the second aspect of the present invention. The remote controller transmits 1-bit data after a predetermined time, and the main unit reads the data after a predetermined time, based on the time when the data is transmitted. That is, every time one bit of data is transmitted and received, the main unit and the remote controller synchronize with each other.

As described above, even when bidirectional communication is performed between the main unit and the remote controller, data to be transmitted is always read at the same timing regardless of the length of the data. .

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A two-wire communication system according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a two-wire communication system according to an embodiment of the present invention. FIGS. 2 and 3 are explanatory diagrams for explaining the operation of the two-wire communication system. Is a flowchart showing the flow of operation in this two-wire communication system. As shown in FIG. 1, the device 1 employing the two-wire communication system of the present embodiment includes a main body device 2 and a remote controller 3 (hereinafter, referred to as “remote controller 3”), and includes two wires. They are connected by a non-polar communication line 4.

The main unit 2 includes a microcomputer 6 for processing operation information and instruction information, or calculating and controlling various signals, and a power supply circuit 7 connected to an external commercial power supply.
And a switch circuit 8 composed of resistors and transistors
And a noise filter 9 composed of a capacitor and a coil.

The microcomputer 6 comprises a power supply means 10, a forced off means 11, a main body side data transmission means 12,
Body-side data receiving means 13 and body-side communication control means 1
4 and so on. The power supply means 10 controls the supply of power from the power supply circuit 7 to the remote controller 3 by turning on / off the switch circuit 8. The power supplied to the remote controller 3 is a DC power supply of 12 V and is supplied intermittently. Further, the forced off means 11 stops the supply of power to the remote controller 3 and the data transmission for a predetermined time,
By this operation, the signal to the remote controller 3 can be changed from the power supply state (ON state) to the power stop state (OFF state).

The main body side data transmitting means 12 performs processing for transmitting data relating to the operation information from the main body device 2 to the remote controller 3. This data is composed of a plurality of bits, but is transmitted in 1-bit units when transmitted. The output terminal of the main body side data transmission means 12 is connected to the base of an npn transistor 15, and the collector of the transistor 15 is connected between the switch circuit 8 and the noise filter 9. That is, when a Hi-level signal is transmitted from the main body side data transmission unit 12, the transistor 15 is turned on and the communication line 4 is turned on.
Becomes Lo level (about 0 V). Further, when a low level signal is transmitted from the main body side data transmission means 12 while the switch circuit 8 is in the ON state, the transistor 15 is turned off and the voltage applied to the communication line 4 becomes Hi level ( About 12V).

The main body side data receiving means 13 is
This is for processing the data relating to the instruction information sent from. An input terminal of the main body side data receiving means 13 is connected between the switch circuit 8 and the noise filter 9 via an npn-type transistor 16, a voltage dividing circuit 17, and the like. That is, the data sent from the remote controller 3 is inverted by the transistor 16, and
3 is input.

The main body side communication control means 14 includes a power supply means 10, a forced off means 11, a main body side data transmission means 12,
And for controlling the operation of the main body side data receiving means 13. Specifically, the main body side communication control means 14
A transmission control unit that operates in a transmission mode; and a reception control unit that operates in a reception mode. The transmission control unit includes a power supply unit, a forced off unit, and a main body side data transmission unit. 12 are sequentially operated as a series of transmission operations, and the transmission operation is repeated until all data of a plurality of bits are transmitted. On the other hand, the reception control unit operates the power supply unit 10, the forcible off unit 11, and the main unit side data reception unit 13 sequentially as a series of reception operations, and performs the reception operation until all data from the remote controller 3 is received. This is to be repeated.

The remote controller 3 includes a microcomputer 18 for processing instruction information and driving information, or calculating and controlling various signals, a bridge circuit 19 for rectifying power supplied from the main unit 2, and a rectified power. As a power supply for operating the remote controller 3, a power supply circuit 20 for supplying display means (not shown) and the microcomputer 18.
And a noise filter 21 composed of a capacitor and a coil.

The microcomputer 18 includes a state change detecting means 22, a remote control data receiving means 23, a remote control data transmitting means 24, and a remote control communication control means 2.
5 and the like. The state change detecting means 22 includes:
This is for detecting that the supply of power from the main unit 2 has stopped, that is, for detecting a change from the power supply state (on state) to the power stop state (off state). Synchronization is established between 2 and remote controller 3. That is, data transmission and reception are performed with the change detection time as a reference point. The specific control method will be described later.

The remote controller-side data receiving means 23 processes data relating to driving information sent from the main unit 2. An input terminal of the remote controller side data receiving unit 23 and an input terminal of the state change detecting unit 22 are connected between the noise filter 21 and the bridge circuit 19 via an npn transistor 26, a diode 27, and the like. That is, the data sent from the main unit 2 is inverted by the transistor 26 and the data
And state change detection means 22.

The remote controller side data transmitting means 24
Data relating to the instruction information is transmitted from the remote controller 3 to the main unit 2.
It performs processing for transmission to the server. This data is also composed of a plurality of bits, but is transmitted in 1-bit units when transmitted. The output terminal of the remote controller side data transmitting means 24 is connected to the base of an npn transistor 28, and the collector of the transistor 28 is connected between the noise filter 21 and the bridge circuit 19 via the diode 27. That is, when a Hi-level signal is transmitted from the remote-control-side data transmission means 24, the transistor 28 is turned on, and the voltage applied to the communication line 4 becomes Lo level. Conversely, when a Lo level signal is transmitted from the remote control side data transmission means 24, the transistor 28 is turned off and the communication line 4 is turned off.
Becomes Hi level.

The remote control communication control means 25 controls the operations of the state change detecting means 22, the remote control data receiving means 23, and the remote control data transmitting means 24. Specifically, the remote control communication control unit 25
Has a reception control unit that operates in the reception mode and a transmission control unit that operates in the transmission mode. The reception control unit includes the state change detection unit 22 and the remote control side data reception unit 23. The operation is sequentially performed as a series of reception operations, and the reception operation is repeated until all data from the main unit 2 is received. On the other hand, the transmission control unit causes the state change detection unit 22 and the remote control-side data transmission unit 24 to sequentially operate as a series of transmission operations, and repeats the transmission operation until all data of a plurality of bits are transmitted. .

Next, the operation of the two-wire communication system will be described with reference to FIGS. FIG. 2 shows a waveform when data is transmitted from main unit 2 to remote controller 3, and FIG. 3 shows a waveform when data is transmitted from remote controller 3 to main unit 2. FIG. 4 shows a control flow in the microcomputer 6 of the main unit 2, and FIG.
Indicates a control flow in the microcomputer 18 of the remote controller 3.

First, the operation when data is transmitted from main unit 2 to remote controller 3 will be described. In FIG.
(A) is an output waveform from the power supply means 10 of the main unit 2, that is, a waveform indicating the power supply state. The upper end of the waveform indicates the power on state, and the lower end of the waveform indicates the power off state. I have. This waveform is in an on state (power supply state) for 1 mSec after an off state (transmission of a start bit) of 2.5 mSec, and is in an off state (power stop state) for 1.5 mSec. Then, the ON state of 1 mSec and the OFF state of 1.5 mSec are alternately repeated. That is, 1 mSec of the 2.5 mSec cycle
Only the ON state is set.

In FIG. 2, (b) shows an output waveform from the main body side data transmission means 12, and the upper end of the waveform is Hi of the signal.
(H), and the lower end of the waveform indicates Lo (L) of the signal. As described above, the main body-side data transmission means 1
When the output of Hi is transmitted from 2, the voltage is not applied to the communication line 4. That is, here, for 0.5 mSec after the supply of power is stopped, the communication line 4 is forcibly turned off (the output is in the Hi state) and no voltage is applied to the communication line 4. Then, the data (1 bit unit) is transmitted for 1 mSec thereafter. That is,
In the period of 2.5 mSec, 0.5 mSec is in the forced off state, and 1 mSec is in the data transmission state. 2 (c) shows a waveform applied to the communication line 4, and this waveform is a waveform (a) indicating power supply.
And a waveform (b) indicating data transmission.

FIG. 2D shows an input waveform to the remote controller side data receiving means 23. That is, the waveform (c) applied to the communication line 4 is inverted by the transistor 26. Then, in the waveform shown in (d), the fact that the supply of power is stopped appears as a change from the Lo state to the Hi state. That is, in this waveform, L
By detecting the change from the state of o to the state of Hi, and adjusting the timing using the change as a reference point, the remote controller 3
Can be synchronized with the main unit 2.

Therefore, the remote controller-side data receiving means 23
Detects the change from the Lo state to the Hi state as shown in (e), reads the data 1 mSec after that,
The data is recognized as data transmitted from the main body side data transmission means 12. Note that this timing corresponds to an intermediate point in time during which data is transmitted from the main body side data transmission means 12 (between 0.5 and 1 mSec after the supply of power is stopped). Even if there is an error, the transmission timing and the reception timing can be surely matched.

Next, the operation when data is transmitted from the remote controller 3 to the main unit 2 will be described. In FIG. 3, (a) shows an output waveform from the power supply means 10 of the main unit 2 and, as in the case of transmission from the main unit 2 to the remote controller 3 (shown in FIG. 2), 1 m of the 2.5 mSec cycle
Only Sec is turned on.

In FIG. 3, (b) shows an output waveform from the main body side data transmitting means 12, and is off (output is Hi) for 0.5 mSec after power supply is stopped. No voltage is applied to the communication line 4. That is, of the period of 2.5 mSec, 0.5 mS
ec is forcibly turned off.

In FIG. 3, (c) shows an input waveform to the main body data receiving means 13, (e) shows a waveform applied to the communication line 4, and (f) shows an input waveform to the remote control data receiving means 23. It is. That is, (c) and (f) have the same waveform, and are obtained by inverting the waveform of (e). The waveform (e) is obtained by synthesizing the waveform (a) indicating the power supply, the output waveform (b) from the main body-side data transmission unit 12, and the output waveform (g) from the remote control-side transmission unit 24. Things.

In the remote controller 3, when it is detected in the input waveform (f) to the remote controller side data receiving means 23 that the supply of power is stopped as a change from the Lo state to the Hi state, the remote controller side transmission is performed. As shown in (g), the means 24 transmits data (in units of 1 bit) for 1 mSec after 0.5 mSec from the detection time. Thereby, the transmission timing of the remote controller 3 can be synchronized with the main unit 2.

On the other hand, as shown in (d), the main body data receiving means 13 of the main body apparatus 2 reads the data 1 mSec after the power supply is stopped, as shown in FIG. 24 is recognized as data transmitted. Note that this timing corresponds to an intermediate point in time during which data is transmitted from the remote controller-side data transmission means 24 (between 0.5 and 1 mSec after the supply of power is stopped). Even if there is an error, the transmission timing and the reception timing can be surely matched.

Next, a control flow in the microcomputer 6 of the main unit 2 and a control flow in the microcomputer 18 of the remote controller 3 will be described. As shown in FIG. 4, the microcomputer 6 of the main device 2 first stops supplying power and transmitting data for 2.5 mSec as a start bit (Step S).
1) Then, for 1 mSec, the operating power is supplied by the power supply means 10 (step S2). continue,
During 0.5 mSec, power supply and data transmission are forcibly stopped (step S3), and then 1m
During Sec, data is transmitted in 1-bit units (step S4). Until all data composed of a plurality of bits is transmitted (NO in step S5), the operation of steps S2 to S4, that is, the transmission operation in the transmission mode, is repeated.

When all data has been transmitted in step S5, a stop bit is transmitted (step S6) and a reply request signal is transmitted (step S7). If the length of the data is constant, that is, if the data has a fixed length, transmission of the stop bit can be omitted.

After transmitting the reply request signal, main unit 2 enters the reception mode. That is, for 1 mSec, the operating power is supplied by the power supply means 10 (step S
8), the power supply and data transmission are forcibly stopped for 0.5 mSec thereafter (step S).
9). Then, after the supply of power is stopped, that is, when 1 mSec has elapsed from the start of the operation in step S9 (YES in step S10), the data transmitted from the remote controller 3 is read by the main body side data receiving means 13. Then, until all data composed of a plurality of bits is received, in other words, until a stop bit is received from the remote controller 3 (N in step S12).
O), the operations of steps S8 to S12, that is, the receiving operation are repeatedly performed. When the stop bit is received in step S12, the process returns to step S1 and returns to the transmission mode (step S13).

On the other hand, as shown in FIG. 5, the microcomputer 18 of the remote controller 3 receives the start bit transmitted from the main unit 2 (Y in step T1).
ES), and the reception mode is set. That is, after that, when it is detected that the supply of the operating power has been stopped (YES in step T2), time measurement is started based on the detection time point, and after elapse of 1 mSec (Y in step T3).
ES), the data transmitted from the main unit 2 is read by the remote controller side data receiving means 23. The operation of steps T2 to T4, that is, the reception operation, is repeated until all the data composed of a plurality of bits is received, in other words, until the stop bit is received from main device 2 (NO in step T5). Do.

When the stop bit is received in step T5, the remote controller 3 enters the transmission mode and the main unit 2
And waits for a reply request signal to be sent from. And
When the remote control side data receiving means 23 receives the reply request signal (YES in step T6) and detects that the supply of the operating power has been stopped (YES in step T7), it counts the time based on the detection time. Is started, and after 0.5 mSec has elapsed (YES in step T8), 1 mS
During ec, data is transmitted in 1-bit units (step T9). Until all data composed of a plurality of bits are transmitted (NO in step T10), the operation from step T7 to step T9, that is, the transmission operation is repeated. When all data is transmitted in step T10, a stop bit is transmitted (step T1).
At the same time as 1), the process returns to step T1 and returns to the reception mode (step T12).

Thus, in the above two-wire communication system,
One bit of data is read after a certain period of time after the supply of the operating power is stopped. In other words, the remote controller 3 synchronizes communication with the main unit 2 every time one bit of data is received. Therefore, the transmitted data can always be read at the matched timing regardless of the length of the data. In particular, in the present embodiment, the synchronization is not performed by transmitting and receiving data for instructing the synchronization, but is performed based on the time when the supply of the operation power is stopped. The time required for the communication can be extremely shortened, and the communication speed is not significantly reduced even in comparison with the conventional one.

In the above-described two-wire communication system, when data is transmitted from the remote controller 3 to the main unit 2, the remote controller 3 synchronizes communication with the main unit 2 every time one bit of data is transmitted. And the main unit 2 performs reading based on the same timing. Therefore, main unit 2
Thus, the data transmitted from the remote controller 3 can always be read at the same timing regardless of the length of the data.

The two-wire communication system described above can be realized only by changing the program of the microcomputer as compared with the conventional configuration, and does not require the use of a high-precision crystal oscillator. It can be commercialized.

By the way, in the two-wire communication system of the above-described embodiment, the bidirectional communication between the main unit 2 and the remote controller 3 is described. The present invention may be applied to a device that performs transmission only to the main device 2 from.

In the two-wire communication system of the above embodiment, the power supply time is set to 1 mSec, the forced stop time is set to 0.5 mSec, and the data transmission time is set to 1 mSec for a period of 2.5 mSec. Although shown, the distribution of the period and the time is not limited to the above numerical values, but can be appropriately set according to the power consumption of the remote controller, the capability of the microcomputer, and the like.

In the two-wire communication system of the above embodiment, only one remote controller is connected to the main unit, but a plurality of remote controllers are connected in parallel to one main unit. The present invention can be applied to such a case. Specifically, data is transmitted from the main unit to all remote controllers, and thereafter, data is sequentially transmitted from each remote controller based on a reply request signal. And
In this case, all the remote controllers are synchronized with the main unit.

[0057]

As described above, in the two-wire communication system according to the first aspect of the invention, every time one bit of data is received, communication can be synchronized with the main unit. Regardless of the length of the transmitted data,
It can always be read at the matched timing. Moreover, since it is not necessary to use a high-precision crystal oscillator or the like, it is possible to commercialize the device at low cost.

In the two-wire communication system according to the second aspect of the present invention, the communication can be synchronized with the main unit every time one bit of data is transmitted. Data can always be read at the correct timing regardless of the length of the data. Moreover, since it is not necessary to use a high-precision crystal oscillator or the like, it is possible to commercialize the device at low cost.

In the two-wire communication system according to the third aspect of the present invention, even when two-way communication is performed between the main unit and the remote controller, one of the main unit and the remote controller transmits data from the other. Data can always be read at the same timing regardless of the length of the data. In addition, in this case, it is not necessary to use a high-precision crystal oscillator or the like, so that the product can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a two-wire communication system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of a two-wire communication system according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an operation of a two-wire communication system according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a control flow in a two-wire communication system according to an embodiment of the present invention.

FIG. 5 is a flowchart showing a control flow in a two-wire communication system according to an embodiment of the present invention.

FIG. 6 is a circuit diagram showing a circuit configuration of a conventional two-wire communication system.

FIG. 7 is an explanatory diagram for explaining an operation of a conventional two-wire communication system.

[Explanation of symbols]

2 Main unit 3 Remote controller (remote controller) 4 Communication line 10 Power supply unit 11 Forced off unit 12 Main unit data transmission unit 13 Main unit data reception unit 14 Main unit communication control unit (main unit transmission control unit, main unit reception control unit) 22) state change detecting means 23 remote control side data receiving means 24 remote control side data transmitting means 25 remote control side communication control means (remote control side transmission control means, remote control side reception control means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // F24H 1/00 H04L 13/00 TF term (reference) 5K034 AA05 AA10 CC06 DD01 DD05 HH01 HH02 HH05 HH07 HH65 KK05 NN13 NN22 PP02 PP03 TT05 TT08 5K046 AA03 BB05 CC16 PP03 PS05 PS36 PS44 5K048 AA08 AA11 BA12 BA14 DC04 EA06 EB02 EB04 EB13 FC01 HA05 HA07 HA32

Claims (3)

[Claims] 1. A two-wire communication system for supplying power for operation and transmitting data from a main device to a remote controller using a two-wire communication line, wherein the main device comprises: Power supply means for supplying the operating power for a predetermined time; forcible off means for stopping supply of the operating power and transmission of the data for a second predetermined time; A data transmission unit that transmits the data composed of a plurality of bits in units of one bit, and the power supply unit, the forcible off unit, and the data transmission unit are sequentially operated as a series of transmission operations, and a plurality of bits are transmitted. A main body side communication control unit that repeats the transmission operation until all the data is transmitted, wherein the remote controller detects that the supply of the operation power is stopped. State change detecting means, data receiving means for reading the data transmitted from the data transmitting means after a fourth predetermined time has elapsed from the time when the supply of the operating power is stopped, and the state change detecting means And a remote control communication control means for operating the data reception means sequentially as a series of reception operations and repeating the reception operation until all the data is received. Communication system. 2. A two-wire communication system that uses a two-wire communication line to supply operating power from a main unit to a remote controller and transmit data from the remote controller to the main unit. The main body device includes: a power supply unit configured to supply the operating power for a first predetermined time; a forced off unit configured to stop supplying the operating power for a second predetermined time; Data receiving means for reading the data transmitted from the data transmitting means, which will be described later, after a third predetermined time has elapsed from the time when the power supply is stopped, the power supply means, the forcible off means, and the data A main body side communication control means for operating the reception means sequentially as a series of reception operations and repeating the reception operation until all the data is received, A state controller for detecting that the supply of the operating power has been stopped, and a plurality of bits after a fourth predetermined time has elapsed since the supply of the operating power was stopped. Data transmission means for transmitting the data to be transmitted in a unit of one bit for a fifth predetermined time, the state change detection means, and the data transmission means are sequentially operated as a series of transmission operations, and the data of a plurality of bits are transmitted. And a remote controller-side communication control means for repeating the transmission operation until all are transmitted. 3. Using a two-wire communication line, the main unit supplies operating power to the remote controller and transmits main unit data, and the remote controller transmits remote control data to the main unit. A two-wire communication system, wherein the main body device includes: a power supply unit configured to supply the operating power for a first predetermined time; and a power supply unit configured to supply the operating power for a second predetermined time. Forcible off means for stopping transmission of main body side data, main body side data transmitting means capable of transmitting the main body side data composed of a plurality of bits in 1-bit units for a third predetermined time, A main body capable of reading the remote control side data transmitted from the remote control side data transmitting means described later after a fourth predetermined time has elapsed since the supply of power for use was stopped. A data receiving unit, the power supply unit, the forcible off unit, and the main unit data transmitting unit are sequentially operated as a series of transmitting operations, and the transmitting operation is performed until all of the plurality of bits of the main unit data are transmitted. The main body side transmission control means, and the power supply means, the forcible off means, and the main body side data reception means are sequentially operated as a series of reception operations, and the reception is performed until all the remote control side data is received. A main body-side reception control unit that repeats the operation, the remote controller includes: a state change detection unit that detects that the supply of the operation power is stopped; and (5) After a predetermined time has elapsed, the remote controller data capable of reading the main body data transmitted from the main body transmission means. Data receiving means, and after a lapse of a sixth predetermined time since the supply of the operating power is stopped, transmitting the remote control data composed of a plurality of bits in a unit of one bit for a seventh predetermined time. Remote control side data transmitting means, the state change detecting means, and the remote control side data receiving means are sequentially operated as a series of receiving operations, and the receiving operation is performed until all the main body side data is received. Repeating the remote control side reception control means, the state change detection means, and the remote control side data transmission means sequentially operate as a series of transmission operations, and perform the transmission operation until all of the plurality of bits of the remote control side data are transmitted. A two-wire communication system comprising: a remote controller-side transmission control means that is repeated.