JPH0332686B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a fixed base unit that is located near combustion equipment and directly controls it, and a fixed base unit that is connected to this base unit via a data transfer and power line. However, regarding a remote control type combustion control device consisting of a remote unit for controlling the combustion equipment from a remote location, in particular if the data transmission and power supply line described above has an abnormality mainly represented by a short circuit, the data The present invention relates to a remote control type combustion control device that is improved so as to quickly cut off the power supply from the base unit side to the transfer and power supply line.

<Prior Art> Recently, remote control type combustion control devices having a remote unit have come to be used as control devices for various combustion devices such as water heaters.

The system configuration is shown in Figure 4, which includes a base unit 10 that directly controls combustion equipment (not shown) such as the water heater, and a remote unit 30 that is installed at a location away from the base unit. -1,30-2,...,30-n (n=1,
2, . . . ) are generally connected by two data transfer and power supply lines 20, and a power supply potential Eo is applied between these two lines.

In other words, in this type of system, the power line 20 is used to connect the base unit 10 and remote units 30-1, 30-2, ..., 30-.
Data signals are transferred to and from N, and as a general rule, a carrier superimposition method as shown in FIG. 5 is adopted as the mode.

That is, if the data signal is exemplified as shown in the upper part of FIG. 5, a frequency component or a carrier corresponding to the data signal is superimposed on the DC power supply potential Eo as shown in the lower part. For example, a carrier signal of a predetermined frequency is superimposed on the DC power supply line 20 during a period when a data signal issued by a microcomputer is at a low level "L" in terms of logic value. However, the power source may be alternating current, and in that case as well, this superimposition method can be similarly adopted by using a frequency different from the power source frequency.

On the other hand, the power supply potential is synchronized with the data signal.
There is also a method of turning Eo on and off, but this requires a relatively large power supply line switching circuit, and is not a very desirable method.

In any case, data signals mutually transferred in this way are generally transmitted between the base unit 10 and a plurality of remote units 30-i (i=1, 2,
3, .

However, as far as the conventional remote-controlled combustion control device with the above system configuration is concerned, there are accidents that can occur in the data transmission and power supply lines, and there are also abnormalities such as short circuits that can easily lead to serious consequences. We cannot recognize any known example in which a safety configuration is implemented to detect this occurrence and cut off the power supply to the data transfer/power supply line.

However, the present invention is not limited to combustion control devices, but is more generally considered as a data transmission/reception system between a base unit and a remote unit, such as the device disclosed in Japanese Patent Application Laid-open No. 10897/1983.

In the device disclosed in this publication, the microcomputer installed in the base unit itself detects data abnormalities in the data transfer and power supply lines, and detects data abnormalities generated by a specific remote unit. In this case, the power supply to the remote unit is cut off by operating a relay via the corresponding driver circuit.

<Problems to be Solved by the Invention> The above-mentioned conventional devices originally monitor data, and although it is possible to stop power supply if an abnormality occurs in the data transfer cycle, etc.
If a short circuit occurs in the data transfer/power supply line itself, this cannot be detected.

In addition, since the device that detects the abnormality is the microcomputer itself installed in the base unit, if an abnormality occurs in this, it is completely impossible to demonstrate the detection function, even for data abnormalities. Therefore, if a power supply short-circuit accident occurs, a serious and extremely dangerous situation may occur, which is a fatal drawback.

The present invention has been made in view of these points, and when an accident such as a short circuit occurs in the data transfer/power line, it is detected and promptly supplies power to the data transfer/power line. It is an object of the present invention to provide a remote control type combustion control device which can be shut off and can detect a short circuit accident regardless of an abnormality occurring in a microcomputer built in a base unit or a remote unit.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a remote control type combustion control device having the following configuration.

A base unit that directly controls combustion equipment,
A microcomputer is used to interconnect one or more remote units via a data transfer and power supply line to control the combustion equipment from a remote location, and to create and send/receive data to be carried on the data transfer line. A remote control combustion control device comprising a computer in each of the base unit and the remote unit; in the base unit and the remote unit, a digital pulse train is transmitted using a digital pulse train created by the microcomputer in each unit. A transmitter circuit that converts data into a transfer waveform suitable for superimposing data on the data transfer/power supply line, and a transfer waveform sent via the data transfer/power supply line and a transfer waveform output from its own transmitter circuit. The base unit is further provided with a receiving circuit that demodulates it into a digital pulse train to create received data and provides the received data to a microcomputer within its own unit; , comparing the transmission data given to the transmission circuit of the base unit with the reception data output from the reception circuit of the base unit, which demodulates the transfer waveform sent by the transmission circuit to the data transfer/power supply line; a power supply monitoring circuit that outputs a power cutoff signal when a difference is found between the transmitted data and the received data; and a power supply monitoring circuit that responds to the power cutoff signal from the power supply monitoring circuit;
A remote control combustion control device comprising: a power cutoff circuit that cuts off power supply to the remote unit via the transfer/power line.

<Operations and Effects> In the remote control type combustion control device of the present invention,
First, a transmitter circuit and a receiver circuit are provided in the base unit as hardware separate from the microcomputer in the base unit.

The transmitter circuit converts transmit data in the form of a digital pulse train output from the microcomputer into a waveform suitable for transfer, for example, as shown in FIG. 5 above.

Conversely, the receiving circuit receives the transfer waveform transferred to the data transfer/power supply line, demodulates this into a digital pulse train corresponding to the transmitted data, and supplies this as received data to the microcomputer.

The receiving circuit is also capable of monitoring the transfer waveform output from the transmitting circuit within the base unit.

Therefore, when the data transfer/power line is functioning normally and data is being transferred normally from the base unit to the remote unit,
The transmission data from the microcomputer given to the transmission circuit in the base unit and the reception data output by the reception circuit in the same base unit are as follows.
If we ignore the transfer time between the transmitting and receiving circuits (in practice,
(can be made extremely small), resulting in a temporally identical or similar pulse waveform sequence.

However, if an accident such as a short circuit occurs in the data transfer and power supply line, the transmission data output by the microcomputer may be outputted as a transfer waveform suitable for transmission via the transmission circuit, but if there is a line short circuit, the transmission data output by the microcomputer may be For example, since the receiving circuit cannot receive this transfer waveform, the received data output from the receiving circuit and the above-mentioned transmitted data are naturally different both in time and form. Generally, at this time, the received data is simply a series of constant potentials or constant logic.

Therefore, since the difference between the two data signals at a certain point in time can be easily determined using known and existing circuit technology, as stated in the summary above, when the microcomputer of the base unit transmits If a power supply monitoring circuit that makes such a determination is provided only in such cases, a power supply cutoff signal can be issued from now on.

Based on this power cutoff signal, the power cutoff circuit cuts off the power supply to the remote unit from the power supply circuit of the base unit.

The specific circuit configuration of the power cutoff circuit itself can be extremely easily realized by a person skilled in the art using known and existing electronic circuit technology, and can be configured reliably in response to a power cutoff signal in a convenient signal form. Since it is definitely possible to release the data transfer/power line (power off), according to the present invention, if a short circuit occurs in the data transfer/power line, the data transfer/power line can be immediately disconnected. It is possible to cut off the power supply and ensure safety.

Furthermore, a transmitting circuit, a receiving circuit, a power supply monitoring circuit,
Since each power cutoff circuit is a separate piece of hardware from the microcomputer built into the base unit, even if an accident such as a runaway occurs in the microcomputer, a short-circuit accident in the data transfer/power line will be reliably detected. be able to.

As an additional effect, since the power source monitoring circuit monitors transmitted data and received data, it is also possible to detect failures in the transmitting/receiving circuit system.

<Embodiment> FIG. 1 shows a combustion control base unit 10 in an embodiment of a remote control type combustion control device having a data transfer and power line abnormality detection function according to the present invention, and a base unit 10 in which the relevant data is stored in the base unit 10. A plurality of remote units 30-1, 30-2, . . . , 3 each connected via the transfer/power line 20
0-n (n=1, 2,...) are shown, and each remote unit 30-i (l=
1, 2, ..., n) may all have the same configuration.

First, as a static configuration, the base unit 10
There is a power supply circuit 12 connected to a commercial power supply AC, and a plurality of pairs of positive and negative DC voltage terminals V1, G1;..., Vn, Gn are generally drawn out from the power supply circuit 12. Actually, the ground side terminal G
1;...;Gn is often common.

In the illustrated embodiment, the terminal pair related to the operation of the present invention is assumed to be V1 and G1, and it is assumed that transmitting and receiving circuits 13 and 14, which will be described later, in the remote unit and the base unit are operated by these terminals.

However, even if each of the hardware parts 13 and 14 receives power from a separate pair of power supply terminals, the gist of the present invention can be satisfied, as will be apparent from the description below.

The V1 and G1 terminals of the power supply circuit 12 are connected to the data transfer/power supply line 20 after passing through the power cutoff circuit 16.
The power supply potentials V1' and G1' are applied to the data transfer and power supply line 20 consisting of these two lines.
As a result, each remote unit 30-i operates.

The base unit 10 is equipped with a microcomputer 11 that controls various combustion operations of combustion equipment (not shown) and exchanges data with each remote unit. Output. This transmission data 17 is generally in the form of a digital pulse train, as will be shown later.

The transmission data 17 is given to a transmission circuit 13 provided according to the present invention, where the transmission data 17 is first
The modulation operation as shown and explained in the figure is performed,
The transmission data 17 is transferred to the data transfer/power line 2
The transfer waveform is suitable for being placed on 0.

On the other hand, the transfer waveform in the data transfer/power supply line 20 is monitored by the receiving circuit 14, and therefore any remote unit 30-i is connected to the data transfer/power supply line 20 at the input of the receiving circuit.
In addition to the transfer waveform similar to the above outputted to the base unit, the transfer waveform outputted by the transmitting circuit 13 itself in the base unit is also inputted.

The receiving circuit 14 demodulates this input waveform to generate received data 19 consisting of the original digital pulse train, and then provides this to the microcomputer 11.

However, although not shown, the above-mentioned microcomputer 11, transmitting circuit 13, and receiving circuit 1
4 is also provided in each remote unit 30-i. Therefore, data can be sent and received between the base unit and the remote unit.

What is further provided uniquely to the base unit is a power supply monitoring circuit 15. This is the transmission data 17 output by the microcomputer 11.
and received data 19 that is fed back from the transmitting circuit 13 to the microcomputer 11 via the receiving circuit 14 when the microcomputer 11 is in the transmitting mode. , that is, when the identity or similarity is lost, a power cutoff signal Ss is issued.

However, when the microcomputer 11 in the base unit 10 is in the reception mode, naturally the transmission data 17 from the microcomputer 11 is not output, and on the other hand, the output of the reception circuit 14 is transmitted from the remote unit 30-i. Since pulses as a result of demodulating the transmitted transfer waveform are generated as received data 19, there is a difference between the two data. At this time, it would be inconvenient if the power supply monitoring circuit 15 outputs the power cutoff signal Ss, so the determination by the power supply monitoring circuit 15 needs to be made only when the microcomputer 11 built into the base unit is in the transmission mode.

There are various means for this purpose using known and existing circuit technology, and there is no problem in adopting any of them.
In this embodiment, the microcomputer 11 outputs a transmission enable signal 18, thereby selectively operating the transmission circuit 13, and only when the transmission enable signal 18 is outputted significantly, the power supply monitoring circuit 15 for comparison and judgment of both transmitted and received data.

Although this embodiment is not related to the gist of the present invention, the output Ps of the power-on reset circuit, which is normally provided in this type of microcomputer, is used to reset the microcomputer 11 after repairing the fault.
Due to the power-on reset associated with the restart,
The power monitoring circuit 15 is returned to its initial state, and the power cutoff circuit 16 is placed in power supply mode.

The following will be explained with reference to the waveform diagram of each part in FIG. At the same time as transmitting the transmission data 16, a transmission enable signal 18 is given to the transmission circuit 13.

Together with these enable signals 18, the transmitted data 1
The transmitting circuit 13 that receives the data 16 transfers the transmitted data 16 to the data transfer/power supply line 20 which also serves as a power supply line, for example, in the transfer mode described above with reference to FIG. Therefore, the transfer waveform of the data transfer/power supply line 20 at this time is as shown by the part and ' in FIG.

This transferred waveform is also monitored by the receiving circuit 14 in the same base unit, and therefore the demodulated output of this receiving circuit 14 is equivalently equal to the transmitted data 17, as shown by the part and ' in FIG. , or received data 19 with temporal correlation.
becomes.

Regarding the data transfer/power supply line 20, all remote control units 30-i are connected in parallel, and the transfer waveform due to the transmitting circuit output in the base unit 10 is transmitted to all remote units 30-i.
However, if only the remote unit 30-i is set to receive this transmission data 17, the remote unit 30-i may have the same configuration as the receiving circuit 14 in the base unit. The receiving circuit in the base unit 30-i extracts the carrier as a data signal component in the data transfer/power supply line, and transmits the received data 17 in the base unit, as shown by the part and ' in FIG.
and inputs it into its own microcomputer.

In response to the transmission data 17 sent from the base unit 10 side, the remote unit 30-i creates predetermined transmission data to be sent back to the base unit 10 according to the transmission data 17, and creates a predetermined transmission data similar to the transmission circuit 13 in the base unit. For example, a transmission waveform of a predetermined pattern as shown by the part and ' in FIG.

The receiving circuit 14 in the base unit 10
This data is detected as received data 19 and inputted to the microcomputer 11, as indicated by the part and ' in the figure.

The illustrated system operates by repeatedly performing this operation for the first to nth remote units 30-i while updating the data. Of course, from the nth number, it returns to the first one.

If only such a data transfer operation is performed, it is a normal or normal operating state, and such a sequence has been used in the past.

On the other hand, as will be explained below, the present invention has the advantage of changing the transmission timing from the base unit when a short circuit occurs in the data transfer/power supply line 20, as shown by arrow S in FIG. It exhibits the following safety functions.

From the microcomputer 11 in the base unit 10, as shown by the section '' in FIG.
If a short-circuit accident has already occurred in the data transfer/power supply line 20 when the transmission data is given to the transmission circuit 13 and the transmission enable signal 18 is given to the transmission circuit 13 and the power supply monitoring circuit 15, the For example, as shown by the phantom line, complementary received data pulses should also occur at the output of the receiving circuit 14 in the base unit 10, but the output of the receiving circuit 14 is in a state where no change occurs. arise.

Therefore, after the time Td required for determination has elapsed (actually, this need not be taken into consideration), a power cutoff signal Ss is generated at the output of the power supply monitoring circuit 15, and the power cutoff circuit is activated. 16 is in operation, and the power supply V1' to the data transfer/power supply line 20 is activated.
Cut off the supply of G1'.

Note that, after the safety function of the device of the present invention has been activated in this way, when the microcomputer 11 is restarted after recovery from the accident, it is desirable to return the power monitoring circuit 15 and the power cutoff circuit 16 to their initial states. To do this, as mentioned earlier, the output Ps of the power-on reset circuit, which is usually provided in this type of microcomputer, is used.
After the failure is repaired, it is reasonable to return the power supply monitoring circuit 15 to its initial state by a power-on reset accompanying the restart of the microcomputer 11, and to set the power cutoff circuit 16 to the power supply mode.

Therefore, in this document, examples of the configurations of the power supply monitoring circuit 15 and the power supply cutoff circuit 16, including such ancillary configurations, are shown in FIGS. 3A and 3B, although not limited thereto.

As shown in FIG. 3A, the power supply monitoring circuit 15 in this example has transmission data 17 and reception data 1.
It has an exclusive OR circuit 151 which receives 9 and 9 at both inputs, and its output is subjected to NAND processing between it and the transmission enable signal 18 by a NAND gate 152.

Therefore, first, the output of this NAND gate 152 constitutes the power cutoff signal under the fault condition shown in the sections ``and'' in FIG.

However, this is not directly the output of the power supply monitoring circuit, but rather the power-on reset signal Ps.
A flip-flop 153 inverts the logic value each time the logic value occurs between the driver 1 and the driver 1.
After passing through 54, it is output as the intended power cutoff signal Ss.

On the other hand, the power cutoff circuit 16 receiving the power cutoff signal Ss has a very simple configuration in the illustrated example, and connects the transistor 161, which is conductive when the base is grounded, to the data transfer and power supply line 2.
It is designed to be inserted in series on the hot side of the
A power cutoff signal Ss is applied to the base of this transistor 161 via a resistor 162.

In this way, the data transfer/power line 20
If no short-circuit accident occurs in
A voltage V1' subtracted from 1 is supplied to the data transfer/power supply line 20.

However, when a difference occurs between the transmitted data 17 and the received data 19, the flip-flop 153 is inverted, the driver output is pulled up to a significant potential, the transistor 161 in the power cutoff circuit 16 is made non-conductive, and the data transfer/power supply line 20.

After that, when the power-on reset signal Ps is applied, the flip-flop 153 is inverted again.
By grounding the driver output, power supply to the data transfer/power line 20 is automatically resumed.

Note that the exclusive OR gate 15 of the power supply monitoring circuit
A capacitor 155 provided at the output of the signal 1 serves to eliminate the time lag between the transmitted data 17 and the received data 19.

As described above, according to the present invention, accidents such as a short circuit in the data transfer/power supply line 20 can be completely detected, and even if the microcomputer 11 is in an abnormal state, the problem will occur regardless of this. Accidents can be detected. However, in the case of the configuration according to the illustrated embodiment, it is possible to detect not only this but also abnormalities in the transmitting circuit 13 and the receiving circuit 14. If either one of them fails, the transmitted data 17 and the received data 1 will be
This is because the correlation with 9 is lost.

In the above description, it has been assumed that there are a plurality of remote units, but as is clear from the effects of the present invention, the present invention can be effectively applied to any combustion control device having at least one remote unit. can.

As for the data transfer mode, the above embodiment has shown the case of following the mode shown in FIG. 5, but other transfer modes may be used.

In addition, in the illustrated case, the transmitting circuit 13 and the receiving circuit 14 are supplied with power from the point after the output of the power cutoff circuit 16, so that when an abnormality is detected, the power to these circuits is cut off. However, this is not essential to the gist of the present invention. However, it is still desirable, so for example, when the transmitter circuit 13 and the receiver circuit 14 are powered from the other power supply terminal pair Vi, Gi of the power supply circuit 12 in the base unit, a power cutoff circuit is also installed between them. You may also insert .

[Brief explanation of drawings]

Fig. 1 is a circuit configuration diagram of the main parts of a remote control type combustion control device according to a preferred embodiment of the present invention, Fig. 2 is a signal waveform diagram of the main parts in the circuit shown in Fig. 1, and Fig. 3 is used in the present invention. Figure 4 is an explanatory diagram of an example of a conventional system configuration of this type of remote control type combustion control device, and Figure 5 is an illustration of a data signal and its transfer. FIG. 3 is an explanatory diagram of an example mode. In the figure, 10 is a base unit, 11 is a microcomputer, 13 is a transmitting circuit, 14 is a receiving circuit, 15 is a power monitoring circuit, 16 is a power cutoff circuit,
17 is transmission data, 18 is a transmission enable signal,
19 is received data, 20 is a data transfer/power supply line, 30 is a remote unit, and Ss is a power cutoff signal.

Claims (1)

[Claims] 1. A base unit that directly controls a combustion device and one or more remote units that control the combustion device from a remote location are interconnected via a data transfer and power line. The base unit and the remote unit each include a microcomputer for creating and transmitting/receiving data to be loaded onto the data transfer line; Each unit has a transmitting circuit that converts the transmitted data generated by the digital pulse train created by the microcomputer in its own unit into a suitable transfer waveform to be superimposed on the data transfer/power supply line, and A receiving circuit is provided, which demodulates the transmitted transfer waveform and the transfer waveform output from its own transmitting circuit into a digital pulse train to create received data, and provides the received data to a microcomputer within its own unit; The base unit further includes the transmission data given to the transmission circuit of the base unit and the transfer waveform sent by the transmission circuit to the data transfer/power supply line only when the base unit is in the transmission mode. a power monitoring circuit that compares demodulated received data output from a receiving circuit of the base unit and outputs a power cutoff signal when a difference is found between the transmitted data and the received data; In response to a power-off signal from the circuit,
A remote control type combustion control device comprising: a power cutoff circuit that cuts off power supply to the remote unit via the transfer/power supply line.