JP2003032321A - Data communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost data communication device provided with a simple backup means that backs up transmission of a control signal for a particular load of high importance. SOLUTION: A data transmission section uses a supervisory circuit to detect an operation fault on the occurrence of the operation fault, in a transmission means for transmitting a fame signal and transmits an output of a pulse- generation circuit for generating a pulse signal with a particular frequency, corresponding to a particular control signal. A data reception section is provided with a reception means, that extracts a control signal from a data part of a received frame signal and with a pulse signal identification circuit that identifies the pulse signal with the particular frequency generated from the pulse generating circuit, to output a particular control signal corresponding to the pulse signal with the particular frequency, and uses an output of the pulse signal identification circuit for the particular control signal output even on the occurrence of faulty operation of the transmission means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication device for transmitting control signals for controlling various electronic devices and electric devices through a communication line.

[0002]

2. Description of the Related Art In recent years, data communication devices for transmitting control signals for controlling various electronic devices and electric devices through communication lines have been widely used. For example, in the control of various electric components (hereinafter, “load”) mounted on an automobile, one in which the operation of the load is remotely controlled via a data communication device is often used. For example, in the remote control of the seat, control items (reclining seat, moving back and forth, moving up and down, front vertical, etc.)
The control signal obtained by selecting the switch corresponding to
The data transmitting unit converts the data into a data unit of a predetermined frame signal, and the frame signal is transmitted to the data receiving unit via a transmission line (for example, an optical communication transmission line). The data receiving section extracts a control signal from the data section of the received frame signal and sends the control signal to a load (for example, a motor that moves the seat forward) or a relay that drives these loads corresponding to the switch operation. Is output.

In general, the frame signal has a header part indicating the start of a frame and a data part, and preferably, a time interval between the error detection part for checking a communication error and the next frame is maintained. Are arranged in time series with an idle section for. The frame signal transmitted from the data transmission unit is a central processing unit (hereinafter,
It is formed according to a predetermined program control by a transmitting means mainly composed of "CPU"). Also in the data receiving section, the receiving means mainly composed of the CPU is
A control signal is extracted from the time-series frame signal according to a predetermined program control.

In such a data communication apparatus using a CPU as the transmitting / receiving means, the data transmitting section forms different frame signals in order to reliably transmit the control signal even if an abnormality such as CPU runaway occurs. First and second 2
There has been proposed a data communication device including a single-system transmission means and a data reception unit including first and second two-system reception means. In such a data communication device, a normal control signal is transmitted by the first transmitting / receiving means, and if an abnormality occurs in the first transmitting / receiving means, the second transmitting / receiving means is used.
The receiving means backs up the transmission of the control signal.

[0005]

However, in a data communication apparatus having two systems of data transmitting / receiving means, all control items of control signals are backed up, but the data transmitting section and the data receiving section respectively have Since two CPUs are required, there are problems that the configuration of the data communication device becomes complicated and the cost increases.

The present invention has been made in order to solve the above problems, and it has been noted that it is generally sufficient to limit the control signal transmission to the control items of high importance, and it is important. An object of the present invention is to provide a data communication device capable of backing up control signal transmission at low cost by providing a simple backup means for backing up control signal transmission limited to control items.

[0007]

In order to achieve the above object, according to the present invention, in claim 1, a data transmitting section for transmitting a plurality of input control signals, and a signal transmitted by the data transmitting section. In the data communication device including a data receiving unit that extracts the plurality of control signals from the data transmitting unit, the data transmitting unit transmits a frame signal having a header unit and a data unit corresponding to the plurality of control signals. ,
A monitoring circuit for detecting an abnormal operation of the transmitting means; a pulse generation circuit for generating a pulse signal of a specific frequency in response to the specific control signal when the input control signal is a specific control signal; When the monitoring circuit detects an abnormal operation of the transmitting means, it includes transmission signal selecting means for transmitting a pulse signal generated by the pulse generating circuit in place of the frame signal transmitted by the transmitting means, and the data receiving section. Is a receiving means for extracting a control signal from the data part of the received frame signal, and the transmission signal selecting means identifies a pulse signal of a specific frequency generated by the pulse generating circuit transmitted in place of the frame signal, There is provided a data communication device including a pulse signal identification circuit that outputs a specific control signal corresponding to the pulse signal of the specific frequency.

In the data transmission section of the data communication apparatus thus constructed, the transmission means composed of the CPU transmits a plurality of control signals to the data reception section as the data section of the frame signal, and the data reception section performs this control. Extract the signal.
If the transmission means malfunctions and it becomes impossible to transmit the frame signal, the pulse generation circuit generates a pulse signal of a specific frequency corresponding to the specific control signal, and the transmission signal selection means outputs the pulse signal. Transmit instead of the frame signal. The data receiving unit identifies and outputs this pulse signal as a specific control signal instead of the frame signal. Therefore, the transmission of the specific control signal is backed up even if an abnormal operation occurs in the transmitting means. As described above, since the CPU is not needed for backup, a data communication device having a simple structure and low cost is provided.

According to a second aspect of the present invention, the pulse generating circuit generates pulse signals of different frequencies corresponding to a plurality of specific control signals, and the pulse signal identifying circuit generates pulse signals of the different frequencies. Since they are identified, a plurality of control signals can be backed up as the specific control signal.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A data communication apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an essential part of an embodiment of a data communication device for remotely controlling a seat of an automobile. The data communication device includes a data transmission unit 10 and a data reception unit 20. In the data transmission unit 10, the switch 1
The control signals input from 4 to 4 are formed as a data portion of a predetermined time-series frame signal formed by the transmitting means 5 mainly composed of the CPU. The frame signal formed by the transmitting means 5 is input to the light emitting circuit 6 from the frame signal output terminal P5s, and is transmitted as an optical signal from the light emitting diode 7 driven by the light emitting circuit 6. A pulse output terminal 8c of the pulse generation circuit 8 described later is also connected to the frame signal output terminal P5s and is also connected to the light emitting circuit 6, and which of these output terminals will be an input to the light emitting circuit 6 will be described later. The monitoring output unit 9a of the monitoring circuit 9 is selected.

The switches 1 to 4 are assigned corresponding to four items of reclining, forward / backward movement, vertical movement, and front vertical of the seat for controlling the seat. One switch is assigned to each control item, for example, the item of forward and backward movement is assigned to the switch 2, and further forward movement (hereinafter, referred to as
"SLD (+)" moves backward to the contact 2a (hereinafter,
"SLD (-)") is assigned to the contact 2b.
When controlling SLD (+), the contact 2c connected to the ground is connected to the contact 2a, and when controlling SLD (-), the contact 2c is connected to the contact 2b. In addition,
When neither SLD (+) nor SLD (-) is controlled, the contact 2c is not connected to any contact.

Similarly, a reclining seat is assigned to the switch 1, a vertical movement is assigned to the switch 3, and a front vertical is assigned to the switch 4. And
The contact 1a of the switch 1 is the control input terminal P5 of the transmitting means 5.
a, the contact 1b of the switch 1 is connected to the control input terminal P5b,
Hereinafter, similarly, the contacts 2a and 2b of the switch 2 to the contacts 4a and 4b of the switch 4 are control input terminals P5c and P, respectively.
5d to P5g and P5h are connected.

FIG. 2 shows an example of the frame signal 11 formed by the transmitting means 5. The frame signal 11 shown in FIG. 2A has a header section 12 indicating the beginning thereof, a control data section 13 having a control signal as a time series signal, and an error detecting section 14.
And an idle unit 15 indicating the end of the frame. FIG. 2B is an enlarged view of the data section 13 on the time axis. In the data section 13, switch 1
The control data of the control items assigned to 4 are arranged in time series. The first and second data of the data unit 13 are two controls of reclining assigned to the switch 1 (reclining front-rear direction, hereinafter, "RCL").
(+) ”And“ RCL (−) ”, and the third and fourth data are the SLD (+) SLD assigned to the switch 2.
The (-), fifth, and sixth data are two controls for the vertical movement assigned to the switch 3 (vertical direction, hereinafter, referred to as "LF
T (+) "and" LFT (-) ", and the seventh and eighth data are two controls of the front vertical assigned to the switch 4 (up and down direction of the front vertical, hereinafter,
“FRV (+)” and “FRV (−)”).

As described above, the control signal of the control item assigned to each control data of the data portion 13 of the frame signal 11 is transmitted from the data transmitting portion 10 to the data receiving portion 20. The frame signal 11 is transmitted at a data transmission rate of 1 kbps, for example. On the other hand, the monitoring circuit 9 monitors the operation of the transmitting means 5. Whether the transmitting means 5 is in the normal operation state is monitored by the monitoring pulse output from the monitoring pulse output terminal P5m. If the transmitting means 5 falls into an abnormal operation, the monitor pulse is output as the monitor pulse output terminal P5.
No output from m.

When the monitoring circuit 9 detects the monitoring pulse output to the monitoring pulse output terminal P5m (transmitting means 5
Is normal operation), the monitoring output unit 9a of the monitoring circuit 9 outputs a low level signal to the pulse generation circuit 8 described later to stop the pulse generation of the pulse generation circuit 8 and the pulse output terminal of the pulse generation circuit 8. 8c is set to high impedance (the output impedance of the pulse output terminal 8c is controlled to be high impedance).

When the monitoring pulse is not output (the transmitting means 5 malfunctions), the monitoring output unit 9a outputs a high level signal to the pulse generating circuit 8 to stop the pulse generation of the pulse generating circuit 8 and to generate the pulse. The high impedance state of the output terminal 8c is released. Thus, the monitoring output unit 9a
Selects and transmits a pulse signal instead of the frame signal 11 (transmission signal selection means).

When the transmitting means 5 malfunctions, the frame signal output terminal P5s of the transmitting means 5 becomes a high impedance (the output impedance of the output terminal P5s is a high impedance), and the pulse generating circuit 8 makes a pulse signal. Is ready to be output. Here, as a specific control signal, SLD (+) SLD (-) controlled by the switch 2 is used.
The contact 2a of the switch 2 is connected to the control input terminal P5c of the transmitting means 5 and also to the first input terminal 8a of the pulse generating circuit 8, and the contact 2b of the switch 2 is connected to the transmitting means 5. The control input terminal P5d is connected to the second input terminal 8b of the pulse generating circuit 8 as well.

Therefore, in the state where the transmitting means 5 falls into an abnormal operation and the pulse generating circuit 8 can transmit the pulse signal, the contact 2a of the switch 2 is operated in the pulse generating circuit 8 as shown in FIG. Then the specific control signal SLD
A pulse signal having a first frequency corresponding to (+) is generated (FIG. 3A), and when the contact 2b of the switch 2 is operated, a pulse signal having a second frequency corresponding to the specific control signal SLD (-) is generated. A signal is generated (FIG. 3 (b)). Pulse generation circuit 8
The pulse signal output from the pulse output terminal 8c is input to the light emitting circuit 6.

That is, when the contact 2a of the switch 2 is operated even when the transmitting means 5 has malfunctioned, the pulse generating circuit 8 causes the pulse signal of the first (specific) frequency shown in FIG. 3 (a). Is generated (for example, 100 Hz), and the contact 2b of the switch 2 is operated, the pulse generation circuit 8 operates as shown in FIG.
A pulse signal of the second (specific) frequency shown in (b) is generated (for example, 50 Hz).

The pulse signal thus generated is output from the pulse output terminal 8c of the pulse generating circuit 8, is input to the light emitting circuit 6 for causing the light emitting diode 7 to emit light, and is transmitted from the light emitting diode 7 as an optical signal. Therefore, the control signals of SLD (+) and SLD (-) are transmitted as pulse signals of a specific frequency from the data transmission unit 10 even if the transmission unit 5 has an abnormal operation.

The frequency of the pulse signal corresponding to the specific control signal generated by the pulse generating circuit 8 (described above) and the frequency corresponding to the data transmission rate of 1 kbp of the frame signal 11 are different from each other so that they can be distinguished from each other. Is set to. Now, in the data receiving section 20 shown in FIG. 1, the photodiode 21 receives (receives) the optical signal transmitted from the data transmitting section 10. The photodiode 21 outputs the received optical signal as an electric signal to the light receiving amplifier 22, and the light receiving amplifier 22 amplifies this electric signal and inputs it to the receiving means 23 mainly composed of the CPU, and at the same time, the pulse signal identifying circuit 24. Also enter.

When the data transmitter 10 is transmitting the frame signal 11 by the transmitter 5, the receiver 23
Extracts a control signal from the data portion 13 of the frame signal 11 according to a predetermined program. Here, the control signals input to the control input terminals P5a to P5h of the transmitting means 5 are the control output terminals P23a to P23h of the receiving means 23.
Are output respectively.

The output circuits of the control output terminals P23a to P23h are formed of open drain circuits, and when the receiving means 23 does not receive the frame signal 11 transmitted from the data transmitting section 10 for a predetermined period, the receiving means 23 outputs. The control output terminals P23a to P23h are open outputs. On the other hand, when the pulse signal is received instead of the frame signal 11, the pulse signal identification circuit 24 identifies the frequency of the pulse signal. When the pulse signal of the first frequency is input to the pulse signal identification circuit 24, the identification circuit output terminal 2 formed by the open-drain circuit
4a becomes low level, and when the pulse signal of the first frequency is not input, the identification circuit output terminal 24a becomes an open output. The same applies to the relationship between the pulse signal of the second frequency and the identification circuit output terminal 24b. Here, the identification circuit output terminal 24a is the control signal output terminal P23c of the receiving means 23.
And the identification circuit output terminal 24b is connected to the receiving means 23.
Connected to the control signal output terminal P23d of each of them to form a wired OR circuit.

Therefore, the pulse signal of the first frequency identified by the pulse signal identification circuit 24 causes the identification circuit output terminal 24a to go to the low level, and the SLD (+) control signal is output from the data receiving section 20. Become. Similarly, the SLD (-) control signal is output from the data receiving unit 20 by the pulse signal of the second frequency that the pulse signal identification circuit 24 identifies.

FIG. 4 is a timing chart showing how control signals are transmitted when the transmitting means 5 is operating normally and when it is in an abnormal operation. FIG. 4A shows the control of the SLD (+) by the contact 2a of the switch 2, and FIG.
Indicates control of SLD (-) by the contact 2b of the switch 2. In addition, in both cases, the control is turned on and the control is turned off.
Indicate.

When SLD (+) is turned on at time t1,
The frame signal 11 formed by the transmission means 5 (see FIG.
(C)) is transmitted from the data transmission unit 10. In FIG. 4, the SLD (+) is turned on until time t2, and the frame signal 11 is transmitted three times from time t1 to t2. After time t2, the SLD (+) is turned off, so that the frame signal 11 is not transmitted. From time t3 to time t4, SLD (-) is turned on and the frame signal 11
Sent by.

FIG. 4D shows the monitor pulse output from the monitor pulse output terminal P5m of the transmitting means 5. The transmitting means 5 operates normally from the time t1 to t5, but becomes abnormal in operation from the time t5 to t6, and the monitoring pulse is not output after the time t6. Therefore, the monitoring output unit 9a of the monitoring circuit 9 is the same as that shown in FIG.
As shown in (e), after time t6, a high level signal is output. When the SLD (+) is turned on at time t7, the data transmission unit 10 transmits the pulse signal (FIG. 4 (f)) generated by the pulse generation circuit 8 instead of the frame signal 11 formed by the transmission means 5. . This pulse signal corresponds to SLD (+) which is one specific control signal, and is the pulse signal of FIG. 3A.

At time t8, when SLD (+) is turned off and SLD (-) is turned on at the same time, the pulse signal transmitted by the data transmission section 10 corresponds to SLD (-) which is another specific control signal. The pulse signal shown in FIG. 3B is obtained. When SLD (-) is turned off at time t9, the data transmission unit 10 stops transmitting the pulse signal. Thus, even if the transmitting means 5 of the data transmitting section 10 falls into an abnormal operation, the SLD (+) control signal and the SLD (-) control signal which are specific control signals are data transmitting section 10 as pulse signals of a specific frequency. Is transmitted to the data receiving unit 20 and backed up.

Here, the pulse generation circuit 8 can be simply configured as an oscillation circuit and a counter whose output is counted down by inputting the input terminals 8a and 8b. It is extremely simple, and since the pulse signal identification circuit 24 also identifies the frequency of the pulse signal, it is much simpler than the CPU. Therefore, the backup of the transmission of the control signal is realized easily and at low cost.

Although the specific control signal has been described as a part of the control signals of the plurality of control signals transmitted by the data transmission unit, it corresponds to all of the plurality of control signals transmitted by the pulse generation circuit of the data transmission unit. If the pulse signal identification circuit of the data receiving section identifies the pulse signals of the respective specific frequencies, all of the control signals transmitted by the data communication device will cause an abnormal operation of the transmission means. Needless to say, it will be backed up against.

Further, the present invention is not limited to the optical communication transmission line, but can be applied to the wireless communication transmission line and the wired communication transmission line, and is not limited to the above embodiment. Furthermore, the present invention is applied to a data communication device that controls various electronic devices / electrical devices without departing from the spirit of the present invention, and is not limited to a data communication device that controls electrical components of an automobile.

[0032]

As described above, according to the data communication apparatus of the present invention, even if the operation of the transmitting means mainly composed of the CPU is abnormal, the control signal can be transmitted at a low cost by the extremely simple backup means. There is an effect that a data communication device capable of backing up transmission can be realized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a main part of a data communication device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a frame signal transmitted from the data transmission unit of FIG.

3 is a diagram showing a pulse signal transmitted from the data transmission unit of FIG. 1 in place of a frame signal.

FIG. 4 is a timing diagram showing a frame signal transmitted by the transmitting unit during normal operation and a pulse signal transmitted by the transmitting unit during abnormal operation in the data communication apparatus of FIG.

[Explanation of symbols]

5 Transmission means 8 pulse generation circuit 9 Monitoring circuit 9a Monitoring output section 10 Data transmitter 11 frame signal 12 Header 13 Data section 20 Data receiver 23 Receiving means 24 pulse signal identification circuit

Continued front page    (72) Inventor Shigeki Itabashi             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. (72) Inventor Osamu Ogura             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. F term (reference) 5K029 AA18 CC05 DD02 GG03 HH21                       JJ01 KK01 KK11 KK31                 5K035 AA07 CC07 CC10 FF03 FF04                       LL03 LL14

Claims (2)

[Claims] 1. A data communication device comprising: a data transmission section for transmitting a plurality of input control signals; and a data reception section for extracting the plurality of control signals from a signal transmitted by the data transmission section, The data transmission section transmits a frame signal having a header section and a data section corresponding to the plurality of control signals, a monitoring circuit for detecting an operation abnormality of the transmission section, and the input control signal is specified. Control signal of
A pulse generation circuit that generates a pulse signal of a specific frequency corresponding to the specific control signal, and when the monitoring circuit detects an operation abnormality of the transmission unit, instead of the frame signal transmitted by the transmission unit,
A transmission signal selecting unit that transmits a pulse signal generated by the pulse generating circuit; the data receiving unit is a receiving unit that extracts a control signal from a data unit of a received frame signal; and the transmission signal selecting unit is a frame. A pulse signal identifying circuit for identifying a pulse signal of a specific frequency generated by the pulse generating circuit, which is transmitted instead of the signal, and outputting a specific control signal corresponding to the pulse signal of the specific frequency. Data communication device. 2. The pulse generating circuit generates pulse signals having different frequencies corresponding to a plurality of specific control signals, and the pulse signal identifying circuit identifies pulse signals having the different frequencies. The data communication device according to claim 1.