JP2720513B2 - Communication method and communication system device used for the communication method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a communication method used in a home automation system for controlling a control device having a home electric appliance as a terminal through a common communication path, and communication thereof. The present invention relates to a communication system used in the method.

(Prior Art) With the development of electronic devices, so-called network control in which a plurality of terminal devices and a plurality of operation devices are connected and controlled via communication circuits to control a plurality of devices in an integrated manner. Methods have come to be used.

As described above, a communication method using a communication device including a plurality of communication devices, as represented by JISC-6325, is a communication method.
A method of transmitting a select signal for selecting a receiving station and a signal for controlling the transmitting station from one transmitting station to one or more receiving stations, and as disclosed in Japanese Patent Application No. 62-334213 previously filed by the present applicant,
There is a method in which a plurality of communication devices connected to one communication path simultaneously transmit and receive communication data including communication contents to and from a communication destination by one synchronization signal.

By the way, such communication signals between a plurality of communication devices cause data errors due to external noise and synchronization delays inside the communication devices. If the errors cannot be determined, malfunctions and runaway of the terminal device may occur, resulting in large errors. It will be an accident.

Therefore, in a method represented by JISC-6325, a redundant part is provided in control data so that data becomes odd or even, and it is confirmed that the data is odd or even in the receiving station. If an error is detected by using a method such as parity check, and if an error occurs, the receiving station must discard the data in which the error has occurred, send an error signal to the transmitting station, and request that the data be sent again. Has been done.

In addition, a plurality of communication devices connected to one communication path
In the method of transmitting and receiving simultaneously using two synchronization signals, since a plurality of communication devices simultaneously transmit and receive between two synchronization signals, when one communication device cannot be synchronized, the fact that the synchronization cannot be performed is transmitted to another communication device. Since there is no means for transmitting, there has been a problem of causing a malfunction, and as shown in Japanese Patent Application No. 63-235197 previously filed, the present applicant indicates the end of synchronization in addition to communication data between synchronization signals. A method has been developed in which a frame end signal is provided so that even if one communication device loses synchronization, another communication device can detect the synchronization loss.

(Problems to be Solved by the Invention) In a method represented by the conventional JISC-6325, when an error occurs, an error detection signal is sent from the receiving side to the transmitting side, and the transmitting side responds accordingly. The data must be sent again, and no other communication takes place during the transmission and reception of the error signal. Therefore, this is an effective means for high-speed communication processing of large volumes of data. However, in applications where small volumes of data and responsiveness are required, such as home automation, the required responsiveness can be obtained. There is a problem that the waiting time increases.

Further, as shown in FIG. 4 (a), a plurality of communication devices 20 connected to one communication path 4 are used.
0 is one synchronization signal 301 of the signal format shown in FIG.
In the method of transmitting and receiving at the same time, when the frame end signal 331 cannot be synchronized with the communication data 302, it can be determined that an error has occurred in the communication and each communication device can perform error processing. Communication data 302
If the synchronization between the synchronization signal 301 and the synchronization signal 301 is shifted, the communication data 302 transmitted to the communication path 4 cannot be received, and even if both the synchronization signal 301 and the frame end signal 331 are synchronized, Data 302 and synchronization signal 301 or communication data 30
If the synchronization between the frame 2 and the frame end signal 331 is out of synchronization, it cannot be detected that an error has occurred, and data may interfere on the communication path 4 and cause a malfunction or a runaway. there were.

The present invention provides a secure communication method that is excellent in error detection and a communication system device used in the communication method.

(Means for Solving the Problems) According to a communication method of the present invention, a plurality of communication devices connected by one communication path simultaneously transmit and receive by one synchronization signal 301 and communication data 302 to be transmitted and received can be distinguished from each other. And a communication flag 312 indicating the presence or absence of a communication failure in each communication device.If there is no error when receiving data transmitted by the own communication device, the communication flag 312 A flag is set, a flag is not set at a corresponding portion if an error occurs, and communication data is discarded when a communication error occurs in one or more communication devices.

In this communication method, as shown in FIG. 1 (a), a signal format in which a synchronization signal 301, a data section 311 of all communication apparatuses, and a flag section 312 of all communication apparatuses are arranged in this order can be used. As shown in FIG. 1B, a signal format in which one or more signals each including a data unit 311 of one communication device and a flag unit 312 of the communication device are arranged after the synchronization signal 301 may be used. . As shown in FIG. 1 (c), such a signal format enables precise control and data collection of terminal equipment connected to the communication device by using extended signals in the data section and / or the flag section. And is preferred. Further, as shown in FIG. 1D, a signal format having an end signal 303 indicating the end of the signal after the communication data 302 can be used.

In such a communication method, in order to improve the reliability of data, as shown in FIG. 1 (e), there is provided a data section 311 in which a synchronization signal 304 encoded separately from the synchronization signal 301 is arranged at the head. However, instead of setting the flag not to be set when there is an error in the transmission and reception of the communication data 302, the flag unit 3
There is a way to not flag 12
In addition to not setting a flag when there is an error in transmission / reception of 302, a method of not setting a flag in the flag unit 312 also when an error occurs in transmission / reception of the encoded synchronization signal 304 may be adopted. Also, as shown in FIG. 1 (f), after the synchronization signal 301, one or more signals in which an encoded synchronization signal 304 and communication data 302 are arranged as a set are arranged.
As shown in FIG. 9G, a signal format in which a synchronization signal 301, an encoded synchronization signal 304, and one or more sets of communication data 302 are arranged can be used. When such a signal format is used, the end signal 303 can be combined after the communication data 302 as shown in FIG. These combinations can be selected depending on the responsiveness required of the controlled object, the number of controlled objects and the required signal reliability. It is possible to design so that it can be selected, and it is suitable for high-mix low-volume production.

In addition, as a method of processing data when an error occurs, a method of discarding only data related to a communication device having a communication failure among the communication data 302, and no matter which communication device has an error, A method of discarding all received data in the cycle that occurred and retransmitting the transmitted data, a method of resetting all communication devices when errors continuously occur, or storing communication data 302 when no error occurs When an error occurs, the method using the stored data can be appropriately selected and used.

The communication system device used in the communication method of the present invention,
Synchronization signal discriminating means 14 for discriminating communication data 302 from synchronization signal 301; transmitting means 12 for transmitting communication data 302 to communication path 4; and receiving means 13 for receiving communication data 302 transmitted to communication path 4; A transmission data storage means 21 for temporarily storing the data part 311 of the transmission data, and a reception data storage means 23 for temporarily storing the data part 311 of the reception data.
Communication flag generating means 22 for generating and storing a communication flag when there is no error in its own communication, flag section storing means 24 for temporarily storing flag section 312 of the received data, and inputting data to the terminal device. Terminal device input / output means 26 for output
And a logical operation means 120, the logical operation means 120 receiving the synchronization signal 301 and the data part 311 stored in the transmission data storage means 21 and the flag part 312 stored in the communication flag generation means 22 for the first time. Means for transmitting to the transmitting means 12 for transmitting to the communication path 4 and communication data 30 transmitted to the receiving means 13
Means for storing the data part 311 in the received data storage means 23 and storing the flag part 312 in the flag part storage means 24; means for determining the presence or absence of an error; and storing the received data by determining whether or not the error exists. A means for determining to discard the data portion in the means 23; a means for determining retransmission of data in the transmission data storage means 21 by determining whether there is an error; and a terminal device input / output means 26. The communication device 20 shown in FIG.
As shown in FIG. 2 (d), a plurality of 0a and the synchronization signal generating means 11 are connected by a communication path 4.

Such a communication system device includes one communication device 200b shown in FIG. 2 (b) provided with a synchronization signal generating means 11 in the communication device 200a, a plurality of the communication devices 200a, and FIG. 2), it is also possible to configure by connecting with a communication path 4, and as shown in FIG.
A plurality of communication devices 200c (shown in FIG. 2 (c)) having switching means 15 for determining whether or not to transmit the synchronization signal 301 to the communication path 4 are connected in the communication path 200b. Instead of the communication device 200a, the synchronization signal 301
Is not transmitted to the communication path 4 and the communication device 20 is selected.
Instead of 0b, transmission of the synchronization signal 301 to the communication path 4 by the switching means 15 can be selected and configured.

In such a device, the communication data 302 and the synchronization signal 3
Various types of comparators can be used as the synchronization signal discriminating means 14 for discriminating between the communication signal 302 and the communication data 302. A voltage comparator is used when the synchronization signal 301 has a different voltage from the communication data 302. Are different, phase comparators can be used. Transmission means 12 for transmitting the communication data 302 to the communication path 4 and reception means 13 for receiving the communication data 302 transmitted to the communication path 4
Is selected according to the signal format of the communication data 302.In the case of transmission by radio waves, known frequency modulation, phase modulation, or amplitude modulation and these demodulation means can be used.In the case of transmission by optical fiber or electric wire, normal transmission is used. Any circuit used for information communication can be used.

Transmission data storage means 21 for temporarily storing transmission data
Receiving data storage means 23 for temporarily storing received data
The communication flag generating means 22 for setting up and storing a flag when there is no error in its own communication can use various registers and semiconductors for memories.

The transmitting means 1 for transmitting the data portion 311 stored in the transmission data storing means 21 and the communication flag 312 stored in the communication flag generating means 22 to the communication path 4 only after receiving the synchronization signal 301.
Means for transmitting to the communication means 302, the data part 311 of the communication data 302 transmitted to the reception means 13 is stored in the reception data storage means 23, and the communication flag 312 is stored in the communication flag storage means 24. Means for making a decision, means for making a decision to discard the data in the received data storage means 23 by judging the presence or absence of the error, and resending the data in the transmission data storage means 21 by judging the presence or absence of the error. Although it is possible to use a circuit fixed in advance using a logic element as the logical operation means 120 including the means for making the determination and the means for transmitting data to and from the terminal device input / output means 26, It is preferable to use a microcomputer in view of the economics of changing the data format according to the type and number of terminal devices to be controlled and mounting the same communication device in common with various devices. .

The transmitting means 1 for transmitting the data portion 311 stored in the transmission data storing means 21 and the communication flag 312 stored in the communication flag generating means 22 to the communication path 4 only after receiving the synchronization signal 301.
The means for transmitting the data signal and the flag signal in a predetermined order may be used as a means for transmitting the data signal and the flag signal over time.
It is also possible to use a method of performing conversion by a serial conversion circuit, or a program for outputting data and flags in the memory to the transmitting means 12 in order from the upper digit.

As means for storing the data part 311 in the received data storage means 23 and storing the communication flag 312 in the communication flag storage means 24 of the communication data 302 transmitted to the receiving means 13, the reverse operation may be performed. It is possible to use a serial-parallel conversion circuit or a program for storing signals from the receiving means 13 in order from the upper digit of a specific memory.

The means for determining the presence or absence of an error may be obtained by performing an exclusive OR operation on a location related to the data itself in the transmission data storage unit 21 and a location related to the data itself in the reception data storage unit 23. It can also be realized by a program. As a result, if there is no error, the communication flag generation means 2 is flagged, and if there is an error, the communication flag generation means 22 is not flagged. As means for determining whether to discard the data in the received data storage means 23 by determining whether or not there is an error, the communication flag generation means 22
No matter which of the communication flags 312 transmitted from the transmission means 12 is missing, the reception data storage means 23 may be cleared, and can be realized by a logic circuit or a program. As means for determining whether to retransmit the data in the transmission data storage means 21 by determining the presence or absence of an error, the transmission data storage means 21 has the following Without data,
The data in the transmission data storage means 21 is sent again. In this case, the means 31 for storing the communication data 302 when there is no communication error is provided separately from the transmission data storage means 21, and when an error occurs, the communication data before the error occurs is held. , Always transmit data storage means 21
Is cleared after each communication, and only when an error occurs, the data is transmitted from the storage means 31 to the transmission data storage means 21.
Is preferable because the operation can be continued.

In addition to the fact that the data in the reception data storage means 23 is discarded by the data of the communication flag 312 and the data in the transmission data storage means 21 is retransmitted, an error has occurred in the data of the flag part continuously for a certain cycle or more. Means 401 for detecting the number of errors by a counter circuit or a program as a means 401 for detecting the error, if a reset circuit for resetting the communication device in conjunction with the detection means 401 or switching means such as a software reset by a program is used. This is preferable because malfunction or runaway due to failure of the device itself or destruction of other programs can be prevented.

Furthermore, it comprises means 28 for storing a pre-encoded synchronization signal 304, wherein the encoded synchronization signal
Comparing 304 with the storage means 28, when the encoded synchronization signal 304 in the received data is different from the storage means 28, as means for not setting a flag in the flag unit 312,
If the code is registered in a certain memory, the exclusive OR is taken with the synchronization signal 304, and the above-mentioned communication flag storage means 24 is set up when the codes coincide with each other, even if the number of communication data 302 becomes large, It is preferable that the synchronization is not lost and the data reliability is high. At this time, the exclusive OR of the location relating to the self of the data in the transmission data storage means 21 and the location relating to the self of the data in the reception data storage means 23, and the flag and logic of the encoded synchronization signal 304 If there is no error in both the communication data 302 and the encoded synchronization signal 304, the communication flag generation means 22 is flagged.If there is an error, the communication flag generation means 22 is not flagged and the processing is performed. For example, it is preferable because the reliability of data can be increased.

In the communication system of the present invention, it is preferable that the level of the synchronization signal 301 be higher than the level of the communication data 302 because a relatively simple circuit such as a voltage comparator can be used for the synchronization signal discriminating means 14. At this time, if the DC power obtained by rectifying the synchronization signal 301 is used as a power supply, the power supply can be centralized in one of the devices in the communication system, thereby saving installation space and electronic components in other devices. It is preferable.

(Operation) The operation of the present invention is shown in FIG. 2 (e) by using two or more communication devices 200a shown in FIG. 2 (a) and one communication device 200b shown in FIG. 2 (b). FIG. 2 (g) shows the program in the logical operation means 120 as the communication system device which made the connection.
The data at the main points are represented by 2
The value data will be described with reference to FIG.

When data is input from the terminal device to the terminal device input / output means 29, the data is stored in the transmission data storage means 21 by the program, and data indicating the communication destination of the self and the communication content are determined from a predetermined synchronization signal 301. When the time for transmission has arrived, a signal whose data becomes 1 at the location of bN is transmitted to the communication path 4 via the transmission means 12. At the same time, the same data is stored in the reception data storage means 23 via the reception means 13, and the data in the transmission data storage means 21 and the data in the reception data storage means 23 are compared by the program. At this time, if the two data match, no error occurs as indicated by the solid line, and if necessary, the data is transferred to the terminal device via the terminal device input / output means 29. On the other hand, if the two data do not match, an error occurs, as indicated by the broken line, is stored in the communication flag storage means 22 and transmitted, and each communication device detects the occurrence of the error and The data in the storage means 23 is reset.

Therefore, if there is an error in the transmitted data,
You can always discard the data in which the error occurred.

Embodiment 1 As an embodiment of the present invention, a communication device is provided in each of a water heater control device and two remote controllers, and the communication device of the hot water control device has a circuit configuration shown in FIG. 3 (a). The communication device of the remote controller has the circuit configuration shown in FIG. 3 (b).
As shown in FIG. 3 (a), the HD146805U / V (Hitachi, Ltd., trade name) which is a one-chip microprocessor 40 having a built-in M and having a RAM as a work area is used. Transistor that outputs a synchronization signal
TR1 and TR2 were provided, but not the actuator.

The synchronization signal was obtained by using a software clock obtained by dividing the synchronization signal used for the microcomputer circuit by a program, connecting the output port Po0 to the base terminal of the transistor TR2, and turning on and off a 12V power supply.

As means for temporarily storing the transmission data and the reception signal, a work area RAM in the microprocessor 40 is used.
Was used. As a means for monitoring an error in its own communication, a program for comparing received own communication data with data stored in transmission data storage means was used. As means for transmitting the transmission data and the error signal to the communication path for the first time after receiving the synchronization signal, a program for outputting the flag signal of the data in the memory to the output terminal Po1 in the microprocessor in order from the upper digit was used. . As a means for receiving the communication data transmitted to the communication channel, a program was used which uses the input terminal Pi0 in the microprocessor and stores the signal in a work area RAM in the microprocessor. Since the synchronization signal used a different voltage from the data, the voltage comparator COMP1 was used to discriminate between the communication data and the synchronization signal. When a flag signal is detected, the program temporarily stores communication data in another part of the memory until the next processing is performed. As the input / output means 29 for connecting the communication device and the terminal device, an input terminal Pi2 for interface and an output terminal Po2 provided in the microprocessor were used. The logical operation means 120 for determining whether to discard the received data based on the data in the flag section does not accumulate the received data and stores the communication data in the accumulating means unless at least one flag is set in the flag signal. The program uses the previous data. At this time, no matter which communication device generates an error, all the received data in the cycle in which the error occurred is discarded, and the transmitted data is retained.

Using the communication device having such a configuration, the program of the flowchart shown in FIG. 3C was written in the ROM in the microprocessor.

The program will be described. When the input port Pi2 signal of the microprocessor MCPU1 shown in FIG. 3A is input, the signal is temporarily stored in a work area in the MCPU1, and then a synchronization signal is output from the output port Po0. After being sent,
The stored data is sent from Po1. The transmission signal is discriminated from the synchronization signal by its own comparator COMP1, stored as a reception signal in a working register in the processor via the input terminal Pi0, and compared with the data of the memory storing the input signal. In the own signal portion, when they match, 1 is output as the data of the communication flag portion, and when they do not match, 0 is output. Next, the communication flag unit is received, and if all the communication flag units are 1, the own data is output from the output port Po2. If any of the communication flag sections is 0, the data in the communication data storage means held is output without outputting the own data.

This program, as shown in FIG.
The same can be applied to the communication device for the remote controller in FIG.

That is, the microprocessor MCPU2 shown in FIG.
Signal is input to the input terminal Pi2 of
When the sync signal discriminated from the data by the comparator COMP2 is input to the interrupt processing terminal INT and stored in the work area in the CPU2, the stored data is stored in Po1.
Sent from The transmission signal is discriminated from the synchronization signal by its own comparator COMP3, stored as a reception signal in a working register in the processor, and compared with the data of the memory storing the input signal. In the own signal portion, when they match, 1 is output as the data of the communication flag portion, and when they do not match, 0 is output. Next, all communication flag units are received, and if all communication flag units are 1,
Outputs its own data from output port Po2. If any one of the communication flag sections is 0, the self-data is not output, and the held data in the communication data storage means is output.

FIG. 3E shows the data format at this time.
That is, following the synchronization signal 301, the switch data 101 of the remote controller 1, the switch data 102 of the remote controller 2, the output display data 103 of the remote controller 1, the output display data 104 of the remote controller 2, the communication flag unit 105 of the hot water supply controller main body, and the remote controller 1
Communication flag unit 106 and remote control 2 communication flag unit 107
The order is as follows. The interval between the synchronization signals was 15 ms.

Embodiment 2 The format shown in FIG. 1 (e) is adopted for the communication signal, and the code of 01011010 is determined in advance as an encoded synchronization signal.
This encoded data is called before the transmission data when comparing the communication data, and the received synchronization data is temporarily stored in the memory together with the encoded synchronization signal and the subsequent communication data. The data was compared with the coded synchronization signal, and the procedure was the same as that of the first embodiment, except that a program was used if a match was found, and a flag was not set if there was an error.

Example 3 An area for counting the number of errors is secured in the RAM, the number of all flags is negated, and the number in the area of the count is compared with the number 12 preset in the ROM for each communication cycle. If they match, the output to TR2 for controlling the output of the power synchronization signal shown in FIG. 3A is not performed for more than 2 seconds, thereby rectifying the synchronization signal and using it as a power source of another microcomputer. Was reset, and at the same time, the MCPU 1 was reset by software.

In such a communication device, if a large noise signal is intentionally applied to the communication path, the control or output display does not change at all while the signal is added, and the remote controller or hot water supply is intentionally applied. The same was true even if one of the communication terminals of the control device was removed.

(Effects of the Invention) As described above, a simple and highly reliable communication method and communication device can be provided by the present invention.

[Brief description of the drawings]

1 (a) is a waveform diagram showing a signal format of one embodiment of the present invention, FIGS. 1 (b) to 1 (h) are waveform diagrams showing a signal format of another embodiment of the present invention, and FIG. (A) is a block diagram of an apparatus used in one embodiment of the present invention, FIGS. 2 (b) and (c) are block diagrams of an apparatus used in another embodiment of the present invention, and FIG. FIGS. 2 (e) and 2 (f) are schematic diagrams showing the outline of an apparatus according to one embodiment of the present invention, and FIGS. 2 (g) and 2 (g) are schematic diagrams showing the outline of an apparatus according to another embodiment of the present invention. FIG. 2 (h) is a flowchart for explaining the operation of the embodiment, FIG. 2 (h) is a waveform diagram showing a transition of data in the apparatus for explaining an embodiment of the present invention, and FIGS. 3 (a) and 3 (b). FIG. 3 is a circuit diagram showing a communication device used in one embodiment of the present invention; FIGS. 3C and 3D are flowcharts showing programs used in one embodiment of the present invention; 3 (e) is a signal waveform diagram for explaining a data format of one embodiment of the present invention, FIG. 4 (a) is a schematic diagram showing an outline of a device showing a conventional example, and FIG. FIG. 9 is a waveform diagram showing a signal format of a conventional example. Description of reference numerals 4 ... communication path, 11 ... synchronous signal generation circuit 12 ... transmitting means, 13 ... receiving means 14 ... synchronous signal discriminating means 15 ... switching means 21 ... transmitted data storage means 22 ... error Unit storage means 23 Received data storage means 24 Communication flag storage means 28 Coded synchronization signal storage means 29 Terminal input / output means 51 Terminal equipment 100 Communication path terminal 101 ... Switch data of remote controller 1 102 Switch data of remote controller 2 103 ... Output display data of remote controller 1 104 ... Output display data of remote controller 2 105 Communication flag of water heater main body 106 Communication flag of remote controller 1 107 Communication flag of remote controller 2 120 Logical operation means 200a.200b.200c Communication device 301 Synchronization signal 302 Communication data 303 End signal 304 Encoded synchronization signal 311 Data part 312 …… Flag part 321 …… Extended Data section 322 Extension flag section AVR Constant voltage IC BUF1 Buffer amplifier 1 BUF2 Buffer amplifier 2 COMP1 Comparator 1 COMP2 Comparator 2 COMP3 Comparator 3 C1 Smoothing capacitor 1 C2 Smoothing capacitor 2 D1 Rectifier diode LED Lamp MCPU1 One-chip microcomputer 1 Vcc: Power supply terminal Po0: Output terminal 0 Po1: Output terminal 1 Po2: Output terminal 2 Pi0: Input terminal 0 Pi1 : Input terminal 1 Pi2: Input terminal 2 MCPU2 ... One-chip microcomputer 2 INT ... Interrupt processing terminals R1 to R8 ... Resistor SW1 ... Switches Tr1 to Tr5 ... Transistors

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-212145 (JP, A) JP-A-60-16743 (JP, A) JP-A-58-120341 (JP, A) JP-A-1- 91551 (JP, A)

Claims (19)

(57) [Claims] 1. A plurality of communication devices connected by one communication path transmit and receive simultaneously by one synchronization signal (301), and communication data (302) to be transmitted and received comprises a communication destination and communication contents that can be distinguished from each other. A communication flag (31) indicating whether or not there is a communication failure between the data section (311) and each communication device.
2), if there is no error in the data transmitted by the own communication device, a flag is set at a corresponding portion of the communication flag (312), if there is an error, no flag is set at the corresponding portion, and one or more A communication method for discarding communication data when a communication error occurs in a communication device. 2. The communication method according to claim 1, wherein the communication format has a signal format in which a synchronization signal (301), a data section (311) of all communication apparatuses, and a communication flag section (312) of all communication apparatuses are arranged in this order. 3. A data section (311) of one communication apparatus and a communication flag section (31) of the communication apparatus after the synchronization signal (301).
2. The communication method according to claim 1, wherein the communication method has a signal format in which one or more signals forming the group 2) are arranged. 4. A synchronization signal (301) and a set of communication data (30)
2. The communication method according to claim 1, wherein the communication method has a signal format in which 2) or more are arranged. 5. The communication method according to claim 1, further comprising an end signal (303) indicating the end of the signal after the communication data (302). 6. A data section (311) having a synchronization signal (304) encoded separately from a synchronization signal (301) arranged at the head thereof.
Instead of setting a flag when an error occurs in the transmission / reception of the communication data (302), a flag unit (31) is provided when an error occurs in the transmission / reception of the encoded synchronization signal (304).
The communication method according to claim 1, wherein no flag is set in (2). 7. In addition to not setting a flag when there is an error in the transmission and reception of the communication data (302), a flag unit (312) is also provided when there is an error in the transmission and reception of the encoded synchronization signal (304). 8. The communication method according to claim 7, wherein no flag is set. 8. The communication data according to claim 1, wherein only data relating to a communication device having a communication failure among the communication data is discarded. Communication method. 9. An apparatus according to claim 1, wherein any received data in the cycle in which the error occurred is discarded, and the transmitted data is retransmitted. 9. The communication method according to any one of 8. 10. The communication method according to claim 6, wherein all the communication devices are reset when an error occurs continuously. 11. The communication data (30) when no error occurs.
12. The method according to claim 1, wherein the stored data is stored in a storage means, and when an error occurs, the stored data is used. Communication method described in any of them. 12. A synchronization signal discriminating means (14) for discriminating communication data (302) from a synchronization signal (301);
(2) transmitting means (2) to the communication path (4), receiving means (13) for receiving communication data (302) transmitted to the communication path (4), and a data part (311) of the transmission data. ), And a reception data storage means (23) for temporarily storing the data portion (311) of the reception data. A communication flag is set when there is no error in its own communication. Means for generating and storing a communication flag (22);
A flag section storing means (24) for temporarily storing a flag section (312) of the received data; a terminal device input / output means (26) for inputting / outputting data to / from the terminal apparatus;
0), and the logical operation means (120) of the synchronization signal (30)
For the first time after receiving (1), the data part (311) stored in the transmission data storage means (21) and the flag part (312) stored in the communication flag generation means (22) are transmitted to the communication path (4). Means for transmitting to the means, and the data part (311) of the communication data (302) transmitted to the receiving means (13) is stored in the received data storage means (23), and the flag part (312) is stored in the flag part storage means ( 24) means for determining whether there is an error, means for determining the presence or absence of an error, means for determining whether to discard the data portion in the received data storage means (23) based on the determination of the presence or absence of the error, and A plurality of communication devices (200a, 200b) provided with means for determining retransmission of the data in the transmission data storage means (21) and means for transmitting data to the terminal device input / output means (26). ) And the synchronization signal generating means (11) through the communication path (4). Connect the communication system equipment. 13. A synchronizing signal discriminating means (14) for discriminating communication data (302) and a synchronizing signal (301);
(2) transmitting means (2) to the communication path (4), receiving means (13) for receiving communication data (302) transmitted to the communication path (4), and a data part (311) of the transmission data. ), And a reception data storage means (23) for temporarily storing the data portion (311) of the reception data. A communication flag is set when there is no error in its own communication. Means for generating and storing a communication flag (22);
A flag section storing means (24) for temporarily storing a flag section (312) of the received data; a terminal device input / output means (26) for inputting / outputting data to / from the terminal apparatus;
0), and the logical operation means (120) of the synchronization signal (30)
For the first time after receiving (1), the data part (311) stored in the transmission data storage means (21) and the flag part (312) stored in the communication flag generation means (22) are transmitted to the communication path (4). Means for transmitting to the means, and the data part (311) of the communication data (302) transmitted to the receiving means (13) is stored in the received data storage means (23), and the flag part (312) is stored in the flag part storage means ( 24) means for determining whether there is an error, means for determining the presence or absence of an error, means for determining whether to discard the data portion in the received data storage means (23) based on the determination of the presence or absence of the error, and A plurality of communication devices (200a, 200b) provided with means for determining retransmission of the data in the transmission data storage means (21) and means for transmitting data to the terminal device input / output means (26). ) And synchronization signal generating means ( A communication system device in which one communication device (200b) having 11) is connected by a communication path (4). 14. A plurality of communication devices (200c) having switching means (15) for determining whether or not to transmit a synchronization signal (301) to a communication path (4) in said communication device (200b). The communication device (200) is connected to the communication device (200a), and the switching means (15) selects not to transmit the synchronization signal (301) to the communication device (200).
In place of b), the synchronizing signal (30
14. The transmission of (1) to the communication path (4) is selected.
A communication system according to claim 1. 15. A means (31) for storing communication data (302) in a logical operation means (120) when there is no communication error.
When an error occurs, the communication data before the error occurs is held.
15. The communication system device according to any one of 2, 13, and 14. 16. The data in the flag section (312) not only discards the data in the reception data storage section (23) and retransmits the data in the transmission data storage section (21), but also causes an error in the data in the flag section. A means (401) for detecting occurrence of continuous occurrence of a certain cycle or more;
Switching means (22) that resets the communication device in conjunction with (01)
Claim 12, 13, 14, or 1 characterized by having 1)
6. The communication system device according to any one of 5. 17. The system according to claim 12, wherein the level of the synchronization signal is higher than the level of the communication data.
17. The communication system device according to any one of 3, 14, 15, and 16. 18. The method according to claim 12, wherein DC power obtained by rectifying the synchronization signal (301) is used as a power supply.
18. The communication system device according to any one of 13, 14, 15, 16 and 17. 19. Means for accumulating a previously encoded synchronization signal (304), comparing the encoded synchronization signal (304) in received data with the accumulation means (29), When the encoded synchronization signal (304) in the received data is different from the storage means (29), the logic operation means (120) has means for not setting a flag in the flag section (312). Claims 12, 13, 14, 15, 16, 17 or
19. The communication system device according to any one of 18.