JPH0775348B2 - Communication error detection device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication error detection device for detecting a communication error between a plurality of communication terminal devices connected to a transmission communication path.

2. Description of the Related Art In recent years, for the purpose of centrally controlling a plurality of communication terminal devices and monitoring the state of each communication terminal device, each communication terminal device is connected by a transmission communication path and signals are mutually transmitted. Various control systems have been reported. These mainly adopt the CSMA / CD system as a communication system, but this system does not normally operate the entire system unless signals are normally transmitted and received between all communication terminal devices.
For example, there are three communication terminal devices, A, B, and C.
It is assumed that the signals B and B and C are normally transmitted and received, but that A and C cannot receive the signal transmitted by A, and vice versa. In this case, A and C are requested to transmit signals at the same time, and even if the information contained in the signals is necessary for B, A and C
Since collision detection (CD) is not performed in B, the signals of A and C are received in B in a mixed state, and not only the information does not reach normally, but in the worst case, incorrect information is received. Sometimes. Also, when a transmission request is generated with a slight time lag between A and C, it is not normally performed to start transmission after confirming that the transmission communication path is unused (CSMA communication method). Therefore, the signals A and C are mixed in the middle of the signal, and the same problem as described above occurs. Therefore, at the time of system construction, it is necessary to inspect whether or not transmission / reception is normally performed in all combinations of communication terminal devices, and conventionally, the work was manually performed.

However, there is a limit to the operation check by hand when the number of communication terminal devices increases, and in a system having 100 communication terminal devices, for example, in a combination of 100 C ₂ = 4,950 ways, Since it is necessary to check the operation, all the checks are impossible at present.

The present invention solves the above problems, and an object of the present invention is to provide a communication abnormality detection device that automatically detects, in all combinations of communication terminal devices, that there is a combination in which transmission / reception is not normally performed. .

Means for Solving the Problem In order to achieve the above object, the present invention provides an individual transmission requesting unit that requests individual transmission to addresses in a settable range, and an own station of an existing communication terminal device. Address storage means for temporarily storing an address; a broadcast transmission request means for requesting transmission of a broadcast notification request signal after the transmission request of the individual transmission request means is exhausted; After individually receiving the output and transmitting the signal to the communication terminal device, when the confirmation signal transmitted by the communication terminal device is received, the address storing means is instructed to store the time station address of the communication terminal device, and After receiving the output of the simultaneous broadcast transmission request means and transmitting the simultaneous broadcast notification request signal, when the notification signal from the communication terminal device is received, the communication stored in the address storage means Arithmetic control for instructing to erase the time station address of the terminal device, and setting the own station address stored in the address storage means after receiving all the annunciation signals as the own station address of the communication terminal device in communication error and outputting that value. Means and a communication abnormality address display means for displaying the communication terminal device having the communication abnormality in response to the output thereof.

Effect of the Invention According to the present invention, by the above configuration, first, the signals are sequentially transmitted individually to the communication terminal device, the own address of the communication terminal device that has returned the confirmation signal is stored, and then the simultaneous broadcast notification request signal is sent. Is sent, and as a result, it is judged that there is no communication error at the address of the communication terminal device that returned the notification signal and it is deleted from the memory, but a confirmation signal is returned for individual transmission, but the same A communication terminal device that does not return the notification signal to the notification notification request signal is a communication terminal device having a communication error.

Example An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a communication abnormality detecting device in an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a transmission communication line which is a signal transmission line, and in this embodiment, is a power line. 2,
3 and 4 are communication terminal devices that transmit a confirmation signal (ACK) when receiving a signal addressed to their own station and transmit a notification signal by CSMA / CD system communication when receiving a simultaneous broadcast notification request signal. In the system, the case where three units are connected is shown. Reference numerals 5, 6 and 7 are own station address setting switches for setting own station addresses which are the identification numbers of the communication terminal devices 2, 3 and 4, respectively. This own station address is set to a different value in each communication terminal device, and when the communication terminal device transmits a signal, the value of this own station address is included in the signal to be transmitted. It is possible to identify whether or not the signal is transmitted by. 8 is communication means for transmitting and receiving signals on the power line 1, 9 is individual transmission requesting means for requesting transmission individually to addresses within a range settable by this system, and 10 is set by this system Address storage means for temporarily storing all of its own station addresses, and 11 is for transmitting a simultaneous broadcast notification request signal for prompting simultaneous transmission of a notification signal to communication terminal devices after the transmission request of the individual transmission request means 9 is exhausted. Is a means for requesting simultaneous broadcast transmission. After receiving the output of the individual transmission requesting means 9 and transmitting individually to the communication terminal equipment by the communication means 8, when the confirmation signal (ACK) is received, the address storage means 10 stores the information of the communication terminal equipment. When an instruction to store the station address is given, the output of the broadcast transmission requesting means 11 is received, and the broadcast means request signal is transmitted by the communication means 8 and then the notification signal from the communication terminal device is received,
The address storage means 10 is instructed to erase the storage of the own station address of the communication terminal device, and after receiving all the notification signals, the own station address stored in the address storage means 10 has a communication error, for example. It is an operation control unit that outputs the value as a communication terminal device. Reference numeral 13 is a communication abnormality address display means for receiving the output of the arithmetic control means 12 and displaying the own station address of the communication terminal equipment in which the communication abnormality has occurred, and 14 is a communication abnormality detection equipment composed of the respective means 8 to 13.

The operation of the communication abnormality detection system configured as described above will be described below.

First, it is assumed that a transmission request is made to the individual transmission requesting means 9 of the communication abnormality detecting device 14. Then, the arithmetic control means 12 receiving this output individually transmits this signal onto the power line 1 according to the transmission request generated by the individual transmission request means 9 by the communication means 8. Now, in this system, the range of the number of the own station address that the communication terminal equipment can take is 1 to 15.
It is assumed that the setting values of the local address setting switches 5, 6, and 7 of 2, 3, and 4 are 1, 2, and 3, respectively. In this case, the individual transmission request means 9 makes an individual transmission request to the communication terminal devices 1 to 15. Further, the arithmetic control means 12 receiving this output performs individual transmission via the transmission communication path 1 to the communication terminal equipment having the address numbers 1 to 15 by the communication means 8. As a result, communication terminal devices 2 with address numbers 1 to 3,
The confirmation signal (ACK) is sent back only from 3 and 4. After the communication control means 12 detects the confirmation signal (ACK) by the communication means 8, the arithmetic control means 12 sends the confirmation signal (ACK) to the address storage means 10 and sends the confirmation signal (ACK). Number 2 and 3
Remember your turn. When there is no more transmission request from the individual transmission requesting means 9, the individual transmission requesting means 9 outputs the information to the simultaneous broadcast transmission requesting means 11 and the arithmetic control means 12. As a result, the simultaneous broadcast transmission request means 11 generates a simultaneous broadcast notification request signal transmission request that prompts all communication terminal devices to transmit the notification signal at the same time. Receiving this, the arithmetic control means 12 sends a simultaneous broadcast notification request signal to the transmission communication path 1 by the communication means 8.
Communication terminal device that receives this signal via the transmission communication path 1
According to the command, 2, 3 and 4 simultaneously start transmission of the notification signal by CSMA / CD system communication. The operation in this case, when each communication terminal device can normally receive the signal transmitted by each other,
The following description will be given separately for the case where the communication terminal devices 2 and 4 cannot receive the signals transmitted from each other.

First, if each communication terminal can normally receive the signals transmitted by each other, even if transmission of the notification signal is started all at once, CSMA / C
D operates normally, and all the annunciation signals transmitted by the communication terminal devices 2, 3 and 4 reach the communication abnormality detection device 14 normally. The arithmetic control means 12 which has received these notification signals by the communication means 8 stores the communication terminal equipment in the address storage means 10.
It is instructed to erase the memories of the own station addresses 1, 2, and 3 of 2, 3, and 4, and as a result, the own station addresses 1, 2, and 3 stored in the address storage means 10 are cleared. To be done. The arithmetic control means 12 displays the information on the communication abnormality address display means 13. That is, in this case, the communication abnormality address display means 13 displays that there is no communication terminal device in which a communication abnormality has occurred, or displays nothing.

Next, a case will be described in which a communication abnormality has occurred and the communication terminal devices 2 and 4 cannot receive signals transmitted from each other.
In this case, when the three communication terminal devices 2, 3, 4 start transmitting the notification signal all at once, only the notification signal of the communication terminal device 3 is normally transmitted to the transmission communication path 1. The reason for this will be described in more detail with reference to FIG. In FIG. 2, reference numeral 15 indicates an AC voltage waveform on the power line 1. FIG. 2a shows a bit string of data "1" and data "0". The data "1" superimposes a high-frequency signal on the first half of the peak value of the AC voltage waveform 15 and the data "0" superimposes on the latter half of the peak value. Expressed by composition. The transmission signal of the communication terminal device has a structure in which a plurality of bits of this data "1" and data "0" are concatenated. FIG. 2b shows a bit string of data “0” and data “1” according to the same definition. If the communication terminal device 2 and the communication terminal device 4 simultaneously transmit the data of FIG. 2a and the communication terminal device 4 respectively, the mutual transmission signals cannot be received, so that collision detection does not operate and eventually, A collision signal as shown in FIG. 2c is transmitted on the power line 1. The received data is "1" to other devices that received this signal.
It is impossible to determine whether it is "0". Therefore, in this case, as described above, even if the communication abnormality detection device 14 transmits the simultaneous broadcast notification request signal and the communication terminal devices 2, 3 and 4 simultaneously start transmitting the notification signal according to the command, the communication terminal Only the notification signal of the device 3 is normally transmitted to the power line 1. Therefore, the communication abnormality detection device 14 that has received the notification signal of the communication terminal device 3 selects the communication error detection device 14 of the communication terminal device 3 among the addresses 1, 2, and 3 stored in the address storage means by the arithmetic control means 12. Instruct to erase only station number 2. As a result, 1 is stored in the address storage means 10.
No. 3 and No. 3 own station addresses are continuously stored, and the arithmetic control unit 12 controls the abnormal communication address display unit 13 to display the value abnormally. Then, in the communication abnormality address display means 13,
It is displayed that the communication terminal devices 2 and 4 have a communication error. In this way, the address of the communication terminal device in which the communication abnormality has occurred can be immediately detected.

As described above, according to the present embodiment, it is possible to immediately determine whether or not there is a communication error between communication terminal devices, and if there is a communication error, which communication terminal device has the communication error, The contents displayed on the address display means 13 will be immediately understood.

Although the number of communication terminal devices is three in this embodiment, the larger the number, the more remarkable the effect of the present invention. Further, although the transmission communication path is an electric power line, this does not affect the gist of the present invention even if another transmission communication path such as a coaxial cable or a communication dedicated line is used.

EFFECTS OF THE INVENTION As is apparent from the above-described embodiment, the present invention first sequentially transmits signals individually to communication terminal devices, stores the own station address of the communication terminal device that has returned the confirmation signal, and then stores it. It sends a simultaneous broadcast notification request signal and, as a result, judges that there is no communication error at the address of the communication terminal device that returned the notification signal and deletes it from the memory, and returns a confirmation signal for individual transmission. However, since the communication terminal device that does not return the notification signal to the simultaneous broadcast notification signal is considered as the communication terminal device with communication error, there is no error in the communication between the detection device and the communication terminal device, but there is no communication error. Communication cannot be performed normally because communication signals between communication terminal devices cannot be received normally due to abnormalities in the communication terminals, etc., and the notification signals sent by all communication terminals simultaneously after simultaneous broadcast cannot detect each other. It has an effect that a terminal can be detected.

[Brief description of drawings]

FIG. 1 is a block diagram of a communication abnormality detecting apparatus in one embodiment of the present invention, and FIGS. 2A to 2C are waveform diagrams showing communication signals in one embodiment of the present invention. 1 ... Transmission communication path, 2-4 ... communication terminal equipment, 8 ... communication means, 9 ... individual transmission request means, 10 ... address storage means, 11 ... broadcast transmission request means, 12 ... Arithmetic control means, 13 ... communication error address display means, 14 ... communication error detection device.

Claims (1)

[Claims] 1. An individual transmission requesting unit for requesting individual transmissions sequentially to addresses within a settable range, an address storing unit for temporarily storing an own station address of an existing communication terminal device, and the individual unit. After the transmission request of the transmission request means is exhausted, a broadcast transmission request means for requesting transmission of a broadcast notification request signal, and after individually outputting a signal to a communication terminal device upon receiving the output of the individual transmission request means When the confirmation signal transmitted by the communication terminal device is received, the address storage means is instructed to store the local address of the communication terminal equipment, and the output of the broadcast transmission request means is received, and the broadcast address is transmitted. When the notification signal from the communication terminal device is received after the notification request signal is transmitted, an instruction is given to erase the record of the own station address of the communication terminal device stored in the address storage means. Arithmetic and control means for outputting the value of the own station address stored in the address storage means after receiving all the notification signals as the own station address of the communication terminal equipment with communication abnormality, and communication terminal equipment receiving the output and having communication abnormality And a communication abnormality address display means for displaying.