JP2737294B2 - Duplex receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a method for detecting a failure in a local area network, and aims at providing a circuit for isolating and limiting a failure point of a transmission line and a transmission / reception device in the local area network. A first receiving unit that receives data from a transmission line via a transmission path, a processing unit that processes the output of the first receiving unit and own device data, and outputs the processing unit to a downstream data transmitting / receiving device. In the data transmitting and receiving apparatus having a transmitting unit that transmits the data through the transmission line, the second receiving unit having the same function as the first receiving unit, and the data from the transmission line and the output of the transmitting unit are input in a loop. A first selecting unit that selects one of the data and outputs a selection result to the first receiving unit, and a data of the data from the transmission path and the data obtained by folding the output of the transmitting unit. And a second selection unit connected in parallel to the first selection unit so as to output a selection result to the second reception unit, wherein the first selection unit and the second selection unit are different from each other. When selecting and outputting data, and detecting an error in the first receiving unit or the second receiving unit,
The first selection unit and the second selection unit are configured so that the selection data can be switched to each other and the first reception unit or the second reception unit can receive the data to isolate the failure.

[Industrial applications]

The present invention relates to a fault finding method in a local area network.

In a local area network (hereinafter, referred to as a LAN), it is very difficult to perform a self-diagnosis of a transmission path failure and to isolate a cause. For this reason, it is desired to provide a circuit that can automatically isolate a faulty part of the transmission line.

[Conventional technology]

FIG. 3 is a diagram showing a circuit configuration of a conventional example.
In the figure, reference numeral 6 denotes a first data transmitting / receiving device, 7 denotes a second data transmitting / receiving device, and 8 denotes a third data transmitting / receiving device. 60,70,
80 is the transmission line 9a, 9
This is a receiving unit that receives data transmitted via b and 9c, and is provided in the first data transmitting / receiving device 6, the second data transmitting / receiving device 7, and the third data transmitting / receiving device 8, respectively. Similarly, reference numerals 61, 71, and 81 denote respective transmission units, which are transmission units that transmit data to the respective data transmission / reception devices connected downstream via the transmission paths 9a, 9b, and 9c. Further, 62, 72, and 82 are processing units that process data from the respective receiving units 60, 70, and 80, and then transmit the data to the transmitting units 61, 71, and 81.

In the circuit configuration described above, for example, a countermeasure method when a failure is detected in the receiving unit 70 of the second data transmitting / receiving device 7 is as follows.

(1) The connection point x between the output end of the transmission section 61 of the first data transmission / reception device 6 and the transmission line 9b is disconnected, and for example, a level meter is connected to the output end to check whether the level is normal. If abnormal, it is determined that the first data transmission / reception device 6 and a failure before the device 6 have occurred.

(2) If the above (1) is normal, the connection point between the input end of the receiving unit 70 of the second data transmitting / receiving device 7 and the transmission line 9b ×
Is removed, and it is confirmed whether the input level from the transmission line 9b is normal using, for example, a level meter. If abnormal, transmission line 9b
Is determined to be a failure.

(3) If the above (2) becomes normal, the transmitting unit 61 of the first data transmitting / receiving device 6 is replaced and the second data transmitting / receiving device 7 is replaced.
Confirm that the receiver 70 operates normally.

(4) If the above (3) is normal, replace the receiving unit 70 of the second data transmitting / receiving device 7 and confirm that it operates normally.

As described above, for example, when a transmission path failure occurs on a transmission path using a local area network, the location of the failure is identified by human operation to find the failure location, and in particular, automatic diagnosis of the transmission path is performed. Also, automatic failure detection of transmission path failure is not performed.

[Problems to be solved by the invention]

Therefore, when a transmission line failure occurs, it is considered that the cause is: 1. Failure of the transmitting part performing transmission 2. Failure of the receiving part performing reception 3. Failure of the transmission line However, there is a problem in that it is difficult to limit these locations due to the transmission path failure.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit for separating and limiting a transmission path in a local area network and a failure point of a transmission / reception device.

[Means for solving the problem]

In the present invention, a first receiving unit 11 for receiving data from an upstream data transmitting / receiving device via a transmission line 2a, the first receiving unit
A data transmission / reception apparatus 1 comprising: a processing unit 16 for processing the output of the processing unit 11 and its own data; and a transmission unit 13 for transmitting an output from the processing unit 16 to a downstream data transmission / reception apparatus via a transmission path 2b. In, the second receiving unit 12 having the same function as the first receiving unit 11, and the data from the transmission line 2a and the output of the transmitting unit 13 is selected one of the input data returned, the selection result Selecting unit 14 that outputs to the first receiving unit 11
And select one of the data from the transmission path 2a and the data obtained by folding the output of the transmission unit 13 and parallel to the first selection unit 14 so as to output the selection result to the second reception unit 12. Is provided, the first selection unit 14 and the second selection unit 15 select and output different data from each other, and generate an error in the first reception unit 11 or the second reception unit 12. If detected, the selection data of the first selection unit 14 and the second selection unit 15 are switched to each other and the data can be received by the first reception unit 11 or the second reception unit 12, thereby enabling the isolation of the failure. Configuration.

[Operation] In the present invention, as shown in FIG. 1, the transmission data from the data transmission / reception device 1 is looped back, received by the second reception unit 12 via the second selection unit 15, and received by the second reception unit 12 in error. When detecting, when the return of the transmission data is switched to the first receiving unit 11 using the first selecting unit 14 and the error detection is performed by the first receiving unit 11, it is determined that the transmission unit 13 has a failure, The transmission data is guaranteed. Furthermore, the transmission unit of the upstream data transmission / reception device ensures the transmission data with the same circuit, and if an error is detected by the first reception unit 11 that receives the transmission data, the second reception unit 12 is defective or A determination is made as to which one of the transmission paths 2a has failed.

Therefore, by switching between the first receiving unit 11 and the second receiving unit 12, it is possible to limit the location of the failure on the upstream side of the own device or any one of the first receiving unit 11 and the transmitting unit 13 of the own device. And

〔Example〕

FIG. 2 is a diagram showing a circuit configuration of one embodiment of the present invention. In the figure, reference numeral 3 denotes a first data transmission / reception device, and a first reception unit 31 that receives either data from an upstream data transmission / reception device or data from a transmission unit 33 sent to a downstream data transmission / reception device, A transmitting unit 33 that transmits data to the data transmitting and receiving device, and data output from the second receiving unit 32 by inputting data from the first receiving unit 31 or the second receiving unit 32 from the transmitting unit 33 and A circuit comprising a processing unit 37 for processing two data of the own device data, and switching and selecting data from the transmission line 5a and data from the transmission unit 33 as a circuit of the present invention and outputting any one data A first selection unit 34 and a second selection unit 35 having a parallel configuration, a second reception unit 32 that is used in a switched manner with the first reception unit 31 and serves to monitor data transmitted from the transmission unit 33, Data from the receiving unit 31 and the second receiving unit 32 It is configured by a third selection unit 36 that switches to output to the processing unit 37. Reference numeral 4 denotes a second data transmission / reception device, which has the same configuration as that of the first data transmission / reception device 3, and different symbols are simply given to them for convenience of explanation. Reference numerals 5a, 5b, and 5c denote transmission paths serving as data paths to the upstream and downstream data transmitting and receiving devices. When an error is detected in the first receiving unit 31, 41 or the second receiving unit 32, 42, the control signal is transmitted to the first selecting unit 34, 44 and the second selecting unit.
Output to 35 and 45 to switch received data.

Normally, data input from a certain upstream data transmission / reception device via the transmission line 5a is input to the first selection unit 34 of the first data transmission / reception device 3, and the first selection unit 34
Is input to the first receiving unit 31. The first receiving unit 31 receives the received data and sends it to the processing unit 37, and the processing unit 37 transmits the processing result of the processing performed by the first receiving unit 31 and the own device data to the transmission path via the transmission unit 33. 5b. At this time, the second selecting unit 35 sends the data sent from the transmitting unit 33 to the second receiving unit 32, and monitors the data sent from the transmitting unit 33. The second data transmitting / receiving device 4 also performs the same receiving and transmitting operations as the first transmitting / receiving device 3.

As an example of the separation in the case where a failure occurs during the above operation, the occurrence of the failure is separated and limited by performing a connection change as shown in FIG.

1. When the initial connection status is as follows.

1-1. In the first data transmitting / receiving device 3, the first receiving unit 31 and the transmission line 5a are connected via the first selecting unit 34.

The second receiving unit 32 and the transmitting unit 33 are connected via the second selecting unit 35.

1-2. In the second data transmitting / receiving device 4, the first receiving unit 41 and the transmitting unit 33 are connected via the transmission line 5b.

The second receiving unit 42 and the transmitting unit 43 are connected via the second selecting unit 45.

2. Failure When an Error Occurs in the First Receiver 41 2-1. Solution The transmitter 43 changes the internal connection of the data transmitting / receiving device 4 to the first receiver 41 via the first selector 44. The transmission unit 33 changes the connection to the second reception unit 42 via the transmission path 5b.

2-2. Status after handling and limitation of failure location (a) Error occurred in first receiving unit 41 ... Failure of first receiving unit 41 (b) Error occurred in second receiving unit 42 ... Transmission line 2b line 3. Failure When an error occurs in the second receiving unit 32 2-1. Solution The connection of the data transmitting / receiving device 3 is changed from the transmitting unit 33 to the first receiving unit 31 via the first selecting unit 34. The connection of the transmission line 5a is changed to the second receiving unit 32 via the first selecting unit 34.

2-2 Status after handling and identification of fault location (a) Error occurred in first receiving unit 31... Fault in transmitting unit 33 (b) Error occurred in second receiving unit 32... Fault in second receiving unit 32 [Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to isolate faults on the transmission line, and therefore, it is possible to simplify automatic self-diagnosis and the like and to rationalize tests such as shortening of fault recovery time. This can contribute to the improvement of the reliability of the transmission path.

[Brief description of the drawings]

 FIG. 1 is a circuit diagram showing a principle configuration of the present invention, FIG. 2 is a diagram showing a circuit configuration of one embodiment according to the present invention, FIG. 3 is a diagram showing a circuit configuration of a conventional embodiment, 1 is a data transmitting and receiving device, 11 is a first receiving unit, 12 is a second receiving unit, 13 is a transmitting unit, 14 is a first selecting unit, 15 is a second selecting unit, 16 is a processing unit, and 2a is an upstream transmission 2b indicates a downstream transmission path.

Claims (1)

(57) [Claims] 1. A first receiving section (11) for receiving data from an upstream data transmitting / receiving apparatus via a transmission line (2a), and an output of the first receiving section (11) and processing of own apparatus data are performed. A data transmission / reception device (1) including a processing unit (16) for performing the processing, and a transmission unit (13) for transmitting an output from the processing unit (16) to a downstream data transmission / reception device via a transmission path (2b). A second receiving unit (12) having the same function as the first receiving unit (11); and data from the transmission line (2a) and data returned by inputting the output of the transmitting unit (13). A first selecting unit (14) for selecting one and outputting a selection result to the first receiving unit (11)
And selecting one of the data from the transmission path (2a) and the data obtained by folding the output of the transmission unit (13), and outputting the selection result to the second reception unit (12). One selection unit (1
4) providing a second selection unit (15) connected in parallel, wherein the first selection unit (14) and the second selection unit (15) select and output different data from each other, and (11) or when an error is detected in the second receiving unit (12), the selection data of the first selecting unit (14) and the second selecting unit (15) are switched to each other, and the first receiving unit (11) or Second receiver (12)
Characterized in that a fault can be isolated by receiving data at the receiver.