JPH03195228A - Redundant system selecting circuit - Google Patents

Abstract

PURPOSE:To prevent momentary production of error for the selection of a data string of a redundant system and to eliminate the abnormality of both systems by providing 2-stage constitution for two 1st selective circuits and a 2nd selective circuit and providing a delay circuit between two stages. CONSTITUTION:DATA i (i=1-n) in a data string of same frame constitution having the redundant system is given to a 1st selective circuit 11 and a DATA ia (i=1-n) is inputted to a 1st selective circuit 12, an output data string is delayed respectively by delay circuits 13, 14 and inputted to a 2nd selective circuit 15. A selection control pulse is outputted from a control circuit 16 before a data string whose error is detected by a path pattern detection circuit 17 or 18 reaches the selective circuit 15 and the data string is subjected to selection control without causing momentary error in the transmission data string. In the selection control, the selective circuit 15 is controlled before the selection circuits 11, 12. After data strings DATA 1-n including the data string DATA j having a fault are switched by the selective circuit 15 and the selective circuit 11 selects a data string DATA k (not equal to j) and this system is in standby as a standby system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit that selects a redundant system using a self-monitoring function based on path pattern detection in the field of digital communication having a redundant system.

[Conventional technology]

Conventionally, this type of O/1 redundant system selection circuit does not have a circuit configuration that can realize a selection circuit that does not cause instantaneous errors in data strings having a redundant system, but only detects a path pattern immediately after a failure occurs in one system. During this period, the system was not switched to the normal system, and after switching to the normal system, unless the failed panel was maintained, it would be one-sided operation, and if the panel in operation failed, both systems would be operated. The circuit configuration caused a system error.

[Problem to be solved by the invention]

In the conventional redundant system selection circuit described above, the data string having the redundant system and the control pulse for selecting the data of the normal system among the data strings of both systems are input to the selection circuit with the same phase delay. With instantaneous errors in the data, and furthermore,
After switching to a normal system, unless the failed panel is maintained, it will be in single system operation, and if the operating panel fails, both systems will become abnormal, so the circuit configuration is such that the system will become abnormal. There is.

[Means to solve the problem]

The redundant system selection circuit of the present invention includes two first selection circuits each inputting 0 data strings (n is an integer of 2 or more) each including a path pattern, and selecting and outputting one column; two path pattern detection circuits that respectively monitor the data strings output from each of the first selection circuits; two delay circuits that receive the data strings output from each of the first selection circuits; a second selection circuit which inputs the data strings output from each, selects and outputs one of them, and controls selection operations of the first and second selection circuits based on the detection results of the path pattern detection circuit; control circuit.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which two sets of data strings each having a redundant system with zero lines are input.

As shown in FIG. 1, data strings D A, T A 1 to D A T A of the same frame structure with redundant system
nDATA 1 a to DATAna are input. Among the input data strings, DATAj (i=1 to n)
is sent to the first selection circuit 11, DATAia(i=]~n)
are input to the first selection circuit 12, and the output data strings are delayed by m bits in delay circuits 13 and 14, respectively, and input to the second selection circuit 15.

The control circuit 1
A selection control pulse is outputted from 6, and the selection control of nine data strings in each system having a redundant system is always performed without causing instantaneous errors in the transmitted data strings. However, the selection control controls the selection circuit 15 before the selection circuits 11 and 12.

The data string selected by one path pattern detection circuit performs self-monitoring by detecting a path pattern inserted into an empty time slot.

Data string D on the side that includes the faulty data string DATAj
After the selection circuit 15 switches ATAI~n, the selection circuit 11 switches it to the data string DATAk (≠j) and stands by as a standby system. The same applies when a failure occurs in the data strings DATA1a to DATAna.

An example of the selected data string and selection control pulse is shown in the timing diagram of FIG.

In the example of FIG. 2, the selection circuit 11 first selects the data string DAT.
AI, the selection circuit 12 selects the data string DATAla, and the selection circuit 15 selects the O-system data string DATAI, and the selected data string is DATA1. Data column D
When a failure occurs in ATAI, the path pattern detection circuit 17
detects this, and based on this detection result, the control circuit 16 generates a selection control pulse, causing the selection circuit 15 to select the - data string DATA1a of the 1st system, and causing the selection circuit 11 to select the data string DATA2. . data string DATAI,
Since la is delayed by the delay circuits 13 and 14, the selection circuit 15 selects the data string DATAI before an error due to a failure in the data string DATAI reaches the selection circuit 15.
Switching to side a, no instantaneous error occurs. Similarly, when a failure occurs in the data string DATA1a next, the selection circuit 15 selects the data string DATA2, and the selection circuit 12 selects the data string DATA2.
selects the data string DATA2a.

〔Effect of the invention〕

As explained above, the present invention has a two-stage configuration of two first selection circuits and a second selection circuit, and a delay circuit is provided between these two stages, so that the selection control pulse can pass through the redundant system. The redundant system data sequence can be selected instantaneously and without error, and even after the normal system has been selected, the data sequence can be transmitted faster than the existing data sequence, regardless of whether the faulty panel is maintained. This has the effect that one-system operation will not occur, and therefore, both systems will not experience an abnormality.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a timing diagram of the embodiment of FIG. ], 1. , 1.2...first selection circuit, 13.1
．． 4...Delay circuit, 15...Second selection circuit, 16.
...Control circuit, 17.1.8.19...Pass pattern detection circuit.

Claims (1)

[Claims] Two first selection circuits each input n data strings (n is an integer of 2 or more) each containing a path pattern, select and output one column, and the two path pattern detection circuits that respectively monitor data strings; two delay circuits that input the data strings output from each of the first selection circuits; and two delay circuits that input the data strings output from each of these delay circuits. and a control circuit that controls selection operations of the first and second selection circuits based on the detection result of the path pattern detection circuit. Features redundant selection circuit.