JPS58161433A - Line switching method by comparison of failure - Google Patents

Abstract

PURPOSE:To operate a line optimizingly, by discriminating the importance and number of each input switching request signal from a common and a spare system, switching the line to the common or the spare system having less failure and preventing the line from being switched to the system having the important failure. CONSTITUTION:The importance of the switching request signal outputted at failure from the common and the spare system device is roughly divided into two ranks, a switching input signal having lower importance of failure is inputted to a low failure comparison circuit 1 (hereinafter DEC2) and the result of signal comparison having the low failure is inputted to a final failure comparison circuit 2 (hereinafter DEC1). The DEC1 processes the switching request signal representing a high failure and the input signal from the DEC2 and discriminates the best system. The system having less failure is selected based on the result of discrimination from the DEC1 and the line is switched with a switching device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a line switching method based on failure degree comparison, which switches the line to a system with a smaller degree of failure based on switching request signals output from devices in the active and standby systems at the time of failure.

Conventional switching devices have one each for the working and standby systems.
Since the switching device is only equipped with an input circuit for switching request signals, if there is a fault in both the working and standby systems at the same time, even if one of the failures is minor, the switching device will It can only be determined that there is a fault. Therefore, even if the force is a minor obstacle,
The line is switched to the other system based on the logic inside the switching device. However, even if the line to be operated after switching has a more serious fault than the line which has been operated up to now, the function of the switching device is not sufficient.

The present invention solves the above-mentioned problems by switching the lines protected by a switching device by comparing the magnitude of the failure on each line of the active and reserved systems, thereby keeping the lines in the best condition possible. It is intended to be used repeatedly. According to the present invention, the switching request signals outputted from devices in one active and backup system in the event of a failure are ranked according to their importance, and switching can be performed even if multiple devices in the active and backup system groups fail at the same time. When line switching request signals are simultaneously input to the device, the switching device determines the importance and quantity of each switching request signal input, and switches the line to the system with the least degree of failure among the active and backup systems. It is characterized by:

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

The figure shows a block diagram of a switching request signal discrimination function of a device to which the present invention is applied.

In the embodiment, the importance of the switching request signals output from the active and standby system devices in the event of a failure is roughly divided into two ranks, and a plurality of switching request signals can be input. The switching input signal with a low fault severity level is manually input to the low fault level comparison circuit 1 (hereinafter referred to as DEC2), where it is processed based on the logic below, and the result of the low fault level signal comparison is sent to the final stage fault level comparison circuit 2 (hereinafter referred to as DEC2). (hereinafter referred to as 2.DECl).

(Low failure level - 1'lJ logic) m: n: Q → No output m) n
→ Reserve m = n\0
→ Current In (n → Current
Here, m indicates the number of low-disability switching request signals from the active system, and n indicates the number of low-disturbance switching request signals from the backup system.

The DEC1 processes the switching request signal indicating a high degree of failure and the input signal from the DEC2 according to the following logic to determine the best system. Then, based on the determination result from DECl, a system with a small degree of failure is selected and the line is switched by the switching device.

x = y = o, z - No manpower → Maintain status quo x = y, z = Current use → Current use x = y, z - Child support
→ Reserve x>y
→ Reserve x(y → Current
Here, X represents the number of high-fault switching request signals from the active system, y represents the number of high-failure switching request signals from the backup system, and 2 represents the type of input signal from the DEC 2.

As described above, the present invention determines the importance and quantity of each input switching request signal from the working and backup systems and switches the line to the working or backup system with a smaller degree of failure. This has the effect of preventing switching to the line of a system with a major failure, and allowing the line to operate in the best possible condition.

[Brief explanation of drawings]

The figure is a block diagram of the switching request signal determination function of the device to which the present invention is applied. 1...Low failure degree comparison circuit, 2...Final stage failure degree comparison circuit Patent applicant NEC Corporation

Claims (1)

[Claims] (1) When multiple devices in the active and standby system device groups fail at the same time and line switching request signals are simultaneously input to the switching device, the switching device determines the importance and quantity of each input switching request signal and and a line switching method based on failure level comparison, characterized in that the line is switched to a system with a smaller failure level among backup systems.