摘要 |
In a cross connecting network wherein a branching device branches a group of digital signals into duplexed groups for supply to two switch matrix devices, each including switch elements in foremost through last stages, at least three in number, to cross switch the digital signals through cross connected paths with a switch request flag superposed on each digital signal downstream of a defective element of the switch elements and wherein a redundancy switching device detects the flag to make a control device control the switch elements of the last stage selectively connect the cross connected paths of the switch matrix devices path by path to switching device paths, a monitor is used in the cross connected paths of each switch matrix device before each switch element of the second through the last stages to detect a monitor datum sent thereto together with each digital signal to locate the defective element, and to assist the control device in path by path selecting the cross connected paths of each switch matrix device. The switch elements may be grouped into switch units. Preferably, a like monitor is connected to each switching device path to detect if each switch element of the last stage is defective. More preferably, an indicator is connected to the monitor to indicate the defective element.
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