ANALOG SIGNAL MONITORING DEVICE AND DIGITAL PROTECTIVE/ CONTROL DEVICE FOR POWER SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a digital protective/control device for a power cable which can surely detect buffer memory abnormality with a simple construction, without additional high speed circuits. ;SOLUTION: '$ OOO' meaning 'all Os' and '$ FFF' meaning 'all 1s' are set as test pattern data. Input signals are converted into digital signals by an A/D converter 104 through analog LPFs 101 and 102 and MPX 103. The converted output signals and the test pattern data are stored alternately and at every sampling period in a buffer 107. A CPU 108 examines the data read out of the buffer memory 107 and discriminate whether or not an abnormality exists in the buffer memory 107.;COPYRIGHT: (C)1999,JPO