DIN EN 60671 VDE 0491-100:2011-12

This standard lays down principles for testing I&C systems performing category A, B and C functions, per IEC 61226, during normal power operation and shutdown, so as to check complete availability especially with regard to the detection of unsafe faults. It covers the possibility of testing at short intervals or continuous surveillance, as well as periodic testing at longer intervals. It also establishes basic rules for the design and application of the test equipment and its interface with the systems important to safety. Further, the effect of any test equipment failure on the reliability of the I&C systems is considered.