The TSO, ACF, SHOW ACTIVE command displays the CA ACF2 for z/OS intercepts that have received control (denoted by YES) initially(after an IPL) intercepts will display NO(ie.TAPE-EOV(NO)), once the intercept is triggered YES will be displayed(ie. TAPE-EOV(YES).
The TAPE-EOV intercept is only triggered when a dataset spans more than one tape volume. The reason for the intercept is to protect the second and subsequent volumes. Virtual tape systems may never invoke this function.