/sys$common/syshlp/helplib.hlb Sys Parameters, PASANITY  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    PASANITY controls whether the CI and DSSI port sanity timers are
    enabled to permit remote systems to detect a system that has been
    hung at IPL 8 or above for 100 seconds. It also controls whether
    virtual circuit checking gets enabled on the local system. The
    TIMVCFAIL parameter controls the time (1-99 seconds).

    PASANITY is normally set to 1 and should be set to 0 only when
    you are debugging with XDELTA or planning to halt the CPU for
    periods of 100 seconds or more.

    PASANITY is only semidynamic. A new value of PASANITY takes
    effect on the next CI or DSSI port reinitialization.

    If CI or DSSI devices are not configured on your system, this
    parameter is ignored.

    PASANITY is a DYNAMIC parameter.