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

    SCSRESPCNT is the total number of response descriptor table
    entries (RDTEs) configured for use by all system applications.

    If SCA or DSA ports are not configured on your system, the system
    ignores SCSRESPCNT.

    SCSRESPCNT has the AUTOGEN, FEEDBACK, and GEN attributes.