Library /sys$common/syshlp/sysmanhelp.hlb IO, CONNECT, Qualifiers, /SYS_ID  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /SYS_ID=number-of-remote-system

    Indicates the SCS system ID of the remote system to which the
    device is to be connected. It is a 64-bit integer; you must
    specify the remote system number in hexadecimal. The default
    is the local system. This qualifier is optional.