VMS Help READ, Qualifiers, /TIME_OUT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /TIME_OUT=n
       /NOTIME_OUT (default)

    Specifies the number of seconds after which the READ command is
    terminated if no input is received. If you enter the /TIME_OUT
    qualifier, you must specify a value from 0 to 255.

    If you enter both the /ERROR=label and /TIME_OUT qualifiers, and
    the time limit expires, the error branch is taken.