Library /sys$common/syshlp/nclhelp.hlb create, modem_connect, line, Exception Messages  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 o  already exists

    A modem connect line entity with the specified name already
    exists on the specified node.

 o  communications port in use

    Another entity has reserved the communications port specified in
    the command. Check that you specified the correct port. Reissue
    the command specifying another port or modify the other entity to
    use a different port.