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

 o  client

    Name supplied by the client when the port was opened. This defines
    which client owns the port.

 o  line

    Name of the modem connect line entity that the client supplied
    when the port was opened.

 o  state

    State of data port.

    open             The port is assigned to a client.

    open disabled    The port is assigned to a client, but the line
                     entity that port refers to is disabled.