Library /sys$common/syshlp/ncphelp.hlb SET, LINE, HANGUP option  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Applies only to asynchronous DDCMP lines.  Indicates whether the modem
 signals are dropped when the line is shut down.  Possible values are:

       ENABLED    Indicates that modem signals should be dropped when
                  the line is shut down.

       DISABLED   Indicates that modem signals should not be dropped
                  when the line is shut down.  This is the default for
                  static asynchronous DDCMP lines.

 This parameter is supplied automatically for dynamic asynchronous
 DDCMP lines.  The default is HANGUP ENABLED if the /HANGUP qualifier
 was specified for the DCL command SET TERMINAL, and HANGUP DISABLED
 if /NOHANGUP was specified.