Library /sys$common/syshlp/nclhelp.hlb set, ddcmp (OpenVMS VAX), link, physical_line  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: No name       Value: Local entity name

    Name of the Physical layer entity that the link operates over. A
    value for this characteristic must be set before the link entity
    is enabled. You can modify this characteristic only when the
    entity is disabled.

    set [node node-id] ddcmp link link-name -
         physical line local-entity-name