o  open physical port failure

    The open operation on the port in the Physical layer failed.

    Arguments:

    reason   Specifies why the open operation failed.

             invalid      The open port call was improperly formed.
             argument

             line not     The line managed by the Physical layer
             available    entity is already allocated to another
                          data link entity. Modify the physical
                          line characteristic to specify an entity
                          not used by any other data link entity,
                          then reissue the enable command.

             no such line The entity specified in the physical
                          line characteristic does not exist.
                          Either create that entity, or modify the
                          value of physical line to name an entity
                          that does exist. Then reissue the enable
                          command.

 o  device constraint

    The value of an attribute is not supported by the device type
    servicing the protocol state machine.

                                   NOTE

       Only the DSF32 device supports SWIFT and CHIPS framing.