HP 3000 Manuals

SPU Switchover/XL User's Guide

Terminal Protocols 

There are two types of terminal protocols on your system, nailed and
nonnailed terminals.


NOTE  The concept of nailed and nonnailed devices deals only with the
      association of a device to an ldev number on a specified system.
      It is independent of the concept of switching, which deals with the
      ability of a single device to establish a connection to any system
      on the LAN.


Nailed Terminals 

These terminals are preconfigured with the same ldev number on each SPU.
This preconfiguration enables the alternate system to open each terminal
when the home system is not available because, the home system does not
own the port.  Consequently, each nailed terminal responds as it would on
the home system.

Nonnailed Terminals 

These terminals have no permanently assigned ldev number.  Ldev numbers
are dynamically associated with a device connection.  When a nonnailed
terminal is logged on to the system, it is assigned an ldev number from a
pool of available ldev numbers.  When the connection is ended, the
assigned ldev number is returned to the pool and becomes available for
use.

The following provides switchover instructions for both nailed and
nonnailed terminal protocols.

MPE/iX 5.0 Documentation