SNAX/XF LU Network Services Manual

Terminal Interface to LUNS
Introduction to LUNS
1–2 097841 Tandem Computers Incorporated
Terminal Interface to
LUNS
LUNS makes it possible for the terminal user to switch from one application program
to another.
In planning the network, the system programmer devises a series of character-coded
commands that the terminal user will enter when logging on or logging off. The
system programmer can also create a menu that will be displayed whenever the
terminal user enters a certain command (for example, HELP). This menu explains
how to log on to and off from each of the various applications. (In creating both
character-coded commands and the menu, the system programmer can employ either
the alphabetic or the single-byte Katakana character set.)
Figure 1-1 is an example of such a menu as it would appear on a 3278 terminal. (This
menu represents the configuration that is implemented in the first part of the
application example in Section 3.) For this example, the TACL process and Order
Entry applications reside on the Tandem system, while TSO resides on the host.
Figure 1-1. HELP Menu Screen
TO ACCESS ENTER
TACL TACL
ORDER ENTRY ORDERENTRY
TSO TSO
HOST HOST
TANDEM TANDEM
TO LOGOFF LOGOFF
When the terminal is started with the Subsystem Control Facility (SCF) START LU
command, it receives an Enhanced System Services (ESS) message 10, consisting of a
Tandem logo. A symbol at the bottom of the screen indicates that the terminal is
already in an SSCP-LU session. By typing HELP (or another command defined by the
system programmer), the terminal user can display the menu and use the appropriate
commands to log on to or off from any of the applications.
Logging On to Order Entry In this example, the application called ORDER ENTRY is a Pathway application residing
on the Tandem system. To log on, the terminal user types in the characters
ORDERENTRY and presses the ENTER key. When the session is established, an “LU-LU
session” symbol appears at the bottom of the screen. To log off, the user presses the
SYSTEM REQUEST key, then enters the LOGOFF command. The ESS message 10 and
the “SSCP-LU session” symbol reappear.