SNAX/XF LU Network Services Manual

LUNS Configuration Tables
Introduction to LUNS
1–6 097841 Tandem Computers Incorporated
The ESS Table To use LUNS for establishing sessions, a terminal must be associated with an ESS
table. Tandem’s ESS tables are similar in form and function to IBM USS tables. For a
discussion of USS tables, see the IBM VTAM™ Resource Definition Reference.
ESS tables hold four types of records: message records, logon records, logoff records,
and order records. All such records are identified by a record-name field. This field
serves as a key when LUNS searches the table for a particular record.
Message Records
Message records contain either system messages or messages defined by the user.
(Appendix B lists all system messages.) Message text can use either the alphabetic or
the single-byte Katakana character set.
A message is displayed when a character-coded command is entered at the terminal.
Logon Records
Logon records are used to start TACL or Pathway processes or to log on to host
applications.
One type of logon record has in its record-name field a character-coded command
matching a character-coded command entered by the terminal user. Such records are
used to log on to applications on a Tandem system or to applications on a host. The
character-coded commands can use either the alphabetic or the single-byte Katakana
character set.
The other type of logon record has in its record-name field a Destination Logical Unit
(DLU) name matching a DLU name in an INIT-SELF command sent by an intelligent
device. Such records can be used to log on to applications on a host system.
Logon records also have a field that explicitly identifies a destination process. In most
cases, this field is one that is separate from the record-name field. Exceptions are
discussed later in this section under “Logon Records for Passthrough Sessions.”
Logon Records for a TACL Process. LUNS knows the Tandem TACL process by its
subdevice name as it was specified in an SCF ADD APPL statement. The ESS table
entry also contains the subdevice name for the TACL process. LUNS uses this
subdevice name to start the process.
When establishing a session, LUNS passes NEWPROCESS parameters to the Creator
process. These parameters are included in the concatenated data field of the logon-
record (for more information, see Section 2).