Reference Guide

ZCOM Tables and Data Structures
Logical Terminal Tables
Chapter 362
Logical Terminal Tables
The Logical Terminal Table (LTT) pages contain the logical configuration
information for each terminal ZLU in the ZCOM system. Each terminal
table consists of the basic table (which is fixed for all terminals) and a
table extension (which is of configurable size specified by
LOGICAL-SIZE parameter in the TTGEN configuration file).
The basic table contains common information for all terminal ZLUs. It is
logically divided into two sections; an area reserved for use by the ZCOM
subsystem and a user area that may be manipulated by application
programs (via the zltup routine).
The table extension may be used to store any application defined data
structure and can be manipulated by the application program that
allocates it (via the zltstore routine).
The layout of a Logical Terminal Table (zltt_type) basic table is shown in
Table 3-9 and Table 3-10. Note that the section reserved for use by the
ZCOM system is immediately followed by the user area.
Table 3-9 Logical Terminal Table (Reserved Area)
Field Name Field Description
Field
Type
Size
(Bytes)
LTZLU Owning terminal ZLU number uns.short 2
LTZCS Owning terminal ZLU checksum uns.short 2
LTMUX MUX i/f number for this terminal uns.short 2
LTPORT Port number within Mux interface uns.char 1
LTTERM Terminal number within port uns.char 1
LTPTERM Pointer to physical terminal table pointer 8
LTGZLK ZLU of next terminal in group uns.short 2
LTDEVC Device type of terminal uns.short 2
LTTYPE Logical type of terminal uns.short 2
LTFLAG System status flags uns.short 2