ACC Programmer's Reference Guide

ZCOM Tables and Data Structures
Logical Terminal Tables
Chapter 3 65
LTTYPE - Logical terminal type
The logical terminal type is used to describe the message format
expected from the terminal. For screen-type terminals this will identify
the terminal as belonging to a class of terminals with the same screen
formatting attributes and message delimiters (e.g., IBM.3278 or
NCR.501).
LTFLAG - System status flags
Currently the system status flags are used to indicate whether the
outbound multiplexing and the inbound multiplexing are enabled.
Figure 3-2 System Status flags
Both are set by TTGEN according to the device type specified. These
flags may be modified dynamically by use of the zltmx routine call.
LTZMXP - ZCOM address of multiplexing program
This field contains the node, ZLU number, and checksum of the outbound
multiplexing program. If the ZCOM_LTFLAG_OMX bit in ltflag is set,
the responsible multiplexing program should set up this field with its
primary ZLU (via the zset_rcvr routine, mode 2). All out-going messages
will then be queued to its primary ZLU.
LTZPRCV R - ZCOM address of primary indirect receiver
This field contains the node, ZLU number, and checksum of the program
to receive data messages from an inbound multiplexed terminal. If the
ZCOM_LTFLAG_IMX bit in ltflag is set, the system sets up this field on
a zset_rcvr (mode 0) call. All incoming messages will be received by the
inbound multiplexing program, which will then route the data to the
receiver specified in this field.
15 10987654321011121314
OM IM
OM -
IM -
Outward bound multiplexing, ZCOM_LTFLAG_OMX bit
Inbound multiplexing, ZCOM_LTFLAG_IMX bit