ACC Utilities Reference Guide

32 Chapter2
TTGEN-ZCOMSystemTableGenerator
Memory Image File Overview
Logical Terminal Tables
Thelogicalterminaltables containinformation such as the terminaltype
and location, and its owning ZLU number. A large area of this table is
reserved for use by the application programs. A number of logical
terminals may be linked to a single physical terminal; for example, it
may be used in any instance where a remote concentrator handles a
number of terminals. This means that there may be more logical
terminal tables than physical terminals . For more detail, see the data
structure zltt_type in /opt/acc/include/zcom/zcomsys.h.
Physical Terminal Tables
The physical terminal tables (one per terminal) include the owning
terminal ZLU number, and the high, low, and unacknowledged queues,
as well as the terminal status, transmit and receive buffer counters, and
terminal poll and select codes. For more det ail, see the data structure
zptt_type in /opt/acc/include/zcom/zcomsys.h.
Interface Tables
There is one interface table per ACC interface card, containing
information such as the ACC interface number, scheduler event flags,
interface terminal count, the current backplane command, and data
transfer command, the high pri ority queue header and the low priority
queue header, and port configuration information. For more detail, see
the data structure zift_type in /opt/ acc/include/zcom/zcomsys.h.
Response Records
A response record is assigned to each application request that specifies
the send-with-wait option (mode 8), for example, zsend or zcntl. It is used
as a temporary storage for the return s tatus when such request is
completed. When the request originator picks up the return status, the
assigned record is returned t o the free pool and may be re-used. For more
detail, see the data structure zrsp_type (response record) in
/opt/acc/include/zcom/zcomsys.h.