ZCOM Tables and Data Structures

ZCOM Header Structure

HLCLND - Local node number

The node number of the local ZCOM subsystem. If the Node-Definitionsection in the TTGEN configuration file is omitted, TTGEN defaults this field to one (1). Otherwise, it is initialized to the value of the Local-Nodeparameter. It is set up by TTGEN as the first node table entry that has zero ZLU number. There may be other numbers that also refer to the local node but HLCLND is the only one that is used to identify the local node on outbound messages.

HLTQTB - Queue label table

Each entry in the queue label table indicates the ownership of a data queue in a logical terminal table. Each entry has a structure of 16 bytes (zqlb_type) as shown in Table 3-2.

Table 3-2

Queue Label Table

 

 

 

 

 

 

Field Name

Field Description

Field Type

Size

(bytes)

 

 

 

 

 

 

 

QLBGRP

Appl. grp. number (0 = globally assigned)

uns.short

2

 

 

 

 

QLBNAM

Queue label name

char

8

 

 

 

 

QLBQNB

Allocated queue number

uns.short

2

 

 

 

 

QLBRSV

<reserved>, unused

char

4

 

 

 

 

The table is initialized by TTGEN from the Logical-Datastatements in the TTGEN configuration file. There is one entry in the Queue label table for each Logical-Datastatement. Additional entries can be added to this table by calling the zltqueue routine (up to a maximum of 20 queue labels).

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Chapter 3