Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual - Manual (Page 50)

Data Table
Chapter 3
3Ć23
As you program your application, you should carefully record the
data table addresses of the program elements. The importance of this
documentation cannot be overemphasized. You will find it invaluable for
avoiding improper use of data table areas and as an aid in troubleshooting
and making program changes.
The data table documentation forms presented at the end of this chapter
can be reproduced or revised as needed. They include two general types:
Data Table Word Map (1024 word) and Data Table Map (128 word)
Data Table Word Assignments (64 word), Data Table Bit Assignments,
and Sequencer Table Bit Assignments
An example showing how the forms are used accompanies the
descriptions.
This form can be used to map the addresses of group data table words and
to concisely describe the function of each group. The groups can include
I/O Image Tables, Block Transfer, Timer/Counter, File and Sequencer
Instructions, Files and Sequencer tables.
The form has prenumbered rows representing addresses from 000
8
-777
8
.
Each row has 32 spaces where each space represents one word address.
Any group of related word addresses can be designated on the map by
labeling or color coding the spaces representing their addresses. For
example, Figure 3.8 shows a completed portion of the data table word map.
The Timer/Counter Accumulated values are labeled in the spaces defined
by word address 040
8
through 071
8
. Other data table areas are similarly
labeled.
3.4
Data Table Documentation
Forms
3.4.1
Data Table Word Map
(1024 Word)