Rockwell Automation 1772-LV Mini-PLC - 2/15 Programmable Controller (Series B) Programming and Operations - Manual (Page 77)

Advanced Instruction Set
Chapter 6
6Ć20
SECTION D
Advance Data Manipulation
This section describes ways to transfer file data to another designated area. In
this section you will read about:
Files
Data monitor mode display
Data transfer file instructions
Sequencer
instructions
Chapter 10 demonstrates the programming techniques when using advanced
data manipulation instructions.
A file is a group of consecutive data table words used to store information. A
file is defined by a counter and a starting word address. the counter has two
functions:
Defines the file length with its preset value.
Points to a particular word in a file with its accumulated value.
The counter address is the file instruction’s address. The processor uses this
address to search for the instruction.
A file can be between 1 and 999 words in length. The address of word 1
defines the address of the file. When displayed, the words of a file are
designated consecutively by positions 001-999 according to the length of the
file.
The word address defines:
The location in the data table to which or from which the data will be moved.
This word address can be manipulated by ladder diagram logic.
There are two types of file instructions. Those that have an externally indexed
counter and those that have an internally indexed counter. The two file
instructions that have an externally indexed counter are: Word-to-file move, and
File-to-word move. The file instruction that has an internally indexed counter
is: File-to-file. Figure 6.10 shows the difference in format between these two
types of file instructions.
What is a File?