Rockwell Automation 1772-LP3 PLC - 2/30 Programmable Controller Programming and Operations Manual - Manual (Page 225)

Data Transfer File Instructions
Chapter 12
12Ć10
Incremental Mode
The incremental mode allows the file to be operated upon one word per
rung transition. Each time the rung containing the instruction goes from
false to true, the instruction operates on the word pointed to by the counter
accumulated value, and then increments to the next word. The operation of
a file instruction in the incremental mode is shown in Figure 12.9. In this
mode, the rate per scan is set equal to zero.
Figure 12.9
Incremental Mode Operation
Data Table
Rates Per Scan = 0
Instruction operates on one word per falseĆtoĆtrue
transition of the rung condition (enable).
The counter resets to position 001 after the last word
is operated upon.
1 Word Operation
1 Word Operation
1 Word Operation
1 Word Operation
File Word #1
File Word #2
File Word #3
Word #14 (Last Word)
1st Rung Enable
2nd Rung Enable
3rd Rung Enable
Last Rung Enable
NOTE: The differences between the incremental mode (r=0) and the
distributed complete mode when r=1 can be compared. In both cases, the
operation defined by the file instruction is performed as the file counter
sequentially points to each word in the file. The rung must go from false
to true in order to initiate the operation. In the distributed complete mode
when r = 1, the entire file operation requires a single false-true transition.
It goes to completion automatically, one word per scan over the number of