Page 233 - Programmable Logic Controllers, Fifth Edition - Mobile version

Input Ladder logic program Input Ladder logic program
L1 FAL L1
A FILE ARITH/LOGICAL A
A Control R6:1 A FAL
FILE ARITH/LOGICAL
Length 6 EN Control R6:6 EN
Position 0 Length 5
Mode All DN Position 0 DN
Destination #N7:50 ER Mode INC ER
528 Destination N29:5
Expression #N7:20
Expression #N29:0
Expression Destination
#N7:20 #N7:50 First move
File # N29:0 Second move Word N29:5
N7:20 528 528 N7:50
621 621 Word 0 Word
778 778 1
File
986 986 2
342 342 3 Fifth move
N7:25 135 135 N7:55 4 Fourth move
Third move
Figure 10-11 File-to-file copy function using the FAL
instruction.
Figure 10-12 File-to-word copy function using the FAL
instruction.
• The length of the two files is set by the value en-
tered in the control element word R6:1.LEN. • If we start with position 0, the data from N7:100
• In this instruction, we have also used the ALL will be copied into N7:101 on the first false-to-true
mode, which means all of the data will be trans- transition of input A.
ferred in the first scan in which the FAL instruction • The second false-to-true transition of input A will
sees a false-to-true transition. copy the data from N7:100 into N7:102.
• The DN bit will also come on in that scan unless an • On successive false-to-true transitions of the instruc-
error occurs in the transfer of data, in which case the tion, the data will be copied into the next position in
ER bit will be set, the instruction will stop operation the file until the end of the file, N7:106, is reached.
at that position, and then the scan will continue at
the next instruction.
Input Ladder logic program
Figure 10-12 shows an example of a file-to-word copy L1
function using the FAL instruction. The operation of the A A FAL
program can be summarized as follows: FILE ARITH/LOGICAL EN
Control R6:2
• With each false-to-true rung transition of input Length 6 DN
0
A, the processor reads one word of integer Position Incremental ER
Mode
file N29. Destination #N7:101
0
• The processor starts reading at word 0, and writes Expression N7:100
the image into word 5 of integer file N29.
• The instruction writes over any data in the
destination.
First move
Figure 10-13 shows an example of a word-to-file copy N7:100 N7:101
function using the FAL instruction. It is similar to the file-
to-word copy function except that the instruction copies
data from a word address into a file. The operation of the
program can be summarized as follows: N7:106
• The expression is a word address (N7:100) and the Figure 10-13 Word-to-file copy function using the FAL
destination is a file address (#N7:101). instruction.

214 Chapter 10 Data Manipulation Instructions

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