Rockwell Automation 1746-FIO4V SLC 500 Fast Analog I/O/ User Manual - Manual (Page 46)

Publication 1746-UM009B-EN-P - September 2007
46 Write Ladder Logic
Standard Math Example
Example Program Using the Scaling Instruction (SCL)
GREATER THAN
Source A
Source B
I:3.1
2750
Rung 2:0
Check for below range
Rung 2:1
Check for above range
Rung 2:2
Scale the analog input
Rung 2:3
Multiply by the
scaled range
Clear fault bit
from overflow
Divide result
by input range
Add offset
Below-range
flag
Above-range
flag
B3/0
(L)
B3/1
(L)
S2:5/0
(U)
LES
GRT
MUL
DDV
ADD
N7:0 contains
process pressure
END
LESS THAN
Source A
Source B
I:3.1
1750
MULTIPLY
Source A
Source
Dest
I:3.1
400
N7:0
DOUBLE DIVIDE
Source A
Dest
4095
N7:0
ADD
Source A
Source B
Dest
N7:0
100
N7:0
GREATER THAN
Source A
Source B
I:3.1
2750
Rung 2:0
Check for below range
Rung 2:1
Check for above range
Rung 2:2
Scale the analog input
Rung 2:3
N7:0 contains
process
temperature
Below-range
flag
Above-range
flag
B3/0
(L)
B3/1
(L)
LES
GRT
SCL
END
LESS THAN
Source A
Source B
I:3.1
1750
SCALE
Source
Rate (/10000)
Offset
Dest
I:3.1
977
100
N7:0