Siemens SIMATIC S7-1200 - Page 43

STEP 7 programming software
3.3 Easy-to-use tools
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
43
For this example, enter the following equation for scaling a raw analog value. (The "In" and
"Out" designations correspond to the parameters of the Calculate instruction.)
Out
value
= ((Out
high
- Out
low
) / (In
high
- In
low
)) * (In
value
- In
low
) + Out
low
Out
= ((in4 - in5) / (in2 - in3)) * (in1 - in3) + in5
Where:
Out
value
(Out)
Scaled output value
In
value
(in1)
Analog input value
In
high
(in2)
Upper limit for the scaled input value
In
low
(in3)
Lower limit for the scaled input value
Out
high
(in4)
Upper limit for the scaled output value
Out
low
(in5)
Lower limit for the scaled output value
In the "Edit Calculate" box, enter the equation with the parameter names:
OUT = ((in4 - in5) / (in2 - in3)) * (in1 - in3) + in5
When you click "OK", the Calculate
instruction creates the inputs r
e-
quired for the inst
ruction.
Enter the tag names for the values
that correspond to the parameters.