Siemens LOGO! - Gain and Offset Calculation; Mathematical Rule

LOGO! Manual
A5E00380835-01
130
Mathematical rule
Actual value Ax =
(internal value at input Ax  gain) + offset
Gain and offset calculation
The gain and offset is calculated based on the relevant high
and low values of the function.
Example 1:
The available thermocouples have the following technical
data: –30 to +70C, 0 to 10 V DC (i.e. 0 to 1000 in LOGO!).
Actual value = (internal value  gain) + offset, thus
–30 = (0  A) + B, i.e. offset B = –30
+70 = (1000  A) –30, i.e. gain A = 0.1
Example 2:
A pressure sensor converts a pressure of 1000 mbar into a
voltage of 0 V, and a pressure of 5000 mbar into a voltage
of 10 V.
Actual value = (internal value  gain) + offset, thus
1000 = (0  A) + B, i.e. offset B = 1000
5000 = (1000  A) +1000, i.e. gain A = 4
LOGO! functions