Mathematical Rule; Gain And Offset Calculation - Siemens Logo! Manual

LOGO! functions

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
+70
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
5000
130
= (0
A) + B, i.e. offset B = –30
= (1000
A) –30, i.e. gain A = 0.1
= (0
A) + B, i.e. offset B = 1000
= (1000
A) +1000, i.e. gain A = 4
LOGO! Manual
A5E00380835-01