Siemens 6ED1050-1AA00-0BE8 Manual De Usuario

LOGO! functions 

 

4.3 Special Functions 

 

LOGO! 

154

 

Manual, 04/2011, A5E03556174-01 

4.3.6 

Calculating the gain and offset of analog values 

A sensor is connected to the analog input and converts a process variable into an electrical 

signal. This value of signal lies within the typical range of this sensor.     
LOGO! always converts the electrical signals at the analog input into digital values from 0 to 

1000. 
A voltage of 0 to 10 V at input AI is transformed internally into a range of values from 0 to 

1000. An input voltage exceeding 10 V is shown as internal value 1000. 
Because you cannot always process the range of values from 0 to 1000 as predetermined by 

LOGO!, you can multiply the digital values by a gain factor and then shift the zero of the 

range of values (offset). This allows you to output an analog value to the LOGO! onboard 

display, which is proportional to the actual process variable.    

 

Parameter 

Minimum 

Maximum 

Input voltage (in V) 

0 

≥ 10 

Internal value 

0 

1000 

Gain 

-10.00 

+10.00 

Offset 

-10000 

+10000 

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