hello

i have problem, i need connect sensor 4-20 mA to LOGO8 with AM2,

what perametr i must set if i wanna that 4 mA is zero and 20 mA is 100 %,

i try it

of 4 mA i get 0 %

but in 6mA i have 100

Let us show what parameters you have set in the analog block.

Post your programm, and we can see whats going wrong.

Hello kormotech,

something to the basics:

The analog converter of the Logo converts an analog input signal in units 0-1000. Whether 0-10V or 0 / 4-20mA. With a 4-20 mA only the range 0-4mA disappears and you are only 800 units available (equivalent to 20mA - 4mA = 16mA). This results in:
0 mA = 0 units
4 mA = 200 units
6 mA = 300 units
8 mA = 400 units
10 mA = 500 units
12 mA = 600 units
14 mA = 700 units
16 mA = 800 units
18 mA = 900 units
20 mA = 1000 Units

Therefore, results in the following in the setting of the analog amplifier:

Gain: 1.25 are a total of 1250 units
Offset: -250 are then 1250 -250 = 1000 units
Min: 0 (-250 corrected offset)
Max: 1000 (1250 -250 corrected offset).
So if you are see at 6 mA the number 300, this is the value after the A / D converter.
300 * 1,25 (Gain) = 375
375 - 250 (Offset) = 125

The corrected and enhanced value is 125, which then corresponds to one decimal place 12.5.