MSDHJP 

A Valve actuator opens the valve between 0 to 100%.

But feedback sensor in the fully closed position (0%) send 5.2 mA and in the 80% opening position, its output will be 20 mA.

How can scale feedback sensor to fully correspond 0 to 100% of valve position?

That's not possible. The maximum what the LOGO! can read of a analog input (by current) is 20mA.

When by 80% is 20 mA, how will read the 100% (greater then 20mA) of the sensor? 

You wrote:

MSDHJP

I appreciate your response. Is it possible to "subtract 200 units from the feedback signal (a feedback scale between 0 and 1000) using mathematical instructions"?

I answer to this: 

ixo65

Subtract 200 units, you don't need any mathematical instructions for that, a simple analog amplifier with an offset of -200 is sufficient.

Then wrote you:

MSDHJP

 

ixo65

Subtract 200 units, you don't need any mathematical instructions for that, a simple analog amplifier with an offset of -200 is sufficient.

CAN I USE THIS PROCEDURE TO FIX THE PROBLEM BELOW?

A Valve actuator opens the valve between 0 to 100%.

But feedback sensor in the fully closed position (0%) send 5.2 mA and in the 80% opening position, its output will be 20 mA.

How can scale feedback sensor to fully correspond 0 to 100% of valve position?

Why are you screaming?

Because you don't understand my answer and think it's wrong?
Then you need to formulate your question better.

You write that 0% = 5.2 mA and 80% = 20.0 mA. 100% would be 23.7 mA and the LOGO! cannot evaluate 23.7 mA. So the LOGO! do not show 100%.

Now I can only guess.
You don't write what a signal the sensor outputs. Because you want to subtract 200 units so I think it's a 4-20 mA signal.

Next guess.
Would you like the 0 to 80% displayed as 0 to 100%?
If so, then like this...