The problem I am actually facing is that despite the fact that i have 4-20mA at the PIW input the values i see at the input of the scaling fc FC105 is -32767 at 4mA and 32767 at 20mA. This is the value i want to scale to 0-20000. I know that FC105 do its calculation base on the following
OUT = [ ((FLOAT (IN) – K1)/(K2–K1)) * (HI_LIM–LO_LIM)] + LO_LIM

The constants K1 and K2 are set based upon whether the input value is BIPOLAR or UNIPOLAR.

·BIPOLAR: The input integer value is assumed to be between –27648 and 27648, therefore, K1 = –27648.0 and K2 = +27648.0

·UNIPOLAR: The input integer value is assumed to be between 0 and 27648, therefore, K1 = 0.0 and K2 = +27648.0

If the input integer value is greater than K2, the output (OUT) is clamped to HI_LIM, and an error is returned. If the input integer value is less than K1, the output is clamped to LO_LIM, and an error is returned.
now my input integer is greather than k1 which supose to be between 0 and 27648 and my output is at 20000. Another issue is that by the time I have 16mA at my PIW input, the scaling input value has already reached 32767. My question now is that what can I do to make the input reads between 0 and 27648 and to correspond with the changes in mA between 4 and 20 at the PIW word. The type of analog input module i am using is 2AI I 2WIRE ST (6ES7 134-4GB01-QAB0). Is there anything else i will do may be in the configuration or in the program to make me achieve my aim.