I am not able to get the correct reading out of me FC105

Hi All,

I am new to the Siemens AI cards... I have a three temperature transducers thatare capable of outputting a 4-20mA signal based on a temperature range of -20 to +185 degree's Fahrenheit. well I am not able to get the correct reading out of me FC105.. the temp at all the transducers is 24C (76degeree's F).... and the raw data comingin on input IW272 is 16256 (8 bit cards thusresolution of 128bits) ~.5 degree's per increase/decrease.. well once the input is put throughtheFC105 scalefunction with an span of -20 to +185 0mA to 20mA I am getting an output of ~ 105 degree’s not anywhere close to 76 degree's I would expect... I have looked at the support resources and understand the analog_values.pdf.. ect.. and do not believe this is my issue as... as far as I understand it if I am at 4mA on my card it will put out a value of 0 (0%) and at 20mA it will put out a value of 27,648 (100%) signed? correct? so the value could go below Int. 0% to a negative Int... or above 100% to a Int. greater then 27648 up to 32,767 possible..(error!!!!!!)

I under stand that I may need to scale my input?? not sure... if I do how do I scale an Integer with a real value like .84377 like some posts suggest? to bring the max possible from 32,767 down to 27,648 think this does not apply to me...one is an integer and the other is a real number what logic function do I use for this?


Any ideas out their please?

Any help appreciated