AUTOMATION PROGRAMMING - PLC - FC 105.

F.C. 105 is a function block which is already exists in our memory and we use in order to convert and scale an integer ( 0 - +27648 ) to a physical size . We use Ladder as we see from the picture we understand the symbol of FC 105 let me explain in short about inputs and outputs of this symbol and how we use them :

EN : If we call FC 105 with C.C. or U.C.

IN : We have to write the address of an analog input which we need to convert-scale for example PIW 256 , we remember that we have logical addresses for analog inputs from *byte 256 to byte 767* .

HI-LIM : We write the high limit of a physical size in which we have to scale an integer +27648 of a analog input .

LO-LIM : We write the low limit of a physical size in which we have to scale an integer -27648 of analog input.

BIPOLAR : We determine if the signal is a single-pole if *merker = 0 , a bipolar if * merker = 1 * .

ENO : We have our *input situation* .

RET_VAL: This is an output with *RLO = 0* if we have our programm run without any errors , so we give an MW adress .

OUT : We have to give an *DW* address in which we store the scaled price of an analog input .

We need to know about the * Analog Signals * theory to understand completely for what we talking about *FC 105* .

In short , we have analog signals because we need to convert and scale them , for a example a liters of water to digital size and after that this digital size convert and scale to its physical size .