Siemens PLC programming FC 105 example program plastic number 22 converts 0.0 to 100.0 into real number and writes why OUT is equal to 50.5508.
Out (output value) = ((22+27648)/27648-(-27648)) * (/kloc -0/00 (upper limit)-0 (lower limit))+0 = 50.0000000001
That is to say, out = ((22+27648)/27648+27648)) *100 = 50.5000000001