| linear time-invariant transfer element the transfer function of which may be written as a quotient of two polynomials in s|
with aj and bj real, an ≠ 0, bm ≠ 0
|ai, bi||are the polynomial coefficients;|
|s||is the complex variable of the Laplace transform;|
|U(s)||is the input transform;|
|V(s)||is the output transform.|
Note 1 to entry: In real controlled systems, m < n. With respect to mathematical denomination these elements would have to be called "proper-fractional rational transfer element" which is not usage.
Note 2 to entry: An element with dead time is an example for a non-rational transfer element.
Note 3 to entry: This entry was numbered 351-24-43 in IEC 60050-351:2006.