// first-order lag derivative term (*

Parameter K must be set to T / (T + T1)

*) FUNCTION_BLOCK DT2

VAR_INPUT

IN : REAL;
K : REAL;

END_VAR VAR_OUTPUT

Q : REAL;

END_VAR VAR

H : REAL := 0.0;

END_VAR

BEGIN

Q := IN - H;
H := H + K * Q;

END_FUNCTION_BLOCK