extended description of the systems by:
Differential Equations + Algebraic Equations ⇒ DAE's (Differential and Algebraic Equations)
representation: F(dX/dt, X, t) == 0
The description of systems is possible as hitherto in VHDL added by algebraic and differential equations (DAE's). These DAE's are having the form: F(dX/dt, X, t)==0; underlined sizes may be vectors. F is an expression, X is the unknown in the equation, dX/dt is the first derivation from X of time and t is the time. The system of equations is only solvable when the number of independent equations is equal to the number of unknowns. These unknowns may be only through quantities, free quantities or interface quantities of node `out'! Thus, an across quantity is no unknown of a system.
Q'Dot | derivate of time |
Q'Integ | time integral |
Q'Delayed(delay_time) | time delayed quantity |
Q'Ltf(numerator_coefficients, denominator_coefficients) | Laplace transfer function |
Q'ZOH(sampling_period [, initial_delay]) | zero - order hold |
Q'Ztf(numerator_coefficients, denominator_coefficients, sampling_period [, initial_delay]) | Z-domain transfer function |
Q'Slew([max_rising_slope [, max_falling_slope]]) | slew rate of a quantity |
S'Ramp([rising_time [, falling_time]]) | ramp of a signal |
S'Slew([max_rising_slope [, max_falling_slope]]) | slew rate of a signal |
i == 1/L * u'Integ; |
|
i == C * u'Dot; |
For the representation of equations the listed operators are available:
I. e., the second derivation of a quantity Q is: Q'Dot'Dot