C="Zintfr (Forward Rectangular Digital Integrator) Model:
Models the equation: y(k) = y(k-1) + dt*x(k-1) where y(k) is the output, x(k) is the input, and dt is the digital update time. The digital update time is set by the user in seconds. The type of integration is seldom used due to its sensitivity to stepsize which often results in instability. Note the external override of the pulse train block to externalize the time between samples parameter.
Limitations:
1. Digital Update Time, sec >0 and >simulation stepsize"