module: step_in_bool
parameters: int vend int vstart double tstep
inputs:  
outputs:  bool step
classes: 
static_variables: double i, int start_val, int end_val;
init: 
i=0.0;
start_val = (vstart == 0) ? 0 : 1;
end_val = (vend == 0) ? 0 : 1;
step = start_val;
code:
i += 1.0;
if (i*Ts >= tstep)
   step = end_val;

