A switching Block
[sim,out_1, out_2] = ld_switch(sim, events, cntrl, in)
inputs = [control_in, signal_in]
if control_in > 0 : signal_in is directed to output 1; output_2 is set to zero
if control_in < 0 : signal_in is directed to output 2; output_1 is set to zero