The open loop digital control system is the following: S x(t) x"(t) With: Go(s) T=1s 1-e-st S Go(s) Gp(s) 2 s(s+2) 1. What is the role of the switch S and what I means? 2. What is the role of zero order hold? 3. Calculate the open loop transfer function G(z) of the system. Gp(s)