Step response in z-domain (FOH)

 

s = tf('s');
k=6.95
G = (k*100)/((s + 10)*(s + 20));
Gd = c2d(G, 0.01,'foh') % first order hold
sys_cl = feedback(G,1)
sys_cld = feedback(Gd,1)
step(sys_cl,'--',sys_cld,'-')

 Sampling time = 0.01 sec