how to insert a time delay?

As a short I have a following question ; -In my thesis I use X Plane(aircraft simulation program) and Simulink. I get aircraft values during the flight like pitch degree directly from X plane through UDP connection to Simulink. Here is everything fine. The problem is I want to insert a time delay for to calculate another parameter like pitch rate (which is pitch_degree(t) - pitch_degree(t-1), current (at time t) pitch degree minus before( t-1)pitch degree). Question is how can I do this? In simulink there is discrete blocks like Unit Delay Block or continous blocks like Variable Time Delay. I try both of them but it seems not functioning. Is there any one who have any idea how to solve this problem

Many thanks from now Tahir

Answer 1

[K E]

Perhaps the solution in this blog entry will help. But more experienced Simulink users than me might recommend a simpler approach.