Staircase timer

[Kuronen]

Being new to LUA I´m finding it difficult to get everything right. Could some one help me with below.?? Please

I have tried to create a simple Staircase timer for lighting control with the following functions:

1bit KNX command = true activates (From presence detector)

(1.) Sends a KNX Byte value  "90%"

(2.) After not receiving (1bit from presence detector) in 30 min send KNX byte value 20%

(3.) After not receiving (1bit from presence detector) in 60 min send KNX byte value 0%

(( If triggered by 1bit from presence detector it should re-trigger the staircase timer.))

I need to run multiple staircase timers for different areas with the same LM unit.!