Duty2 already contains the value from the lookuptable - that is what your Lookup does, it assignes the value pointed at by Duty1 to the variable Duty2 in this case.

For each iteration thru the loop Duty2 will contain the value pointed at by Duty1 and since Duty1 counts 0,1,2,3...44 Duty2 will contain 0,18,35,53...0

/Henrik.