Gday Ralph
As per Peters original request
If I copy the routine and have 3 of them for a.1, a.2, a.3 I run out of code space.
Having been down the track he went down, i understood his post as meaning he currently had a routine that he would have to copy three times unless he could pass by reference, a port as a variable ( which you cant do ).
As such all other inputs/outputs were irrelevant at the time, just how to ref a port.
If he has other probs with his routines, i dont know, i merely advised of a different method i have used to get around referencing ports in subroutines.

Andrew