Your attempt to use INPUTs as general purpose data storage has a small problem. When the PLC ladder logic is running it will overwrite all of the INPUT values during each scan of ladder logic. You are using INPUTs that your PLC does not physically have but the ladder logic code does not know how many INPUTs your PLC actually has (or are actually being used) so it scans the maximum number of INPUTs that ladder logic can handle. This number is way more that 16. This is why your are seeing your "special" INPUTs getting cleared to 0.
I suggest that you store data in either DM[] or RELAYs. If you store your DATA in RELAYs you can make it visible on the first page of the simulator / on-line monitor.
If you insist on using INPUTs for data storage you may need to use the SetSystem 16,n statement on the the first scan of your PLC program. The SetSystem 16,n sets the number of I/O pins that will be accessed. The "n" argument affects the number of I/Os to access. When n=1 the I/0 pins 1-16 will be scanned. When n=2 then pins 1-32 will be scanned.
SetSystem 16,n is intended to help speedup the execution of ladder logic by restricting the number of I/Os that must be processed on each pass thru the ladder logic.
I use SetSystem 16,n for it's intended purpose to speed up the ladder logic execution. It works for this purpose You will need to test and verify if SetSystem 16,1 will solve the problem that you have created.
Gary Dickinson