Otr il tutto tramite un cavo compatibile USB lato APP che si collega poi alla presa RS232 connettore RJ11 posto sulla base della montatura.
To connect RS232 protocol to USB, you need an adapter -- I assume that is what you meant by "compatible cable." Often, the adapter chip is built into one of the cable connectors.
FTDI, Prolific and Silicon Labs are the three major manufactures of these chips. The others are pretty much bootleg copies of these three. FTDI chips were at one time so profusely bootlegged by Chinese copies that FTDI released a driver which bricked all the copycats :-).
One thing that you can check is if the adapter has a Prolific chip or the Silicon Labs chip. The ASIAIR has all sorts of problems working with Prolific drivers, and I don't know if it even has the Silicon Labs driver. Try to use a cable/adapter that uses an authentic FTDI chip. Don't buy a cable that does not document what chip is included in it -- it is very likely to be a bootleg.
The next thing to check is to see if you need a "null modem." Check the RxD and TxD pins (pins 2 and 3 -- you can search Google for pin designation) on the RS-232 connectors. If both ends (the ASIAIR end and the Meade end) have TxD voltage coming from the same pin, you will need a null modem.
The first indication that you may need a null modem is if both ends of the connector are female, or both ends are male, and you need a female-female or male-male adapter in between. Some of these gender swapping adapters are "null-modems" (RxD and TxD pins are swapped) while some are straight through connections.
You need to make sure RxD of one end of the mating is connected to TxD of the other end. You never want to connect RxD to RxD or TxD to TxD.
Chen