Gday Carlton
Have you tried doing a loopback test by shorting the Tx/Rx pins
and seeing if you get an echo???
My PEC editor can detect and scan all ports to try and find a Meade
and will log what it gets back.
http://members.optusnet.com.au/johansea/
It also allows you to send and read data manually, so can be used for loopback testing.
What firmware is in your handbox????
There is a known problem in A4S1 but it shouldnt affect getting a connection.
Andrew