Console output
--------------
cmd; AT @2 x x
AT_@2          Cmd; AT @2 Length; 15  Response; 0123456789AB__>.

cmd; 01 00 x x

PIDs01_20      Cmd; 01 00 Length; 21  Response; 41 00 BE 1F B8 11 __>.

cmd; 01 20 x x

PIDs21_40      Cmd; 01 20 Length; 21  Response; 41 20 80 06 00 11 __>.

cmd; 01 40 x x

PIDs41_60      Cmd; 01 40 Length; 21  Response; 41 40 78 D0 00 00 __>.

TPA 
$cmd; 0101 
cmd; 0101 xWin32::API::Call: parameter 2 had a buffer overflow at C:/Strawberry/perl/vendor/lib/Win32API/CommPort.pm line 217.