Sample HD13xx
Note : 
Use direct-echo RS232 adaptor for instance 
performance.
Also, refer to the bitwise serial 
protocol defining section.
Bit-level protocol configuration is possible by choosing 'bit (byte)' type in  
[FX] category field in serial protocol configuration dialog.
 

Bit configuration of 's0' (or 'r0') protocol is

The 'Bit test' button sends 's0' and expects to receive 'r0' which is same with 's0' in protocol configuration. To emulate this 'echo' situation, it would be better to use direct-echo RS232 adaptor. If the deployed applet or application does not receive 'r0', the red LEDs will not be updated.