cable connection between PC and AX12 modem

You didn't really give us much to go off. 

1. you have the RAX120? you put that in the signature. Or what actual model do you have? 

2. what firmware is on it? 

3. what is giving you error code 6 (details are key)

4. what were you trying to do? 

5. what device were you trying on?

We're not there to see whats going on, whats been done, or even what your using. so the more details you give us, the better we can help