[MC65 DEX] COM port ?

I'm currently working on an MC65 with the specific DEX cable (REF: 25-127558-01R).


My problem is that I can't open the com port to send data. The normal port is "COM2:" but when I try to open this port it doesn't work and I get an "55" error code means:


ERROR_DEV_NOT_EXIST

55 (0x37)

The specified network resource or device is no longer available.



I made a loop to test each port, I just can open COM1: and COM6: but non of these ports work properly to send data. I can send data, but nothing come outside the cable.


Any idea about the correct com port name ?


Best regards,


Olivier.