I got the answer of 1, so I will write it. Sockets (onboard) Molex0537800470 or compatible parts are: AdamTech125SH-G-04-TR-SMT-T / R Plug: Molex0511460400 + Pin Molex0506418041 Or compatible parts are: AdamTech125CH-G-04 + Pin AdamTech125CTG-B-G-R
After firmware 2.70 + UART2 was moved to an additional pin, it became UART_opt in the hardware design. Therefore, you must enable UART2 in the GUI to use this connector.