This adapter by Delock can be connected to the Sub-D 9 pin connector of your device or system and use it as a null modem. Furthermore, a standard serial cable into a null modem cable can be converted, with which you can connect two computers directly. Specification https://elecena.pl/product/18170040/65255-adaptor-sub-d-9pin-plug-jack 2021-05-01 https://elecena.pl/product/18170040/65255-adaptor-sub-d-9pin-plug-jack 2022-05-19