I've bought an USB to UART CP2102 and I want to connect it to a router to see the booting process. However, although I can see five pins in the router, I don't know which one is TX, RX and GND.

Could I test each router's pin one by one to find out which one is TX, RX and GND? or if I do this I could break the router?

--------Edit--------

This is the router/ont -> ONT I-240G-T. It works like this:

[![enter image description here](https://i.stack.imgur.com/L6Y4t.jpg)](https://i.stack.imgur.com/L6Y4t.jpg)

Thanks, best regards.