Hi,

I bought a Serial (RS232 to USB) cable:
https://cdn.shopifycdn.net/s/files/1/05 ... 1639401799

Under System -> Resources -> USB it shows up
under Ports -> nothing.


Please tell me how to fix this!!

The problem exists with ROSv6.49.6 and ROSv7.2.3

You have check, before purchase, if the USB-to-Serial device if is compatible with RouterOS?

rextended is right, basically if a Serial adapter support Linux without add'l drivers, it should work. If it requires a driver or installer, the serial adapter can't work on RouterOS.

The only WAG in V7 is to set "serial" under the Interface>LTE>Modem settings, since I guess it's possible LTE might be trying to use it BUT I doubt it.

I had tried using Prolific usb to serial chips in the past and they were nothing but trouble. Fake chips everywhere, old chips not supported by new drivers, newer chips causing windows driver to BSOD on removal, chips dropping data at higher baudrates, ... etc etc.
Prolific = Avoid at all costs!!

If you want proper brand name adapter, buy FTDI.
If you want something cheap, even CH340 is better than Prolific.

old chips not supported by new drivers
Prolific = Avoid at all costs!!

Prolific has stopped this now.. FTDI did the same thing for a while too, eventually they stopped.

newer chips causing windows driver to BSOD on removal

Only if the port was open.. I've had this happen on a few chipsets, not just Prolific.

Please tell me how to fix this!!

The problem exists with ROSv6.49.6 and ROSv7.2.3

Did you reboot the router after connecting the USB-Serial adapter?