As with the null modem cable, beware that you might need a cross-over UTP cable.

There are cables or adapters that plug into a regular UTP cable. In case your serial port is a RJ45 connector (which may be the case on network hardware), you also need a DB-9 to RJ-45 convertor. If it is about 1 centimeter long, the cabling is 'straight' and it will not work as a serial cable (these straight connectors are used to extend old VGA cables). If the connector is about 4 centimeter long, this is probably the case. You can also buy a female-to-female DB9 connector, but make sure that the internal wiring is cross-over like is the case with a null modem. The USB-to-serial cable, as well as the network device will have a DB9-male connector. A null modem cable is a cable with DB9-female connectors on both ends. Make sure to also purchase a null modem cable, or a female-to-female DB9 connector. The Prolific PL-2303 is a very common controller, and one I recommend. Like mine, the actual conversion from USB to serial is done by a Prolific PL-2303 USB to Serial Bridge Controller buried in the connector. I bought a Icidu C-707607 USB to Serial cable. In case the serial port is a DB-9 connector or RJ45 connector, you need a USB-to-serial adapter. Top right: two different methods to convert a DB-9 to a RJ45 connector. Bottom right: male-to-female DB-9 adapter. Bottom center: a USB-to-serial adapter with male DB-9 connector.

On the left: regular USB cable with micro-B and mini-B connector.

Serial terminal emulator mac