USB to RS485 converter, being connected to the computer works as a virtual COM port.

Works under "CH340" driver widely available in the web. 

This versioncontains autodetect of data direction in RS485 line, terminal and push/pull resistors, and ground pin on connector, but it DOES NOT have galvanic isolation. 

We also have more advanced version with full galvanic isolation and LED data transfering indication (look among other our items or contact us).