CEM ECM/200/000 Ethernet communication module with PSU and enclosure is a serial to Ethernet converter that enables CEM serial communication ... The ECM can support a chain of up to 16 RS485 CEM ...

[André Sarmento] needed to connect a computer to an RS-485 bus. A simple converter can be sourced online, but the only thing he could find locally that was even close was a USB to RS-232 converter.