Xantrex inverters can be accessed using either the Xantrex Modbus protocol or using the proprietry Xantrex ASCII protocol. Both protocols communicate with the inverter using a serial port such as COM3.
The Xantrex ASCII protocol communicates with a single Xantrex inverter using a dedicated serial port. With the Xantrex ASCII protocol, each Xantrex inverter accessed from PVBC requires a dedicated serial port.
When the inverters use the Modbus protocol and are connected in an RS485 daisy chain, the inverters can be accessed via a single serial port. Devices of different types and manufacture that use the ModBus protocol can be accessed via a single serial port when connected in an RS485 daisy chain.