The USB XpressNet interface suports three modes of operation. The mode is selected by software and can be changed without unplugging the USB XpressNet interface from the USB port.
In device mode the USB XpressNet interface is a XpressNet device. The host PC can send/receive XpressNet messages to/from the command station.
In station mode the USB XpressNet interface is the XpressNet controller. It provides the timeslots for XpressNet devices and sends their messages to the host PC. The USB XpressNet interface can optionally supply the 12V bus power up to 100mA, this should be enough for five bus powered XpressNet devices (bus powered devices may use up to 20mA according to the Lenz XpressNet specification).
In monitor mode the USB XpressNet interface doesn't send any XpressNet messages, it only listens and sends all received messages to the host PC.
The software stack consists of two parts: