The serial interface and network are provided as two separate EXOS
device drivers as far as the user is concerned, with device names
"SERIAL:" and "NET:" respectively. However
since they share the same hardware only one of the devices can be
supported at a time. So if the user wishes to open a channel to the
serial device he must first close any channels open to the network, and
vice versa.
Only one serial channel may exist at a time, while any number of channels may be opened to the network device provided there is sufficient RAM for the 512 bytes of buffer for each channel. All channels opened to the network or the serial device support both input and output.