Data routing between the Ethernet and serial ports of the DS is effected through two routing buffers*, one for each routing direction. Buffers are necessary because Ethernet and serial ports operate in fundamentally different ways and at different speeds. Ethernet port receives and sends the data in packets (groups) while the serial port sends and receives serial data stream where each data byte is independent. Here is how the DS transforms Ethernet packets into the serial stream and back:
Ethernet-to-serial data routing . The DS outputs the contents of arriving Ethernet data packets byte by byte via the serial port. The DS does not check or filter the contents of the data arriving from the network host.
Serial-to-Ethernet data routing . **** This requires grouping arriving serial data into Ethernet packets of suitable size. Several settings define what data is accepted into the buffer and when and how this data is combined into the Ethernet packets and sent out- see serial-to-Ethernet data routing for details.
Routing buffers are initialized (their data discarded) each time the data connection is closed.
* The size of routing buffers is hardware-dependent and is different for different models and modifications of Tibbo Device Servers. Routing buffer size can be verified using the Status (U) command.