Port Settings

Since release of the blue PiraT2 Mainboard 2 and blue PiraT Mini, there is a possibility to configure the behavior of ethernet ports on the back of the device.

Logging of High-Level Protocols (Switch or Port Expander)

For Logging of high-level protocols (GNLog, DLT, etc.) over ethernet, as well as Camera and XCP over ethernet, use the port setting switch or port expander. You will find the latter in early releases of Mainboard 2.

The ports, which are configured as a switch (or port expander), are ready for operation, after the logger has started up.
In default mode, all ports are configured as switch (or port expander).

While the port expander sends its outgoing ethernet packages to all of its ports, the switch forwards the packages based on the target MAC address to the relevant target port.

Low Latency Logging (Spy or Tap)

The spy and tap are logging incoming ethernet traffic in "Promiscuous Mode" on MII level ("Spy Logging").

A port which is configured as spy is ready for operation after very short latency and can log incomming data even when the logger has not started up yet.
The tap has the same functionality as two spys and additionally forwards all incoming traffic from one port to the other (in both directions). This forwarding is also optimized for low latency.

The trace files for spy logging are recorded with a separate range of channel numbers.

Notes

As the behavior of the ports can be configured flexibly, the port configuration must be considered while plugging the cables. Look out which cable is connected to which port.

A port, which is configured as spy or tap, cannot be used for high-level protocols. In the other way round, a port, which is configured as switch, could do a spy logging if the firmware of your logger supports it.

Please note that the described functionality is possibly not available for your logger variant.