Take an ethernet cable and cut off one of the connectors. Attach a parallel port (printer) connector. The diagram and photos below show how the pins should be connected.
Once you have the crate connected to the computer, use the program kermit to watch the connection. Download kermit from here. Once kermit is installed and the cable has been connected, start kermit with the command kermit. Once in kermit, run the following commands to connect to the parallel port.
set line /dev/ttyS0 (you may have to change the device to ttyS1 or something else)
set speed 9600
set carrier-watch off
c (this will connect)
You should then be able to see everything coming over the debug port on the crate computer. And now be able to set the crate computer up.