To convert an Epson U220 model printer you will need an Epson compatible Connect-IT interface card.
Enabling communication between the card and the printer
Turn the printer over and remove the screw holding the protection plate over the dip switchs
Locate the 2nd bank of dip switches
Set switch 2-4 to ON
You can then self-test the printer to see if the Serial interface has been changed. If the interface still says "Serial", set 2-4 to OFF and set 2-8 to ON. You can then power off printer and perform another self-test. With 2-8 ON, it should now show as "Parallel or other" as its interface. This may vary from older U220s to newer ones, so results may vary.
Change your computer to the IP range of the Connect-IT Card (default IP is 192.168.192.168)
Navigate to the default IP address
Under Configuration -> Network -> TCP/IP
Confirm & configure the following:
Get IP Address
Set using Automatic Private IP Addressing (APIPA)
Set using PING
Use the IP schema as necessary for the site. Remember all IP printers start at 192.168.X.231 and above
Unless extenuating circumstances require a different IP subnet
Use the sites default gateway as determined for the site.
The printer will now load its settings.
You can confirm the configuration by pressing & holding the Connect-IT IF Card button on the card itself for 3-seconds while the printer is on.