The Epson TM-U220B (model M188B) is a receipt printer with a DB25-DB9 cable. It will be connected to the host via Serial port and recognized in Linux as /dev/ttyS[X]

In this post is explained how to find out which device was detected by the operative system. In my case:

setserial -g /dev/ttyS[0123]
/dev/tty0, UART: 16550A, Port: 0x03f8, IRQ:4
/dev/tty1, UART: unknown, Port: 0x02f8, IRQ:3

To test the print capabilities the easier way is to send an echo message to that device:

echo "printing test" > /dev/tty0

And it was correctly printed.The host used in this test was ThinkCentre M715q with serial port and Lubuntu 12.04.