Epson TM-U325D Operator's Manual page 26

2. Turn the printer over and remove the DIP switch access cover,
as shown below.
3. There are two sets of switches. Notice that ON is marked on
each set of switches. Use tweezers or another narrow tool to
move the switches.
4. Use the following tables to set the DIP switches. Numbers
starting with 1 are in the first set, and numbers starting with 2
are in the second.
1–16 Setting Up the Printer
DSW1
DSW2