Epson TM-U200D series Operator's Manual page 43

To use the hex dump feature, follow these steps:
1. After you make sure that the printer is off, set DIP switch 1-2 to
ON.
2. Turn on the printer while you hold down the PAPER FEED
button; then release and press the PAPER FEED button quickly.
Note:
Releasing and pressing the PAPER FEED button should be
performed before the printer finishes initializing; otherwise the
printer begins the self test.
3. When the printer enters the hex dump mode, it prints
"Hexadecimal Dump."
4. Run any software program that sends data to the printer. The
printer prints all the codes it receives in a two-column format.
The first column contains the hexadecimal codes and the
second column gives the ASCII characters that correspond to
the codes.
A period (.) is printed for each code that has no ASCII
equivalent.
During the hex dump all commands except DLE EOT and
DLE ENQ are disabled.
5. When the printing finishes, turn off the printer or reset it to
turn off the hex dump mode.
6. If you changed the DIP switch 1-2, set it back to OFF.
3-6 Troubleshooting
Hexadecimal Dump
1B 21 00 1B 26 02 40 40 : . ! . . & . @ @
1B 25 01 1B 63 34 00 1B :
41 42 43 44 45 46 47 48 : ABCDEFGH
. % . . c4 . .