Printer Prints "?" Or Incorrect Data With Serial Interface; Print Speed Is Slow When Using Windows Printer Driver; Printer Doesn't Cut Roll Paper With The Autocutter; Hexadecimal Dump Mode - Epson TM-U220 Reference Manual

4.5 Printer prints "?" or Incorrect Data With Serial Interface

If one of the following errors occurs during serial interface communication, the printer prints "?"
or ignores the data, depending on the setting of DIP switch 1-1.
❏ Parity error
❏ Framing error
❏ Overrun error
Note:
For other errors, we recommend confirming the transmission setting of DIP switch 1-3: Handshaking.

4.6 Print Speed is Slow When Using Windows Printer Driver

When the printer prints a Windows font using the EPSON Advanced Printer Driver, the print
speed is slow. To improve the print speed, use a printer font.

4.7 Printer doesn't cut roll paper with the autocutter

TM-U220 Type D does not have an autocutter unit. If you use the type D model, you can't use
the autocutter function. Use the manual cutter.

4.8 Hexadecimal Dump mode

This feature allows experienced users to see exactly what data is coming to the printer. This can
be useful in finding software problems. When you turn on the hex dump function, the printer
prints all commands and other data in hexadecimal format, along with a guide section to help
you find specific commands.
To use the hex dump feature, follow these steps:
1. After you make sure the printer is off, open the paper roll cover.
2. While you hold down the FEED button, turn on the printer.
3. Close the cover.
Rev. E
TM-U220 Technical Reference Guide
Troubleshooting 4-7