Intermec EasyCoder 7421 User Manual page 64

If your printer is not receiving downloaded data, try the
solutions in this table.
Printer does not Incorrect
communicate communications
with the host. parameters.
Damaged or incorrect
I/O cable.
Use Data Line Print mode to troubleshoot communications
between the printer and the host, and to test the operation of the
printer. When the printer is in Data Line Print mode, it prints out
all downloaded data with the hexadecimal equivalent directly
underneath it.
1. Turn the On/Off switch to the off position.
2. Press down and hold the Feed/Pause button while turning on
the printer.
The hardware configuration test label prints out and the
firmware program and version number are sent to the host.
You are now in Data Line Print mode.
3. Send a few characters down from the host. The printer prints
out your data with the hexadecimal equivalent directly
underneath it.
Use PrintSet to make sure
that you have the correct
communications
parameters set (such as
baud rate).
Check the connections at
both ends or replace the
cable. See Appendix B for
cable information.