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Troubleshooting for Serial Interface Communications
Problem
Printer prints one
character then stops
Recommendation
The LQ uses the DTR signal and the
X-on/X-off protocol (via TXD) to tell the
computer whether it is ready to receive
characters or whether it is busy printing.
Refer to your computer’s documentation
and ensure that the computer is using
one of these systems. You may also need
to check your cable wiring or ask your
dealer to do it for you.
READY light flickers
but nothing is printed
Data is getting through to the printer but
is not being interpreted correctly Make
sure that both the printer and computer
are using the same baud rate, number of
start and stop bits, and the same panty
All printing is garbled
Make sure that both the computer and
printer are set to use the same number of
data bits per word (8) and that they both
use the same parity, baud rates. and
number of start and stop bits.
Hex Dump Mode
The LQ has a special feature that makes it easy for experienced
printer users to find the causes of problems. The hexadecimal (hex) or
data dump mode gives a printout of exactly what codes reach the
printer.
Enter this mode by turning on the printer while holding
down
the
FORM FEED and LINE FEED
buttons at the same time. Then, when you
run a program, either an application program or one you have written
in any programming language, the LQ prints, in the hex format, all the
codes being sent to the printer.
The data dump below was made while writing this appendix. By
comparing the guide section on the right with the printout of hex
codes,
Problem Solving and Maintenance
D-5