Oki MICROLINE ML380 Maintenance Manual page 313

(b) Circuit test mode function
After the settings outlined in Section (a) are completed and power is turned on, the
serial interface checks the message buffer memory and interface driver and receiver
circuits, then prints all characters. To start and stop this test, press the SEL switch
on the front of the printer.
Details of this test are explained below.
Print the program revision with two numerical characters.
Print "LOOP TEST."
Check memory for message buffer.
√ Print "GOOD" if memory check is OK, and print "BAD" if memory check fails.
Output LOW to DTR, RTS, and SSD signals. If a CTS, DSR, or CD signal is
HIGH, print "BAD". If the CTS, DSR, and CD signals are all LOW, print "IF
GOOD".
≈ Output HIGH to DTR, RTS, and SSD signals. If a CTS, DSR, or CD signal is
LOW, print "IF BAD." If the CTS, DSR and CD signals are all HIGH, print "IF
GOOD."
∆ Transmit characters from code 20H to 7FH by TD signals. At the same time,
characters are received from the RD signal and stored in the message buffer.
Print the characters that were stored in the message buffer as indicated in ∆ .
Repeat from
40959201TX Rev.1
.
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