Oki ML1120, Technical Reference Manual

Page: 33 / 254

Technical Reference Guide – Interface specifications > 33
Test connector: Connect the test connectors as shown below to
the interface connectors.
Circuit Test mode function
After the settings outlined in Circuit Test mode setting 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.
1. Print the program revision with two numerical characters.
2. Print “LOOP TEST.”
3. Check memory for message buffer.
Print “GOOD” if memory check is OK, and print “BAD” if
memory check fails.
4. 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.
5. Print the characters that were stored in the message
buffer as indicated in Step 4.
6. Repeat from Step 1.
TD
RD
RTS
SSD
DTR
Equivalent to Cannon DB-25P
2
3
4
11
20