Communication Procedures - Oki MICROLINE 591Elite User Manual

Place the printer in the circuit test mode by specifying " Yes" in response to the menu
item in the DIAG TEST. Now you can run the local test.
1. Plug the test connector into the serial interface receptacle.
2. Turn the printer ON. The serial interface will check the memory function of the
printer's message buffer, the interface driver and the receiver circuit, and then
print all the characters in a test pattern.
3. This test can be stopped only by turning the printer OFF or pressing the SELECT
button.
4. The test produces the following:
• The printer prints this message: "LOOP TEST"
• The message buffer size is printed.
• The printer checks the memory function of the message buffer, then prints
"OK" if the memory check is good, of "BAD" if the memory check is faulty.
• The signal logic is checked, and if this is faulty, "BAD" is also printed.
Note: If "BAD" is printed, call your dealer for assistance.
• Hexadecimal characters from 20 to 7F are transmitted through the TD
(Transmit DATA) line, and received through the RD (Receive DATA) line,
then written to the message buffer. The above stored data is then printed.
• This process repeats until the printer is turned OFF or until you press the
SELECT button.

Communication Procedures

Two types of communication procedures for the serail interfaces RS-232C and RS-
422A can be selected by menu. These procedures or protocols are briefly described
below.
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