Epson I+ - Manual (Page 117)

Parallel Port (on Video Adapter) Check
Use the Parallel port (on video adapter) check to test the functions of the
primary port. This tests either the built-in port, if it is set up to act as the
primary port, or the parallel port on a monochrome adapter (such as the
IBM monochrome display and printer adapter) if you have one installed in
your computer.
To perform the test, you must insert the special loop-back connector into
the parallel port so that the computer can check individual pins of the port.
This test is identical to the Parallel port check. For more details, refer to the
description of the Parallel port (printer interface) check above.
Serial Port (RS-232C) Check
Use this option to test the functions of the primary serial communi-
cations (KS-232C) port. To perform the test, you must insert a special
loop-back connector into the KS-232C port so that the computer can check
individual pins of the port. Contact your dealer if you need a loop-back
connector. Note that a different connector is required to test the parallel
port.
‘When you select option 11 from the DEVICE LIST, you see these
prompts:
Attach loop-back connector to serial port.
Enter Y to start this check when connector is
attached, or
Enter N to return to the menu.
Insert the loop-back connector. Then press Y and Enter to start the check.
First, the computer checks the serial port control lines to see that they
are able to change from high to low and vice versa. No messages are dis-
played during this part of the test unless an error occurs.
The second test is an echo back check during which the port sends data
to itself in a fixed data format, at all the possible baud rates. When this test
begins, you see these messages:
RS232C echo back check - at various baud rates
Current baud rate is 75
Current test data is 00
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