Indicators; Functions; Error Processing; Error Detection - Epson TM-U375 Technical Manual

CONFIDENTIAL

1.3.6 Indicators

The indicators are located on the operation panel (see
Figure 1-1.)
POWER LED (green)
On: Stable power (+24 V) is supplied.
Off: Stable power (+24 V) is not supplied.
ERROR LED (red)
On: Off-line (except during paper feeding using the
PAPER FEED button).
Off: Normal operation
Blinking: An error has occurred (see Section 4.3, Error
Types And Countermeasures )
JOURNAL OUT LED (red)
On: Near-end or paper end is detected for the paper
roll.
Off: Sufficient paper remains on the paper roll (nor-
mal condition).
Blinking: Waiting to restart test printing on the paper roll.
(See Section 4.1.1, Self-test. )
VALIDATION/SLIP LED (green)
On: Cut sheet mode
Off: Paper roll mode
Blinking: Waiting for cut sheet insertion/removal.
Wait for insertion
Wait for removal
Figure 1-18. VALIDATION/SLIP LED Blinking Pattern
Note
If a cut sheet is removed when the printer is waiting for cut
sheet removal, VALIDATION/SLIP LED stays on. (The
LED was blinking in the waiting state.) Then approximately
two seconds later, the printer automatically enters paper
roll mode.

1.4 FUNCTIONS

1.4.1 Error Processing

Error detection

When the printer detects an error, it carries out the following
operation sequence:
• All running operations are stopped.
• The printer goes off-line.
• The ERROR LED flashes. (Refer to Section 4.3, Error
Types And Countermeasures .)
1-14

Error recovery

Recoverable errors are recovered using DLE ENQ 1 and
DLE ENQ 2 commands. They are also recovered when the
printer power is turned off and on again after the cause is
removed. (However, in this case any data in the buffer is
lost.)
Notes
• If cut sheet is selected and DLE ENQ 1 is used to recover
from a recoverable error ( 1), the printer ejects the
remaining cut sheet and repeats the loading process.
• If cut sheet is selected and DLE ENQ 2 is used to recover
from a recoverable error ( 1), the printer checks the cut
sheet ejection and goes to paper roll mode.
• When an unrecoverable error ( 2) has occurred, turn off
the printer as soon as possible.
( 1) Errors (2) to (4) in Table 4-4 in Section 4.3 are
recoverable errors.
( 2) Errors (5) to (9) in Table 4-4 in Section 4.3 are
unrecoverable errors.

Data receive error

When an error is detected in data received by the printer
(parity, framing, or overrun error), the data is either ignored
or replaced by "?", depending on the DIP switch1-1 setting.

1.4.2 Self-test

The self-test checks the following items:
• Control circuit operation
• Printer mechanism operation
• Print quality
• Control ROM version (on status printout)
• DIP switch settings (on status printout)
For details about the self-test, refer to Section 4.1.1, Self-
test .