Epson TM-U375 - Page 27

1-12
XON/XOFF control
When XON/XOFF control is selected, the XON and XOFF
output timing is as described below. (XON code: 11H;
XOFF code: 13H) Transmit timing differs depending on the
setting of DIP switch 3 on bank 2.
Table 1-8. XON/XOFF Transmit Timing
(✽1) XON is not transmitted when the receive buffer is full.
(✽2) XOFF is not transmitted when the receive buffer is full.
Notes on setting DIP switch 2-3 to ON
1) The printer mechanism stops but does not become
BUSY in the following cases:
• When an error occurs.
• When the cover is open.
• When the printer stops printing due to a paper-end.
• When paper is fed using the PAPER FEED button.
2) When handshaking with the printer while using this
switch setting, make sure to monitor the printer with the
GS a command and the ASB function.
With this switch setting, the default value of the GS a
command (
n ) is 2. This automatically transmits the
printer status, depending on on-line/off-line changes.
3) When using the DLE EOT or DLE ENQ command, make
sure that the receive buffer does not become full.
• Note on using a host that cannot transmit data when the
printer is BUSY:
If an error occurs when the receive buffer is full and the
printer is BUSY, the DLE EOT and DLE ENQ com-
mands cannot be used.
• Notes on using a host that can transmit data when the
printer is BUSY:
If a DLE EOT or DLE ENQ command is used while
sending bit-image data, and the receive buffer-full state
is encountered during transmission of the data, the
DLE
EOT or DLE ENQ is processed as bit-image data.
In addition, the data transmitted during the receive
buffer-full state may be lost.
Example of use:
Set the receive buffer to 4K bytes, and check the status
with ESC v or ESC u for each line of printing transmit-
ted. Make sure that the data for printing each line does
not cause the printer to enter the receive buffer-full
state.
On-line/off-line switching
This printer has no on-line/off-line switch. It automatically
goes off-line in the following cases:
• The period from power-on (or initialization of the mecha-
nism due to resetting through the interface) until the
printer is ready to receive data.
• During the self-test.
• When the printer cover is open.
• During paper feeding using the PAPER FEED button.
• When the printer stops due to a paper-end (if enabled by
ESC c 4).
• When an error has occurred.
Example serial interface connection
The following illustrates an example serial interface
connection:
Figure 1-17. Serial Interface Connection Example
XON
transmis-
sion
XOFF
trans-
mission
Printer Status
When the printer goes on-
line after power-on or after
resetting with the interface.
When the receive buffer is
released from the buffer-
full state.
When the printer status
changes to on-line. (✽1)
When the printer recovers
from an error by using DLE
ENQ 1 or DLE ENQ 2.
When receive buffer be-
comes full.
When the printer status
changes to off-line. (✽2)
DIP SW 2-3
Status
ON OFF
Transmit Transmit
Transmit Transmit
— Transmit
— Transmit
Transmit Transmit
— Transmit
...........................................................................................
TXD
DSR
CTS
RXD
DTR
FG
SG

RXD
DTR
RTS
TXD
DSR
FG
SG
Host (DTEexample 8251) Printer
When connected to a DCE-type device, data should not
be sent non-stop (without handshaking).

DTE = Date Terminal Equipment
DCE = Data Circuit Terminating Equipment

CONFIDENTIAL