Functions Of Each Connector Pin; Xon/Xoff - Epson T88IIIP - TM B/W Thermal Line Printer Technical Reference Manual

A.1.2 Functions of each Connector Pin
Table A-2 Pin assignments
Pin Signal
no. name
1 FG
2 TXD
3 RXD
4 RTS
6 DSR
7 SG
20 DTR
25 INIT
A.1.3 XON/XOFF
When XON/XOFF control is selected, the printer transmits the XON or XOFF signals as follows.
The transmission timing of XON/XOFF differs, depending on the setting of DIP SW2-1.
Table A-3 XON/XOFF transmissions
Signal Printer status
XON 1) When the printer goes online after turning on the power (or reset using
the interface)
2) When the receive buffer is released from the buffer full state
3) When the printer switches from offline to online
4) When the printer recovers from an error using some ESC/POS commands —
XOFF 5) When the receive buffer becomes full
6) When the printer switches from online to offline
A-2 Interfaces and Connectors
Signal
direction Function

Frame ground
Output Transmission data
Input Reception data
Output Equivalent to DTR signal (pin 20)
Input This signal indicates whether the host computer can receive data.
SPACE indicates that the host computer can receive data.
MARK indicates that the host computer cannot receive data.
When DTR/DSR control is selected, the printer transmits data after confirming this
signal (except if transmitted using some ESC/POS commands). When XON/XOFF
control is selected, the printer does not check this signal. Changing DIP SW2-7 lets
this signal be used as a printer reset signal. When you use this signal as the printer's
reset signal, the printer is reset when the signal remains MARK for a pulse width of
1 ms or more.

Signal ground
Output 1) When DTR/DSR control is selected, this signal indicates whether the printer is Busy.
SPACE status — indicates the printer is ready to receive data.
MARK status — indicates the printer is Busy. Set Busy conditions with DIP SW2-1.
(Refer to "Busy State" on page 3-11).
2) When XON/XOFF control is selected, the signal indicates that the printer is
properly connected and ready to receive data from the host.
SPACE status — indicates the printer is properly connected and ready to receive
data from the host. The signal is always SPACE, except in the following cases:
• During the period from when power is turned on to when the printer is
ready to receive data.
• During the self-test.
Input Changing DIP SW2-8 enables this signal to be used as a reset signal for the printer.
The printer is reset if the signal remains at SPACE for a pulse width of 1 ms or more.
DIP SW2-1 status
1 (ON) 0 (OFF)
Transmit Transmit
Transmit Transmit
— Transmit
Transmit
Transmit Transmit
— Transmit
Rev. A