Epson TM-T88 Series Technical Reference Manual page 101

Functions of interface connector pins
Signal Signal
Pin no.
name direction
1 FG -
2 TXD Output
3 RXD Input
4 RTS Output
6 DSR Input
7 SG -
20 DTR Output
25 INIT Input
Function
Frame ground
Transmission data
Reception data
Equivalent to DTR signal (pin 20)
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.
Signal ground
1) When DTR/DSR control is selected, this signal indicates whether the
printer is BUSY.
• SPACE status
Indicates that the printer is ready to receive data.
• MARK status
Indicates that the printer is BUSY. The BUSY condition can be specified
using memory switch 1-3.
2) When XON/XOFF control is selected, this signal indicates whether the
printer is properly connected and ready to receive data from the
host.
• SPACE status
The signal indicates that 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.
While the self-test is in progress.
The printer can use this signal as a reset signal.
The printer is reset if the signal remains at SPACE for a pulse width of 1
ms or more.
Appendix
101