A-2 Interface And Connectors Rev. B

A.1.2 Functions of each connector pin
Pin no.
Signal
name
Signal
direction Function
1FG- Frame ground
2 TXD Output Transfer data
3 RXD Input Reception data
4 RTS Output Memory Switch Msw 1-6 OFF:Same as DTR signal (Pin 20)
Memory Switch Msw 1-6 ON: Logical product of DTR signals of DM-D and TM
(If both are SPACE, the printer can receive data
(SPACE).)
6 DSR Input This signal indicates whether the host computer can receive data.
SPACE indicates that the host computer can receive data, and MARK indicates
that the host computer cannot receive data.
When DTR/DSR control is selected, the printer transmits data after confirming this
signal.(Except as transmitted using some ESC/POS commands)
When XON/XOFF control is selected, the printer does not check this signal.
Changing the memory switch 1-7 setting enables this signal to be used as a reset
signal for the printer.
The printer is reset when the signal remains MARK for 1 ms or more.
7 SG - Signal ground
20 DTR Output 1) When DTR/DSR control is selected, this signal indicates whether the printer is
busy. SPACE indicates that the printer is ready to receive data, and MARK
indicates that the printer is busy. The busy condition can be changed by using
memory switch 1-3. (Refer to “Busy state” on page 4-9)
2) When XON/XOFF control is selected:
The signal indicates whether the printer is correctly connected and is ready to
receive data. SPACE indicates that the printer is ready to receive data. The
signal is always SPACE except in the following cases:
•During the period from when the power is turned on to when the printer is
ready to receive data.
•During the self test
25 INIT Input Changing the memory switch 1-8 setting enables this signal to be used as a reset
signal for the printer.
The printer is reset when the signal remains SPACE for 1 ms or more.