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13-2. RS-232C Connector
Pin No.
Signal name
Direction
Function
25 Pin 9 Pin
1
—
F-GND
—
Frame ground
2
3
TXD
OUT
Transmission data
3
2
RXD
IN
Receive data
4
7
RTS
OUT
Same control as DTR
5
—
N/C
Not used.
—
8
CTS
IN
Same control as DSR
6
6
DSR
IN
1) STAR Mode
Not used.
2) ESC/POS Mode
When DIP Switch 3-7 = OFF;
A) DTR/DSR communication mode
Indicates whether data receive from host is enabled or
disabled.
Space: Receive enabled
Mark: Receive disabled
(except when transmitting data by DLE EOT, and GS a)
B) X-ON/X-OFF communication mode
Status of this signal is not checked.
When DIP Switch 3-7 = ON;
This is an externally reset signal.
A space above 1 ms pulse width engages reset.
7
5
S-GND
—
Signal ground
8~19
1,9
N/C
Not used.
20
4
DTR
OUT
1) STAR Mode
A) DTR communication mode
Indicates whether data receive from host is enabled or
disabled.
Space: Receive enabled
Mark: Receive disabled
B) X-ON/X-OFF communication mode
Always space, except during following condi-
tions:
• Period between reset and communication ena-
bled
• During self printing
