Service manual

109
Serial Interface
Pin Name Function
1 GND Printer’s chassis ground.
2 TXD This pin carries data from the printer.
3 RXD This pin carries data to the printer.
4 RTS This pin is always set to space.
5 CTS This pin is Space when the conputer is ready to send data.
This printer does not check this pin.
6 N/C
7 GND Signal ground.
8 - 10 N/C
11 RCH This printer turns this pin Space when it is ready to receive
data. This line carries the same signal as pin 20.
12 N/C
13 GND Signal ground.
14 - 19 N/C
20 DTR This printer turns this pin Space when it is ready to receive
data.
21 - 25 N/C